bearer.c revision c61b666e260d5cc2e0203b21c689321e6ab0d676
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 44static struct media *media_list[MAX_MEDIA]; 45static u32 media_count; 46 47struct tipc_bearer tipc_bearers[MAX_BEARERS]; 48 49static 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 57static 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 71static 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 86static 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 103int 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; 126exit: 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 137void tipc_media_addr_printf(struct print_buf *pb, struct tipc_media_addr *a) 138{ 139 char addr_str[MAX_ADDR_STR]; 140 struct media *m_ptr; 141 u32 media_type; 142 143 media_type = ntohl(a->type); 144 m_ptr = media_find_id(media_type); 145 146 if (m_ptr && !m_ptr->addr2str(a, addr_str, sizeof(addr_str))) 147 tipc_printf(pb, "%s(%s)", m_ptr->name, addr_str); 148 else { 149 unchar *addr = (unchar *)&a->dev_addr; 150 u32 i; 151 152 tipc_printf(pb, "UNKNOWN(%u)", media_type); 153 for (i = 0; i < (sizeof(*a) - sizeof(a->type)); i++) 154 tipc_printf(pb, "-%02x", addr[i]); 155 } 156} 157 158/** 159 * tipc_media_get_names - record names of registered media in buffer 160 */ 161 162struct sk_buff *tipc_media_get_names(void) 163{ 164 struct sk_buff *buf; 165 int i; 166 167 buf = tipc_cfg_reply_alloc(MAX_MEDIA * TLV_SPACE(TIPC_MAX_MEDIA_NAME)); 168 if (!buf) 169 return NULL; 170 171 read_lock_bh(&tipc_net_lock); 172 for (i = 0; i < media_count; i++) { 173 tipc_cfg_append_tlv(buf, TIPC_TLV_MEDIA_NAME, 174 media_list[i]->name, 175 strlen(media_list[i]->name) + 1); 176 } 177 read_unlock_bh(&tipc_net_lock); 178 return buf; 179} 180 181/** 182 * bearer_name_validate - validate & (optionally) deconstruct bearer name 183 * @name - ptr to bearer name string 184 * @name_parts - ptr to area for bearer name components (or NULL if not needed) 185 * 186 * Returns 1 if bearer name is valid, otherwise 0. 187 */ 188 189static int bearer_name_validate(const char *name, 190 struct bearer_name *name_parts) 191{ 192 char name_copy[TIPC_MAX_BEARER_NAME]; 193 char *media_name; 194 char *if_name; 195 u32 media_len; 196 u32 if_len; 197 198 /* copy bearer name & ensure length is OK */ 199 200 name_copy[TIPC_MAX_BEARER_NAME - 1] = 0; 201 /* need above in case non-Posix strncpy() doesn't pad with nulls */ 202 strncpy(name_copy, name, TIPC_MAX_BEARER_NAME); 203 if (name_copy[TIPC_MAX_BEARER_NAME - 1] != 0) 204 return 0; 205 206 /* ensure all component parts of bearer name are present */ 207 208 media_name = name_copy; 209 if_name = strchr(media_name, ':'); 210 if (if_name == NULL) 211 return 0; 212 *(if_name++) = 0; 213 media_len = if_name - media_name; 214 if_len = strlen(if_name) + 1; 215 216 /* validate component parts of bearer name */ 217 218 if ((media_len <= 1) || (media_len > TIPC_MAX_MEDIA_NAME) || 219 (if_len <= 1) || (if_len > TIPC_MAX_IF_NAME) || 220 (strspn(media_name, tipc_alphabet) != (media_len - 1)) || 221 (strspn(if_name, tipc_alphabet) != (if_len - 1))) 222 return 0; 223 224 /* return bearer name components, if necessary */ 225 226 if (name_parts) { 227 strcpy(name_parts->media_name, media_name); 228 strcpy(name_parts->if_name, if_name); 229 } 230 return 1; 231} 232 233/** 234 * bearer_find - locates bearer object with matching bearer name 235 */ 236 237static struct tipc_bearer *bearer_find(const char *name) 238{ 239 struct tipc_bearer *b_ptr; 240 u32 i; 241 242 for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) { 243 if (b_ptr->active && (!strcmp(b_ptr->name, name))) 244 return b_ptr; 245 } 246 return NULL; 247} 248 249/** 250 * tipc_bearer_find_interface - locates bearer object with matching interface name 251 */ 252 253struct tipc_bearer *tipc_bearer_find_interface(const char *if_name) 254{ 255 struct tipc_bearer *b_ptr; 256 char *b_if_name; 257 u32 i; 258 259 for (i = 0, b_ptr = tipc_bearers; i < MAX_BEARERS; i++, b_ptr++) { 260 if (!b_ptr->active) 261 continue; 262 b_if_name = strchr(b_ptr->name, ':') + 1; 263 if (!strcmp(b_if_name, if_name)) 264 return b_ptr; 265 } 266 return NULL; 267} 268 269/** 270 * tipc_bearer_get_names - record names of bearers in buffer 271 */ 272 273struct sk_buff *tipc_bearer_get_names(void) 274{ 275 struct sk_buff *buf; 276 struct tipc_bearer *b_ptr; 277 int i, j; 278 279 buf = tipc_cfg_reply_alloc(MAX_BEARERS * TLV_SPACE(TIPC_MAX_BEARER_NAME)); 280 if (!buf) 281 return NULL; 282 283 read_lock_bh(&tipc_net_lock); 284 for (i = 0; i < media_count; i++) { 285 for (j = 0; j < MAX_BEARERS; j++) { 286 b_ptr = &tipc_bearers[j]; 287 if (b_ptr->active && (b_ptr->media == media_list[i])) { 288 tipc_cfg_append_tlv(buf, TIPC_TLV_BEARER_NAME, 289 b_ptr->name, 290 strlen(b_ptr->name) + 1); 291 } 292 } 293 } 294 read_unlock_bh(&tipc_net_lock); 295 return buf; 296} 297 298void tipc_bearer_add_dest(struct tipc_bearer *b_ptr, u32 dest) 299{ 300 tipc_nmap_add(&b_ptr->nodes, dest); 301 tipc_bcbearer_sort(); 302 tipc_disc_add_dest(b_ptr->link_req); 303} 304 305void tipc_bearer_remove_dest(struct tipc_bearer *b_ptr, u32 dest) 306{ 307 tipc_nmap_remove(&b_ptr->nodes, dest); 308 tipc_bcbearer_sort(); 309 tipc_disc_remove_dest(b_ptr->link_req); 310} 311 312/* 313 * bearer_push(): Resolve bearer congestion. Force the waiting 314 * links to push out their unsent packets, one packet per link 315 * per iteration, until all packets are gone or congestion reoccurs. 316 * 'tipc_net_lock' is read_locked when this function is called 317 * bearer.lock must be taken before calling 318 * Returns binary true(1) ore false(0) 319 */ 320static int bearer_push(struct tipc_bearer *b_ptr) 321{ 322 u32 res = 0; 323 struct link *ln, *tln; 324 325 if (b_ptr->blocked) 326 return 0; 327 328 while (!list_empty(&b_ptr->cong_links) && (res != PUSH_FAILED)) { 329 list_for_each_entry_safe(ln, tln, &b_ptr->cong_links, link_list) { 330 res = tipc_link_push_packet(ln); 331 if (res == PUSH_FAILED) 332 break; 333 if (res == PUSH_FINISHED) 334 list_move_tail(&ln->link_list, &b_ptr->links); 335 } 336 } 337 return list_empty(&b_ptr->cong_links); 338} 339 340void tipc_bearer_lock_push(struct tipc_bearer *b_ptr) 341{ 342 spin_lock_bh(&b_ptr->lock); 343 bearer_push(b_ptr); 344 spin_unlock_bh(&b_ptr->lock); 345} 346 347 348/* 349 * Interrupt enabling new requests after bearer congestion or blocking: 350 * See bearer_send(). 351 */ 352void tipc_continue(struct tipc_bearer *b_ptr) 353{ 354 spin_lock_bh(&b_ptr->lock); 355 if (!list_empty(&b_ptr->cong_links)) 356 tipc_k_signal((Handler)tipc_bearer_lock_push, (unsigned long)b_ptr); 357 b_ptr->blocked = 0; 358 spin_unlock_bh(&b_ptr->lock); 359} 360 361/* 362 * Schedule link for sending of messages after the bearer 363 * has been deblocked by 'continue()'. This method is called 364 * when somebody tries to send a message via this link while 365 * the bearer is congested. 'tipc_net_lock' is in read_lock here 366 * bearer.lock is busy 367 */ 368 369static void tipc_bearer_schedule_unlocked(struct tipc_bearer *b_ptr, struct link *l_ptr) 370{ 371 list_move_tail(&l_ptr->link_list, &b_ptr->cong_links); 372} 373 374/* 375 * Schedule link for sending of messages after the bearer 376 * has been deblocked by 'continue()'. This method is called 377 * when somebody tries to send a message via this link while 378 * the bearer is congested. 'tipc_net_lock' is in read_lock here, 379 * bearer.lock is free 380 */ 381 382void tipc_bearer_schedule(struct tipc_bearer *b_ptr, struct link *l_ptr) 383{ 384 spin_lock_bh(&b_ptr->lock); 385 tipc_bearer_schedule_unlocked(b_ptr, l_ptr); 386 spin_unlock_bh(&b_ptr->lock); 387} 388 389 390/* 391 * tipc_bearer_resolve_congestion(): Check if there is bearer congestion, 392 * and if there is, try to resolve it before returning. 393 * 'tipc_net_lock' is read_locked when this function is called 394 */ 395int tipc_bearer_resolve_congestion(struct tipc_bearer *b_ptr, struct link *l_ptr) 396{ 397 int res = 1; 398 399 if (list_empty(&b_ptr->cong_links)) 400 return 1; 401 spin_lock_bh(&b_ptr->lock); 402 if (!bearer_push(b_ptr)) { 403 tipc_bearer_schedule_unlocked(b_ptr, l_ptr); 404 res = 0; 405 } 406 spin_unlock_bh(&b_ptr->lock); 407 return res; 408} 409 410/** 411 * tipc_bearer_congested - determines if bearer is currently congested 412 */ 413 414int tipc_bearer_congested(struct tipc_bearer *b_ptr, struct link *l_ptr) 415{ 416 if (unlikely(b_ptr->blocked)) 417 return 1; 418 if (likely(list_empty(&b_ptr->cong_links))) 419 return 0; 420 return !tipc_bearer_resolve_congestion(b_ptr, l_ptr); 421} 422 423/** 424 * tipc_enable_bearer - enable bearer with the given name 425 */ 426 427int tipc_enable_bearer(const char *name, u32 disc_domain, u32 priority) 428{ 429 struct tipc_bearer *b_ptr; 430 struct media *m_ptr; 431 struct bearer_name b_name; 432 char addr_string[16]; 433 u32 bearer_id; 434 u32 with_this_prio; 435 u32 i; 436 int res = -EINVAL; 437 438 if (tipc_mode != TIPC_NET_MODE) { 439 warn("Bearer <%s> rejected, not supported in standalone mode\n", 440 name); 441 return -ENOPROTOOPT; 442 } 443 if (!bearer_name_validate(name, &b_name)) { 444 warn("Bearer <%s> rejected, illegal name\n", name); 445 return -EINVAL; 446 } 447 if (tipc_addr_domain_valid(disc_domain) && 448 (disc_domain != tipc_own_addr)) { 449 if (tipc_in_scope(disc_domain, tipc_own_addr)) { 450 disc_domain = tipc_own_addr & TIPC_CLUSTER_MASK; 451 res = 0; /* accept any node in own cluster */ 452 } else if (in_own_cluster(disc_domain)) 453 res = 0; /* accept specified node in own cluster */ 454 } 455 if (res) { 456 warn("Bearer <%s> rejected, illegal discovery domain\n", name); 457 return -EINVAL; 458 } 459 if ((priority < TIPC_MIN_LINK_PRI || 460 priority > TIPC_MAX_LINK_PRI) && 461 (priority != TIPC_MEDIA_LINK_PRI)) { 462 warn("Bearer <%s> rejected, illegal priority\n", name); 463 return -EINVAL; 464 } 465 466 write_lock_bh(&tipc_net_lock); 467 468 m_ptr = media_find(b_name.media_name); 469 if (!m_ptr) { 470 warn("Bearer <%s> rejected, media <%s> not registered\n", name, 471 b_name.media_name); 472 goto exit; 473 } 474 475 if (priority == TIPC_MEDIA_LINK_PRI) 476 priority = m_ptr->priority; 477 478restart: 479 bearer_id = MAX_BEARERS; 480 with_this_prio = 1; 481 for (i = MAX_BEARERS; i-- != 0; ) { 482 if (!tipc_bearers[i].active) { 483 bearer_id = i; 484 continue; 485 } 486 if (!strcmp(name, tipc_bearers[i].name)) { 487 warn("Bearer <%s> rejected, already enabled\n", name); 488 goto exit; 489 } 490 if ((tipc_bearers[i].priority == priority) && 491 (++with_this_prio > 2)) { 492 if (priority-- == 0) { 493 warn("Bearer <%s> rejected, duplicate priority\n", 494 name); 495 goto exit; 496 } 497 warn("Bearer <%s> priority adjustment required %u->%u\n", 498 name, priority + 1, priority); 499 goto restart; 500 } 501 } 502 if (bearer_id >= MAX_BEARERS) { 503 warn("Bearer <%s> rejected, bearer limit reached (%u)\n", 504 name, MAX_BEARERS); 505 goto exit; 506 } 507 508 b_ptr = &tipc_bearers[bearer_id]; 509 strcpy(b_ptr->name, name); 510 res = m_ptr->enable_bearer(b_ptr); 511 if (res) { 512 warn("Bearer <%s> rejected, enable failure (%d)\n", name, -res); 513 goto exit; 514 } 515 516 b_ptr->identity = bearer_id; 517 b_ptr->media = m_ptr; 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); 534exit: 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 544int 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 = 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 580static 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 599int 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 = 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 619void 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