Per Liden | b97bf3f | 2006-01-02 19:04:38 +0100 | [diff] [blame] | 1 | /* |
| 2 | * net/tipc/subscr.c: TIPC subscription service |
| 3 | * |
| 4 | * Copyright (c) 2003-2005, Ericsson Research Canada |
| 5 | * Copyright (c) 2005, Wind River Systems |
| 6 | * Copyright (c) 2005-2006, Ericsson AB |
| 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 | * Redistributions of source code must retain the above copyright notice, this |
| 13 | * list of conditions and the following disclaimer. |
| 14 | * Redistributions in binary form must reproduce the above copyright notice, |
| 15 | * this list of conditions and the following disclaimer in the documentation |
| 16 | * and/or other materials provided with the distribution. |
| 17 | * Neither the names of the copyright holders nor the names of its |
| 18 | * contributors may be used to endorse or promote products derived from this |
| 19 | * software without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| 22 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| 25 | * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| 26 | * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| 27 | * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| 28 | * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| 29 | * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 30 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| 31 | * POSSIBILITY OF SUCH DAMAGE. |
| 32 | */ |
| 33 | |
| 34 | #include "core.h" |
| 35 | #include "dbg.h" |
| 36 | #include "subscr.h" |
| 37 | #include "name_table.h" |
| 38 | #include "ref.h" |
| 39 | |
| 40 | /** |
| 41 | * struct subscriber - TIPC network topology subscriber |
| 42 | * @ref: object reference to subscriber object itself |
| 43 | * @lock: pointer to spinlock controlling access to subscriber object |
| 44 | * @subscriber_list: adjacent subscribers in top. server's list of subscribers |
| 45 | * @subscription_list: list of subscription objects for this subscriber |
| 46 | * @port_ref: object reference to port used to communicate with subscriber |
| 47 | * @swap: indicates if subscriber uses opposite endianness in its messages |
| 48 | */ |
| 49 | |
| 50 | struct subscriber { |
| 51 | u32 ref; |
| 52 | spinlock_t *lock; |
| 53 | struct list_head subscriber_list; |
| 54 | struct list_head subscription_list; |
| 55 | u32 port_ref; |
| 56 | int swap; |
| 57 | }; |
| 58 | |
| 59 | /** |
| 60 | * struct top_srv - TIPC network topology subscription service |
| 61 | * @user_ref: TIPC userid of subscription service |
| 62 | * @setup_port: reference to TIPC port that handles subscription requests |
| 63 | * @subscription_count: number of active subscriptions (not subscribers!) |
| 64 | * @subscriber_list: list of ports subscribing to service |
| 65 | * @lock: spinlock govering access to subscriber list |
| 66 | */ |
| 67 | |
| 68 | struct top_srv { |
| 69 | u32 user_ref; |
| 70 | u32 setup_port; |
| 71 | atomic_t subscription_count; |
| 72 | struct list_head subscriber_list; |
| 73 | spinlock_t lock; |
| 74 | }; |
| 75 | |
| 76 | static struct top_srv topsrv = { 0 }; |
| 77 | |
| 78 | /** |
| 79 | * htohl - convert value to endianness used by destination |
| 80 | * @in: value to convert |
| 81 | * @swap: non-zero if endianness must be reversed |
| 82 | * |
| 83 | * Returns converted value |
| 84 | */ |
| 85 | |
| 86 | static inline u32 htohl(u32 in, int swap) |
| 87 | { |
| 88 | char *c = (char *)∈ |
| 89 | |
| 90 | return swap ? ((c[3] << 3) + (c[2] << 2) + (c[1] << 1) + c[0]) : in; |
| 91 | } |
| 92 | |
| 93 | /** |
| 94 | * subscr_send_event - send a message containing a tipc_event to the subscriber |
| 95 | */ |
| 96 | |
| 97 | static void subscr_send_event(struct subscription *sub, |
| 98 | u32 found_lower, |
| 99 | u32 found_upper, |
| 100 | u32 event, |
| 101 | u32 port_ref, |
| 102 | u32 node) |
| 103 | { |
| 104 | struct iovec msg_sect; |
| 105 | |
| 106 | msg_sect.iov_base = (void *)&sub->evt; |
| 107 | msg_sect.iov_len = sizeof(struct tipc_event); |
| 108 | |
| 109 | sub->evt.event = htohl(event, sub->owner->swap); |
| 110 | sub->evt.found_lower = htohl(found_lower, sub->owner->swap); |
| 111 | sub->evt.found_upper = htohl(found_upper, sub->owner->swap); |
| 112 | sub->evt.port.ref = htohl(port_ref, sub->owner->swap); |
| 113 | sub->evt.port.node = htohl(node, sub->owner->swap); |
| 114 | tipc_send(sub->owner->port_ref, 1, &msg_sect); |
| 115 | } |
| 116 | |
| 117 | /** |
| 118 | * subscr_overlap - test for subscription overlap with the given values |
| 119 | * |
| 120 | * Returns 1 if there is overlap, otherwise 0. |
| 121 | */ |
| 122 | |
| 123 | int subscr_overlap(struct subscription *sub, |
| 124 | u32 found_lower, |
| 125 | u32 found_upper) |
| 126 | |
| 127 | { |
| 128 | if (found_lower < sub->seq.lower) |
| 129 | found_lower = sub->seq.lower; |
| 130 | if (found_upper > sub->seq.upper) |
| 131 | found_upper = sub->seq.upper; |
| 132 | if (found_lower > found_upper) |
| 133 | return 0; |
| 134 | return 1; |
| 135 | } |
| 136 | |
| 137 | /** |
| 138 | * subscr_report_overlap - issue event if there is subscription overlap |
| 139 | * |
| 140 | * Protected by nameseq.lock in name_table.c |
| 141 | */ |
| 142 | |
| 143 | void subscr_report_overlap(struct subscription *sub, |
| 144 | u32 found_lower, |
| 145 | u32 found_upper, |
| 146 | u32 event, |
| 147 | u32 port_ref, |
| 148 | u32 node, |
| 149 | int must) |
| 150 | { |
| 151 | dbg("Rep overlap %u:%u,%u<->%u,%u\n", sub->seq.type, sub->seq.lower, |
| 152 | sub->seq.upper, found_lower, found_upper); |
| 153 | if (!subscr_overlap(sub, found_lower, found_upper)) |
| 154 | return; |
| 155 | if (!must && (sub->filter != TIPC_SUB_PORTS)) |
| 156 | return; |
| 157 | subscr_send_event(sub, found_lower, found_upper, event, port_ref, node); |
| 158 | } |
| 159 | |
| 160 | /** |
| 161 | * subscr_timeout - subscription timeout has occurred |
| 162 | */ |
| 163 | |
| 164 | static void subscr_timeout(struct subscription *sub) |
| 165 | { |
| 166 | struct subscriber *subscriber; |
| 167 | u32 subscriber_ref; |
| 168 | |
| 169 | /* Validate subscriber reference (in case subscriber is terminating) */ |
| 170 | |
| 171 | subscriber_ref = sub->owner->ref; |
| 172 | subscriber = (struct subscriber *)ref_lock(subscriber_ref); |
| 173 | if (subscriber == NULL) |
| 174 | return; |
| 175 | |
| 176 | /* Unlink subscription from name table */ |
| 177 | |
| 178 | nametbl_unsubscribe(sub); |
| 179 | |
| 180 | /* Notify subscriber of timeout, then unlink subscription */ |
| 181 | |
| 182 | subscr_send_event(sub, |
| 183 | sub->evt.s.seq.lower, |
| 184 | sub->evt.s.seq.upper, |
| 185 | TIPC_SUBSCR_TIMEOUT, |
| 186 | 0, |
| 187 | 0); |
| 188 | list_del(&sub->subscription_list); |
| 189 | |
| 190 | /* Now destroy subscription */ |
| 191 | |
| 192 | ref_unlock(subscriber_ref); |
| 193 | k_term_timer(&sub->timer); |
| 194 | kfree(sub); |
| 195 | atomic_dec(&topsrv.subscription_count); |
| 196 | } |
| 197 | |
| 198 | /** |
| 199 | * subscr_terminate - terminate communication with a subscriber |
| 200 | * |
| 201 | * Called with subscriber locked. Routine must temporarily release this lock |
| 202 | * to enable subscription timeout routine(s) to finish without deadlocking; |
| 203 | * the lock is then reclaimed to allow caller to release it upon return. |
| 204 | * (This should work even in the unlikely event some other thread creates |
| 205 | * a new object reference in the interim that uses this lock; this routine will |
| 206 | * simply wait for it to be released, then claim it.) |
| 207 | */ |
| 208 | |
| 209 | static void subscr_terminate(struct subscriber *subscriber) |
| 210 | { |
| 211 | struct subscription *sub; |
| 212 | struct subscription *sub_temp; |
| 213 | |
| 214 | /* Invalidate subscriber reference */ |
| 215 | |
| 216 | ref_discard(subscriber->ref); |
| 217 | spin_unlock_bh(subscriber->lock); |
| 218 | |
| 219 | /* Destroy any existing subscriptions for subscriber */ |
| 220 | |
| 221 | list_for_each_entry_safe(sub, sub_temp, &subscriber->subscription_list, |
| 222 | subscription_list) { |
| 223 | if (sub->timeout != TIPC_WAIT_FOREVER) { |
| 224 | k_cancel_timer(&sub->timer); |
| 225 | k_term_timer(&sub->timer); |
| 226 | } |
| 227 | nametbl_unsubscribe(sub); |
| 228 | list_del(&sub->subscription_list); |
| 229 | dbg("Term: Removed sub %u,%u,%u from subscriber %x list\n", |
| 230 | sub->seq.type, sub->seq.lower, sub->seq.upper, subscriber); |
| 231 | kfree(sub); |
| 232 | atomic_dec(&topsrv.subscription_count); |
| 233 | } |
| 234 | |
| 235 | /* Sever connection to subscriber */ |
| 236 | |
| 237 | tipc_shutdown(subscriber->port_ref); |
| 238 | tipc_deleteport(subscriber->port_ref); |
| 239 | |
| 240 | /* Remove subscriber from topology server's subscriber list */ |
| 241 | |
| 242 | spin_lock_bh(&topsrv.lock); |
| 243 | list_del(&subscriber->subscriber_list); |
| 244 | spin_unlock_bh(&topsrv.lock); |
| 245 | |
| 246 | /* Now destroy subscriber */ |
| 247 | |
| 248 | spin_lock_bh(subscriber->lock); |
| 249 | kfree(subscriber); |
| 250 | } |
| 251 | |
| 252 | /** |
| 253 | * subscr_subscribe - create subscription for subscriber |
| 254 | * |
| 255 | * Called with subscriber locked |
| 256 | */ |
| 257 | |
| 258 | static void subscr_subscribe(struct tipc_subscr *s, |
| 259 | struct subscriber *subscriber) |
| 260 | { |
| 261 | struct subscription *sub; |
| 262 | |
| 263 | /* Refuse subscription if global limit exceeded */ |
| 264 | |
| 265 | if (atomic_read(&topsrv.subscription_count) >= tipc_max_subscriptions) { |
| 266 | warn("Failed: max %u subscriptions\n", tipc_max_subscriptions); |
| 267 | subscr_terminate(subscriber); |
| 268 | return; |
| 269 | } |
| 270 | |
| 271 | /* Allocate subscription object */ |
| 272 | |
| 273 | sub = kmalloc(sizeof(*sub), GFP_ATOMIC); |
| 274 | if (sub == NULL) { |
| 275 | warn("Memory squeeze; ignoring subscription\n"); |
| 276 | subscr_terminate(subscriber); |
| 277 | return; |
| 278 | } |
| 279 | |
| 280 | /* Determine/update subscriber's endianness */ |
| 281 | |
| 282 | if ((s->filter == TIPC_SUB_PORTS) || (s->filter == TIPC_SUB_SERVICE)) |
| 283 | subscriber->swap = 0; |
| 284 | else |
| 285 | subscriber->swap = 1; |
| 286 | |
| 287 | /* Initialize subscription object */ |
| 288 | |
| 289 | memset(sub, 0, sizeof(*sub)); |
| 290 | sub->seq.type = htohl(s->seq.type, subscriber->swap); |
| 291 | sub->seq.lower = htohl(s->seq.lower, subscriber->swap); |
| 292 | sub->seq.upper = htohl(s->seq.upper, subscriber->swap); |
| 293 | sub->timeout = htohl(s->timeout, subscriber->swap); |
| 294 | sub->filter = htohl(s->filter, subscriber->swap); |
| 295 | if ((((sub->filter != TIPC_SUB_PORTS) |
| 296 | && (sub->filter != TIPC_SUB_SERVICE))) |
| 297 | || (sub->seq.lower > sub->seq.upper)) { |
| 298 | warn("Rejecting illegal subscription %u,%u,%u\n", |
| 299 | sub->seq.type, sub->seq.lower, sub->seq.upper); |
| 300 | kfree(sub); |
| 301 | subscr_terminate(subscriber); |
| 302 | return; |
| 303 | } |
| 304 | memcpy(&sub->evt.s, s, sizeof(struct tipc_subscr)); |
| 305 | INIT_LIST_HEAD(&sub->subscription_list); |
| 306 | INIT_LIST_HEAD(&sub->nameseq_list); |
| 307 | list_add(&sub->subscription_list, &subscriber->subscription_list); |
| 308 | atomic_inc(&topsrv.subscription_count); |
| 309 | if (sub->timeout != TIPC_WAIT_FOREVER) { |
| 310 | k_init_timer(&sub->timer, |
| 311 | (Handler)subscr_timeout, (unsigned long)sub); |
| 312 | k_start_timer(&sub->timer, sub->timeout); |
| 313 | } |
| 314 | sub->owner = subscriber; |
| 315 | nametbl_subscribe(sub); |
| 316 | } |
| 317 | |
| 318 | /** |
| 319 | * subscr_conn_shutdown_event - handle termination request from subscriber |
| 320 | */ |
| 321 | |
| 322 | static void subscr_conn_shutdown_event(void *usr_handle, |
| 323 | u32 portref, |
| 324 | struct sk_buff **buf, |
| 325 | unsigned char const *data, |
| 326 | unsigned int size, |
| 327 | int reason) |
| 328 | { |
| 329 | struct subscriber *subscriber = ref_lock((u32)usr_handle); |
| 330 | spinlock_t *subscriber_lock; |
| 331 | |
| 332 | if (subscriber == NULL) |
| 333 | return; |
| 334 | |
| 335 | subscriber_lock = subscriber->lock; |
| 336 | subscr_terminate(subscriber); |
| 337 | spin_unlock_bh(subscriber_lock); |
| 338 | } |
| 339 | |
| 340 | /** |
| 341 | * subscr_conn_msg_event - handle new subscription request from subscriber |
| 342 | */ |
| 343 | |
| 344 | static void subscr_conn_msg_event(void *usr_handle, |
| 345 | u32 port_ref, |
| 346 | struct sk_buff **buf, |
| 347 | const unchar *data, |
| 348 | u32 size) |
| 349 | { |
| 350 | struct subscriber *subscriber = ref_lock((u32)usr_handle); |
| 351 | spinlock_t *subscriber_lock; |
| 352 | |
| 353 | if (subscriber == NULL) |
| 354 | return; |
| 355 | |
| 356 | subscriber_lock = subscriber->lock; |
| 357 | if (size != sizeof(struct tipc_subscr)) |
| 358 | subscr_terminate(subscriber); |
| 359 | else |
| 360 | subscr_subscribe((struct tipc_subscr *)data, subscriber); |
| 361 | |
| 362 | spin_unlock_bh(subscriber_lock); |
| 363 | } |
| 364 | |
| 365 | /** |
| 366 | * subscr_named_msg_event - handle request to establish a new subscriber |
| 367 | */ |
| 368 | |
| 369 | static void subscr_named_msg_event(void *usr_handle, |
| 370 | u32 port_ref, |
| 371 | struct sk_buff **buf, |
| 372 | const unchar *data, |
| 373 | u32 size, |
| 374 | u32 importance, |
| 375 | struct tipc_portid const *orig, |
| 376 | struct tipc_name_seq const *dest) |
| 377 | { |
| 378 | struct subscriber *subscriber; |
| 379 | struct iovec msg_sect = {0, 0}; |
| 380 | spinlock_t *subscriber_lock; |
| 381 | |
| 382 | dbg("subscr_named_msg_event: orig = %x own = %x,\n", |
| 383 | orig->node, tipc_own_addr); |
| 384 | if (size && (size != sizeof(struct tipc_subscr))) { |
| 385 | warn("Received tipc_subscr of invalid size\n"); |
| 386 | return; |
| 387 | } |
| 388 | |
| 389 | /* Create subscriber object */ |
| 390 | |
| 391 | subscriber = kmalloc(sizeof(struct subscriber), GFP_ATOMIC); |
| 392 | if (subscriber == NULL) { |
| 393 | warn("Memory squeeze; ignoring subscriber setup\n"); |
| 394 | return; |
| 395 | } |
| 396 | memset(subscriber, 0, sizeof(struct subscriber)); |
| 397 | INIT_LIST_HEAD(&subscriber->subscription_list); |
| 398 | INIT_LIST_HEAD(&subscriber->subscriber_list); |
| 399 | subscriber->ref = ref_acquire(subscriber, &subscriber->lock); |
| 400 | if (subscriber->ref == 0) { |
| 401 | warn("Failed to acquire subscriber reference\n"); |
| 402 | kfree(subscriber); |
| 403 | return; |
| 404 | } |
| 405 | |
| 406 | /* Establish a connection to subscriber */ |
| 407 | |
| 408 | tipc_createport(topsrv.user_ref, |
| 409 | (void *)subscriber->ref, |
| 410 | importance, |
| 411 | 0, |
| 412 | 0, |
| 413 | subscr_conn_shutdown_event, |
| 414 | 0, |
| 415 | 0, |
| 416 | subscr_conn_msg_event, |
| 417 | 0, |
| 418 | &subscriber->port_ref); |
| 419 | if (subscriber->port_ref == 0) { |
| 420 | warn("Memory squeeze; failed to create subscription port\n"); |
| 421 | ref_discard(subscriber->ref); |
| 422 | kfree(subscriber); |
| 423 | return; |
| 424 | } |
| 425 | tipc_connect2port(subscriber->port_ref, orig); |
| 426 | |
| 427 | |
| 428 | /* Add subscriber to topology server's subscriber list */ |
| 429 | |
| 430 | ref_lock(subscriber->ref); |
| 431 | spin_lock_bh(&topsrv.lock); |
| 432 | list_add(&subscriber->subscriber_list, &topsrv.subscriber_list); |
| 433 | spin_unlock_bh(&topsrv.lock); |
| 434 | |
| 435 | /* |
| 436 | * Subscribe now if message contains a subscription, |
| 437 | * otherwise send an empty response to complete connection handshaking |
| 438 | */ |
| 439 | |
| 440 | subscriber_lock = subscriber->lock; |
| 441 | if (size) |
| 442 | subscr_subscribe((struct tipc_subscr *)data, subscriber); |
| 443 | else |
| 444 | tipc_send(subscriber->port_ref, 1, &msg_sect); |
| 445 | |
| 446 | spin_unlock_bh(subscriber_lock); |
| 447 | } |
| 448 | |
| 449 | int subscr_start(void) |
| 450 | { |
| 451 | struct tipc_name_seq seq = {TIPC_TOP_SRV, TIPC_TOP_SRV, TIPC_TOP_SRV}; |
| 452 | int res = -1; |
| 453 | |
| 454 | memset(&topsrv, 0, sizeof (topsrv)); |
| 455 | topsrv.lock = SPIN_LOCK_UNLOCKED; |
| 456 | INIT_LIST_HEAD(&topsrv.subscriber_list); |
| 457 | |
| 458 | spin_lock_bh(&topsrv.lock); |
| 459 | res = tipc_attach(&topsrv.user_ref, 0, 0); |
| 460 | if (res) { |
| 461 | spin_unlock_bh(&topsrv.lock); |
| 462 | return res; |
| 463 | } |
| 464 | |
| 465 | res = tipc_createport(topsrv.user_ref, |
| 466 | 0, |
| 467 | TIPC_CRITICAL_IMPORTANCE, |
| 468 | 0, |
| 469 | 0, |
| 470 | 0, |
| 471 | 0, |
| 472 | subscr_named_msg_event, |
| 473 | 0, |
| 474 | 0, |
| 475 | &topsrv.setup_port); |
| 476 | if (res) |
| 477 | goto failed; |
| 478 | |
| 479 | res = nametbl_publish_rsv(topsrv.setup_port, TIPC_NODE_SCOPE, &seq); |
| 480 | if (res) |
| 481 | goto failed; |
| 482 | |
| 483 | spin_unlock_bh(&topsrv.lock); |
| 484 | return 0; |
| 485 | |
| 486 | failed: |
| 487 | err("Unable to create subscription service\n"); |
| 488 | tipc_detach(topsrv.user_ref); |
| 489 | topsrv.user_ref = 0; |
| 490 | spin_unlock_bh(&topsrv.lock); |
| 491 | return res; |
| 492 | } |
| 493 | |
| 494 | void subscr_stop(void) |
| 495 | { |
| 496 | struct subscriber *subscriber; |
| 497 | struct subscriber *subscriber_temp; |
| 498 | spinlock_t *subscriber_lock; |
| 499 | |
| 500 | if (topsrv.user_ref) { |
| 501 | tipc_deleteport(topsrv.setup_port); |
| 502 | list_for_each_entry_safe(subscriber, subscriber_temp, |
| 503 | &topsrv.subscriber_list, |
| 504 | subscriber_list) { |
| 505 | ref_lock(subscriber->ref); |
| 506 | subscriber_lock = subscriber->lock; |
| 507 | subscr_terminate(subscriber); |
| 508 | spin_unlock_bh(subscriber_lock); |
| 509 | } |
| 510 | tipc_detach(topsrv.user_ref); |
| 511 | topsrv.user_ref = 0; |
| 512 | } |
| 513 | } |
| 514 | |
| 515 | |
| 516 | int tipc_ispublished(struct tipc_name const *name) |
| 517 | { |
| 518 | u32 domain = 0; |
| 519 | |
| 520 | return(nametbl_translate(name->type, name->instance,&domain) != 0); |
| 521 | } |
| 522 | |