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Per Lidenb97bf3f2006-01-02 19:04:38 +01001/*
2 * net/tipc/subscr.c: TIPC subscription service
3 *
Per Liden593a5f22006-01-11 19:14:19 +01004 * Copyright (c) 2000-2006, Ericsson AB
Per Lidenb97bf3f2006-01-02 19:04:38 +01005 * Copyright (c) 2005, Wind River Systems
Per Lidenb97bf3f2006-01-02 19:04:38 +01006 * All rights reserved.
7 *
Per Liden9ea1fd32006-01-11 13:30:43 +01008 * Redistribution and use in source and binary forms, with or without
Per Lidenb97bf3f2006-01-02 19:04:38 +01009 * modification, are permitted provided that the following conditions are met:
10 *
Per Liden9ea1fd32006-01-11 13:30:43 +010011 * 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.
Per Lidenb97bf3f2006-01-02 19:04:38 +010019 *
Per Liden9ea1fd32006-01-11 13:30:43 +010020 * 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
Per Lidenb97bf3f2006-01-02 19:04:38 +010034 * 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
53struct 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
71struct 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
79static 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
89static 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
100static 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
126int 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
146void 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
167static 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
212static 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
261static 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
325static 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{
David S. Miller880b0052006-01-12 13:22:32 -0800332 struct subscriber *subscriber;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100333 spinlock_t *subscriber_lock;
334
David S. Miller880b0052006-01-12 13:22:32 -0800335 subscriber = ref_lock((u32)(unsigned long)usr_handle);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100336 if (subscriber == NULL)
337 return;
338
339 subscriber_lock = subscriber->lock;
340 subscr_terminate(subscriber);
341 spin_unlock_bh(subscriber_lock);
342}
343
344/**
345 * subscr_conn_msg_event - handle new subscription request from subscriber
346 */
347
348static void subscr_conn_msg_event(void *usr_handle,
349 u32 port_ref,
350 struct sk_buff **buf,
351 const unchar *data,
352 u32 size)
353{
David S. Miller880b0052006-01-12 13:22:32 -0800354 struct subscriber *subscriber;
Per Lidenb97bf3f2006-01-02 19:04:38 +0100355 spinlock_t *subscriber_lock;
356
David S. Miller880b0052006-01-12 13:22:32 -0800357 subscriber = ref_lock((u32)(unsigned long)usr_handle);
Per Lidenb97bf3f2006-01-02 19:04:38 +0100358 if (subscriber == NULL)
359 return;
360
361 subscriber_lock = subscriber->lock;
362 if (size != sizeof(struct tipc_subscr))
363 subscr_terminate(subscriber);
364 else
365 subscr_subscribe((struct tipc_subscr *)data, subscriber);
366
367 spin_unlock_bh(subscriber_lock);
368}
369
370/**
371 * subscr_named_msg_event - handle request to establish a new subscriber
372 */
373
374static void subscr_named_msg_event(void *usr_handle,
375 u32 port_ref,
376 struct sk_buff **buf,
377 const unchar *data,
378 u32 size,
379 u32 importance,
380 struct tipc_portid const *orig,
381 struct tipc_name_seq const *dest)
382{
383 struct subscriber *subscriber;
384 struct iovec msg_sect = {0, 0};
385 spinlock_t *subscriber_lock;
386
387 dbg("subscr_named_msg_event: orig = %x own = %x,\n",
388 orig->node, tipc_own_addr);
389 if (size && (size != sizeof(struct tipc_subscr))) {
390 warn("Received tipc_subscr of invalid size\n");
391 return;
392 }
393
394 /* Create subscriber object */
395
396 subscriber = kmalloc(sizeof(struct subscriber), GFP_ATOMIC);
397 if (subscriber == NULL) {
398 warn("Memory squeeze; ignoring subscriber setup\n");
399 return;
400 }
401 memset(subscriber, 0, sizeof(struct subscriber));
402 INIT_LIST_HEAD(&subscriber->subscription_list);
403 INIT_LIST_HEAD(&subscriber->subscriber_list);
404 subscriber->ref = ref_acquire(subscriber, &subscriber->lock);
405 if (subscriber->ref == 0) {
406 warn("Failed to acquire subscriber reference\n");
407 kfree(subscriber);
408 return;
409 }
410
411 /* Establish a connection to subscriber */
412
413 tipc_createport(topsrv.user_ref,
David S. Miller880b0052006-01-12 13:22:32 -0800414 (void *)(unsigned long)subscriber->ref,
Per Lidenb97bf3f2006-01-02 19:04:38 +0100415 importance,
416 0,
417 0,
418 subscr_conn_shutdown_event,
419 0,
420 0,
421 subscr_conn_msg_event,
422 0,
423 &subscriber->port_ref);
424 if (subscriber->port_ref == 0) {
425 warn("Memory squeeze; failed to create subscription port\n");
426 ref_discard(subscriber->ref);
427 kfree(subscriber);
428 return;
429 }
430 tipc_connect2port(subscriber->port_ref, orig);
431
432
433 /* Add subscriber to topology server's subscriber list */
434
435 ref_lock(subscriber->ref);
436 spin_lock_bh(&topsrv.lock);
437 list_add(&subscriber->subscriber_list, &topsrv.subscriber_list);
438 spin_unlock_bh(&topsrv.lock);
439
440 /*
441 * Subscribe now if message contains a subscription,
442 * otherwise send an empty response to complete connection handshaking
443 */
444
445 subscriber_lock = subscriber->lock;
446 if (size)
447 subscr_subscribe((struct tipc_subscr *)data, subscriber);
448 else
449 tipc_send(subscriber->port_ref, 1, &msg_sect);
450
451 spin_unlock_bh(subscriber_lock);
452}
453
454int subscr_start(void)
455{
456 struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV};
457 int res = -1;
458
459 memset(&topsrv, 0, sizeof (topsrv));
460 topsrv.lock = SPIN_LOCK_UNLOCKED;
461 INIT_LIST_HEAD(&topsrv.subscriber_list);
462
463 spin_lock_bh(&topsrv.lock);
464 res = tipc_attach(&topsrv.user_ref, 0, 0);
465 if (res) {
466 spin_unlock_bh(&topsrv.lock);
467 return res;
468 }
469
470 res = tipc_createport(topsrv.user_ref,
471 0,
472 TIPC_CRITICAL_IMPORTANCE,
473 0,
474 0,
475 0,
476 0,
477 subscr_named_msg_event,
478 0,
479 0,
480 &topsrv.setup_port);
481 if (res)
482 goto failed;
483
484 res = nametbl_publish_rsv(topsrv.setup_port, TIPC_NODE_SCOPE, &seq);
485 if (res)
486 goto failed;
487
488 spin_unlock_bh(&topsrv.lock);
489 return 0;
490
491failed:
Per Lidend0a14a92006-01-11 13:52:51 +0100492 err("Failed to create subscription service\n");
Per Lidenb97bf3f2006-01-02 19:04:38 +0100493 tipc_detach(topsrv.user_ref);
494 topsrv.user_ref = 0;
495 spin_unlock_bh(&topsrv.lock);
496 return res;
497}
498
499void subscr_stop(void)
500{
501 struct subscriber *subscriber;
502 struct subscriber *subscriber_temp;
503 spinlock_t *subscriber_lock;
504
505 if (topsrv.user_ref) {
506 tipc_deleteport(topsrv.setup_port);
507 list_for_each_entry_safe(subscriber, subscriber_temp,
508 &topsrv.subscriber_list,
509 subscriber_list) {
510 ref_lock(subscriber->ref);
511 subscriber_lock = subscriber->lock;
512 subscr_terminate(subscriber);
513 spin_unlock_bh(subscriber_lock);
514 }
515 tipc_detach(topsrv.user_ref);
516 topsrv.user_ref = 0;
517 }
518}
519
520
521int tipc_ispublished(struct tipc_name const *name)
522{
523 u32 domain = 0;
524
525 return(nametbl_translate(name->type, name->instance,&domain) != 0);
526}
527