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 57 static int media_name_valid(const char *name) 58 { 59 u32 len; 60 61 len = strlen(name); 62 if ((len + 1) > TIPC_MAX_MEDIA_NAME) 63 return 0; 64 return strspn(name, tipc_alphabet) == len; 65 } 66 67 /** 68 * tipc_media_find - locates specified media object by name 69 */ 70 71 struct tipc_media *tipc_media_find(const char *name) 72 { 73 u32 i; 74 75 for (i = 0; i < media_count; i++) { 76 if (!strcmp(media_list[i]->name, name)) 77 return media_list[i]; 78 } 79 return NULL; 80 } 81 82 /** 83 * media_find_id - locates specified media object by type identifier 84 */ 85 86 static struct tipc_media *media_find_id(u8 type) 87 { 88 u32 i; 89 90 for (i = 0; i < media_count; i++) { 91 if (media_list[i]->type_id == type) 92 return media_list[i]; 93 } 94 return NULL; 95 } 96 97 /** 98 * tipc_register_media - register a media type 99 * 100 * Bearers for this media type must be activated separately at a later stage. 101 */ 102 103 int tipc_register_media(struct tipc_media *m_ptr) 104 { 105 int res = -EINVAL; 106 107 write_lock_bh(&tipc_net_lock); 108 109 if (!media_name_valid(m_ptr->name)) 110 goto exit; 111 if ((m_ptr->bcast_addr.media_id != m_ptr->type_id) || 112 !m_ptr->bcast_addr.broadcast) 113 goto exit; 114 if (m_ptr->priority > TIPC_MAX_LINK_PRI) 115 goto exit; 116 if ((m_ptr->tolerance < TIPC_MIN_LINK_TOL) || 117 (m_ptr->tolerance > TIPC_MAX_LINK_TOL)) 118 goto exit; 119 if (media_count >= MAX_MEDIA) 120 goto exit; 121 if (tipc_media_find(m_ptr->name) || media_find_id(m_ptr->type_id)) 122 goto exit; 123 124 media_list[media_count] = m_ptr; 125 media_count++; 126 res = 0; 127 exit: 128 write_unlock_bh(&tipc_net_lock); 129 if (res) 130 warn("Media <%s> registration error\n", m_ptr->name); 131 return res; 132 } 133 134 /** 135 * tipc_media_addr_printf - record media address in print buffer 136 */ 137 138 void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a) 139 { 140 char addr_str[MAX_ADDR_STR]; 141 struct tipc_media *m_ptr; 142 143 m_ptr = media_find_id(a->media_id); 144 145 if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str))) 146 tipc_printf(pb, "%s(%s)", m_ptr->name, addr_str); 147 else { 148 u32 i; 149 150 tipc_printf(pb, "UNKNOWN(%u)", a->media_id); 151 for (i = 0; i < sizeof(a->value); i++) 152 tipc_printf(pb, "-%02x", a->value[i]); 153 } 154 } 155 156 /** 157 * tipc_media_get_names - record names of registered media in buffer 158 */ 159 160 struct sk_buff *tipc_media_get_names(void) 161 { 162 struct sk_buff *buf; 163 int i; 164 165 buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME)); 166 if (!buf) 167 return NULL; 168 169 read_lock_bh(&tipc_net_lock); 170 for (i = 0; i < media_count; i++) { 171 tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME, 172 media_list[i]->name, 173 strlen(media_list[i]->name) + 1); 174 } 175 read_unlock_bh(&tipc_net_lock); 176 return buf; 177 } 178 179 /** 180 * bearer_name_validate - validate & (optionally) deconstruct bearer name 181 * @name - ptr to bearer name string 182 * @name_parts - ptr to area for bearer name components (or NULL if not needed) 183 * 184 * Returns 1 if bearer name is valid, otherwise 0. 185 */ 186 187 static int bearer_name_validate(const char *name, 188 struct bearer_name *name_parts) 189 { 190 char name_copy[TIPC_MAX_BEARER_NAME]; 191 char *media_name; 192 char *if_name; 193 u32 media_len; 194 u32 if_len; 195 196 /* copy bearer name & ensure length is OK */ 197 198 name_copy[TIPC_MAX_BEARER_NAME - 1] = 0; 199 /* need above in case non-Posix strncpy() doesn't pad with nulls */ 200 strncpy(name_copy, name, TIPC_MAX_BEARER_NAME); 201 if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0) 202 return 0; 203 204 /* ensure all component parts of bearer name are present */ 205 206 media_name = name_copy; 207 if_name = strchr(media_name, ':'); 208 if (if_name == NULL) 209 return 0; 210 *(if_name++) = 0; 211 media_len = if_name - media_name; 212 if_len = strlen(if_name) + 1; 213 214 /* validate component parts of bearer name */ 215 216 if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) || 217 (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME) || 218 (strspn(media_name, tipc_alphabet) != (media_len - 1)) || 219 (strspn(if_name, tipc_alphabet) != (if_len - 1))) 220 return 0; 221 222 /* return bearer name components, if necessary */ 223 224 if (name_parts) { 225 strcpy(name_parts->media_name, media_name); 226 strcpy(name_parts->if_name, if_name); 227 } 228 return 1; 229 } 230 231 /** 232 * tipc_bearer_find - locates bearer object with matching bearer name 233 */ 234 235 struct tipc_bearer *tipc_bearer_find(const char *name) 236 { 237 struct tipc_bearer *b_ptr; 238 u32 i; 239 240 for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) { 241 if (b_ptr->active && (!strcmp(b_ptr->name, name))) 242 return b_ptr; 243 } 244 return NULL; 245 } 246 247 /** 248 * tipc_bearer_find_interface - locates bearer object with matching interface name 249 */ 250 251 struct tipc_bearer *tipc_bearer_find_interface(const char *if_name) 252 { 253 struct tipc_bearer *b_ptr; 254 char *b_if_name; 255 u32 i; 256 257 for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) { 258 if (!b_ptr->active) 259 continue; 260 b_if_name = strchr(b_ptr->name, ':') + 1; 261 if (!strcmp(b_if_name, if_name)) 262 return b_ptr; 263 } 264 return NULL; 265 } 266 267 /** 268 * tipc_bearer_get_names - record names of bearers in buffer 269 */ 270 271 struct sk_buff *tipc_bearer_get_names(void) 272 { 273 struct sk_buff *buf; 274 struct tipc_bearer *b_ptr; 275 int i, j; 276 277 buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME)); 278 if (!buf) 279 return NULL; 280 281 read_lock_bh(&tipc_net_lock); 282 for (i = 0; i < media_count; i++) { 283 for (j = 0; j < MAX_BEARERS; j++) { 284 b_ptr = &tipc_bearers[j]; 285 if (b_ptr->active && (b_ptr->media == media_list[i])) { 286 tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME, 287 b_ptr->name, 288 strlen(b_ptr->name) + 1); 289 } 290 } 291 } 292 read_unlock_bh(&tipc_net_lock); 293 return buf; 294 } 295 296 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest) 297 { 298 tipc_nmap_add(&b_ptr->nodes, dest); 299 tipc_bcbearer_sort(); 300 tipc_disc_add_dest(b_ptr->link_req); 301 } 302 303 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest) 304 { 305 tipc_nmap_remove(&b_ptr->nodes, dest); 306 tipc_bcbearer_sort(); 307 tipc_disc_remove_dest(b_ptr->link_req); 308 } 309 310 /* 311 * bearer_push(): Resolve bearer congestion. Force the waiting 312 * links to push out their unsent packets, one packet per link 313 * per iteration, until all packets are gone or congestion reoccurs. 314 * 'tipc_net_lock' is read_locked when this function is called 315 * bearer.lock must be taken before calling 316 * Returns binary true(1) ore false(0) 317 */ 318 static int bearer_push(struct tipc_bearer *b_ptr) 319 { 320 u32 res = 0; 321 struct link *ln, *tln; 322 323 if (b_ptr->blocked) 324 return 0; 325 326 while (!list_empty(&b_ptr->cong_links) && (res != PUSH_FAILED)) { 327 list_for_each_entry_safe(ln, tln, &b_ptr->cong_links, link_list) { 328 res = tipc_link_push_packet(ln); 329 if (res == PUSH_FAILED) 330 break; 331 if (res == PUSH_FINISHED) 332 list_move_tail(&ln->link_list, &b_ptr->links); 333 } 334 } 335 return list_empty(&b_ptr->cong_links); 336 } 337 338 void tipc_bearer_lock_push(struct tipc_bearer *b_ptr) 339 { 340 spin_lock_bh(&b_ptr->lock); 341 bearer_push(b_ptr); 342 spin_unlock_bh(&b_ptr->lock); 343 } 344 345 346 /* 347 * Interrupt enabling new requests after bearer congestion or blocking: 348 * See bearer_send(). 349 */ 350 void tipc_continue(struct tipc_bearer *b_ptr) 351 { 352 spin_lock_bh(&b_ptr->lock); 353 if (!list_empty(&b_ptr->cong_links)) 354 tipc_k_signal((Handler)tipc_bearer_lock_push, (unsigned long)b_ptr); 355 b_ptr->blocked = 0; 356 spin_unlock_bh(&b_ptr->lock); 357 } 358 359 /* 360 * Schedule link for sending of messages after the bearer 361 * has been deblocked by 'continue()'. This method is called 362 * when somebody tries to send a message via this link while 363 * the bearer is congested. 'tipc_net_lock' is in read_lock here 364 * bearer.lock is busy 365 */ 366 367 static void tipc_bearer_schedule_unlocked(struct tipc_bearer *b_ptr, struct link *l_ptr) 368 { 369 list_move_tail(&l_ptr->link_list, &b_ptr->cong_links); 370 } 371 372 /* 373 * Schedule link for sending of messages after the bearer 374 * has been deblocked by 'continue()'. This method is called 375 * when somebody tries to send a message via this link while 376 * the bearer is congested. 'tipc_net_lock' is in read_lock here, 377 * bearer.lock is free 378 */ 379 380 void tipc_bearer_schedule(struct tipc_bearer *b_ptr, struct link *l_ptr) 381 { 382 spin_lock_bh(&b_ptr->lock); 383 tipc_bearer_schedule_unlocked(b_ptr, l_ptr); 384 spin_unlock_bh(&b_ptr->lock); 385 } 386 387 388 /* 389 * tipc_bearer_resolve_congestion(): Check if there is bearer congestion, 390 * and if there is, try to resolve it before returning. 391 * 'tipc_net_lock' is read_locked when this function is called 392 */ 393 int tipc_bearer_resolve_congestion(struct tipc_bearer *b_ptr, struct link *l_ptr) 394 { 395 int res = 1; 396 397 if (list_empty(&b_ptr->cong_links)) 398 return 1; 399 spin_lock_bh(&b_ptr->lock); 400 if (!bearer_push(b_ptr)) { 401 tipc_bearer_schedule_unlocked(b_ptr, l_ptr); 402 res = 0; 403 } 404 spin_unlock_bh(&b_ptr->lock); 405 return res; 406 } 407 408 /** 409 * tipc_bearer_congested - determines if bearer is currently congested 410 */ 411 412 int tipc_bearer_congested(struct tipc_bearer *b_ptr, struct link *l_ptr) 413 { 414 if (unlikely(b_ptr->blocked)) 415 return 1; 416 if (likely(list_empty(&b_ptr->cong_links))) 417 return 0; 418 return !tipc_bearer_resolve_congestion(b_ptr, l_ptr); 419 } 420 421 /** 422 * tipc_enable_bearer - enable bearer with the given name 423 */ 424 425 int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority) 426 { 427 struct tipc_bearer *b_ptr; 428 struct tipc_media *m_ptr; 429 struct bearer_name b_name; 430 char addr_string[16]; 431 u32 bearer_id; 432 u32 with_this_prio; 433 u32 i; 434 int res = -EINVAL; 435 436 if (tipc_mode != TIPC_NET_MODE) { 437 warn("Bearer <%s> rejected, not supported in standalone mode\n", 438 name); 439 return -ENOPROTOOPT; 440 } 441 if (!bearer_name_validate(name, &b_name)) { 442 warn("Bearer <%s> rejected, illegal name\n", name); 443 return -EINVAL; 444 } 445 if (tipc_addr_domain_valid(disc_domain) && 446 (disc_domain != tipc_own_addr)) { 447 if (tipc_in_scope(disc_domain, tipc_own_addr)) { 448 disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK; 449 res = 0; /* accept any node in own cluster */ 450 } else if (in_own_cluster(disc_domain)) 451 res = 0; /* accept specified node in own cluster */ 452 } 453 if (res) { 454 warn("Bearer <%s> rejected, illegal discovery domain\n", name); 455 return -EINVAL; 456 } 457 if ((priority < TIPC_MIN_LINK_PRI || 458 priority > TIPC_MAX_LINK_PRI) && 459 (priority != TIPC_MEDIA_LINK_PRI)) { 460 warn("Bearer <%s> rejected, illegal priority\n", name); 461 return -EINVAL; 462 } 463 464 write_lock_bh(&tipc_net_lock); 465 466 m_ptr = tipc_media_find(b_name.media_name); 467 if (!m_ptr) { 468 warn("Bearer <%s> rejected, media <%s> not registered\n", name, 469 b_name.media_name); 470 goto exit; 471 } 472 473 if (priority == TIPC_MEDIA_LINK_PRI) 474 priority = m_ptr->priority; 475 476 restart: 477 bearer_id = MAX_BEARERS; 478 with_this_prio = 1; 479 for (i = MAX_BEARERS; i-- != 0; ) { 480 if (!tipc_bearers[i].active) { 481 bearer_id = i; 482 continue; 483 } 484 if (!strcmp(name, tipc_bearers[i].name)) { 485 warn("Bearer <%s> rejected, already enabled\n", name); 486 goto exit; 487 } 488 if ((tipc_bearers[i].priority == priority) && 489 (++with_this_prio > 2)) { 490 if (priority-- == 0) { 491 warn("Bearer <%s> rejected, duplicate priority\n", 492 name); 493 goto exit; 494 } 495 warn("Bearer <%s> priority adjustment required %u->%u\n", 496 name, priority + 1, priority); 497 goto restart; 498 } 499 } 500 if (bearer_id >= MAX_BEARERS) { 501 warn("Bearer <%s> rejected, bearer limit reached (%u)\n", 502 name, MAX_BEARERS); 503 goto exit; 504 } 505 506 b_ptr = &tipc_bearers[bearer_id]; 507 strcpy(b_ptr->name, name); 508 res = m_ptr->enable_bearer(b_ptr); 509 if (res) { 510 warn("Bearer <%s> rejected, enable failure (%d)\n", name, -res); 511 goto exit; 512 } 513 514 b_ptr->identity = bearer_id; 515 b_ptr->media = m_ptr; 516 b_ptr->tolerance = m_ptr->tolerance; 517 b_ptr->window = m_ptr->window; 518 b_ptr->net_plane = bearer_id + 'A'; 519 b_ptr->active = 1; 520 b_ptr->priority = priority; 521 INIT_LIST_HEAD(&b_ptr->cong_links); 522 INIT_LIST_HEAD(&b_ptr->links); 523 spin_lock_init(&b_ptr->lock); 524 525 res = tipc_disc_create(b_ptr, &m_ptr->bcast_addr, disc_domain); 526 if (res) { 527 bearer_disable(b_ptr); 528 warn("Bearer <%s> rejected, discovery object creation failed\n", 529 name); 530 goto exit; 531 } 532 info("Enabled bearer <%s>, discovery domain %s, priority %u\n", 533 name, tipc_addr_string_fill(addr_string, disc_domain), priority); 534 exit: 535 write_unlock_bh(&tipc_net_lock); 536 return res; 537 } 538 539 /** 540 * tipc_block_bearer(): Block the bearer with the given name, 541 * and reset all its links 542 */ 543 544 int tipc_block_bearer(const char *name) 545 { 546 struct tipc_bearer *b_ptr = NULL; 547 struct link *l_ptr; 548 struct link *temp_l_ptr; 549 550 read_lock_bh(&tipc_net_lock); 551 b_ptr = tipc_bearer_find(name); 552 if (!b_ptr) { 553 warn("Attempt to block unknown bearer <%s>\n", name); 554 read_unlock_bh(&tipc_net_lock); 555 return -EINVAL; 556 } 557 558 info("Blocking bearer <%s>\n", name); 559 spin_lock_bh(&b_ptr->lock); 560 b_ptr->blocked = 1; 561 list_splice_init(&b_ptr->cong_links, &b_ptr->links); 562 list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) { 563 struct tipc_node *n_ptr = l_ptr->owner; 564 565 spin_lock_bh(&n_ptr->lock); 566 tipc_link_reset(l_ptr); 567 spin_unlock_bh(&n_ptr->lock); 568 } 569 spin_unlock_bh(&b_ptr->lock); 570 read_unlock_bh(&tipc_net_lock); 571 return 0; 572 } 573 574 /** 575 * bearer_disable - 576 * 577 * Note: This routine assumes caller holds tipc_net_lock. 578 */ 579 580 static void bearer_disable(struct tipc_bearer *b_ptr) 581 { 582 struct link *l_ptr; 583 struct link *temp_l_ptr; 584 585 info("Disabling bearer <%s>\n", b_ptr->name); 586 spin_lock_bh(&b_ptr->lock); 587 b_ptr->blocked = 1; 588 b_ptr->media->disable_bearer(b_ptr); 589 list_splice_init(&b_ptr->cong_links, &b_ptr->links); 590 list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) { 591 tipc_link_delete(l_ptr); 592 } 593 if (b_ptr->link_req) 594 tipc_disc_delete(b_ptr->link_req); 595 spin_unlock_bh(&b_ptr->lock); 596 memset(b_ptr, 0, sizeof(struct tipc_bearer)); 597 } 598 599 int tipc_disable_bearer(const char *name) 600 { 601 struct tipc_bearer *b_ptr; 602 int res; 603 604 write_lock_bh(&tipc_net_lock); 605 b_ptr = tipc_bearer_find(name); 606 if (b_ptr == NULL) { 607 warn("Attempt to disable unknown bearer <%s>\n", name); 608 res = -EINVAL; 609 } else { 610 bearer_disable(b_ptr); 611 res = 0; 612 } 613 write_unlock_bh(&tipc_net_lock); 614 return res; 615 } 616 617 618 619 void tipc_bearer_stop(void) 620 { 621 u32 i; 622 623 for (i = 0; i < MAX_BEARERS; i++) { 624 if (tipc_bearers[i].active) 625 bearer_disable(&tipc_bearers[i]); 626 } 627 media_count = 0; 628 } 629