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1/*
2 * net/tipc/subscr.c: TIPC network topology service
3 *
4 * Copyright (c) 2000-2006, Ericsson AB
5 * Copyright (c) 2005-2007, 2010-2011, 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 "core.h"
38#include "name_table.h"
39#include "port.h"
40#include "subscr.h"
41
42/**
43 * struct subscriber - TIPC network topology subscriber
44 * @port_ref: object reference to server port connecting to subscriber
45 * @lock: pointer to spinlock controlling access to subscriber's server port
46 * @subscriber_list: adjacent subscribers in top. server's list of subscribers
47 * @subscription_list: list of subscription objects for this subscriber
48 */
49
50struct subscriber {
51 u32 port_ref;
52 spinlock_t *lock;
53 struct list_head subscriber_list;
54 struct list_head subscription_list;
55};
56
57/**
58 * struct top_srv - TIPC network topology subscription service
59 * @user_ref: TIPC userid of subscription service
60 * @setup_port: reference to TIPC port that handles subscription requests
61 * @subscription_count: number of active subscriptions (not subscribers!)
62 * @subscriber_list: list of ports subscribing to service
63 * @lock: spinlock govering access to subscriber list
64 */
65
66struct top_srv {
67 u32 setup_port;
68 atomic_t subscription_count;
69 struct list_head subscriber_list;
70 spinlock_t lock;
71};
72
73static struct top_srv topsrv;
74
75/**
76 * htohl - convert value to endianness used by destination
77 * @in: value to convert
78 * @swap: non-zero if endianness must be reversed
79 *
80 * Returns converted value
81 */
82
83static u32 htohl(u32 in, int swap)
84{
85 return swap ? swab32(in) : in;
86}
87
88/**
89 * subscr_send_event - send a message containing a tipc_event to the subscriber
90 *
91 * Note: Must not hold subscriber's server port lock, since tipc_send() will
92 * try to take the lock if the message is rejected and returned!
93 */
94
95static void subscr_send_event(struct subscription *sub,
96 u32 found_lower,
97 u32 found_upper,
98 u32 event,
99 u32 port_ref,
100 u32 node)
101{
102 struct iovec msg_sect;
103
104 msg_sect.iov_base = (void *)&sub->evt;
105 msg_sect.iov_len = sizeof(struct tipc_event);
106
107 sub->evt.event = htohl(event, sub->swap);
108 sub->evt.found_lower = htohl(found_lower, sub->swap);
109 sub->evt.found_upper = htohl(found_upper, sub->swap);
110 sub->evt.port.ref = htohl(port_ref, sub->swap);
111 sub->evt.port.node = htohl(node, sub->swap);
112 tipc_send(sub->server_ref, 1, &msg_sect, msg_sect.iov_len);
113}
114
115/**
116 * tipc_subscr_overlap - test for subscription overlap with the given values
117 *
118 * Returns 1 if there is overlap, otherwise 0.
119 */
120
121int tipc_subscr_overlap(struct subscription *sub,
122 u32 found_lower,
123 u32 found_upper)
124
125{
126 if (found_lower < sub->seq.lower)
127 found_lower = sub->seq.lower;
128 if (found_upper > sub->seq.upper)
129 found_upper = sub->seq.upper;
130 if (found_lower > found_upper)
131 return 0;
132 return 1;
133}
134
135/**
136 * tipc_subscr_report_overlap - issue event if there is subscription overlap
137 *
138 * Protected by nameseq.lock in name_table.c
139 */
140
141void tipc_subscr_report_overlap(struct subscription *sub,
142 u32 found_lower,
143 u32 found_upper,
144 u32 event,
145 u32 port_ref,
146 u32 node,
147 int must)
148{
149 if (!tipc_subscr_overlap(sub, found_lower, found_upper))
150 return;
151 if (!must && !(sub->filter & TIPC_SUB_PORTS))
152 return;
153
154 sub->event_cb(sub, found_lower, found_upper, event, port_ref, node);
155}
156
157/**
158 * subscr_timeout - subscription timeout has occurred
159 */
160
161static void subscr_timeout(struct subscription *sub)
162{
163 struct tipc_port *server_port;
164
165 /* Validate server port reference (in case subscriber is terminating) */
166
167 server_port = tipc_port_lock(sub->server_ref);
168 if (server_port == NULL)
169 return;
170
171 /* Validate timeout (in case subscription is being cancelled) */
172
173 if (sub->timeout == TIPC_WAIT_FOREVER) {
174 tipc_port_unlock(server_port);
175 return;
176 }
177
178 /* Unlink subscription from name table */
179
180 tipc_nametbl_unsubscribe(sub);
181
182 /* Unlink subscription from subscriber */
183
184 list_del(&sub->subscription_list);
185
186 /* Release subscriber's server port */
187
188 tipc_port_unlock(server_port);
189
190 /* Notify subscriber of timeout */
191
192 subscr_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
193 TIPC_SUBSCR_TIMEOUT, 0, 0);
194
195 /* Now destroy subscription */
196
197 k_term_timer(&sub->timer);
198 kfree(sub);
199 atomic_dec(&topsrv.subscription_count);
200}
201
202/**
203 * subscr_del - delete a subscription within a subscription list
204 *
205 * Called with subscriber port locked.
206 */
207
208static void subscr_del(struct subscription *sub)
209{
210 tipc_nametbl_unsubscribe(sub);
211 list_del(&sub->subscription_list);
212 kfree(sub);
213 atomic_dec(&topsrv.subscription_count);
214}
215
216/**
217 * subscr_terminate - terminate communication with a subscriber
218 *
219 * Called with subscriber port locked. Routine must temporarily release lock
220 * to enable subscription timeout routine(s) to finish without deadlocking;
221 * the lock is then reclaimed to allow caller to release it upon return.
222 * (This should work even in the unlikely event some other thread creates
223 * a new object reference in the interim that uses this lock; this routine will
224 * simply wait for it to be released, then claim it.)
225 */
226
227static void subscr_terminate(struct subscriber *subscriber)
228{
229 u32 port_ref;
230 struct subscription *sub;
231 struct subscription *sub_temp;
232
233 /* Invalidate subscriber reference */
234
235 port_ref = subscriber->port_ref;
236 subscriber->port_ref = 0;
237 spin_unlock_bh(subscriber->lock);
238
239 /* Sever connection to subscriber */
240
241 tipc_shutdown(port_ref);
242 tipc_deleteport(port_ref);
243
244 /* Destroy any existing subscriptions for subscriber */
245
246 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
247 subscription_list) {
248 if (sub->timeout != TIPC_WAIT_FOREVER) {
249 k_cancel_timer(&sub->timer);
250 k_term_timer(&sub->timer);
251 }
252 subscr_del(sub);
253 }
254
255 /* Remove subscriber from topology server's subscriber list */
256
257 spin_lock_bh(&topsrv.lock);
258 list_del(&subscriber->subscriber_list);
259 spin_unlock_bh(&topsrv.lock);
260
261 /* Reclaim subscriber lock */
262
263 spin_lock_bh(subscriber->lock);
264
265 /* Now destroy subscriber */
266
267 kfree(subscriber);
268}
269
270/**
271 * subscr_cancel - handle subscription cancellation request
272 *
273 * Called with subscriber port locked. Routine must temporarily release lock
274 * to enable the subscription timeout routine to finish without deadlocking;
275 * the lock is then reclaimed to allow caller to release it upon return.
276 *
277 * Note that fields of 's' use subscriber's endianness!
278 */
279
280static void subscr_cancel(struct tipc_subscr *s,
281 struct subscriber *subscriber)
282{
283 struct subscription *sub;
284 struct subscription *sub_temp;
285 int found = 0;
286
287 /* Find first matching subscription, exit if not found */
288
289 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
290 subscription_list) {
291 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
292 found = 1;
293 break;
294 }
295 }
296 if (!found)
297 return;
298
299 /* Cancel subscription timer (if used), then delete subscription */
300
301 if (sub->timeout != TIPC_WAIT_FOREVER) {
302 sub->timeout = TIPC_WAIT_FOREVER;
303 spin_unlock_bh(subscriber->lock);
304 k_cancel_timer(&sub->timer);
305 k_term_timer(&sub->timer);
306 spin_lock_bh(subscriber->lock);
307 }
308 subscr_del(sub);
309}
310
311/**
312 * subscr_subscribe - create subscription for subscriber
313 *
314 * Called with subscriber port locked.
315 */
316
317static struct subscription *subscr_subscribe(struct tipc_subscr *s,
318 struct subscriber *subscriber)
319{
320 struct subscription *sub;
321 int swap;
322
323 /* Determine subscriber's endianness */
324
325 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
326
327 /* Detect & process a subscription cancellation request */
328
329 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
330 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
331 subscr_cancel(s, subscriber);
332 return NULL;
333 }
334
335 /* Refuse subscription if global limit exceeded */
336
337 if (atomic_read(&topsrv.subscription_count) >= tipc_max_subscriptions) {
338 warn("Subscription rejected, subscription limit reached (%u)\n",
339 tipc_max_subscriptions);
340 subscr_terminate(subscriber);
341 return NULL;
342 }
343
344 /* Allocate subscription object */
345
346 sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
347 if (!sub) {
348 warn("Subscription rejected, no memory\n");
349 subscr_terminate(subscriber);
350 return NULL;
351 }
352
353 /* Initialize subscription object */
354
355 sub->seq.type = htohl(s->seq.type, swap);
356 sub->seq.lower = htohl(s->seq.lower, swap);
357 sub->seq.upper = htohl(s->seq.upper, swap);
358 sub->timeout = htohl(s->timeout, swap);
359 sub->filter = htohl(s->filter, swap);
360 if ((!(sub->filter & TIPC_SUB_PORTS) ==
361 !(sub->filter & TIPC_SUB_SERVICE)) ||
362 (sub->seq.lower > sub->seq.upper)) {
363 warn("Subscription rejected, illegal request\n");
364 kfree(sub);
365 subscr_terminate(subscriber);
366 return NULL;
367 }
368 sub->event_cb = subscr_send_event;
369 INIT_LIST_HEAD(&sub->nameseq_list);
370 list_add(&sub->subscription_list, &subscriber->subscription_list);
371 sub->server_ref = subscriber->port_ref;
372 sub->swap = swap;
373 memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr));
374 atomic_inc(&topsrv.subscription_count);
375 if (sub->timeout != TIPC_WAIT_FOREVER) {
376 k_init_timer(&sub->timer,
377 (Handler)subscr_timeout, (unsigned long)sub);
378 k_start_timer(&sub->timer, sub->timeout);
379 }
380
381 return sub;
382}
383
384/**
385 * subscr_conn_shutdown_event - handle termination request from subscriber
386 *
387 * Called with subscriber's server port unlocked.
388 */
389
390static void subscr_conn_shutdown_event(void *usr_handle,
391 u32 port_ref,
392 struct sk_buff **buf,
393 unsigned char const *data,
394 unsigned int size,
395 int reason)
396{
397 struct subscriber *subscriber = usr_handle;
398 spinlock_t *subscriber_lock;
399
400 if (tipc_port_lock(port_ref) == NULL)
401 return;
402
403 subscriber_lock = subscriber->lock;
404 subscr_terminate(subscriber);
405 spin_unlock_bh(subscriber_lock);
406}
407
408/**
409 * subscr_conn_msg_event - handle new subscription request from subscriber
410 *
411 * Called with subscriber's server port unlocked.
412 */
413
414static void subscr_conn_msg_event(void *usr_handle,
415 u32 port_ref,
416 struct sk_buff **buf,
417 const unchar *data,
418 u32 size)
419{
420 struct subscriber *subscriber = usr_handle;
421 spinlock_t *subscriber_lock;
422 struct subscription *sub;
423
424 /*
425 * Lock subscriber's server port (& make a local copy of lock pointer,
426 * in case subscriber is deleted while processing subscription request)
427 */
428
429 if (tipc_port_lock(port_ref) == NULL)
430 return;
431
432 subscriber_lock = subscriber->lock;
433
434 if (size != sizeof(struct tipc_subscr)) {
435 subscr_terminate(subscriber);
436 spin_unlock_bh(subscriber_lock);
437 } else {
438 sub = subscr_subscribe((struct tipc_subscr *)data, subscriber);
439 spin_unlock_bh(subscriber_lock);
440 if (sub != NULL) {
441
442 /*
443 * We must release the server port lock before adding a
444 * subscription to the name table since TIPC needs to be
445 * able to (re)acquire the port lock if an event message
446 * issued by the subscription process is rejected and
447 * returned. The subscription cannot be deleted while
448 * it is being added to the name table because:
449 * a) the single-threading of the native API port code
450 * ensures the subscription cannot be cancelled and
451 * the subscriber connection cannot be broken, and
452 * b) the name table lock ensures the subscription
453 * timeout code cannot delete the subscription,
454 * so the subscription object is still protected.
455 */
456
457 tipc_nametbl_subscribe(sub);
458 }
459 }
460}
461
462/**
463 * subscr_named_msg_event - handle request to establish a new subscriber
464 */
465
466static void subscr_named_msg_event(void *usr_handle,
467 u32 port_ref,
468 struct sk_buff **buf,
469 const unchar *data,
470 u32 size,
471 u32 importance,
472 struct tipc_portid const *orig,
473 struct tipc_name_seq const *dest)
474{
475 struct subscriber *subscriber;
476 u32 server_port_ref;
477
478 /* Create subscriber object */
479
480 subscriber = kzalloc(sizeof(struct subscriber), GFP_ATOMIC);
481 if (subscriber == NULL) {
482 warn("Subscriber rejected, no memory\n");
483 return;
484 }
485 INIT_LIST_HEAD(&subscriber->subscription_list);
486 INIT_LIST_HEAD(&subscriber->subscriber_list);
487
488 /* Create server port & establish connection to subscriber */
489
490 tipc_createport(subscriber,
491 importance,
492 NULL,
493 NULL,
494 subscr_conn_shutdown_event,
495 NULL,
496 NULL,
497 subscr_conn_msg_event,
498 NULL,
499 &subscriber->port_ref);
500 if (subscriber->port_ref == 0) {
501 warn("Subscriber rejected, unable to create port\n");
502 kfree(subscriber);
503 return;
504 }
505 tipc_connect2port(subscriber->port_ref, orig);
506
507 /* Lock server port (& save lock address for future use) */
508
509 subscriber->lock = tipc_port_lock(subscriber->port_ref)->lock;
510
511 /* Add subscriber to topology server's subscriber list */
512
513 spin_lock_bh(&topsrv.lock);
514 list_add(&subscriber->subscriber_list, &topsrv.subscriber_list);
515 spin_unlock_bh(&topsrv.lock);
516
517 /* Unlock server port */
518
519 server_port_ref = subscriber->port_ref;
520 spin_unlock_bh(subscriber->lock);
521
522 /* Send an ACK- to complete connection handshaking */
523
524 tipc_send(server_port_ref, 0, NULL, 0);
525
526 /* Handle optional subscription request */
527
528 if (size != 0) {
529 subscr_conn_msg_event(subscriber, server_port_ref,
530 buf, data, size);
531 }
532}
533
534int tipc_subscr_start(void)
535{
536 struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV};
537 int res;
538
539 memset(&topsrv, 0, sizeof(topsrv));
540 spin_lock_init(&topsrv.lock);
541 INIT_LIST_HEAD(&topsrv.subscriber_list);
542
543 res = tipc_createport(NULL,
544 TIPC_CRITICAL_IMPORTANCE,
545 NULL,
546 NULL,
547 NULL,
548 NULL,
549 subscr_named_msg_event,
550 NULL,
551 NULL,
552 &topsrv.setup_port);
553 if (res)
554 goto failed;
555
556 res = tipc_nametbl_publish_rsv(topsrv.setup_port, TIPC_NODE_SCOPE, &seq);
557 if (res) {
558 tipc_deleteport(topsrv.setup_port);
559 topsrv.setup_port = 0;
560 goto failed;
561 }
562
563 return 0;
564
565failed:
566 err("Failed to create subscription service\n");
567 return res;
568}
569
570void tipc_subscr_stop(void)
571{
572 struct subscriber *subscriber;
573 struct subscriber *subscriber_temp;
574 spinlock_t *subscriber_lock;
575
576 if (topsrv.setup_port) {
577 tipc_deleteport(topsrv.setup_port);
578 topsrv.setup_port = 0;
579
580 list_for_each_entry_safe(subscriber, subscriber_temp,
581 &topsrv.subscriber_list,
582 subscriber_list) {
583 subscriber_lock = subscriber->lock;
584 spin_lock_bh(subscriber_lock);
585 subscr_terminate(subscriber);
586 spin_unlock_bh(subscriber_lock);
587 }
588 }
589}
1/*
2 * net/tipc/subscr.c: TIPC network topology service
3 *
4 * Copyright (c) 2000-2006, Ericsson AB
5 * Copyright (c) 2005-2007, 2010-2013, 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 "core.h"
38#include "name_table.h"
39#include "port.h"
40#include "subscr.h"
41
42/**
43 * struct tipc_subscriber - TIPC network topology subscriber
44 * @conid: connection identifier to server connecting to subscriber
45 * @lock: control access to subscriber
46 * @subscription_list: list of subscription objects for this subscriber
47 */
48struct tipc_subscriber {
49 int conid;
50 spinlock_t lock;
51 struct list_head subscription_list;
52};
53
54static void subscr_conn_msg_event(int conid, struct sockaddr_tipc *addr,
55 void *usr_data, void *buf, size_t len);
56static void *subscr_named_msg_event(int conid);
57static void subscr_conn_shutdown_event(int conid, void *usr_data);
58
59static atomic_t subscription_count = ATOMIC_INIT(0);
60
61static struct sockaddr_tipc topsrv_addr __read_mostly = {
62 .family = AF_TIPC,
63 .addrtype = TIPC_ADDR_NAMESEQ,
64 .addr.nameseq.type = TIPC_TOP_SRV,
65 .addr.nameseq.lower = TIPC_TOP_SRV,
66 .addr.nameseq.upper = TIPC_TOP_SRV,
67 .scope = TIPC_NODE_SCOPE
68};
69
70static struct tipc_server topsrv __read_mostly = {
71 .saddr = &topsrv_addr,
72 .imp = TIPC_CRITICAL_IMPORTANCE,
73 .type = SOCK_SEQPACKET,
74 .max_rcvbuf_size = sizeof(struct tipc_subscr),
75 .name = "topology_server",
76 .tipc_conn_recvmsg = subscr_conn_msg_event,
77 .tipc_conn_new = subscr_named_msg_event,
78 .tipc_conn_shutdown = subscr_conn_shutdown_event,
79};
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 */
88static u32 htohl(u32 in, int swap)
89{
90 return swap ? swab32(in) : in;
91}
92
93static void subscr_send_event(struct tipc_subscription *sub, u32 found_lower,
94 u32 found_upper, u32 event, u32 port_ref,
95 u32 node)
96{
97 struct tipc_subscriber *subscriber = sub->subscriber;
98 struct kvec msg_sect;
99
100 msg_sect.iov_base = (void *)&sub->evt;
101 msg_sect.iov_len = sizeof(struct tipc_event);
102 sub->evt.event = htohl(event, sub->swap);
103 sub->evt.found_lower = htohl(found_lower, sub->swap);
104 sub->evt.found_upper = htohl(found_upper, sub->swap);
105 sub->evt.port.ref = htohl(port_ref, sub->swap);
106 sub->evt.port.node = htohl(node, sub->swap);
107 tipc_conn_sendmsg(&topsrv, subscriber->conid, NULL, msg_sect.iov_base,
108 msg_sect.iov_len);
109}
110
111/**
112 * tipc_subscr_overlap - test for subscription overlap with the given values
113 *
114 * Returns 1 if there is overlap, otherwise 0.
115 */
116int tipc_subscr_overlap(struct tipc_subscription *sub, u32 found_lower,
117 u32 found_upper)
118{
119 if (found_lower < sub->seq.lower)
120 found_lower = sub->seq.lower;
121 if (found_upper > sub->seq.upper)
122 found_upper = sub->seq.upper;
123 if (found_lower > found_upper)
124 return 0;
125 return 1;
126}
127
128/**
129 * tipc_subscr_report_overlap - issue event if there is subscription overlap
130 *
131 * Protected by nameseq.lock in name_table.c
132 */
133void tipc_subscr_report_overlap(struct tipc_subscription *sub, u32 found_lower,
134 u32 found_upper, u32 event, u32 port_ref,
135 u32 node, int must)
136{
137 if (!tipc_subscr_overlap(sub, found_lower, found_upper))
138 return;
139 if (!must && !(sub->filter & TIPC_SUB_PORTS))
140 return;
141
142 subscr_send_event(sub, found_lower, found_upper, event, port_ref, node);
143}
144
145static void subscr_timeout(struct tipc_subscription *sub)
146{
147 struct tipc_subscriber *subscriber = sub->subscriber;
148
149 /* The spin lock per subscriber is used to protect its members */
150 spin_lock_bh(&subscriber->lock);
151
152 /* Validate timeout (in case subscription is being cancelled) */
153 if (sub->timeout == TIPC_WAIT_FOREVER) {
154 spin_unlock_bh(&subscriber->lock);
155 return;
156 }
157
158 /* Unlink subscription from name table */
159 tipc_nametbl_unsubscribe(sub);
160
161 /* Unlink subscription from subscriber */
162 list_del(&sub->subscription_list);
163
164 spin_unlock_bh(&subscriber->lock);
165
166 /* Notify subscriber of timeout */
167 subscr_send_event(sub, sub->evt.s.seq.lower, sub->evt.s.seq.upper,
168 TIPC_SUBSCR_TIMEOUT, 0, 0);
169
170 /* Now destroy subscription */
171 k_term_timer(&sub->timer);
172 kfree(sub);
173 atomic_dec(&subscription_count);
174}
175
176/**
177 * subscr_del - delete a subscription within a subscription list
178 *
179 * Called with subscriber lock held.
180 */
181static void subscr_del(struct tipc_subscription *sub)
182{
183 tipc_nametbl_unsubscribe(sub);
184 list_del(&sub->subscription_list);
185 kfree(sub);
186 atomic_dec(&subscription_count);
187}
188
189/**
190 * subscr_terminate - terminate communication with a subscriber
191 *
192 * Note: Must call it in process context since it might sleep.
193 */
194static void subscr_terminate(struct tipc_subscriber *subscriber)
195{
196 tipc_conn_terminate(&topsrv, subscriber->conid);
197}
198
199static void subscr_release(struct tipc_subscriber *subscriber)
200{
201 struct tipc_subscription *sub;
202 struct tipc_subscription *sub_temp;
203
204 spin_lock_bh(&subscriber->lock);
205
206 /* Destroy any existing subscriptions for subscriber */
207 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
208 subscription_list) {
209 if (sub->timeout != TIPC_WAIT_FOREVER) {
210 spin_unlock_bh(&subscriber->lock);
211 k_cancel_timer(&sub->timer);
212 k_term_timer(&sub->timer);
213 spin_lock_bh(&subscriber->lock);
214 }
215 subscr_del(sub);
216 }
217 spin_unlock_bh(&subscriber->lock);
218
219 /* Now destroy subscriber */
220 kfree(subscriber);
221}
222
223/**
224 * subscr_cancel - handle subscription cancellation request
225 *
226 * Called with subscriber lock held. Routine must temporarily release lock
227 * to enable the subscription timeout routine to finish without deadlocking;
228 * the lock is then reclaimed to allow caller to release it upon return.
229 *
230 * Note that fields of 's' use subscriber's endianness!
231 */
232static void subscr_cancel(struct tipc_subscr *s,
233 struct tipc_subscriber *subscriber)
234{
235 struct tipc_subscription *sub;
236 struct tipc_subscription *sub_temp;
237 int found = 0;
238
239 /* Find first matching subscription, exit if not found */
240 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list,
241 subscription_list) {
242 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) {
243 found = 1;
244 break;
245 }
246 }
247 if (!found)
248 return;
249
250 /* Cancel subscription timer (if used), then delete subscription */
251 if (sub->timeout != TIPC_WAIT_FOREVER) {
252 sub->timeout = TIPC_WAIT_FOREVER;
253 spin_unlock_bh(&subscriber->lock);
254 k_cancel_timer(&sub->timer);
255 k_term_timer(&sub->timer);
256 spin_lock_bh(&subscriber->lock);
257 }
258 subscr_del(sub);
259}
260
261/**
262 * subscr_subscribe - create subscription for subscriber
263 *
264 * Called with subscriber lock held.
265 */
266static int subscr_subscribe(struct tipc_subscr *s,
267 struct tipc_subscriber *subscriber,
268 struct tipc_subscription **sub_p) {
269 struct tipc_subscription *sub;
270 int swap;
271
272 /* Determine subscriber's endianness */
273 swap = !(s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE));
274
275 /* Detect & process a subscription cancellation request */
276 if (s->filter & htohl(TIPC_SUB_CANCEL, swap)) {
277 s->filter &= ~htohl(TIPC_SUB_CANCEL, swap);
278 subscr_cancel(s, subscriber);
279 return 0;
280 }
281
282 /* Refuse subscription if global limit exceeded */
283 if (atomic_read(&subscription_count) >= TIPC_MAX_SUBSCRIPTIONS) {
284 pr_warn("Subscription rejected, limit reached (%u)\n",
285 TIPC_MAX_SUBSCRIPTIONS);
286 return -EINVAL;
287 }
288
289 /* Allocate subscription object */
290 sub = kmalloc(sizeof(*sub), GFP_ATOMIC);
291 if (!sub) {
292 pr_warn("Subscription rejected, no memory\n");
293 return -ENOMEM;
294 }
295
296 /* Initialize subscription object */
297 sub->seq.type = htohl(s->seq.type, swap);
298 sub->seq.lower = htohl(s->seq.lower, swap);
299 sub->seq.upper = htohl(s->seq.upper, swap);
300 sub->timeout = htohl(s->timeout, swap);
301 sub->filter = htohl(s->filter, swap);
302 if ((!(sub->filter & TIPC_SUB_PORTS) ==
303 !(sub->filter & TIPC_SUB_SERVICE)) ||
304 (sub->seq.lower > sub->seq.upper)) {
305 pr_warn("Subscription rejected, illegal request\n");
306 kfree(sub);
307 return -EINVAL;
308 }
309 INIT_LIST_HEAD(&sub->nameseq_list);
310 list_add(&sub->subscription_list, &subscriber->subscription_list);
311 sub->subscriber = subscriber;
312 sub->swap = swap;
313 memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr));
314 atomic_inc(&subscription_count);
315 if (sub->timeout != TIPC_WAIT_FOREVER) {
316 k_init_timer(&sub->timer,
317 (Handler)subscr_timeout, (unsigned long)sub);
318 k_start_timer(&sub->timer, sub->timeout);
319 }
320 *sub_p = sub;
321 return 0;
322}
323
324/* Handle one termination request for the subscriber */
325static void subscr_conn_shutdown_event(int conid, void *usr_data)
326{
327 subscr_release((struct tipc_subscriber *)usr_data);
328}
329
330/* Handle one request to create a new subscription for the subscriber */
331static void subscr_conn_msg_event(int conid, struct sockaddr_tipc *addr,
332 void *usr_data, void *buf, size_t len)
333{
334 struct tipc_subscriber *subscriber = usr_data;
335 struct tipc_subscription *sub = NULL;
336
337 spin_lock_bh(&subscriber->lock);
338 if (subscr_subscribe((struct tipc_subscr *)buf, subscriber, &sub) < 0) {
339 spin_unlock_bh(&subscriber->lock);
340 subscr_terminate(subscriber);
341 return;
342 }
343 if (sub)
344 tipc_nametbl_subscribe(sub);
345 spin_unlock_bh(&subscriber->lock);
346}
347
348
349/* Handle one request to establish a new subscriber */
350static void *subscr_named_msg_event(int conid)
351{
352 struct tipc_subscriber *subscriber;
353
354 /* Create subscriber object */
355 subscriber = kzalloc(sizeof(struct tipc_subscriber), GFP_ATOMIC);
356 if (subscriber == NULL) {
357 pr_warn("Subscriber rejected, no memory\n");
358 return NULL;
359 }
360 INIT_LIST_HEAD(&subscriber->subscription_list);
361 subscriber->conid = conid;
362 spin_lock_init(&subscriber->lock);
363
364 return (void *)subscriber;
365}
366
367int tipc_subscr_start(void)
368{
369 return tipc_server_start(&topsrv);
370}
371
372void tipc_subscr_stop(void)
373{
374 tipc_server_stop(&topsrv);
375}