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 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 * media_find - locates specified media object by name 69 */ 70 71 static struct media *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 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 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.type != htonl(m_ptr->type_id)) 112 goto exit; 113 if (m_ptr->priority > TIPC_MAX_LINK_PRI) 114 goto exit; 115 if ((m_ptr->tolerance < TIPC_MIN_LINK_TOL) || 116 (m_ptr->tolerance > TIPC_MAX_LINK_TOL)) 117 goto exit; 118 if (media_count >= MAX_MEDIA) 119 goto exit; 120 if (media_find(m_ptr->name) || media_find_id(m_ptr->type_id)) 121 goto exit; 122 123 media_list[media_count] = m_ptr; 124 media_count++; 125 res = 0; 126 exit: 127 write_unlock_bh(&tipc_net_lock); 128 if (res) 129 warn("Media <%s> registration error\n", m_ptr->name); 130 return res; 131 } 132 133 /** 134 * tipc_media_addr_printf - record media address in print buffer 135 */ 136 137 void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a) 138 { 139 struct media *m_ptr; 140 u32 media_type; 141 u32 i; 142 143 media_type = ntohl(a->type); 144 m_ptr = media_find_id(media_type); 145 146 if (m_ptr && (m_ptr->addr2str != NULL)) { 147 char addr_str[MAX_ADDR_STR]; 148 149 tipc_printf(pb, "%s(%s)", m_ptr->name, 150 m_ptr->addr2str(a, addr_str, sizeof(addr_str))); 151 } else { 152 unchar *addr = (unchar *)&a->dev_addr; 153 154 tipc_printf(pb, "UNKNOWN(%u)", media_type); 155 for (i = 0; i < (sizeof(*a) - sizeof(a->type)); i++) 156 tipc_printf(pb, "-%02x", addr[i]); 157 } 158 } 159 160 /** 161 * tipc_media_get_names - record names of registered media in buffer 162 */ 163 164 struct sk_buff *tipc_media_get_names(void) 165 { 166 struct sk_buff *buf; 167 int i; 168 169 buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME)); 170 if (!buf) 171 return NULL; 172 173 read_lock_bh(&tipc_net_lock); 174 for (i = 0; i < media_count; i++) { 175 tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME, 176 media_list[i]->name, 177 strlen(media_list[i]->name) + 1); 178 } 179 read_unlock_bh(&tipc_net_lock); 180 return buf; 181 } 182 183 /** 184 * bearer_name_validate - validate & (optionally) deconstruct bearer name 185 * @name - ptr to bearer name string 186 * @name_parts - ptr to area for bearer name components (or NULL if not needed) 187 * 188 * Returns 1 if bearer name is valid, otherwise 0. 189 */ 190 191 static int bearer_name_validate(const char *name, 192 struct bearer_name *name_parts) 193 { 194 char name_copy[TIPC_MAX_BEARER_NAME]; 195 char *media_name; 196 char *if_name; 197 u32 media_len; 198 u32 if_len; 199 200 /* copy bearer name & ensure length is OK */ 201 202 name_copy[TIPC_MAX_BEARER_NAME - 1] = 0; 203 /* need above in case non-Posix strncpy() doesn't pad with nulls */ 204 strncpy(name_copy, name, TIPC_MAX_BEARER_NAME); 205 if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0) 206 return 0; 207 208 /* ensure all component parts of bearer name are present */ 209 210 media_name = name_copy; 211 if_name = strchr(media_name, ':'); 212 if (if_name == NULL) 213 return 0; 214 *(if_name++) = 0; 215 media_len = if_name - media_name; 216 if_len = strlen(if_name) + 1; 217 218 /* validate component parts of bearer name */ 219 220 if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) || 221 (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME) || 222 (strspn(media_name, tipc_alphabet) != (media_len - 1)) || 223 (strspn(if_name, tipc_alphabet) != (if_len - 1))) 224 return 0; 225 226 /* return bearer name components, if necessary */ 227 228 if (name_parts) { 229 strcpy(name_parts->media_name, media_name); 230 strcpy(name_parts->if_name, if_name); 231 } 232 return 1; 233 } 234 235 /** 236 * bearer_find - locates bearer object with matching bearer name 237 */ 238 239 static struct tipc_bearer *bearer_find(const char *name) 240 { 241 struct tipc_bearer *b_ptr; 242 u32 i; 243 244 for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) { 245 if (b_ptr->active && (!strcmp(b_ptr->name, name))) 246 return b_ptr; 247 } 248 return NULL; 249 } 250 251 /** 252 * tipc_bearer_find_interface - locates bearer object with matching interface name 253 */ 254 255 struct tipc_bearer *tipc_bearer_find_interface(const char *if_name) 256 { 257 struct tipc_bearer *b_ptr; 258 char *b_if_name; 259 u32 i; 260 261 for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) { 262 if (!b_ptr->active) 263 continue; 264 b_if_name = strchr(b_ptr->name, ':') + 1; 265 if (!strcmp(b_if_name, if_name)) 266 return b_ptr; 267 } 268 return NULL; 269 } 270 271 /** 272 * tipc_bearer_get_names - record names of bearers in buffer 273 */ 274 275 struct sk_buff *tipc_bearer_get_names(void) 276 { 277 struct sk_buff *buf; 278 struct tipc_bearer *b_ptr; 279 int i, j; 280 281 buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME)); 282 if (!buf) 283 return NULL; 284 285 read_lock_bh(&tipc_net_lock); 286 for (i = 0; i < media_count; i++) { 287 for (j = 0; j < MAX_BEARERS; j++) { 288 b_ptr = &tipc_bearers[j]; 289 if (b_ptr->active && (b_ptr->media == media_list[i])) { 290 tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME, 291 b_ptr->name, 292 strlen(b_ptr->name) + 1); 293 } 294 } 295 } 296 read_unlock_bh(&tipc_net_lock); 297 return buf; 298 } 299 300 void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest) 301 { 302 tipc_nmap_add(&b_ptr->nodes, dest); 303 tipc_bcbearer_sort(); 304 tipc_disc_add_dest(b_ptr->link_req); 305 } 306 307 void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest) 308 { 309 tipc_nmap_remove(&b_ptr->nodes, dest); 310 tipc_bcbearer_sort(); 311 tipc_disc_remove_dest(b_ptr->link_req); 312 } 313 314 /* 315 * bearer_push(): Resolve bearer congestion. Force the waiting 316 * links to push out their unsent packets, one packet per link 317 * per iteration, until all packets are gone or congestion reoccurs. 318 * 'tipc_net_lock' is read_locked when this function is called 319 * bearer.lock must be taken before calling 320 * Returns binary true(1) ore false(0) 321 */ 322 static int bearer_push(struct tipc_bearer *b_ptr) 323 { 324 u32 res = 0; 325 struct link *ln, *tln; 326 327 if (b_ptr->blocked) 328 return 0; 329 330 while (!list_empty(&b_ptr->cong_links) && (res != PUSH_FAILED)) { 331 list_for_each_entry_safe(ln, tln, &b_ptr->cong_links, link_list) { 332 res = tipc_link_push_packet(ln); 333 if (res == PUSH_FAILED) 334 break; 335 if (res == PUSH_FINISHED) 336 list_move_tail(&ln->link_list, &b_ptr->links); 337 } 338 } 339 return list_empty(&b_ptr->cong_links); 340 } 341 342 void tipc_bearer_lock_push(struct tipc_bearer *b_ptr) 343 { 344 spin_lock_bh(&b_ptr->lock); 345 bearer_push(b_ptr); 346 spin_unlock_bh(&b_ptr->lock); 347 } 348 349 350 /* 351 * Interrupt enabling new requests after bearer congestion or blocking: 352 * See bearer_send(). 353 */ 354 void tipc_continue(struct tipc_bearer *b_ptr) 355 { 356 spin_lock_bh(&b_ptr->lock); 357 if (!list_empty(&b_ptr->cong_links)) 358 tipc_k_signal((Handler)tipc_bearer_lock_push, (unsigned long)b_ptr); 359 b_ptr->blocked = 0; 360 spin_unlock_bh(&b_ptr->lock); 361 } 362 363 /* 364 * Schedule link for sending of messages after the bearer 365 * has been deblocked by 'continue()'. This method is called 366 * when somebody tries to send a message via this link while 367 * the bearer is congested. 'tipc_net_lock' is in read_lock here 368 * bearer.lock is busy 369 */ 370 371 static void tipc_bearer_schedule_unlocked(struct tipc_bearer *b_ptr, struct link *l_ptr) 372 { 373 list_move_tail(&l_ptr->link_list, &b_ptr->cong_links); 374 } 375 376 /* 377 * Schedule link for sending of messages after the bearer 378 * has been deblocked by 'continue()'. This method is called 379 * when somebody tries to send a message via this link while 380 * the bearer is congested. 'tipc_net_lock' is in read_lock here, 381 * bearer.lock is free 382 */ 383 384 void tipc_bearer_schedule(struct tipc_bearer *b_ptr, struct link *l_ptr) 385 { 386 spin_lock_bh(&b_ptr->lock); 387 tipc_bearer_schedule_unlocked(b_ptr, l_ptr); 388 spin_unlock_bh(&b_ptr->lock); 389 } 390 391 392 /* 393 * tipc_bearer_resolve_congestion(): Check if there is bearer congestion, 394 * and if there is, try to resolve it before returning. 395 * 'tipc_net_lock' is read_locked when this function is called 396 */ 397 int tipc_bearer_resolve_congestion(struct tipc_bearer *b_ptr, struct link *l_ptr) 398 { 399 int res = 1; 400 401 if (list_empty(&b_ptr->cong_links)) 402 return 1; 403 spin_lock_bh(&b_ptr->lock); 404 if (!bearer_push(b_ptr)) { 405 tipc_bearer_schedule_unlocked(b_ptr, l_ptr); 406 res = 0; 407 } 408 spin_unlock_bh(&b_ptr->lock); 409 return res; 410 } 411 412 /** 413 * tipc_bearer_congested - determines if bearer is currently congested 414 */ 415 416 int tipc_bearer_congested(struct tipc_bearer *b_ptr, struct link *l_ptr) 417 { 418 if (unlikely(b_ptr->blocked)) 419 return 1; 420 if (likely(list_empty(&b_ptr->cong_links))) 421 return 0; 422 return !tipc_bearer_resolve_congestion(b_ptr, l_ptr); 423 } 424 425 /** 426 * tipc_enable_bearer - enable bearer with the given name 427 */ 428 429 int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority) 430 { 431 struct tipc_bearer *b_ptr; 432 struct media *m_ptr; 433 struct bearer_name b_name; 434 char addr_string[16]; 435 u32 bearer_id; 436 u32 with_this_prio; 437 u32 i; 438 int res = -EINVAL; 439 440 if (tipc_mode != TIPC_NET_MODE) { 441 warn("Bearer <%s> rejected, not supported in standalone mode\n", 442 name); 443 return -ENOPROTOOPT; 444 } 445 if (!bearer_name_validate(name, &b_name)) { 446 warn("Bearer <%s> rejected, illegal name\n", name); 447 return -EINVAL; 448 } 449 if (tipc_addr_domain_valid(disc_domain) && 450 (disc_domain != tipc_own_addr)) { 451 if (tipc_in_scope(disc_domain, tipc_own_addr)) { 452 disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK; 453 res = 0; /* accept any node in own cluster */ 454 } else if (in_own_cluster(disc_domain)) 455 res = 0; /* accept specified node in own cluster */ 456 } 457 if (res) { 458 warn("Bearer <%s> rejected, illegal discovery domain\n", name); 459 return -EINVAL; 460 } 461 if ((priority < TIPC_MIN_LINK_PRI || 462 priority > TIPC_MAX_LINK_PRI) && 463 (priority != TIPC_MEDIA_LINK_PRI)) { 464 warn("Bearer <%s> rejected, illegal priority\n", name); 465 return -EINVAL; 466 } 467 468 write_lock_bh(&tipc_net_lock); 469 470 m_ptr = media_find(b_name.media_name); 471 if (!m_ptr) { 472 warn("Bearer <%s> rejected, media <%s> not registered\n", name, 473 b_name.media_name); 474 goto exit; 475 } 476 477 if (priority == TIPC_MEDIA_LINK_PRI) 478 priority = m_ptr->priority; 479 480 restart: 481 bearer_id = MAX_BEARERS; 482 with_this_prio = 1; 483 for (i = MAX_BEARERS; i-- != 0; ) { 484 if (!tipc_bearers[i].active) { 485 bearer_id = i; 486 continue; 487 } 488 if (!strcmp(name, tipc_bearers[i].name)) { 489 warn("Bearer <%s> rejected, already enabled\n", name); 490 goto exit; 491 } 492 if ((tipc_bearers[i].priority == priority) && 493 (++with_this_prio > 2)) { 494 if (priority-- == 0) { 495 warn("Bearer <%s> rejected, duplicate priority\n", 496 name); 497 goto exit; 498 } 499 warn("Bearer <%s> priority adjustment required %u->%u\n", 500 name, priority + 1, priority); 501 goto restart; 502 } 503 } 504 if (bearer_id >= MAX_BEARERS) { 505 warn("Bearer <%s> rejected, bearer limit reached (%u)\n", 506 name, MAX_BEARERS); 507 goto exit; 508 } 509 510 b_ptr = &tipc_bearers[bearer_id]; 511 strcpy(b_ptr->name, name); 512 res = m_ptr->enable_bearer(b_ptr); 513 if (res) { 514 warn("Bearer <%s> rejected, enable failure (%d)\n", name, -res); 515 goto exit; 516 } 517 518 b_ptr->identity = bearer_id; 519 b_ptr->media = m_ptr; 520 b_ptr->net_plane = bearer_id + 'A'; 521 b_ptr->active = 1; 522 b_ptr->priority = priority; 523 INIT_LIST_HEAD(&b_ptr->cong_links); 524 INIT_LIST_HEAD(&b_ptr->links); 525 spin_lock_init(&b_ptr->lock); 526 527 res = tipc_disc_create(b_ptr, &m_ptr->bcast_addr, disc_domain); 528 if (res) { 529 bearer_disable(b_ptr); 530 warn("Bearer <%s> rejected, discovery object creation failed\n", 531 name); 532 goto exit; 533 } 534 info("Enabled bearer <%s>, discovery domain %s, priority %u\n", 535 name, tipc_addr_string_fill(addr_string, disc_domain), priority); 536 exit: 537 write_unlock_bh(&tipc_net_lock); 538 return res; 539 } 540 541 /** 542 * tipc_block_bearer(): Block the bearer with the given name, 543 * and reset all its links 544 */ 545 546 int tipc_block_bearer(const char *name) 547 { 548 struct tipc_bearer *b_ptr = NULL; 549 struct link *l_ptr; 550 struct link *temp_l_ptr; 551 552 read_lock_bh(&tipc_net_lock); 553 b_ptr = bearer_find(name); 554 if (!b_ptr) { 555 warn("Attempt to block unknown bearer <%s>\n", name); 556 read_unlock_bh(&tipc_net_lock); 557 return -EINVAL; 558 } 559 560 info("Blocking bearer <%s>\n", name); 561 spin_lock_bh(&b_ptr->lock); 562 b_ptr->blocked = 1; 563 list_splice_init(&b_ptr->cong_links, &b_ptr->links); 564 list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) { 565 struct tipc_node *n_ptr = l_ptr->owner; 566 567 spin_lock_bh(&n_ptr->lock); 568 tipc_link_reset(l_ptr); 569 spin_unlock_bh(&n_ptr->lock); 570 } 571 spin_unlock_bh(&b_ptr->lock); 572 read_unlock_bh(&tipc_net_lock); 573 return 0; 574 } 575 576 /** 577 * bearer_disable - 578 * 579 * Note: This routine assumes caller holds tipc_net_lock. 580 */ 581 582 static void bearer_disable(struct tipc_bearer *b_ptr) 583 { 584 struct link *l_ptr; 585 struct link *temp_l_ptr; 586 587 info("Disabling bearer <%s>\n", b_ptr->name); 588 spin_lock_bh(&b_ptr->lock); 589 b_ptr->blocked = 1; 590 b_ptr->media->disable_bearer(b_ptr); 591 list_splice_init(&b_ptr->cong_links, &b_ptr->links); 592 list_for_each_entry_safe(l_ptr, temp_l_ptr, &b_ptr->links, link_list) { 593 tipc_link_delete(l_ptr); 594 } 595 if (b_ptr->link_req) 596 tipc_disc_delete(b_ptr->link_req); 597 spin_unlock_bh(&b_ptr->lock); 598 memset(b_ptr, 0, sizeof(struct tipc_bearer)); 599 } 600 601 int tipc_disable_bearer(const char *name) 602 { 603 struct tipc_bearer *b_ptr; 604 int res; 605 606 write_lock_bh(&tipc_net_lock); 607 b_ptr = bearer_find(name); 608 if (b_ptr == NULL) { 609 warn("Attempt to disable unknown bearer <%s>\n", name); 610 res = -EINVAL; 611 } else { 612 bearer_disable(b_ptr); 613 res = 0; 614 } 615 write_unlock_bh(&tipc_net_lock); 616 return res; 617 } 618 619 620 621 void tipc_bearer_stop(void) 622 { 623 u32 i; 624 625 for (i = 0; i < MAX_BEARERS; i++) { 626 if (tipc_bearers[i].active) 627 bearer_disable(&tipc_bearers[i]); 628 } 629 media_count = 0; 630 } 631