1 /* 2 * net/tipc/subscr.c: TIPC subscription service 3 * 4 * Copyright (c) 2000-2006, Ericsson AB 5 * Copyright (c) 2005, 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 "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 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 * tipc_subscr_overlap - test for subscription overlap with the given values 122 * 123 * Returns 1 if there is overlap, otherwise 0. 124 */ 125 126 int tipc_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 * tipc_subscr_report_overlap - issue event if there is subscription overlap 142 * 143 * Protected by nameseq.lock in name_table.c 144 */ 145 146 void tipc_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 (!tipc_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 *)tipc_ref_lock(subscriber_ref); 176 if (subscriber == NULL) 177 return; 178 179 /* Validate timeout (in case subscription is being cancelled) */ 180 181 if (sub->timeout == TIPC_WAIT_FOREVER) { 182 tipc_ref_unlock(subscriber_ref); 183 return; 184 } 185 186 /* Unlink subscription from name table */ 187 188 tipc_nametbl_unsubscribe(sub); 189 190 /* Notify subscriber of timeout, then unlink subscription */ 191 192 subscr_send_event(sub, 193 sub->evt.s.seq.lower, 194 sub->evt.s.seq.upper, 195 TIPC_SUBSCR_TIMEOUT, 196 0, 197 0); 198 list_del(&sub->subscription_list); 199 200 /* Now destroy subscription */ 201 202 tipc_ref_unlock(subscriber_ref); 203 k_term_timer(&sub->timer); 204 kfree(sub); 205 atomic_dec(&topsrv.subscription_count); 206 } 207 208 /** 209 * subscr_del - delete a subscription within a subscription list 210 * 211 * Called with subscriber locked. 212 */ 213 214 static void subscr_del(struct subscription *sub) 215 { 216 tipc_nametbl_unsubscribe(sub); 217 list_del(&sub->subscription_list); 218 kfree(sub); 219 atomic_dec(&topsrv.subscription_count); 220 } 221 222 /** 223 * subscr_terminate - terminate communication with a subscriber 224 * 225 * Called with subscriber locked. Routine must temporarily release this lock 226 * to enable subscription timeout routine(s) to finish without deadlocking; 227 * the lock is then reclaimed to allow caller to release it upon return. 228 * (This should work even in the unlikely event some other thread creates 229 * a new object reference in the interim that uses this lock; this routine will 230 * simply wait for it to be released, then claim it.) 231 */ 232 233 static void subscr_terminate(struct subscriber *subscriber) 234 { 235 struct subscription *sub; 236 struct subscription *sub_temp; 237 238 /* Invalidate subscriber reference */ 239 240 tipc_ref_discard(subscriber->ref); 241 spin_unlock_bh(subscriber->lock); 242 243 /* Destroy any existing subscriptions for subscriber */ 244 245 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list, 246 subscription_list) { 247 if (sub->timeout != TIPC_WAIT_FOREVER) { 248 k_cancel_timer(&sub->timer); 249 k_term_timer(&sub->timer); 250 } 251 dbg("Term: Removing sub %u,%u,%u from subscriber %x list\n", 252 sub->seq.type, sub->seq.lower, sub->seq.upper, subscriber); 253 subscr_del(sub); 254 } 255 256 /* Sever connection to subscriber */ 257 258 tipc_shutdown(subscriber->port_ref); 259 tipc_deleteport(subscriber->port_ref); 260 261 /* Remove subscriber from topology server's subscriber list */ 262 263 spin_lock_bh(&topsrv.lock); 264 list_del(&subscriber->subscriber_list); 265 spin_unlock_bh(&topsrv.lock); 266 267 /* Now destroy subscriber */ 268 269 spin_lock_bh(subscriber->lock); 270 kfree(subscriber); 271 } 272 273 /** 274 * subscr_cancel - handle subscription cancellation request 275 * 276 * Called with subscriber locked. Routine must temporarily release this lock 277 * to enable the subscription timeout routine to finish without deadlocking; 278 * the lock is then reclaimed to allow caller to release it upon return. 279 * 280 * Note that fields of 's' use subscriber's endianness! 281 */ 282 283 static void subscr_cancel(struct tipc_subscr *s, 284 struct subscriber *subscriber) 285 { 286 struct subscription *sub; 287 struct subscription *sub_temp; 288 int found = 0; 289 290 /* Find first matching subscription, exit if not found */ 291 292 list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list, 293 subscription_list) { 294 if (!memcmp(s, &sub->evt.s, sizeof(struct tipc_subscr))) { 295 found = 1; 296 break; 297 } 298 } 299 if (!found) 300 return; 301 302 /* Cancel subscription timer (if used), then delete subscription */ 303 304 if (sub->timeout != TIPC_WAIT_FOREVER) { 305 sub->timeout = TIPC_WAIT_FOREVER; 306 spin_unlock_bh(subscriber->lock); 307 k_cancel_timer(&sub->timer); 308 k_term_timer(&sub->timer); 309 spin_lock_bh(subscriber->lock); 310 } 311 dbg("Cancel: removing sub %u,%u,%u from subscriber %x list\n", 312 sub->seq.type, sub->seq.lower, sub->seq.upper, subscriber); 313 subscr_del(sub); 314 } 315 316 /** 317 * subscr_subscribe - create subscription for subscriber 318 * 319 * Called with subscriber locked 320 */ 321 322 static void subscr_subscribe(struct tipc_subscr *s, 323 struct subscriber *subscriber) 324 { 325 struct subscription *sub; 326 327 /* Determine/update subscriber's endianness */ 328 329 if (s->filter & (TIPC_SUB_PORTS | TIPC_SUB_SERVICE)) 330 subscriber->swap = 0; 331 else 332 subscriber->swap = 1; 333 334 /* Detect & process a subscription cancellation request */ 335 336 if (s->filter & htohl(TIPC_SUB_CANCEL, subscriber->swap)) { 337 s->filter &= ~htohl(TIPC_SUB_CANCEL, subscriber->swap); 338 subscr_cancel(s, subscriber); 339 return; 340 } 341 342 /* Refuse subscription if global limit exceeded */ 343 344 if (atomic_read(&topsrv.subscription_count) >= tipc_max_subscriptions) { 345 warn("Subscription rejected, subscription limit reached (%u)\n", 346 tipc_max_subscriptions); 347 subscr_terminate(subscriber); 348 return; 349 } 350 351 /* Allocate subscription object */ 352 353 sub = kzalloc(sizeof(*sub), GFP_ATOMIC); 354 if (!sub) { 355 warn("Subscription rejected, no memory\n"); 356 subscr_terminate(subscriber); 357 return; 358 } 359 360 /* Initialize subscription object */ 361 362 sub->seq.type = htohl(s->seq.type, subscriber->swap); 363 sub->seq.lower = htohl(s->seq.lower, subscriber->swap); 364 sub->seq.upper = htohl(s->seq.upper, subscriber->swap); 365 sub->timeout = htohl(s->timeout, subscriber->swap); 366 sub->filter = htohl(s->filter, subscriber->swap); 367 if ((!(sub->filter & TIPC_SUB_PORTS) 368 == !(sub->filter & TIPC_SUB_SERVICE)) 369 || (sub->seq.lower > sub->seq.upper)) { 370 warn("Subscription rejected, illegal request\n"); 371 kfree(sub); 372 subscr_terminate(subscriber); 373 return; 374 } 375 memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr)); 376 INIT_LIST_HEAD(&sub->subscription_list); 377 INIT_LIST_HEAD(&sub->nameseq_list); 378 list_add(&sub->subscription_list, &subscriber->subscription_list); 379 atomic_inc(&topsrv.subscription_count); 380 if (sub->timeout != TIPC_WAIT_FOREVER) { 381 k_init_timer(&sub->timer, 382 (Handler)subscr_timeout, (unsigned long)sub); 383 k_start_timer(&sub->timer, sub->timeout); 384 } 385 sub->owner = subscriber; 386 tipc_nametbl_subscribe(sub); 387 } 388 389 /** 390 * subscr_conn_shutdown_event - handle termination request from subscriber 391 */ 392 393 static void subscr_conn_shutdown_event(void *usr_handle, 394 u32 portref, 395 struct sk_buff **buf, 396 unsigned char const *data, 397 unsigned int size, 398 int reason) 399 { 400 struct subscriber *subscriber; 401 spinlock_t *subscriber_lock; 402 403 subscriber = tipc_ref_lock((u32)(unsigned long)usr_handle); 404 if (subscriber == NULL) 405 return; 406 407 subscriber_lock = subscriber->lock; 408 subscr_terminate(subscriber); 409 spin_unlock_bh(subscriber_lock); 410 } 411 412 /** 413 * subscr_conn_msg_event - handle new subscription request from subscriber 414 */ 415 416 static void subscr_conn_msg_event(void *usr_handle, 417 u32 port_ref, 418 struct sk_buff **buf, 419 const unchar *data, 420 u32 size) 421 { 422 struct subscriber *subscriber; 423 spinlock_t *subscriber_lock; 424 425 subscriber = tipc_ref_lock((u32)(unsigned long)usr_handle); 426 if (subscriber == NULL) 427 return; 428 429 subscriber_lock = subscriber->lock; 430 if (size != sizeof(struct tipc_subscr)) 431 subscr_terminate(subscriber); 432 else 433 subscr_subscribe((struct tipc_subscr *)data, subscriber); 434 435 spin_unlock_bh(subscriber_lock); 436 } 437 438 /** 439 * subscr_named_msg_event - handle request to establish a new subscriber 440 */ 441 442 static void subscr_named_msg_event(void *usr_handle, 443 u32 port_ref, 444 struct sk_buff **buf, 445 const unchar *data, 446 u32 size, 447 u32 importance, 448 struct tipc_portid const *orig, 449 struct tipc_name_seq const *dest) 450 { 451 struct subscriber *subscriber; 452 struct iovec msg_sect = {NULL, 0}; 453 spinlock_t *subscriber_lock; 454 455 dbg("subscr_named_msg_event: orig = %x own = %x,\n", 456 orig->node, tipc_own_addr); 457 if (size && (size != sizeof(struct tipc_subscr))) { 458 warn("Subscriber rejected, invalid subscription size\n"); 459 return; 460 } 461 462 /* Create subscriber object */ 463 464 subscriber = kzalloc(sizeof(struct subscriber), GFP_ATOMIC); 465 if (subscriber == NULL) { 466 warn("Subscriber rejected, no memory\n"); 467 return; 468 } 469 INIT_LIST_HEAD(&subscriber->subscription_list); 470 INIT_LIST_HEAD(&subscriber->subscriber_list); 471 subscriber->ref = tipc_ref_acquire(subscriber, &subscriber->lock); 472 if (subscriber->ref == 0) { 473 warn("Subscriber rejected, reference table exhausted\n"); 474 kfree(subscriber); 475 return; 476 } 477 478 /* Establish a connection to subscriber */ 479 480 tipc_createport(topsrv.user_ref, 481 (void *)(unsigned long)subscriber->ref, 482 importance, 483 NULL, 484 NULL, 485 subscr_conn_shutdown_event, 486 NULL, 487 NULL, 488 subscr_conn_msg_event, 489 NULL, 490 &subscriber->port_ref); 491 if (subscriber->port_ref == 0) { 492 warn("Subscriber rejected, unable to create port\n"); 493 tipc_ref_discard(subscriber->ref); 494 kfree(subscriber); 495 return; 496 } 497 tipc_connect2port(subscriber->port_ref, orig); 498 499 500 /* Add subscriber to topology server's subscriber list */ 501 502 tipc_ref_lock(subscriber->ref); 503 spin_lock_bh(&topsrv.lock); 504 list_add(&subscriber->subscriber_list, &topsrv.subscriber_list); 505 spin_unlock_bh(&topsrv.lock); 506 507 /* 508 * Subscribe now if message contains a subscription, 509 * otherwise send an empty response to complete connection handshaking 510 */ 511 512 subscriber_lock = subscriber->lock; 513 if (size) 514 subscr_subscribe((struct tipc_subscr *)data, subscriber); 515 else 516 tipc_send(subscriber->port_ref, 1, &msg_sect); 517 518 spin_unlock_bh(subscriber_lock); 519 } 520 521 int tipc_subscr_start(void) 522 { 523 struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV}; 524 int res = -1; 525 526 memset(&topsrv, 0, sizeof (topsrv)); 527 spin_lock_init(&topsrv.lock); 528 INIT_LIST_HEAD(&topsrv.subscriber_list); 529 530 spin_lock_bh(&topsrv.lock); 531 res = tipc_attach(&topsrv.user_ref, NULL, NULL); 532 if (res) { 533 spin_unlock_bh(&topsrv.lock); 534 return res; 535 } 536 537 res = tipc_createport(topsrv.user_ref, 538 NULL, 539 TIPC_CRITICAL_IMPORTANCE, 540 NULL, 541 NULL, 542 NULL, 543 NULL, 544 subscr_named_msg_event, 545 NULL, 546 NULL, 547 &topsrv.setup_port); 548 if (res) 549 goto failed; 550 551 res = tipc_nametbl_publish_rsv(topsrv.setup_port, TIPC_NODE_SCOPE, &seq); 552 if (res) 553 goto failed; 554 555 spin_unlock_bh(&topsrv.lock); 556 return 0; 557 558 failed: 559 err("Failed to create subscription service\n"); 560 tipc_detach(topsrv.user_ref); 561 topsrv.user_ref = 0; 562 spin_unlock_bh(&topsrv.lock); 563 return res; 564 } 565 566 void tipc_subscr_stop(void) 567 { 568 struct subscriber *subscriber; 569 struct subscriber *subscriber_temp; 570 spinlock_t *subscriber_lock; 571 572 if (topsrv.user_ref) { 573 tipc_deleteport(topsrv.setup_port); 574 list_for_each_entry_safe(subscriber, subscriber_temp, 575 &topsrv.subscriber_list, 576 subscriber_list) { 577 tipc_ref_lock(subscriber->ref); 578 subscriber_lock = subscriber->lock; 579 subscr_terminate(subscriber); 580 spin_unlock_bh(subscriber_lock); 581 } 582 tipc_detach(topsrv.user_ref); 583 topsrv.user_ref = 0; 584 } 585 } 586 587 588 int tipc_ispublished(struct tipc_name const *name) 589 { 590 u32 domain = 0; 591 592 return(tipc_nametbl_translate(name->type, name->instance,&domain) != 0); 593 } 594 595