1 /* 2 * net/tipc/bearer.c: TIPC bearer code 3 * 4 * Copyright (c) 1996-2006, Ericsson AB 5 * Copyright (c) 2004-2006, 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 "config.h" 39 #include "bearer.h" 40 #include "discover.h" 41 42 #define MAX_ADDR_STR 32 43 44 static struct tipc_media *media_list[MAX_MEDIA]; 45 static u32 media_count; 46 47 struct tipc_bearer tipc_bearers[MAX_BEARERS]; 48 49 static void bearer_disable(struct tipc_bearer *b_ptr); 50 51 /** 52 * media_name_valid - validate media name 53 * 54 * Returns 1 if media name is valid, otherwise 0. 55 */ 56 static int media_name_valid(const char *name) 57 { 58 u32 len; 59 60 len = strlen(name); 61 if ((len + 1) > TIPC_MAX_MEDIA_NAME) 62 return 0; 63 return strspn(name, tipc_alphabet) == len; 64 } 65 66 /** 67 * tipc_media_find - locates specified media object by name 68 */ 69 struct tipc_media *tipc_media_find(const char *name) 70 { 71 u32 i; 72 73 for (i = 0; i < media_count; i++) { 74 if (!strcmp(media_list[i]->name, name)) 75 return media_list[i]; 76 } 77 return NULL; 78 } 79 80 /** 81 * media_find_id - locates specified media object by type identifier 82 */ 83 static struct tipc_media *media_find_id(u8 type) 84 { 85 u32 i; 86 87 for (i = 0; i < media_count; i++) { 88 if (media_list[i]->type_id == type) 89 return media_list[i]; 90 } 91 return NULL; 92 } 93 94 /** 95 * tipc_register_media - register a media type 96 * 97 * Bearers for this media type must be activated separately at a later stage. 98 */ 99 int tipc_register_media(struct tipc_media *m_ptr) 100 { 101 int res = -EINVAL; 102 103 write_lock_bh(&tipc_net_lock); 104 105 if (!media_name_valid(m_ptr->name)) 106 goto exit; 107 if ((m_ptr->bcast_addr.media_id != m_ptr->type_id) || 108 !m_ptr->bcast_addr.broadcast) 109 goto exit; 110 if (m_ptr->priority > TIPC_MAX_LINK_PRI) 111 goto exit; 112 if ((m_ptr->tolerance < TIPC_MIN_LINK_TOL) || 113 (m_ptr->tolerance > TIPC_MAX_LINK_TOL)) 114 goto exit; 115 if (media_count >= MAX_MEDIA) 116 goto exit; 117 if (tipc_media_find(m_ptr->name) || media_find_id(m_ptr->type_id)) 118 goto exit; 119 120 media_list[media_count] = m_ptr; 121 media_count++; 122 res = 0; 123 exit: 124 write_unlock_bh(&tipc_net_lock); 125 if (res) 126 warn("Media <%s> registration error\n", m_ptr->name); 127 return res; 128 } 129 130 /** 131 * tipc_media_addr_printf - record media address in print buffer 132 */ 133 void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a) 134 { 135 char addr_str[MAX_ADDR_STR]; 136 struct tipc_media *m_ptr; 137 138 m_ptr = media_find_id(a->media_id); 139 140 if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str))) 141 tipc_printf(pb, "%s(%s)", m_ptr->name, addr_str); 142 else { 143 u32 i; 144 145 tipc_printf(pb, "UNKNOWN(%u)", a->media_id); 146 for (i = 0; i < sizeof(a->value); i++) 147 tipc_printf(pb, "-%02x", a->value[i]); 148 } 149 } 150 151 /** 152 * tipc_media_get_names - record names of registered media in buffer 153 */ 154 struct sk_buff *tipc_media_get_names(void) 155 { 156 struct sk_buff *buf; 157 int i; 158 159 buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME)); 160 if (!buf) 161 return NULL; 162 163 read_lock_bh(&tipc_net_lock); 164 for (i = 0; i < media_count; i++) { 165 tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME, 166 media_list[i]->name, 167 strlen(media_list[i]->name) + 1); 168 } 169 read_unlock_bh(&tipc_net_lock); 170 return buf; 171 } 172 173 /** 174 * bearer_name_validate - validate & (optionally) deconstruct bearer name 175 * @name: ptr to bearer name string 176 * @name_parts: ptr to area for bearer name components (or NULL if not needed) 177 * 178 * Returns 1 if bearer name is valid, otherwise 0. 179 */ 180 static int bearer_name_validate(const char *name, 181 struct tipc_bearer_names *name_parts) 182 { 183 char name_copy[TIPC_MAX_BEARER_NAME]; 184 char *media_name; 185 char *if_name; 186 u32 media_len; 187 u32 if_len; 188 189 /* copy bearer name & ensure length is OK */ 190 name_copy[TIPC_MAX_BEARER_NAME - 1] = 0; 191 /* need above in case non-Posix strncpy() doesn't pad with nulls */ 192 strncpy(name_copy, name, TIPC_MAX_BEARER_NAME); 193 if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0) 194 return 0; 195 196 /* ensure all component parts of bearer name are present */ 197 media_name = name_copy; 198 if_name = strchr(media_name, ':'); 199 if (if_name == NULL) 200 return 0; 201 *(if_name++) = 0; 202 media_len = if_name - media_name; 203 if_len = strlen(if_name) + 1; 204 205 /* validate component parts of bearer name */ 206 if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) || 207 (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME) || 208 (strspn(media_name, tipc_alphabet) != (media_len - 1)) || 209 (strspn(if_name, tipc_alphabet) != (if_len - 1))) 210 return 0; 211 212 /* return bearer name components, if necessary */ 213 if (name_parts) { 214 strcpy(name_parts->media_name, media_name); 215 strcpy(name_parts->if_name, if_name); 216 } 217 return 1; 218 } 219 220 /** 221 * tipc_bearer_find - locates bearer object with matching bearer name 222 */ 223 struct tipc_bearer *tipc_bearer_find(const char *name) 224 { 225 struct tipc_bearer *b_ptr; 226 u32 i; 227 228 for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) { 229 if (b_ptr->active && (!strcmp(b_ptr->name, name))) 230 return b_ptr; 231 } 232 return NULL; 233 } 234 235 /** 236 * tipc_bearer_find_interface - locates bearer object with matching interface name 237 */ 238 struct tipc_bearer *tipc_bearer_find_interface(const char *if_name) 239 { 240 struct tipc_bearer *b_ptr; 241 char *b_if_name; 242 u32 i; 243 244 for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) { 245 if (!b_ptr->active) 246 continue; 247 b_if_name = strchr(b_ptr->name, ':') + 1; 248 if (!strcmp(b_if_name, if_name)) 249 return b_ptr; 250 } 251 return NULL; 252 } 253 254 /** 255 * tipc_bearer_get_names - record names of bearers in buffer 256 */ 257 struct sk_buff *tipc_bearer_get_names(void) 258 { 259 struct sk_buff *buf; 260 struct tipc_bearer *b_ptr; 261 int i, j; 262 263 buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME)); 264 if (!buf) 265 return NULL; 266 267 read_lock_bh(&tipc_net_lock); 268 for (i = 0; i < media_count; i++) { 269 for (j = 0; j < MAX_BEARERS; j++) { 270 b_ptr = &tipc_bearers[j]; 271 if (b_ptr->active && (b_ptr->media == media_list[i])) { 272 tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME, 273 b_ptr->name, 274 strlen(b_ptr->name) + 1); 275 } 276 } 277 } 278 read_unlock_bh(&tipc_net_lock); 279 return buf; 280 } 281 282 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest) 283 { 284 tipc_nmap_add(&b_ptr->nodes, dest); 285 tipc_bcbearer_sort(); 286 tipc_disc_add_dest(b_ptr->link_req); 287 } 288 289 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest) 290 { 291 tipc_nmap_remove(&b_ptr->nodes, dest); 292 tipc_bcbearer_sort(); 293 tipc_disc_remove_dest(b_ptr->link_req); 294 } 295 296 /* 297 * bearer_push(): Resolve bearer congestion. Force the waiting 298 * links to push out their unsent packets, one packet per link 299 * per iteration, until all packets are gone or congestion reoccurs. 300 * 'tipc_net_lock' is read_locked when this function is called 301 * bearer.lock must be taken before calling 302 * Returns binary true(1) ore false(0) 303 */ 304 static int bearer_push(struct tipc_bearer *b_ptr) 305 { 306 u32 res = 0; 307 struct tipc_link *ln, *tln; 308 309 if (b_ptr->blocked) 310 return 0; 311 312 while (!list_empty(&b_ptr->cong_links) && (res != PUSH_FAILED)) { 313 list_for_each_entry_safe(ln, tln, &b_ptr->cong_links, link_list) { 314 res = tipc_link_push_packet(ln); 315 if (res == PUSH_FAILED) 316 break; 317 if (res == PUSH_FINISHED) 318 list_move_tail(&ln->link_list, &b_ptr->links); 319 } 320 } 321 return list_empty(&b_ptr->cong_links); 322 } 323 324 void tipc_bearer_lock_push(struct tipc_bearer *b_ptr) 325 { 326 spin_lock_bh(&b_ptr->lock); 327 bearer_push(b_ptr); 328 spin_unlock_bh(&b_ptr->lock); 329 } 330 331 332 /* 333 * Interrupt enabling new requests after bearer congestion or blocking: 334 * See bearer_send(). 335 */ 336 void tipc_continue(struct tipc_bearer *b_ptr) 337 { 338 spin_lock_bh(&b_ptr->lock); 339 if (!list_empty(&b_ptr->cong_links)) 340 tipc_k_signal((Handler)tipc_bearer_lock_push, (unsigned long)b_ptr); 341 b_ptr->blocked = 0; 342 spin_unlock_bh(&b_ptr->lock); 343 } 344 345 /* 346 * Schedule link for sending of messages after the bearer 347 * has been deblocked by 'continue()'. This method is called 348 * when somebody tries to send a message via this link while 349 * the bearer is congested. 'tipc_net_lock' is in read_lock here 350 * bearer.lock is busy 351 */ 352 static void tipc_bearer_schedule_unlocked(struct tipc_bearer *b_ptr, 353 struct tipc_link *l_ptr) 354 { 355 list_move_tail(&l_ptr->link_list, &b_ptr->cong_links); 356 } 357 358 /* 359 * Schedule link for sending of messages after the bearer 360 * has been deblocked by 'continue()'. This method is called 361 * when somebody tries to send a message via this link while 362 * the bearer is congested. 'tipc_net_lock' is in read_lock here, 363 * bearer.lock is free 364 */ 365 void tipc_bearer_schedule(struct tipc_bearer *b_ptr, struct tipc_link *l_ptr) 366 { 367 spin_lock_bh(&b_ptr->lock); 368 tipc_bearer_schedule_unlocked(b_ptr, l_ptr); 369 spin_unlock_bh(&b_ptr->lock); 370 } 371 372 373 /* 374 * tipc_bearer_resolve_congestion(): Check if there is bearer congestion, 375 * and if there is, try to resolve it before returning. 376 * 'tipc_net_lock' is read_locked when this function is called 377 */ 378 int tipc_bearer_resolve_congestion(struct tipc_bearer *b_ptr, 379 struct tipc_link *l_ptr) 380 { 381 int res = 1; 382 383 if (list_empty(&b_ptr->cong_links)) 384 return 1; 385 spin_lock_bh(&b_ptr->lock); 386 if (!bearer_push(b_ptr)) { 387 tipc_bearer_schedule_unlocked(b_ptr, l_ptr); 388 res = 0; 389 } 390 spin_unlock_bh(&b_ptr->lock); 391 return res; 392 } 393 394 /** 395 * tipc_bearer_congested - determines if bearer is currently congested 396 */ 397 int tipc_bearer_congested(struct tipc_bearer *b_ptr, struct tipc_link *l_ptr) 398 { 399 if (unlikely(b_ptr->blocked)) 400 return 1; 401 if (likely(list_empty(&b_ptr->cong_links))) 402 return 0; 403 return !tipc_bearer_resolve_congestion(b_ptr, l_ptr); 404 } 405 406 /** 407 * tipc_enable_bearer - enable bearer with the given name 408 */ 409 int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority) 410 { 411 struct tipc_bearer *b_ptr; 412 struct tipc_media *m_ptr; 413 struct tipc_bearer_names b_names; 414 char addr_string[16]; 415 u32 bearer_id; 416 u32 with_this_prio; 417 u32 i; 418 int res = -EINVAL; 419 420 if (!tipc_own_addr) { 421 warn("Bearer <%s> rejected, not supported in standalone mode\n", 422 name); 423 return -ENOPROTOOPT; 424 } 425 if (!bearer_name_validate(name, &b_names)) { 426 warn("Bearer <%s> rejected, illegal name\n", name); 427 return -EINVAL; 428 } 429 if (tipc_addr_domain_valid(disc_domain) && 430 (disc_domain != tipc_own_addr)) { 431 if (tipc_in_scope(disc_domain, tipc_own_addr)) { 432 disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK; 433 res = 0; /* accept any node in own cluster */ 434 } else if (in_own_cluster_exact(disc_domain)) 435 res = 0; /* accept specified node in own cluster */ 436 } 437 if (res) { 438 warn("Bearer <%s> rejected, illegal discovery domain\n", name); 439 return -EINVAL; 440 } 441 if ((priority > TIPC_MAX_LINK_PRI) && 442 (priority != TIPC_MEDIA_LINK_PRI)) { 443 warn("Bearer <%s> rejected, illegal priority\n", name); 444 return -EINVAL; 445 } 446 447 write_lock_bh(&tipc_net_lock); 448 449 m_ptr = tipc_media_find(b_names.media_name); 450 if (!m_ptr) { 451 warn("Bearer <%s> rejected, media <%s> not registered\n", name, 452 b_names.media_name); 453 goto exit; 454 } 455 456 if (priority == TIPC_MEDIA_LINK_PRI) 457 priority = m_ptr->priority; 458 459 restart: 460 bearer_id = MAX_BEARERS; 461 with_this_prio = 1; 462 for (i = MAX_BEARERS; i-- != 0; ) { 463 if (!tipc_bearers[i].active) { 464 bearer_id = i; 465 continue; 466 } 467 if (!strcmp(name, tipc_bearers[i].name)) { 468 warn("Bearer <%s> rejected, already enabled\n", name); 469 goto exit; 470 } 471 if ((tipc_bearers[i].priority == priority) && 472 (++with_this_prio > 2)) { 473 if (priority-- == 0) { 474 warn("Bearer <%s> rejected, duplicate priority\n", 475 name); 476 goto exit; 477 } 478 warn("Bearer <%s> priority adjustment required %u->%u\n", 479 name, priority + 1, priority); 480 goto restart; 481 } 482 } 483 if (bearer_id >= MAX_BEARERS) { 484 warn("Bearer <%s> rejected, bearer limit reached (%u)\n", 485 name, MAX_BEARERS); 486 goto exit; 487 } 488 489 b_ptr = &tipc_bearers[bearer_id]; 490 strcpy(b_ptr->name, name); 491 res = m_ptr->enable_bearer(b_ptr); 492 if (res) { 493 warn("Bearer <%s> rejected, enable failure (%d)\n", name, -res); 494 goto exit; 495 } 496 497 b_ptr->identity = bearer_id; 498 b_ptr->media = m_ptr; 499 b_ptr->tolerance = m_ptr->tolerance; 500 b_ptr->window = m_ptr->window; 501 b_ptr->net_plane = bearer_id + 'A'; 502 b_ptr->active = 1; 503 b_ptr->priority = priority; 504 INIT_LIST_HEAD(&b_ptr->cong_links); 505 INIT_LIST_HEAD(&b_ptr->links); 506 spin_lock_init(&b_ptr->lock); 507 508 res = tipc_disc_create(b_ptr, &m_ptr->bcast_addr, disc_domain); 509 if (res) { 510 bearer_disable(b_ptr); 511 warn("Bearer <%s> rejected, discovery object creation failed\n", 512 name); 513 goto exit; 514 } 515 info("Enabled bearer <%s>, discovery domain %s, priority %u\n", 516 name, tipc_addr_string_fill(addr_string, disc_domain), priority); 517 exit: 518 write_unlock_bh(&tipc_net_lock); 519 return res; 520 } 521 522 /** 523 * tipc_block_bearer - Block the bearer with the given name, and reset all its links 524 */ 525 int tipc_block_bearer(const char *name) 526 { 527 struct tipc_bearer *b_ptr = NULL; 528 struct tipc_link *l_ptr; 529 struct tipc_link *temp_l_ptr; 530 531 read_lock_bh(&tipc_net_lock); 532 b_ptr = tipc_bearer_find(name); 533 if (!b_ptr) { 534 warn("Attempt to block unknown bearer <%s>\n", name); 535 read_unlock_bh(&tipc_net_lock); 536 return -EINVAL; 537 } 538 539 info("Blocking bearer <%s>\n", name); 540 spin_lock_bh(&b_ptr->lock); 541 b_ptr->blocked = 1; 542 list_splice_init(&b_ptr->cong_links, &b_ptr->links); 543 list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) { 544 struct tipc_node *n_ptr = l_ptr->owner; 545 546 spin_lock_bh(&n_ptr->lock); 547 tipc_link_reset(l_ptr); 548 spin_unlock_bh(&n_ptr->lock); 549 } 550 spin_unlock_bh(&b_ptr->lock); 551 read_unlock_bh(&tipc_net_lock); 552 return 0; 553 } 554 555 /** 556 * bearer_disable 557 * 558 * Note: This routine assumes caller holds tipc_net_lock. 559 */ 560 static void bearer_disable(struct tipc_bearer *b_ptr) 561 { 562 struct tipc_link *l_ptr; 563 struct tipc_link *temp_l_ptr; 564 565 info("Disabling bearer <%s>\n", b_ptr->name); 566 spin_lock_bh(&b_ptr->lock); 567 b_ptr->blocked = 1; 568 b_ptr->media->disable_bearer(b_ptr); 569 list_splice_init(&b_ptr->cong_links, &b_ptr->links); 570 list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) { 571 tipc_link_delete(l_ptr); 572 } 573 if (b_ptr->link_req) 574 tipc_disc_delete(b_ptr->link_req); 575 spin_unlock_bh(&b_ptr->lock); 576 memset(b_ptr, 0, sizeof(struct tipc_bearer)); 577 } 578 579 int tipc_disable_bearer(const char *name) 580 { 581 struct tipc_bearer *b_ptr; 582 int res; 583 584 write_lock_bh(&tipc_net_lock); 585 b_ptr = tipc_bearer_find(name); 586 if (b_ptr == NULL) { 587 warn("Attempt to disable unknown bearer <%s>\n", name); 588 res = -EINVAL; 589 } else { 590 bearer_disable(b_ptr); 591 res = 0; 592 } 593 write_unlock_bh(&tipc_net_lock); 594 return res; 595 } 596 597 598 599 void tipc_bearer_stop(void) 600 { 601 u32 i; 602 603 for (i = 0; i < MAX_BEARERS; i++) { 604 if (tipc_bearers[i].active) 605 bearer_disable(&tipc_bearers[i]); 606 } 607 media_count = 0; 608 } 609