1 /* 2 * net/tipc/link.c: TIPC link code 3 * 4 * Copyright (c) 1996-2007, 2012-2014, Ericsson AB 5 * Copyright (c) 2004-2007, 2010-2013, 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 "link.h" 39 #include "bcast.h" 40 #include "socket.h" 41 #include "name_distr.h" 42 #include "discover.h" 43 #include "netlink.h" 44 45 #include <linux/pkt_sched.h> 46 47 /* 48 * Error message prefixes 49 */ 50 static const char *link_co_err = "Link changeover error, "; 51 static const char *link_rst_msg = "Resetting link "; 52 static const char *link_unk_evt = "Unknown link event "; 53 54 static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = { 55 [TIPC_NLA_LINK_UNSPEC] = { .type = NLA_UNSPEC }, 56 [TIPC_NLA_LINK_NAME] = { 57 .type = NLA_STRING, 58 .len = TIPC_MAX_LINK_NAME 59 }, 60 [TIPC_NLA_LINK_MTU] = { .type = NLA_U32 }, 61 [TIPC_NLA_LINK_BROADCAST] = { .type = NLA_FLAG }, 62 [TIPC_NLA_LINK_UP] = { .type = NLA_FLAG }, 63 [TIPC_NLA_LINK_ACTIVE] = { .type = NLA_FLAG }, 64 [TIPC_NLA_LINK_PROP] = { .type = NLA_NESTED }, 65 [TIPC_NLA_LINK_STATS] = { .type = NLA_NESTED }, 66 [TIPC_NLA_LINK_RX] = { .type = NLA_U32 }, 67 [TIPC_NLA_LINK_TX] = { .type = NLA_U32 } 68 }; 69 70 /* Properties valid for media, bearar and link */ 71 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = { 72 [TIPC_NLA_PROP_UNSPEC] = { .type = NLA_UNSPEC }, 73 [TIPC_NLA_PROP_PRIO] = { .type = NLA_U32 }, 74 [TIPC_NLA_PROP_TOL] = { .type = NLA_U32 }, 75 [TIPC_NLA_PROP_WIN] = { .type = NLA_U32 } 76 }; 77 78 /* 79 * Out-of-range value for link session numbers 80 */ 81 #define INVALID_SESSION 0x10000 82 83 /* 84 * Link state events: 85 */ 86 #define STARTING_EVT 856384768 /* link processing trigger */ 87 #define TRAFFIC_MSG_EVT 560815u /* rx'd ??? */ 88 #define TIMEOUT_EVT 560817u /* link timer expired */ 89 90 /* 91 * The following two 'message types' is really just implementation 92 * data conveniently stored in the message header. 93 * They must not be considered part of the protocol 94 */ 95 #define OPEN_MSG 0 96 #define CLOSED_MSG 1 97 98 /* 99 * State value stored in 'exp_msg_count' 100 */ 101 #define START_CHANGEOVER 100000u 102 103 static void link_handle_out_of_seq_msg(struct tipc_link *link, 104 struct sk_buff *skb); 105 static void tipc_link_proto_rcv(struct tipc_link *link, 106 struct sk_buff *skb); 107 static int tipc_link_tunnel_rcv(struct tipc_node *node, 108 struct sk_buff **skb); 109 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol); 110 static void link_state_event(struct tipc_link *l_ptr, u32 event); 111 static void link_reset_statistics(struct tipc_link *l_ptr); 112 static void link_print(struct tipc_link *l_ptr, const char *str); 113 static void tipc_link_sync_xmit(struct tipc_link *l); 114 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf); 115 static void tipc_link_input(struct tipc_link *l, struct sk_buff *skb); 116 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb); 117 118 /* 119 * Simple link routines 120 */ 121 static unsigned int align(unsigned int i) 122 { 123 return (i + 3) & ~3u; 124 } 125 126 static void tipc_link_release(struct kref *kref) 127 { 128 kfree(container_of(kref, struct tipc_link, ref)); 129 } 130 131 static void tipc_link_get(struct tipc_link *l_ptr) 132 { 133 kref_get(&l_ptr->ref); 134 } 135 136 static void tipc_link_put(struct tipc_link *l_ptr) 137 { 138 kref_put(&l_ptr->ref, tipc_link_release); 139 } 140 141 static void link_init_max_pkt(struct tipc_link *l_ptr) 142 { 143 struct tipc_node *node = l_ptr->owner; 144 struct tipc_net *tn = net_generic(node->net, tipc_net_id); 145 struct tipc_bearer *b_ptr; 146 u32 max_pkt; 147 148 rcu_read_lock(); 149 b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]); 150 if (!b_ptr) { 151 rcu_read_unlock(); 152 return; 153 } 154 max_pkt = (b_ptr->mtu & ~3); 155 rcu_read_unlock(); 156 157 if (max_pkt > MAX_MSG_SIZE) 158 max_pkt = MAX_MSG_SIZE; 159 160 l_ptr->max_pkt_target = max_pkt; 161 if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT) 162 l_ptr->max_pkt = l_ptr->max_pkt_target; 163 else 164 l_ptr->max_pkt = MAX_PKT_DEFAULT; 165 166 l_ptr->max_pkt_probes = 0; 167 } 168 169 /* 170 * Simple non-static link routines (i.e. referenced outside this file) 171 */ 172 int tipc_link_is_up(struct tipc_link *l_ptr) 173 { 174 if (!l_ptr) 175 return 0; 176 return link_working_working(l_ptr) || link_working_unknown(l_ptr); 177 } 178 179 int tipc_link_is_active(struct tipc_link *l_ptr) 180 { 181 return (l_ptr->owner->active_links[0] == l_ptr) || 182 (l_ptr->owner->active_links[1] == l_ptr); 183 } 184 185 /** 186 * link_timeout - handle expiration of link timer 187 * @l_ptr: pointer to link 188 */ 189 static void link_timeout(unsigned long data) 190 { 191 struct tipc_link *l_ptr = (struct tipc_link *)data; 192 struct sk_buff *skb; 193 194 tipc_node_lock(l_ptr->owner); 195 196 /* update counters used in statistical profiling of send traffic */ 197 l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->outqueue); 198 l_ptr->stats.queue_sz_counts++; 199 200 skb = skb_peek(&l_ptr->outqueue); 201 if (skb) { 202 struct tipc_msg *msg = buf_msg(skb); 203 u32 length = msg_size(msg); 204 205 if ((msg_user(msg) == MSG_FRAGMENTER) && 206 (msg_type(msg) == FIRST_FRAGMENT)) { 207 length = msg_size(msg_get_wrapped(msg)); 208 } 209 if (length) { 210 l_ptr->stats.msg_lengths_total += length; 211 l_ptr->stats.msg_length_counts++; 212 if (length <= 64) 213 l_ptr->stats.msg_length_profile[0]++; 214 else if (length <= 256) 215 l_ptr->stats.msg_length_profile[1]++; 216 else if (length <= 1024) 217 l_ptr->stats.msg_length_profile[2]++; 218 else if (length <= 4096) 219 l_ptr->stats.msg_length_profile[3]++; 220 else if (length <= 16384) 221 l_ptr->stats.msg_length_profile[4]++; 222 else if (length <= 32768) 223 l_ptr->stats.msg_length_profile[5]++; 224 else 225 l_ptr->stats.msg_length_profile[6]++; 226 } 227 } 228 229 /* do all other link processing performed on a periodic basis */ 230 link_state_event(l_ptr, TIMEOUT_EVT); 231 232 if (l_ptr->next_out) 233 tipc_link_push_packets(l_ptr); 234 235 tipc_node_unlock(l_ptr->owner); 236 tipc_link_put(l_ptr); 237 } 238 239 static void link_set_timer(struct tipc_link *link, unsigned long time) 240 { 241 if (!mod_timer(&link->timer, jiffies + time)) 242 tipc_link_get(link); 243 } 244 245 /** 246 * tipc_link_create - create a new link 247 * @n_ptr: pointer to associated node 248 * @b_ptr: pointer to associated bearer 249 * @media_addr: media address to use when sending messages over link 250 * 251 * Returns pointer to link. 252 */ 253 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr, 254 struct tipc_bearer *b_ptr, 255 const struct tipc_media_addr *media_addr) 256 { 257 struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id); 258 struct tipc_link *l_ptr; 259 struct tipc_msg *msg; 260 char *if_name; 261 char addr_string[16]; 262 u32 peer = n_ptr->addr; 263 264 if (n_ptr->link_cnt >= MAX_BEARERS) { 265 tipc_addr_string_fill(addr_string, n_ptr->addr); 266 pr_err("Attempt to establish %uth link to %s. Max %u allowed.\n", 267 n_ptr->link_cnt, addr_string, MAX_BEARERS); 268 return NULL; 269 } 270 271 if (n_ptr->links[b_ptr->identity]) { 272 tipc_addr_string_fill(addr_string, n_ptr->addr); 273 pr_err("Attempt to establish second link on <%s> to %s\n", 274 b_ptr->name, addr_string); 275 return NULL; 276 } 277 278 l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC); 279 if (!l_ptr) { 280 pr_warn("Link creation failed, no memory\n"); 281 return NULL; 282 } 283 kref_init(&l_ptr->ref); 284 l_ptr->addr = peer; 285 if_name = strchr(b_ptr->name, ':') + 1; 286 sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown", 287 tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr), 288 tipc_node(tn->own_addr), 289 if_name, 290 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer)); 291 /* note: peer i/f name is updated by reset/activate message */ 292 memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr)); 293 l_ptr->owner = n_ptr; 294 l_ptr->checkpoint = 1; 295 l_ptr->peer_session = INVALID_SESSION; 296 l_ptr->bearer_id = b_ptr->identity; 297 link_set_supervision_props(l_ptr, b_ptr->tolerance); 298 l_ptr->state = RESET_UNKNOWN; 299 300 l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg; 301 msg = l_ptr->pmsg; 302 tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, 303 l_ptr->addr); 304 msg_set_size(msg, sizeof(l_ptr->proto_msg)); 305 msg_set_session(msg, (tn->random & 0xffff)); 306 msg_set_bearer_id(msg, b_ptr->identity); 307 strcpy((char *)msg_data(msg), if_name); 308 309 l_ptr->priority = b_ptr->priority; 310 tipc_link_set_queue_limits(l_ptr, b_ptr->window); 311 312 l_ptr->net_plane = b_ptr->net_plane; 313 link_init_max_pkt(l_ptr); 314 315 l_ptr->next_out_no = 1; 316 __skb_queue_head_init(&l_ptr->outqueue); 317 __skb_queue_head_init(&l_ptr->deferred_queue); 318 skb_queue_head_init(&l_ptr->wakeupq); 319 skb_queue_head_init(&l_ptr->inputq); 320 skb_queue_head_init(&l_ptr->namedq); 321 link_reset_statistics(l_ptr); 322 tipc_node_attach_link(n_ptr, l_ptr); 323 setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr); 324 link_state_event(l_ptr, STARTING_EVT); 325 326 return l_ptr; 327 } 328 329 /** 330 * link_delete - Conditional deletion of link. 331 * If timer still running, real delete is done when it expires 332 * @link: link to be deleted 333 */ 334 void tipc_link_delete(struct tipc_link *link) 335 { 336 tipc_link_reset_fragments(link); 337 tipc_node_detach_link(link->owner, link); 338 tipc_link_put(link); 339 } 340 341 void tipc_link_delete_list(struct net *net, unsigned int bearer_id, 342 bool shutting_down) 343 { 344 struct tipc_net *tn = net_generic(net, tipc_net_id); 345 struct tipc_link *link; 346 struct tipc_node *node; 347 348 rcu_read_lock(); 349 list_for_each_entry_rcu(node, &tn->node_list, list) { 350 tipc_node_lock(node); 351 link = node->links[bearer_id]; 352 if (!link) { 353 tipc_node_unlock(node); 354 continue; 355 } 356 tipc_link_reset(link); 357 if (del_timer(&link->timer)) 358 tipc_link_put(link); 359 link->flags |= LINK_STOPPED; 360 /* Delete link now, or when failover is finished: */ 361 if (shutting_down || !tipc_node_is_up(node)) 362 tipc_link_delete(link); 363 tipc_node_unlock(node); 364 } 365 rcu_read_unlock(); 366 } 367 368 /** 369 * link_schedule_user - schedule user for wakeup after congestion 370 * @link: congested link 371 * @oport: sending port 372 * @chain_sz: size of buffer chain that was attempted sent 373 * @imp: importance of message attempted sent 374 * Create pseudo msg to send back to user when congestion abates 375 */ 376 static bool link_schedule_user(struct tipc_link *link, u32 oport, 377 uint chain_sz, uint imp) 378 { 379 struct sk_buff *buf; 380 381 buf = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0, 382 link_own_addr(link), link_own_addr(link), 383 oport, 0, 0); 384 if (!buf) 385 return false; 386 TIPC_SKB_CB(buf)->chain_sz = chain_sz; 387 TIPC_SKB_CB(buf)->chain_imp = imp; 388 skb_queue_tail(&link->wakeupq, buf); 389 link->stats.link_congs++; 390 return true; 391 } 392 393 /** 394 * link_prepare_wakeup - prepare users for wakeup after congestion 395 * @link: congested link 396 * Move a number of waiting users, as permitted by available space in 397 * the send queue, from link wait queue to node wait queue for wakeup 398 */ 399 void link_prepare_wakeup(struct tipc_link *link) 400 { 401 uint pend_qsz = skb_queue_len(&link->outqueue); 402 struct sk_buff *skb, *tmp; 403 404 skb_queue_walk_safe(&link->wakeupq, skb, tmp) { 405 if (pend_qsz >= link->queue_limit[TIPC_SKB_CB(skb)->chain_imp]) 406 break; 407 pend_qsz += TIPC_SKB_CB(skb)->chain_sz; 408 skb_unlink(skb, &link->wakeupq); 409 skb_queue_tail(&link->inputq, skb); 410 link->owner->inputq = &link->inputq; 411 link->owner->action_flags |= TIPC_MSG_EVT; 412 } 413 } 414 415 /** 416 * tipc_link_reset_fragments - purge link's inbound message fragments queue 417 * @l_ptr: pointer to link 418 */ 419 void tipc_link_reset_fragments(struct tipc_link *l_ptr) 420 { 421 kfree_skb(l_ptr->reasm_buf); 422 l_ptr->reasm_buf = NULL; 423 } 424 425 /** 426 * tipc_link_purge_queues - purge all pkt queues associated with link 427 * @l_ptr: pointer to link 428 */ 429 void tipc_link_purge_queues(struct tipc_link *l_ptr) 430 { 431 __skb_queue_purge(&l_ptr->deferred_queue); 432 __skb_queue_purge(&l_ptr->outqueue); 433 tipc_link_reset_fragments(l_ptr); 434 } 435 436 void tipc_link_reset(struct tipc_link *l_ptr) 437 { 438 u32 prev_state = l_ptr->state; 439 u32 checkpoint = l_ptr->next_in_no; 440 int was_active_link = tipc_link_is_active(l_ptr); 441 struct tipc_node *owner = l_ptr->owner; 442 443 msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff)); 444 445 /* Link is down, accept any session */ 446 l_ptr->peer_session = INVALID_SESSION; 447 448 /* Prepare for max packet size negotiation */ 449 link_init_max_pkt(l_ptr); 450 451 l_ptr->state = RESET_UNKNOWN; 452 453 if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET)) 454 return; 455 456 tipc_node_link_down(l_ptr->owner, l_ptr); 457 tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr); 458 459 if (was_active_link && tipc_node_active_links(l_ptr->owner)) { 460 l_ptr->reset_checkpoint = checkpoint; 461 l_ptr->exp_msg_count = START_CHANGEOVER; 462 } 463 464 /* Clean up all queues, except inputq: */ 465 __skb_queue_purge(&l_ptr->outqueue); 466 __skb_queue_purge(&l_ptr->deferred_queue); 467 if (!owner->inputq) 468 owner->inputq = &l_ptr->inputq; 469 skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq); 470 if (!skb_queue_empty(owner->inputq)) 471 owner->action_flags |= TIPC_MSG_EVT; 472 l_ptr->next_out = NULL; 473 l_ptr->unacked_window = 0; 474 l_ptr->checkpoint = 1; 475 l_ptr->next_out_no = 1; 476 l_ptr->fsm_msg_cnt = 0; 477 l_ptr->stale_count = 0; 478 link_reset_statistics(l_ptr); 479 } 480 481 void tipc_link_reset_list(struct net *net, unsigned int bearer_id) 482 { 483 struct tipc_net *tn = net_generic(net, tipc_net_id); 484 struct tipc_link *l_ptr; 485 struct tipc_node *n_ptr; 486 487 rcu_read_lock(); 488 list_for_each_entry_rcu(n_ptr, &tn->node_list, list) { 489 tipc_node_lock(n_ptr); 490 l_ptr = n_ptr->links[bearer_id]; 491 if (l_ptr) 492 tipc_link_reset(l_ptr); 493 tipc_node_unlock(n_ptr); 494 } 495 rcu_read_unlock(); 496 } 497 498 static void link_activate(struct tipc_link *link) 499 { 500 struct tipc_node *node = link->owner; 501 502 link->next_in_no = 1; 503 link->stats.recv_info = 1; 504 tipc_node_link_up(node, link); 505 tipc_bearer_add_dest(node->net, link->bearer_id, link->addr); 506 } 507 508 /** 509 * link_state_event - link finite state machine 510 * @l_ptr: pointer to link 511 * @event: state machine event to process 512 */ 513 static void link_state_event(struct tipc_link *l_ptr, unsigned int event) 514 { 515 struct tipc_link *other; 516 unsigned long cont_intv = l_ptr->cont_intv; 517 518 if (l_ptr->flags & LINK_STOPPED) 519 return; 520 521 if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT)) 522 return; /* Not yet. */ 523 524 /* Check whether changeover is going on */ 525 if (l_ptr->exp_msg_count) { 526 if (event == TIMEOUT_EVT) 527 link_set_timer(l_ptr, cont_intv); 528 return; 529 } 530 531 switch (l_ptr->state) { 532 case WORKING_WORKING: 533 switch (event) { 534 case TRAFFIC_MSG_EVT: 535 case ACTIVATE_MSG: 536 break; 537 case TIMEOUT_EVT: 538 if (l_ptr->next_in_no != l_ptr->checkpoint) { 539 l_ptr->checkpoint = l_ptr->next_in_no; 540 if (tipc_bclink_acks_missing(l_ptr->owner)) { 541 tipc_link_proto_xmit(l_ptr, STATE_MSG, 542 0, 0, 0, 0, 0); 543 l_ptr->fsm_msg_cnt++; 544 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) { 545 tipc_link_proto_xmit(l_ptr, STATE_MSG, 546 1, 0, 0, 0, 0); 547 l_ptr->fsm_msg_cnt++; 548 } 549 link_set_timer(l_ptr, cont_intv); 550 break; 551 } 552 l_ptr->state = WORKING_UNKNOWN; 553 l_ptr->fsm_msg_cnt = 0; 554 tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); 555 l_ptr->fsm_msg_cnt++; 556 link_set_timer(l_ptr, cont_intv / 4); 557 break; 558 case RESET_MSG: 559 pr_debug("%s<%s>, requested by peer\n", 560 link_rst_msg, l_ptr->name); 561 tipc_link_reset(l_ptr); 562 l_ptr->state = RESET_RESET; 563 l_ptr->fsm_msg_cnt = 0; 564 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, 565 0, 0, 0, 0, 0); 566 l_ptr->fsm_msg_cnt++; 567 link_set_timer(l_ptr, cont_intv); 568 break; 569 default: 570 pr_debug("%s%u in WW state\n", link_unk_evt, event); 571 } 572 break; 573 case WORKING_UNKNOWN: 574 switch (event) { 575 case TRAFFIC_MSG_EVT: 576 case ACTIVATE_MSG: 577 l_ptr->state = WORKING_WORKING; 578 l_ptr->fsm_msg_cnt = 0; 579 link_set_timer(l_ptr, cont_intv); 580 break; 581 case RESET_MSG: 582 pr_debug("%s<%s>, requested by peer while probing\n", 583 link_rst_msg, l_ptr->name); 584 tipc_link_reset(l_ptr); 585 l_ptr->state = RESET_RESET; 586 l_ptr->fsm_msg_cnt = 0; 587 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, 588 0, 0, 0, 0, 0); 589 l_ptr->fsm_msg_cnt++; 590 link_set_timer(l_ptr, cont_intv); 591 break; 592 case TIMEOUT_EVT: 593 if (l_ptr->next_in_no != l_ptr->checkpoint) { 594 l_ptr->state = WORKING_WORKING; 595 l_ptr->fsm_msg_cnt = 0; 596 l_ptr->checkpoint = l_ptr->next_in_no; 597 if (tipc_bclink_acks_missing(l_ptr->owner)) { 598 tipc_link_proto_xmit(l_ptr, STATE_MSG, 599 0, 0, 0, 0, 0); 600 l_ptr->fsm_msg_cnt++; 601 } 602 link_set_timer(l_ptr, cont_intv); 603 } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) { 604 tipc_link_proto_xmit(l_ptr, STATE_MSG, 605 1, 0, 0, 0, 0); 606 l_ptr->fsm_msg_cnt++; 607 link_set_timer(l_ptr, cont_intv / 4); 608 } else { /* Link has failed */ 609 pr_debug("%s<%s>, peer not responding\n", 610 link_rst_msg, l_ptr->name); 611 tipc_link_reset(l_ptr); 612 l_ptr->state = RESET_UNKNOWN; 613 l_ptr->fsm_msg_cnt = 0; 614 tipc_link_proto_xmit(l_ptr, RESET_MSG, 615 0, 0, 0, 0, 0); 616 l_ptr->fsm_msg_cnt++; 617 link_set_timer(l_ptr, cont_intv); 618 } 619 break; 620 default: 621 pr_err("%s%u in WU state\n", link_unk_evt, event); 622 } 623 break; 624 case RESET_UNKNOWN: 625 switch (event) { 626 case TRAFFIC_MSG_EVT: 627 break; 628 case ACTIVATE_MSG: 629 other = l_ptr->owner->active_links[0]; 630 if (other && link_working_unknown(other)) 631 break; 632 l_ptr->state = WORKING_WORKING; 633 l_ptr->fsm_msg_cnt = 0; 634 link_activate(l_ptr); 635 tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); 636 l_ptr->fsm_msg_cnt++; 637 if (l_ptr->owner->working_links == 1) 638 tipc_link_sync_xmit(l_ptr); 639 link_set_timer(l_ptr, cont_intv); 640 break; 641 case RESET_MSG: 642 l_ptr->state = RESET_RESET; 643 l_ptr->fsm_msg_cnt = 0; 644 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, 645 1, 0, 0, 0, 0); 646 l_ptr->fsm_msg_cnt++; 647 link_set_timer(l_ptr, cont_intv); 648 break; 649 case STARTING_EVT: 650 l_ptr->flags |= LINK_STARTED; 651 l_ptr->fsm_msg_cnt++; 652 link_set_timer(l_ptr, cont_intv); 653 break; 654 case TIMEOUT_EVT: 655 tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0, 0); 656 l_ptr->fsm_msg_cnt++; 657 link_set_timer(l_ptr, cont_intv); 658 break; 659 default: 660 pr_err("%s%u in RU state\n", link_unk_evt, event); 661 } 662 break; 663 case RESET_RESET: 664 switch (event) { 665 case TRAFFIC_MSG_EVT: 666 case ACTIVATE_MSG: 667 other = l_ptr->owner->active_links[0]; 668 if (other && link_working_unknown(other)) 669 break; 670 l_ptr->state = WORKING_WORKING; 671 l_ptr->fsm_msg_cnt = 0; 672 link_activate(l_ptr); 673 tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0); 674 l_ptr->fsm_msg_cnt++; 675 if (l_ptr->owner->working_links == 1) 676 tipc_link_sync_xmit(l_ptr); 677 link_set_timer(l_ptr, cont_intv); 678 break; 679 case RESET_MSG: 680 break; 681 case TIMEOUT_EVT: 682 tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG, 683 0, 0, 0, 0, 0); 684 l_ptr->fsm_msg_cnt++; 685 link_set_timer(l_ptr, cont_intv); 686 break; 687 default: 688 pr_err("%s%u in RR state\n", link_unk_evt, event); 689 } 690 break; 691 default: 692 pr_err("Unknown link state %u/%u\n", l_ptr->state, event); 693 } 694 } 695 696 /* tipc_link_cong: determine return value and how to treat the 697 * sent buffer during link congestion. 698 * - For plain, errorless user data messages we keep the buffer and 699 * return -ELINKONG. 700 * - For all other messages we discard the buffer and return -EHOSTUNREACH 701 * - For TIPC internal messages we also reset the link 702 */ 703 static int tipc_link_cong(struct tipc_link *link, struct sk_buff_head *list) 704 { 705 struct sk_buff *skb = skb_peek(list); 706 struct tipc_msg *msg = buf_msg(skb); 707 uint imp = tipc_msg_tot_importance(msg); 708 u32 oport = msg_tot_origport(msg); 709 710 if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) { 711 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name); 712 tipc_link_reset(link); 713 goto drop; 714 } 715 if (unlikely(msg_errcode(msg))) 716 goto drop; 717 if (unlikely(msg_reroute_cnt(msg))) 718 goto drop; 719 if (TIPC_SKB_CB(skb)->wakeup_pending) 720 return -ELINKCONG; 721 if (link_schedule_user(link, oport, skb_queue_len(list), imp)) 722 return -ELINKCONG; 723 drop: 724 __skb_queue_purge(list); 725 return -EHOSTUNREACH; 726 } 727 728 /** 729 * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked 730 * @link: link to use 731 * @list: chain of buffers containing message 732 * 733 * Consumes the buffer chain, except when returning -ELINKCONG 734 * Returns 0 if success, otherwise errno: -ELINKCONG, -EMSGSIZE (plain socket 735 * user data messages) or -EHOSTUNREACH (all other messages/senders) 736 * Only the socket functions tipc_send_stream() and tipc_send_packet() need 737 * to act on the return value, since they may need to do more send attempts. 738 */ 739 int __tipc_link_xmit(struct net *net, struct tipc_link *link, 740 struct sk_buff_head *list) 741 { 742 struct tipc_msg *msg = buf_msg(skb_peek(list)); 743 uint psz = msg_size(msg); 744 uint sndlim = link->queue_limit[0]; 745 uint imp = tipc_msg_tot_importance(msg); 746 uint mtu = link->max_pkt; 747 uint ack = mod(link->next_in_no - 1); 748 uint seqno = link->next_out_no; 749 uint bc_last_in = link->owner->bclink.last_in; 750 struct tipc_media_addr *addr = &link->media_addr; 751 struct sk_buff_head *outqueue = &link->outqueue; 752 struct sk_buff *skb, *tmp; 753 754 /* Match queue limits against msg importance: */ 755 if (unlikely(skb_queue_len(outqueue) >= link->queue_limit[imp])) 756 return tipc_link_cong(link, list); 757 758 /* Has valid packet limit been used ? */ 759 if (unlikely(psz > mtu)) { 760 __skb_queue_purge(list); 761 return -EMSGSIZE; 762 } 763 764 /* Prepare each packet for sending, and add to outqueue: */ 765 skb_queue_walk_safe(list, skb, tmp) { 766 __skb_unlink(skb, list); 767 msg = buf_msg(skb); 768 msg_set_word(msg, 2, ((ack << 16) | mod(seqno))); 769 msg_set_bcast_ack(msg, bc_last_in); 770 771 if (skb_queue_len(outqueue) < sndlim) { 772 __skb_queue_tail(outqueue, skb); 773 tipc_bearer_send(net, link->bearer_id, 774 skb, addr); 775 link->next_out = NULL; 776 link->unacked_window = 0; 777 } else if (tipc_msg_bundle(outqueue, skb, mtu)) { 778 link->stats.sent_bundled++; 779 continue; 780 } else if (tipc_msg_make_bundle(outqueue, skb, mtu, 781 link->addr)) { 782 link->stats.sent_bundled++; 783 link->stats.sent_bundles++; 784 if (!link->next_out) 785 link->next_out = skb_peek_tail(outqueue); 786 } else { 787 __skb_queue_tail(outqueue, skb); 788 if (!link->next_out) 789 link->next_out = skb; 790 } 791 seqno++; 792 } 793 link->next_out_no = seqno; 794 return 0; 795 } 796 797 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list) 798 { 799 skb_queue_head_init(list); 800 __skb_queue_tail(list, skb); 801 } 802 803 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb) 804 { 805 struct sk_buff_head head; 806 807 skb2list(skb, &head); 808 return __tipc_link_xmit(link->owner->net, link, &head); 809 } 810 811 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode, 812 u32 selector) 813 { 814 struct sk_buff_head head; 815 816 skb2list(skb, &head); 817 return tipc_link_xmit(net, &head, dnode, selector); 818 } 819 820 /** 821 * tipc_link_xmit() is the general link level function for message sending 822 * @net: the applicable net namespace 823 * @list: chain of buffers containing message 824 * @dsz: amount of user data to be sent 825 * @dnode: address of destination node 826 * @selector: a number used for deterministic link selection 827 * Consumes the buffer chain, except when returning -ELINKCONG 828 * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE 829 */ 830 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode, 831 u32 selector) 832 { 833 struct tipc_link *link = NULL; 834 struct tipc_node *node; 835 int rc = -EHOSTUNREACH; 836 837 node = tipc_node_find(net, dnode); 838 if (node) { 839 tipc_node_lock(node); 840 link = node->active_links[selector & 1]; 841 if (link) 842 rc = __tipc_link_xmit(net, link, list); 843 tipc_node_unlock(node); 844 } 845 if (link) 846 return rc; 847 848 if (likely(in_own_node(net, dnode))) 849 return tipc_sk_rcv(net, list); 850 851 __skb_queue_purge(list); 852 return rc; 853 } 854 855 /* 856 * tipc_link_sync_xmit - synchronize broadcast link endpoints. 857 * 858 * Give a newly added peer node the sequence number where it should 859 * start receiving and acking broadcast packets. 860 * 861 * Called with node locked 862 */ 863 static void tipc_link_sync_xmit(struct tipc_link *link) 864 { 865 struct sk_buff *skb; 866 struct tipc_msg *msg; 867 868 skb = tipc_buf_acquire(INT_H_SIZE); 869 if (!skb) 870 return; 871 872 msg = buf_msg(skb); 873 tipc_msg_init(link_own_addr(link), msg, BCAST_PROTOCOL, STATE_MSG, 874 INT_H_SIZE, link->addr); 875 msg_set_last_bcast(msg, link->owner->bclink.acked); 876 __tipc_link_xmit_skb(link, skb); 877 } 878 879 /* 880 * tipc_link_sync_rcv - synchronize broadcast link endpoints. 881 * Receive the sequence number where we should start receiving and 882 * acking broadcast packets from a newly added peer node, and open 883 * up for reception of such packets. 884 * 885 * Called with node locked 886 */ 887 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf) 888 { 889 struct tipc_msg *msg = buf_msg(buf); 890 891 n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg); 892 n->bclink.recv_permitted = true; 893 kfree_skb(buf); 894 } 895 896 struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list, 897 const struct sk_buff *skb) 898 { 899 if (skb_queue_is_last(list, skb)) 900 return NULL; 901 return skb->next; 902 } 903 904 /* 905 * tipc_link_push_packets - push unsent packets to bearer 906 * 907 * Push out the unsent messages of a link where congestion 908 * has abated. Node is locked. 909 * 910 * Called with node locked 911 */ 912 void tipc_link_push_packets(struct tipc_link *l_ptr) 913 { 914 struct sk_buff_head *outqueue = &l_ptr->outqueue; 915 struct sk_buff *skb = l_ptr->next_out; 916 struct tipc_msg *msg; 917 u32 next, first; 918 919 skb_queue_walk_from(outqueue, skb) { 920 msg = buf_msg(skb); 921 next = msg_seqno(msg); 922 first = buf_seqno(skb_peek(outqueue)); 923 924 if (mod(next - first) < l_ptr->queue_limit[0]) { 925 msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); 926 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); 927 if (msg_user(msg) == MSG_BUNDLER) 928 TIPC_SKB_CB(skb)->bundling = false; 929 tipc_bearer_send(l_ptr->owner->net, 930 l_ptr->bearer_id, skb, 931 &l_ptr->media_addr); 932 l_ptr->next_out = tipc_skb_queue_next(outqueue, skb); 933 } else { 934 break; 935 } 936 } 937 } 938 939 void tipc_link_reset_all(struct tipc_node *node) 940 { 941 char addr_string[16]; 942 u32 i; 943 944 tipc_node_lock(node); 945 946 pr_warn("Resetting all links to %s\n", 947 tipc_addr_string_fill(addr_string, node->addr)); 948 949 for (i = 0; i < MAX_BEARERS; i++) { 950 if (node->links[i]) { 951 link_print(node->links[i], "Resetting link\n"); 952 tipc_link_reset(node->links[i]); 953 } 954 } 955 956 tipc_node_unlock(node); 957 } 958 959 static void link_retransmit_failure(struct tipc_link *l_ptr, 960 struct sk_buff *buf) 961 { 962 struct tipc_msg *msg = buf_msg(buf); 963 struct net *net = l_ptr->owner->net; 964 965 pr_warn("Retransmission failure on link <%s>\n", l_ptr->name); 966 967 if (l_ptr->addr) { 968 /* Handle failure on standard link */ 969 link_print(l_ptr, "Resetting link\n"); 970 tipc_link_reset(l_ptr); 971 972 } else { 973 /* Handle failure on broadcast link */ 974 struct tipc_node *n_ptr; 975 char addr_string[16]; 976 977 pr_info("Msg seq number: %u, ", msg_seqno(msg)); 978 pr_cont("Outstanding acks: %lu\n", 979 (unsigned long) TIPC_SKB_CB(buf)->handle); 980 981 n_ptr = tipc_bclink_retransmit_to(net); 982 tipc_node_lock(n_ptr); 983 984 tipc_addr_string_fill(addr_string, n_ptr->addr); 985 pr_info("Broadcast link info for %s\n", addr_string); 986 pr_info("Reception permitted: %d, Acked: %u\n", 987 n_ptr->bclink.recv_permitted, 988 n_ptr->bclink.acked); 989 pr_info("Last in: %u, Oos state: %u, Last sent: %u\n", 990 n_ptr->bclink.last_in, 991 n_ptr->bclink.oos_state, 992 n_ptr->bclink.last_sent); 993 994 tipc_node_unlock(n_ptr); 995 996 tipc_bclink_set_flags(net, TIPC_BCLINK_RESET); 997 l_ptr->stale_count = 0; 998 } 999 } 1000 1001 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb, 1002 u32 retransmits) 1003 { 1004 struct tipc_msg *msg; 1005 1006 if (!skb) 1007 return; 1008 1009 msg = buf_msg(skb); 1010 1011 /* Detect repeated retransmit failures */ 1012 if (l_ptr->last_retransmitted == msg_seqno(msg)) { 1013 if (++l_ptr->stale_count > 100) { 1014 link_retransmit_failure(l_ptr, skb); 1015 return; 1016 } 1017 } else { 1018 l_ptr->last_retransmitted = msg_seqno(msg); 1019 l_ptr->stale_count = 1; 1020 } 1021 1022 skb_queue_walk_from(&l_ptr->outqueue, skb) { 1023 if (!retransmits || skb == l_ptr->next_out) 1024 break; 1025 msg = buf_msg(skb); 1026 msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); 1027 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); 1028 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb, 1029 &l_ptr->media_addr); 1030 retransmits--; 1031 l_ptr->stats.retransmitted++; 1032 } 1033 } 1034 1035 static void link_retrieve_defq(struct tipc_link *link, 1036 struct sk_buff_head *list) 1037 { 1038 u32 seq_no; 1039 1040 if (skb_queue_empty(&link->deferred_queue)) 1041 return; 1042 1043 seq_no = buf_seqno(skb_peek(&link->deferred_queue)); 1044 if (seq_no == mod(link->next_in_no)) 1045 skb_queue_splice_tail_init(&link->deferred_queue, list); 1046 } 1047 1048 /** 1049 * link_recv_buf_validate - validate basic format of received message 1050 * 1051 * This routine ensures a TIPC message has an acceptable header, and at least 1052 * as much data as the header indicates it should. The routine also ensures 1053 * that the entire message header is stored in the main fragment of the message 1054 * buffer, to simplify future access to message header fields. 1055 * 1056 * Note: Having extra info present in the message header or data areas is OK. 1057 * TIPC will ignore the excess, under the assumption that it is optional info 1058 * introduced by a later release of the protocol. 1059 */ 1060 static int link_recv_buf_validate(struct sk_buff *buf) 1061 { 1062 static u32 min_data_hdr_size[8] = { 1063 SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE, 1064 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE 1065 }; 1066 1067 struct tipc_msg *msg; 1068 u32 tipc_hdr[2]; 1069 u32 size; 1070 u32 hdr_size; 1071 u32 min_hdr_size; 1072 1073 /* If this packet comes from the defer queue, the skb has already 1074 * been validated 1075 */ 1076 if (unlikely(TIPC_SKB_CB(buf)->deferred)) 1077 return 1; 1078 1079 if (unlikely(buf->len < MIN_H_SIZE)) 1080 return 0; 1081 1082 msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr); 1083 if (msg == NULL) 1084 return 0; 1085 1086 if (unlikely(msg_version(msg) != TIPC_VERSION)) 1087 return 0; 1088 1089 size = msg_size(msg); 1090 hdr_size = msg_hdr_sz(msg); 1091 min_hdr_size = msg_isdata(msg) ? 1092 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE; 1093 1094 if (unlikely((hdr_size < min_hdr_size) || 1095 (size < hdr_size) || 1096 (buf->len < size) || 1097 (size - hdr_size > TIPC_MAX_USER_MSG_SIZE))) 1098 return 0; 1099 1100 return pskb_may_pull(buf, hdr_size); 1101 } 1102 1103 /** 1104 * tipc_rcv - process TIPC packets/messages arriving from off-node 1105 * @net: the applicable net namespace 1106 * @skb: TIPC packet 1107 * @b_ptr: pointer to bearer message arrived on 1108 * 1109 * Invoked with no locks held. Bearer pointer must point to a valid bearer 1110 * structure (i.e. cannot be NULL), but bearer can be inactive. 1111 */ 1112 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr) 1113 { 1114 struct tipc_net *tn = net_generic(net, tipc_net_id); 1115 struct sk_buff_head head; 1116 struct tipc_node *n_ptr; 1117 struct tipc_link *l_ptr; 1118 struct sk_buff *skb1, *tmp; 1119 struct tipc_msg *msg; 1120 u32 seq_no; 1121 u32 ackd; 1122 u32 released; 1123 1124 skb2list(skb, &head); 1125 1126 while ((skb = __skb_dequeue(&head))) { 1127 /* Ensure message is well-formed */ 1128 if (unlikely(!link_recv_buf_validate(skb))) 1129 goto discard; 1130 1131 /* Ensure message data is a single contiguous unit */ 1132 if (unlikely(skb_linearize(skb))) 1133 goto discard; 1134 1135 /* Handle arrival of a non-unicast link message */ 1136 msg = buf_msg(skb); 1137 1138 if (unlikely(msg_non_seq(msg))) { 1139 if (msg_user(msg) == LINK_CONFIG) 1140 tipc_disc_rcv(net, skb, b_ptr); 1141 else 1142 tipc_bclink_rcv(net, skb); 1143 continue; 1144 } 1145 1146 /* Discard unicast link messages destined for another node */ 1147 if (unlikely(!msg_short(msg) && 1148 (msg_destnode(msg) != tn->own_addr))) 1149 goto discard; 1150 1151 /* Locate neighboring node that sent message */ 1152 n_ptr = tipc_node_find(net, msg_prevnode(msg)); 1153 if (unlikely(!n_ptr)) 1154 goto discard; 1155 tipc_node_lock(n_ptr); 1156 1157 /* Locate unicast link endpoint that should handle message */ 1158 l_ptr = n_ptr->links[b_ptr->identity]; 1159 if (unlikely(!l_ptr)) 1160 goto unlock; 1161 1162 /* Verify that communication with node is currently allowed */ 1163 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) && 1164 msg_user(msg) == LINK_PROTOCOL && 1165 (msg_type(msg) == RESET_MSG || 1166 msg_type(msg) == ACTIVATE_MSG) && 1167 !msg_redundant_link(msg)) 1168 n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN; 1169 1170 if (tipc_node_blocked(n_ptr)) 1171 goto unlock; 1172 1173 /* Validate message sequence number info */ 1174 seq_no = msg_seqno(msg); 1175 ackd = msg_ack(msg); 1176 1177 /* Release acked messages */ 1178 if (n_ptr->bclink.recv_permitted) 1179 tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg)); 1180 1181 released = 0; 1182 skb_queue_walk_safe(&l_ptr->outqueue, skb1, tmp) { 1183 if (skb1 == l_ptr->next_out || 1184 more(buf_seqno(skb1), ackd)) 1185 break; 1186 __skb_unlink(skb1, &l_ptr->outqueue); 1187 kfree_skb(skb1); 1188 released = 1; 1189 } 1190 1191 /* Try sending any messages link endpoint has pending */ 1192 if (unlikely(l_ptr->next_out)) 1193 tipc_link_push_packets(l_ptr); 1194 1195 if (released && !skb_queue_empty(&l_ptr->wakeupq)) 1196 link_prepare_wakeup(l_ptr); 1197 1198 /* Process the incoming packet */ 1199 if (unlikely(!link_working_working(l_ptr))) { 1200 if (msg_user(msg) == LINK_PROTOCOL) { 1201 tipc_link_proto_rcv(l_ptr, skb); 1202 link_retrieve_defq(l_ptr, &head); 1203 skb = NULL; 1204 goto unlock; 1205 } 1206 1207 /* Traffic message. Conditionally activate link */ 1208 link_state_event(l_ptr, TRAFFIC_MSG_EVT); 1209 1210 if (link_working_working(l_ptr)) { 1211 /* Re-insert buffer in front of queue */ 1212 __skb_queue_head(&head, skb); 1213 skb = NULL; 1214 goto unlock; 1215 } 1216 goto unlock; 1217 } 1218 1219 /* Link is now in state WORKING_WORKING */ 1220 if (unlikely(seq_no != mod(l_ptr->next_in_no))) { 1221 link_handle_out_of_seq_msg(l_ptr, skb); 1222 link_retrieve_defq(l_ptr, &head); 1223 skb = NULL; 1224 goto unlock; 1225 } 1226 l_ptr->next_in_no++; 1227 if (unlikely(!skb_queue_empty(&l_ptr->deferred_queue))) 1228 link_retrieve_defq(l_ptr, &head); 1229 1230 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) { 1231 l_ptr->stats.sent_acks++; 1232 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0); 1233 } 1234 tipc_link_input(l_ptr, skb); 1235 skb = NULL; 1236 unlock: 1237 tipc_node_unlock(n_ptr); 1238 discard: 1239 if (unlikely(skb)) 1240 kfree_skb(skb); 1241 } 1242 } 1243 1244 /* tipc_data_input - deliver data and name distr msgs to upper layer 1245 * 1246 * Consumes buffer if message is of right type 1247 * Node lock must be held 1248 */ 1249 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb) 1250 { 1251 struct tipc_node *node = link->owner; 1252 struct tipc_msg *msg = buf_msg(skb); 1253 u32 dport = msg_destport(msg); 1254 1255 switch (msg_user(msg)) { 1256 case TIPC_LOW_IMPORTANCE: 1257 case TIPC_MEDIUM_IMPORTANCE: 1258 case TIPC_HIGH_IMPORTANCE: 1259 case TIPC_CRITICAL_IMPORTANCE: 1260 case CONN_MANAGER: 1261 if (tipc_skb_queue_tail(&link->inputq, skb, dport)) { 1262 node->inputq = &link->inputq; 1263 node->action_flags |= TIPC_MSG_EVT; 1264 } 1265 return true; 1266 case NAME_DISTRIBUTOR: 1267 node->bclink.recv_permitted = true; 1268 node->namedq = &link->namedq; 1269 skb_queue_tail(&link->namedq, skb); 1270 if (skb_queue_len(&link->namedq) == 1) 1271 node->action_flags |= TIPC_NAMED_MSG_EVT; 1272 return true; 1273 case MSG_BUNDLER: 1274 case CHANGEOVER_PROTOCOL: 1275 case MSG_FRAGMENTER: 1276 case BCAST_PROTOCOL: 1277 return false; 1278 default: 1279 pr_warn("Dropping received illegal msg type\n"); 1280 kfree_skb(skb); 1281 return false; 1282 }; 1283 } 1284 1285 /* tipc_link_input - process packet that has passed link protocol check 1286 * 1287 * Consumes buffer 1288 * Node lock must be held 1289 */ 1290 static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb) 1291 { 1292 struct tipc_node *node = link->owner; 1293 struct tipc_msg *msg = buf_msg(skb); 1294 struct sk_buff *iskb; 1295 int pos = 0; 1296 1297 if (likely(tipc_data_input(link, skb))) 1298 return; 1299 1300 switch (msg_user(msg)) { 1301 case CHANGEOVER_PROTOCOL: 1302 if (!tipc_link_tunnel_rcv(node, &skb)) 1303 break; 1304 if (msg_user(buf_msg(skb)) != MSG_BUNDLER) { 1305 tipc_data_input(link, skb); 1306 break; 1307 } 1308 case MSG_BUNDLER: 1309 link->stats.recv_bundles++; 1310 link->stats.recv_bundled += msg_msgcnt(msg); 1311 1312 while (tipc_msg_extract(skb, &iskb, &pos)) 1313 tipc_data_input(link, iskb); 1314 break; 1315 case MSG_FRAGMENTER: 1316 link->stats.recv_fragments++; 1317 if (tipc_buf_append(&link->reasm_buf, &skb)) { 1318 link->stats.recv_fragmented++; 1319 tipc_data_input(link, skb); 1320 } else if (!link->reasm_buf) { 1321 tipc_link_reset(link); 1322 } 1323 break; 1324 case BCAST_PROTOCOL: 1325 tipc_link_sync_rcv(node, skb); 1326 break; 1327 default: 1328 break; 1329 }; 1330 } 1331 1332 /** 1333 * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue 1334 * 1335 * Returns increase in queue length (i.e. 0 or 1) 1336 */ 1337 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb) 1338 { 1339 struct sk_buff *skb1; 1340 u32 seq_no = buf_seqno(skb); 1341 1342 /* Empty queue ? */ 1343 if (skb_queue_empty(list)) { 1344 __skb_queue_tail(list, skb); 1345 return 1; 1346 } 1347 1348 /* Last ? */ 1349 if (less(buf_seqno(skb_peek_tail(list)), seq_no)) { 1350 __skb_queue_tail(list, skb); 1351 return 1; 1352 } 1353 1354 /* Locate insertion point in queue, then insert; discard if duplicate */ 1355 skb_queue_walk(list, skb1) { 1356 u32 curr_seqno = buf_seqno(skb1); 1357 1358 if (seq_no == curr_seqno) { 1359 kfree_skb(skb); 1360 return 0; 1361 } 1362 1363 if (less(seq_no, curr_seqno)) 1364 break; 1365 } 1366 1367 __skb_queue_before(list, skb1, skb); 1368 return 1; 1369 } 1370 1371 /* 1372 * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet 1373 */ 1374 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr, 1375 struct sk_buff *buf) 1376 { 1377 u32 seq_no = buf_seqno(buf); 1378 1379 if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) { 1380 tipc_link_proto_rcv(l_ptr, buf); 1381 return; 1382 } 1383 1384 /* Record OOS packet arrival (force mismatch on next timeout) */ 1385 l_ptr->checkpoint--; 1386 1387 /* 1388 * Discard packet if a duplicate; otherwise add it to deferred queue 1389 * and notify peer of gap as per protocol specification 1390 */ 1391 if (less(seq_no, mod(l_ptr->next_in_no))) { 1392 l_ptr->stats.duplicates++; 1393 kfree_skb(buf); 1394 return; 1395 } 1396 1397 if (tipc_link_defer_pkt(&l_ptr->deferred_queue, buf)) { 1398 l_ptr->stats.deferred_recv++; 1399 TIPC_SKB_CB(buf)->deferred = true; 1400 if ((skb_queue_len(&l_ptr->deferred_queue) % 16) == 1) 1401 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0); 1402 } else { 1403 l_ptr->stats.duplicates++; 1404 } 1405 } 1406 1407 /* 1408 * Send protocol message to the other endpoint. 1409 */ 1410 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg, 1411 u32 gap, u32 tolerance, u32 priority, u32 ack_mtu) 1412 { 1413 struct sk_buff *buf = NULL; 1414 struct tipc_msg *msg = l_ptr->pmsg; 1415 u32 msg_size = sizeof(l_ptr->proto_msg); 1416 int r_flag; 1417 1418 /* Don't send protocol message during link changeover */ 1419 if (l_ptr->exp_msg_count) 1420 return; 1421 1422 /* Abort non-RESET send if communication with node is prohibited */ 1423 if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG)) 1424 return; 1425 1426 /* Create protocol message with "out-of-sequence" sequence number */ 1427 msg_set_type(msg, msg_typ); 1428 msg_set_net_plane(msg, l_ptr->net_plane); 1429 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); 1430 msg_set_last_bcast(msg, tipc_bclink_get_last_sent(l_ptr->owner->net)); 1431 1432 if (msg_typ == STATE_MSG) { 1433 u32 next_sent = mod(l_ptr->next_out_no); 1434 1435 if (!tipc_link_is_up(l_ptr)) 1436 return; 1437 if (l_ptr->next_out) 1438 next_sent = buf_seqno(l_ptr->next_out); 1439 msg_set_next_sent(msg, next_sent); 1440 if (!skb_queue_empty(&l_ptr->deferred_queue)) { 1441 u32 rec = buf_seqno(skb_peek(&l_ptr->deferred_queue)); 1442 gap = mod(rec - mod(l_ptr->next_in_no)); 1443 } 1444 msg_set_seq_gap(msg, gap); 1445 if (gap) 1446 l_ptr->stats.sent_nacks++; 1447 msg_set_link_tolerance(msg, tolerance); 1448 msg_set_linkprio(msg, priority); 1449 msg_set_max_pkt(msg, ack_mtu); 1450 msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); 1451 msg_set_probe(msg, probe_msg != 0); 1452 if (probe_msg) { 1453 u32 mtu = l_ptr->max_pkt; 1454 1455 if ((mtu < l_ptr->max_pkt_target) && 1456 link_working_working(l_ptr) && 1457 l_ptr->fsm_msg_cnt) { 1458 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3; 1459 if (l_ptr->max_pkt_probes == 10) { 1460 l_ptr->max_pkt_target = (msg_size - 4); 1461 l_ptr->max_pkt_probes = 0; 1462 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3; 1463 } 1464 l_ptr->max_pkt_probes++; 1465 } 1466 1467 l_ptr->stats.sent_probes++; 1468 } 1469 l_ptr->stats.sent_states++; 1470 } else { /* RESET_MSG or ACTIVATE_MSG */ 1471 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1)); 1472 msg_set_seq_gap(msg, 0); 1473 msg_set_next_sent(msg, 1); 1474 msg_set_probe(msg, 0); 1475 msg_set_link_tolerance(msg, l_ptr->tolerance); 1476 msg_set_linkprio(msg, l_ptr->priority); 1477 msg_set_max_pkt(msg, l_ptr->max_pkt_target); 1478 } 1479 1480 r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr)); 1481 msg_set_redundant_link(msg, r_flag); 1482 msg_set_linkprio(msg, l_ptr->priority); 1483 msg_set_size(msg, msg_size); 1484 1485 msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2))); 1486 1487 buf = tipc_buf_acquire(msg_size); 1488 if (!buf) 1489 return; 1490 1491 skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg)); 1492 buf->priority = TC_PRIO_CONTROL; 1493 1494 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, buf, 1495 &l_ptr->media_addr); 1496 l_ptr->unacked_window = 0; 1497 kfree_skb(buf); 1498 } 1499 1500 /* 1501 * Receive protocol message : 1502 * Note that network plane id propagates through the network, and may 1503 * change at any time. The node with lowest address rules 1504 */ 1505 static void tipc_link_proto_rcv(struct tipc_link *l_ptr, 1506 struct sk_buff *buf) 1507 { 1508 u32 rec_gap = 0; 1509 u32 max_pkt_info; 1510 u32 max_pkt_ack; 1511 u32 msg_tol; 1512 struct tipc_msg *msg = buf_msg(buf); 1513 1514 /* Discard protocol message during link changeover */ 1515 if (l_ptr->exp_msg_count) 1516 goto exit; 1517 1518 if (l_ptr->net_plane != msg_net_plane(msg)) 1519 if (link_own_addr(l_ptr) > msg_prevnode(msg)) 1520 l_ptr->net_plane = msg_net_plane(msg); 1521 1522 switch (msg_type(msg)) { 1523 1524 case RESET_MSG: 1525 if (!link_working_unknown(l_ptr) && 1526 (l_ptr->peer_session != INVALID_SESSION)) { 1527 if (less_eq(msg_session(msg), l_ptr->peer_session)) 1528 break; /* duplicate or old reset: ignore */ 1529 } 1530 1531 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) || 1532 link_working_unknown(l_ptr))) { 1533 /* 1534 * peer has lost contact -- don't allow peer's links 1535 * to reactivate before we recognize loss & clean up 1536 */ 1537 l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN; 1538 } 1539 1540 link_state_event(l_ptr, RESET_MSG); 1541 1542 /* fall thru' */ 1543 case ACTIVATE_MSG: 1544 /* Update link settings according other endpoint's values */ 1545 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg)); 1546 1547 msg_tol = msg_link_tolerance(msg); 1548 if (msg_tol > l_ptr->tolerance) 1549 link_set_supervision_props(l_ptr, msg_tol); 1550 1551 if (msg_linkprio(msg) > l_ptr->priority) 1552 l_ptr->priority = msg_linkprio(msg); 1553 1554 max_pkt_info = msg_max_pkt(msg); 1555 if (max_pkt_info) { 1556 if (max_pkt_info < l_ptr->max_pkt_target) 1557 l_ptr->max_pkt_target = max_pkt_info; 1558 if (l_ptr->max_pkt > l_ptr->max_pkt_target) 1559 l_ptr->max_pkt = l_ptr->max_pkt_target; 1560 } else { 1561 l_ptr->max_pkt = l_ptr->max_pkt_target; 1562 } 1563 1564 /* Synchronize broadcast link info, if not done previously */ 1565 if (!tipc_node_is_up(l_ptr->owner)) { 1566 l_ptr->owner->bclink.last_sent = 1567 l_ptr->owner->bclink.last_in = 1568 msg_last_bcast(msg); 1569 l_ptr->owner->bclink.oos_state = 0; 1570 } 1571 1572 l_ptr->peer_session = msg_session(msg); 1573 l_ptr->peer_bearer_id = msg_bearer_id(msg); 1574 1575 if (msg_type(msg) == ACTIVATE_MSG) 1576 link_state_event(l_ptr, ACTIVATE_MSG); 1577 break; 1578 case STATE_MSG: 1579 1580 msg_tol = msg_link_tolerance(msg); 1581 if (msg_tol) 1582 link_set_supervision_props(l_ptr, msg_tol); 1583 1584 if (msg_linkprio(msg) && 1585 (msg_linkprio(msg) != l_ptr->priority)) { 1586 pr_debug("%s<%s>, priority change %u->%u\n", 1587 link_rst_msg, l_ptr->name, 1588 l_ptr->priority, msg_linkprio(msg)); 1589 l_ptr->priority = msg_linkprio(msg); 1590 tipc_link_reset(l_ptr); /* Enforce change to take effect */ 1591 break; 1592 } 1593 1594 /* Record reception; force mismatch at next timeout: */ 1595 l_ptr->checkpoint--; 1596 1597 link_state_event(l_ptr, TRAFFIC_MSG_EVT); 1598 l_ptr->stats.recv_states++; 1599 if (link_reset_unknown(l_ptr)) 1600 break; 1601 1602 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) { 1603 rec_gap = mod(msg_next_sent(msg) - 1604 mod(l_ptr->next_in_no)); 1605 } 1606 1607 max_pkt_ack = msg_max_pkt(msg); 1608 if (max_pkt_ack > l_ptr->max_pkt) { 1609 l_ptr->max_pkt = max_pkt_ack; 1610 l_ptr->max_pkt_probes = 0; 1611 } 1612 1613 max_pkt_ack = 0; 1614 if (msg_probe(msg)) { 1615 l_ptr->stats.recv_probes++; 1616 if (msg_size(msg) > sizeof(l_ptr->proto_msg)) 1617 max_pkt_ack = msg_size(msg); 1618 } 1619 1620 /* Protocol message before retransmits, reduce loss risk */ 1621 if (l_ptr->owner->bclink.recv_permitted) 1622 tipc_bclink_update_link_state(l_ptr->owner, 1623 msg_last_bcast(msg)); 1624 1625 if (rec_gap || (msg_probe(msg))) { 1626 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, rec_gap, 0, 1627 0, max_pkt_ack); 1628 } 1629 if (msg_seq_gap(msg)) { 1630 l_ptr->stats.recv_nacks++; 1631 tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->outqueue), 1632 msg_seq_gap(msg)); 1633 } 1634 break; 1635 } 1636 exit: 1637 kfree_skb(buf); 1638 } 1639 1640 1641 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to 1642 * a different bearer. Owner node is locked. 1643 */ 1644 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr, 1645 struct tipc_msg *tunnel_hdr, 1646 struct tipc_msg *msg, 1647 u32 selector) 1648 { 1649 struct tipc_link *tunnel; 1650 struct sk_buff *skb; 1651 u32 length = msg_size(msg); 1652 1653 tunnel = l_ptr->owner->active_links[selector & 1]; 1654 if (!tipc_link_is_up(tunnel)) { 1655 pr_warn("%stunnel link no longer available\n", link_co_err); 1656 return; 1657 } 1658 msg_set_size(tunnel_hdr, length + INT_H_SIZE); 1659 skb = tipc_buf_acquire(length + INT_H_SIZE); 1660 if (!skb) { 1661 pr_warn("%sunable to send tunnel msg\n", link_co_err); 1662 return; 1663 } 1664 skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE); 1665 skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length); 1666 __tipc_link_xmit_skb(tunnel, skb); 1667 } 1668 1669 1670 /* tipc_link_failover_send_queue(): A link has gone down, but a second 1671 * link is still active. We can do failover. Tunnel the failing link's 1672 * whole send queue via the remaining link. This way, we don't lose 1673 * any packets, and sequence order is preserved for subsequent traffic 1674 * sent over the remaining link. Owner node is locked. 1675 */ 1676 void tipc_link_failover_send_queue(struct tipc_link *l_ptr) 1677 { 1678 u32 msgcount = skb_queue_len(&l_ptr->outqueue); 1679 struct tipc_link *tunnel = l_ptr->owner->active_links[0]; 1680 struct tipc_msg tunnel_hdr; 1681 struct sk_buff *skb; 1682 int split_bundles; 1683 1684 if (!tunnel) 1685 return; 1686 1687 tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, CHANGEOVER_PROTOCOL, 1688 ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr); 1689 msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id); 1690 msg_set_msgcnt(&tunnel_hdr, msgcount); 1691 1692 if (skb_queue_empty(&l_ptr->outqueue)) { 1693 skb = tipc_buf_acquire(INT_H_SIZE); 1694 if (skb) { 1695 skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE); 1696 msg_set_size(&tunnel_hdr, INT_H_SIZE); 1697 __tipc_link_xmit_skb(tunnel, skb); 1698 } else { 1699 pr_warn("%sunable to send changeover msg\n", 1700 link_co_err); 1701 } 1702 return; 1703 } 1704 1705 split_bundles = (l_ptr->owner->active_links[0] != 1706 l_ptr->owner->active_links[1]); 1707 1708 skb_queue_walk(&l_ptr->outqueue, skb) { 1709 struct tipc_msg *msg = buf_msg(skb); 1710 1711 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) { 1712 struct tipc_msg *m = msg_get_wrapped(msg); 1713 unchar *pos = (unchar *)m; 1714 1715 msgcount = msg_msgcnt(msg); 1716 while (msgcount--) { 1717 msg_set_seqno(m, msg_seqno(msg)); 1718 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m, 1719 msg_link_selector(m)); 1720 pos += align(msg_size(m)); 1721 m = (struct tipc_msg *)pos; 1722 } 1723 } else { 1724 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg, 1725 msg_link_selector(msg)); 1726 } 1727 } 1728 } 1729 1730 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a 1731 * duplicate of the first link's send queue via the new link. This way, we 1732 * are guaranteed that currently queued packets from a socket are delivered 1733 * before future traffic from the same socket, even if this is using the 1734 * new link. The last arriving copy of each duplicate packet is dropped at 1735 * the receiving end by the regular protocol check, so packet cardinality 1736 * and sequence order is preserved per sender/receiver socket pair. 1737 * Owner node is locked. 1738 */ 1739 void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr, 1740 struct tipc_link *tunnel) 1741 { 1742 struct sk_buff *skb; 1743 struct tipc_msg tunnel_hdr; 1744 1745 tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, CHANGEOVER_PROTOCOL, 1746 DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr); 1747 msg_set_msgcnt(&tunnel_hdr, skb_queue_len(&l_ptr->outqueue)); 1748 msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id); 1749 skb_queue_walk(&l_ptr->outqueue, skb) { 1750 struct sk_buff *outskb; 1751 struct tipc_msg *msg = buf_msg(skb); 1752 u32 length = msg_size(msg); 1753 1754 if (msg_user(msg) == MSG_BUNDLER) 1755 msg_set_type(msg, CLOSED_MSG); 1756 msg_set_ack(msg, mod(l_ptr->next_in_no - 1)); /* Update */ 1757 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in); 1758 msg_set_size(&tunnel_hdr, length + INT_H_SIZE); 1759 outskb = tipc_buf_acquire(length + INT_H_SIZE); 1760 if (outskb == NULL) { 1761 pr_warn("%sunable to send duplicate msg\n", 1762 link_co_err); 1763 return; 1764 } 1765 skb_copy_to_linear_data(outskb, &tunnel_hdr, INT_H_SIZE); 1766 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE, skb->data, 1767 length); 1768 __tipc_link_xmit_skb(tunnel, outskb); 1769 if (!tipc_link_is_up(l_ptr)) 1770 return; 1771 } 1772 } 1773 1774 /** 1775 * buf_extract - extracts embedded TIPC message from another message 1776 * @skb: encapsulating message buffer 1777 * @from_pos: offset to extract from 1778 * 1779 * Returns a new message buffer containing an embedded message. The 1780 * encapsulating buffer is left unchanged. 1781 */ 1782 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos) 1783 { 1784 struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos); 1785 u32 size = msg_size(msg); 1786 struct sk_buff *eb; 1787 1788 eb = tipc_buf_acquire(size); 1789 if (eb) 1790 skb_copy_to_linear_data(eb, msg, size); 1791 return eb; 1792 } 1793 1794 /* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet. 1795 * Owner node is locked. 1796 */ 1797 static void tipc_link_dup_rcv(struct tipc_link *l_ptr, 1798 struct sk_buff *t_buf) 1799 { 1800 struct sk_buff *buf; 1801 1802 if (!tipc_link_is_up(l_ptr)) 1803 return; 1804 1805 buf = buf_extract(t_buf, INT_H_SIZE); 1806 if (buf == NULL) { 1807 pr_warn("%sfailed to extract inner dup pkt\n", link_co_err); 1808 return; 1809 } 1810 1811 /* Add buffer to deferred queue, if applicable: */ 1812 link_handle_out_of_seq_msg(l_ptr, buf); 1813 } 1814 1815 /* tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet 1816 * Owner node is locked. 1817 */ 1818 static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr, 1819 struct sk_buff *t_buf) 1820 { 1821 struct tipc_msg *t_msg = buf_msg(t_buf); 1822 struct sk_buff *buf = NULL; 1823 struct tipc_msg *msg; 1824 1825 if (tipc_link_is_up(l_ptr)) 1826 tipc_link_reset(l_ptr); 1827 1828 /* First failover packet? */ 1829 if (l_ptr->exp_msg_count == START_CHANGEOVER) 1830 l_ptr->exp_msg_count = msg_msgcnt(t_msg); 1831 1832 /* Should there be an inner packet? */ 1833 if (l_ptr->exp_msg_count) { 1834 l_ptr->exp_msg_count--; 1835 buf = buf_extract(t_buf, INT_H_SIZE); 1836 if (buf == NULL) { 1837 pr_warn("%sno inner failover pkt\n", link_co_err); 1838 goto exit; 1839 } 1840 msg = buf_msg(buf); 1841 1842 if (less(msg_seqno(msg), l_ptr->reset_checkpoint)) { 1843 kfree_skb(buf); 1844 buf = NULL; 1845 goto exit; 1846 } 1847 if (msg_user(msg) == MSG_FRAGMENTER) { 1848 l_ptr->stats.recv_fragments++; 1849 tipc_buf_append(&l_ptr->reasm_buf, &buf); 1850 } 1851 } 1852 exit: 1853 if ((!l_ptr->exp_msg_count) && (l_ptr->flags & LINK_STOPPED)) 1854 tipc_link_delete(l_ptr); 1855 return buf; 1856 } 1857 1858 /* tipc_link_tunnel_rcv(): Receive a tunnelled packet, sent 1859 * via other link as result of a failover (ORIGINAL_MSG) or 1860 * a new active link (DUPLICATE_MSG). Failover packets are 1861 * returned to the active link for delivery upwards. 1862 * Owner node is locked. 1863 */ 1864 static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr, 1865 struct sk_buff **buf) 1866 { 1867 struct sk_buff *t_buf = *buf; 1868 struct tipc_link *l_ptr; 1869 struct tipc_msg *t_msg = buf_msg(t_buf); 1870 u32 bearer_id = msg_bearer_id(t_msg); 1871 1872 *buf = NULL; 1873 1874 if (bearer_id >= MAX_BEARERS) 1875 goto exit; 1876 1877 l_ptr = n_ptr->links[bearer_id]; 1878 if (!l_ptr) 1879 goto exit; 1880 1881 if (msg_type(t_msg) == DUPLICATE_MSG) 1882 tipc_link_dup_rcv(l_ptr, t_buf); 1883 else if (msg_type(t_msg) == ORIGINAL_MSG) 1884 *buf = tipc_link_failover_rcv(l_ptr, t_buf); 1885 else 1886 pr_warn("%sunknown tunnel pkt received\n", link_co_err); 1887 exit: 1888 kfree_skb(t_buf); 1889 return *buf != NULL; 1890 } 1891 1892 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol) 1893 { 1894 unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4; 1895 1896 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL)) 1897 return; 1898 1899 l_ptr->tolerance = tol; 1900 l_ptr->cont_intv = msecs_to_jiffies(intv); 1901 l_ptr->abort_limit = tol / (jiffies_to_msecs(l_ptr->cont_intv) / 4); 1902 } 1903 1904 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window) 1905 { 1906 /* Data messages from this node, inclusive FIRST_FRAGM */ 1907 l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window; 1908 l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4; 1909 l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5; 1910 l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6; 1911 /* Transiting data messages,inclusive FIRST_FRAGM */ 1912 l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300; 1913 l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600; 1914 l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900; 1915 l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200; 1916 l_ptr->queue_limit[CONN_MANAGER] = 1200; 1917 l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500; 1918 l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000; 1919 /* FRAGMENT and LAST_FRAGMENT packets */ 1920 l_ptr->queue_limit[MSG_FRAGMENTER] = 4000; 1921 } 1922 1923 /* tipc_link_find_owner - locate owner node of link by link's name 1924 * @net: the applicable net namespace 1925 * @name: pointer to link name string 1926 * @bearer_id: pointer to index in 'node->links' array where the link was found. 1927 * 1928 * Returns pointer to node owning the link, or 0 if no matching link is found. 1929 */ 1930 static struct tipc_node *tipc_link_find_owner(struct net *net, 1931 const char *link_name, 1932 unsigned int *bearer_id) 1933 { 1934 struct tipc_net *tn = net_generic(net, tipc_net_id); 1935 struct tipc_link *l_ptr; 1936 struct tipc_node *n_ptr; 1937 struct tipc_node *found_node = NULL; 1938 int i; 1939 1940 *bearer_id = 0; 1941 rcu_read_lock(); 1942 list_for_each_entry_rcu(n_ptr, &tn->node_list, list) { 1943 tipc_node_lock(n_ptr); 1944 for (i = 0; i < MAX_BEARERS; i++) { 1945 l_ptr = n_ptr->links[i]; 1946 if (l_ptr && !strcmp(l_ptr->name, link_name)) { 1947 *bearer_id = i; 1948 found_node = n_ptr; 1949 break; 1950 } 1951 } 1952 tipc_node_unlock(n_ptr); 1953 if (found_node) 1954 break; 1955 } 1956 rcu_read_unlock(); 1957 1958 return found_node; 1959 } 1960 1961 /** 1962 * link_reset_statistics - reset link statistics 1963 * @l_ptr: pointer to link 1964 */ 1965 static void link_reset_statistics(struct tipc_link *l_ptr) 1966 { 1967 memset(&l_ptr->stats, 0, sizeof(l_ptr->stats)); 1968 l_ptr->stats.sent_info = l_ptr->next_out_no; 1969 l_ptr->stats.recv_info = l_ptr->next_in_no; 1970 } 1971 1972 static void link_print(struct tipc_link *l_ptr, const char *str) 1973 { 1974 struct tipc_net *tn = net_generic(l_ptr->owner->net, tipc_net_id); 1975 struct tipc_bearer *b_ptr; 1976 1977 rcu_read_lock(); 1978 b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]); 1979 if (b_ptr) 1980 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name); 1981 rcu_read_unlock(); 1982 1983 if (link_working_unknown(l_ptr)) 1984 pr_cont(":WU\n"); 1985 else if (link_reset_reset(l_ptr)) 1986 pr_cont(":RR\n"); 1987 else if (link_reset_unknown(l_ptr)) 1988 pr_cont(":RU\n"); 1989 else if (link_working_working(l_ptr)) 1990 pr_cont(":WW\n"); 1991 else 1992 pr_cont("\n"); 1993 } 1994 1995 /* Parse and validate nested (link) properties valid for media, bearer and link 1996 */ 1997 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]) 1998 { 1999 int err; 2000 2001 err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop, 2002 tipc_nl_prop_policy); 2003 if (err) 2004 return err; 2005 2006 if (props[TIPC_NLA_PROP_PRIO]) { 2007 u32 prio; 2008 2009 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]); 2010 if (prio > TIPC_MAX_LINK_PRI) 2011 return -EINVAL; 2012 } 2013 2014 if (props[TIPC_NLA_PROP_TOL]) { 2015 u32 tol; 2016 2017 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]); 2018 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL)) 2019 return -EINVAL; 2020 } 2021 2022 if (props[TIPC_NLA_PROP_WIN]) { 2023 u32 win; 2024 2025 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]); 2026 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN)) 2027 return -EINVAL; 2028 } 2029 2030 return 0; 2031 } 2032 2033 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info) 2034 { 2035 int err; 2036 int res = 0; 2037 int bearer_id; 2038 char *name; 2039 struct tipc_link *link; 2040 struct tipc_node *node; 2041 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1]; 2042 struct net *net = sock_net(skb->sk); 2043 2044 if (!info->attrs[TIPC_NLA_LINK]) 2045 return -EINVAL; 2046 2047 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX, 2048 info->attrs[TIPC_NLA_LINK], 2049 tipc_nl_link_policy); 2050 if (err) 2051 return err; 2052 2053 if (!attrs[TIPC_NLA_LINK_NAME]) 2054 return -EINVAL; 2055 2056 name = nla_data(attrs[TIPC_NLA_LINK_NAME]); 2057 2058 node = tipc_link_find_owner(net, name, &bearer_id); 2059 if (!node) 2060 return -EINVAL; 2061 2062 tipc_node_lock(node); 2063 2064 link = node->links[bearer_id]; 2065 if (!link) { 2066 res = -EINVAL; 2067 goto out; 2068 } 2069 2070 if (attrs[TIPC_NLA_LINK_PROP]) { 2071 struct nlattr *props[TIPC_NLA_PROP_MAX + 1]; 2072 2073 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], 2074 props); 2075 if (err) { 2076 res = err; 2077 goto out; 2078 } 2079 2080 if (props[TIPC_NLA_PROP_TOL]) { 2081 u32 tol; 2082 2083 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]); 2084 link_set_supervision_props(link, tol); 2085 tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0, 0); 2086 } 2087 if (props[TIPC_NLA_PROP_PRIO]) { 2088 u32 prio; 2089 2090 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]); 2091 link->priority = prio; 2092 tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio, 0); 2093 } 2094 if (props[TIPC_NLA_PROP_WIN]) { 2095 u32 win; 2096 2097 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]); 2098 tipc_link_set_queue_limits(link, win); 2099 } 2100 } 2101 2102 out: 2103 tipc_node_unlock(node); 2104 2105 return res; 2106 } 2107 2108 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s) 2109 { 2110 int i; 2111 struct nlattr *stats; 2112 2113 struct nla_map { 2114 u32 key; 2115 u32 val; 2116 }; 2117 2118 struct nla_map map[] = { 2119 {TIPC_NLA_STATS_RX_INFO, s->recv_info}, 2120 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments}, 2121 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented}, 2122 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles}, 2123 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled}, 2124 {TIPC_NLA_STATS_TX_INFO, s->sent_info}, 2125 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments}, 2126 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented}, 2127 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles}, 2128 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled}, 2129 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ? 2130 s->msg_length_counts : 1}, 2131 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts}, 2132 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total}, 2133 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]}, 2134 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]}, 2135 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]}, 2136 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]}, 2137 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]}, 2138 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]}, 2139 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]}, 2140 {TIPC_NLA_STATS_RX_STATES, s->recv_states}, 2141 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes}, 2142 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks}, 2143 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv}, 2144 {TIPC_NLA_STATS_TX_STATES, s->sent_states}, 2145 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes}, 2146 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks}, 2147 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks}, 2148 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted}, 2149 {TIPC_NLA_STATS_DUPLICATES, s->duplicates}, 2150 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs}, 2151 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz}, 2152 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ? 2153 (s->accu_queue_sz / s->queue_sz_counts) : 0} 2154 }; 2155 2156 stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS); 2157 if (!stats) 2158 return -EMSGSIZE; 2159 2160 for (i = 0; i < ARRAY_SIZE(map); i++) 2161 if (nla_put_u32(skb, map[i].key, map[i].val)) 2162 goto msg_full; 2163 2164 nla_nest_end(skb, stats); 2165 2166 return 0; 2167 msg_full: 2168 nla_nest_cancel(skb, stats); 2169 2170 return -EMSGSIZE; 2171 } 2172 2173 /* Caller should hold appropriate locks to protect the link */ 2174 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg, 2175 struct tipc_link *link) 2176 { 2177 int err; 2178 void *hdr; 2179 struct nlattr *attrs; 2180 struct nlattr *prop; 2181 struct tipc_net *tn = net_generic(net, tipc_net_id); 2182 2183 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, 2184 NLM_F_MULTI, TIPC_NL_LINK_GET); 2185 if (!hdr) 2186 return -EMSGSIZE; 2187 2188 attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK); 2189 if (!attrs) 2190 goto msg_full; 2191 2192 if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name)) 2193 goto attr_msg_full; 2194 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, 2195 tipc_cluster_mask(tn->own_addr))) 2196 goto attr_msg_full; 2197 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->max_pkt)) 2198 goto attr_msg_full; 2199 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->next_in_no)) 2200 goto attr_msg_full; 2201 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->next_out_no)) 2202 goto attr_msg_full; 2203 2204 if (tipc_link_is_up(link)) 2205 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP)) 2206 goto attr_msg_full; 2207 if (tipc_link_is_active(link)) 2208 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE)) 2209 goto attr_msg_full; 2210 2211 prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP); 2212 if (!prop) 2213 goto attr_msg_full; 2214 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority)) 2215 goto prop_msg_full; 2216 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance)) 2217 goto prop_msg_full; 2218 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, 2219 link->queue_limit[TIPC_LOW_IMPORTANCE])) 2220 goto prop_msg_full; 2221 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority)) 2222 goto prop_msg_full; 2223 nla_nest_end(msg->skb, prop); 2224 2225 err = __tipc_nl_add_stats(msg->skb, &link->stats); 2226 if (err) 2227 goto attr_msg_full; 2228 2229 nla_nest_end(msg->skb, attrs); 2230 genlmsg_end(msg->skb, hdr); 2231 2232 return 0; 2233 2234 prop_msg_full: 2235 nla_nest_cancel(msg->skb, prop); 2236 attr_msg_full: 2237 nla_nest_cancel(msg->skb, attrs); 2238 msg_full: 2239 genlmsg_cancel(msg->skb, hdr); 2240 2241 return -EMSGSIZE; 2242 } 2243 2244 /* Caller should hold node lock */ 2245 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg, 2246 struct tipc_node *node, u32 *prev_link) 2247 { 2248 u32 i; 2249 int err; 2250 2251 for (i = *prev_link; i < MAX_BEARERS; i++) { 2252 *prev_link = i; 2253 2254 if (!node->links[i]) 2255 continue; 2256 2257 err = __tipc_nl_add_link(net, msg, node->links[i]); 2258 if (err) 2259 return err; 2260 } 2261 *prev_link = 0; 2262 2263 return 0; 2264 } 2265 2266 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb) 2267 { 2268 struct net *net = sock_net(skb->sk); 2269 struct tipc_net *tn = net_generic(net, tipc_net_id); 2270 struct tipc_node *node; 2271 struct tipc_nl_msg msg; 2272 u32 prev_node = cb->args[0]; 2273 u32 prev_link = cb->args[1]; 2274 int done = cb->args[2]; 2275 int err; 2276 2277 if (done) 2278 return 0; 2279 2280 msg.skb = skb; 2281 msg.portid = NETLINK_CB(cb->skb).portid; 2282 msg.seq = cb->nlh->nlmsg_seq; 2283 2284 rcu_read_lock(); 2285 2286 if (prev_node) { 2287 node = tipc_node_find(net, prev_node); 2288 if (!node) { 2289 /* We never set seq or call nl_dump_check_consistent() 2290 * this means that setting prev_seq here will cause the 2291 * consistence check to fail in the netlink callback 2292 * handler. Resulting in the last NLMSG_DONE message 2293 * having the NLM_F_DUMP_INTR flag set. 2294 */ 2295 cb->prev_seq = 1; 2296 goto out; 2297 } 2298 2299 list_for_each_entry_continue_rcu(node, &tn->node_list, 2300 list) { 2301 tipc_node_lock(node); 2302 err = __tipc_nl_add_node_links(net, &msg, node, 2303 &prev_link); 2304 tipc_node_unlock(node); 2305 if (err) 2306 goto out; 2307 2308 prev_node = node->addr; 2309 } 2310 } else { 2311 err = tipc_nl_add_bc_link(net, &msg); 2312 if (err) 2313 goto out; 2314 2315 list_for_each_entry_rcu(node, &tn->node_list, list) { 2316 tipc_node_lock(node); 2317 err = __tipc_nl_add_node_links(net, &msg, node, 2318 &prev_link); 2319 tipc_node_unlock(node); 2320 if (err) 2321 goto out; 2322 2323 prev_node = node->addr; 2324 } 2325 } 2326 done = 1; 2327 out: 2328 rcu_read_unlock(); 2329 2330 cb->args[0] = prev_node; 2331 cb->args[1] = prev_link; 2332 cb->args[2] = done; 2333 2334 return skb->len; 2335 } 2336 2337 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info) 2338 { 2339 struct net *net = genl_info_net(info); 2340 struct sk_buff *ans_skb; 2341 struct tipc_nl_msg msg; 2342 struct tipc_link *link; 2343 struct tipc_node *node; 2344 char *name; 2345 int bearer_id; 2346 int err; 2347 2348 if (!info->attrs[TIPC_NLA_LINK_NAME]) 2349 return -EINVAL; 2350 2351 name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]); 2352 node = tipc_link_find_owner(net, name, &bearer_id); 2353 if (!node) 2354 return -EINVAL; 2355 2356 ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); 2357 if (!ans_skb) 2358 return -ENOMEM; 2359 2360 msg.skb = ans_skb; 2361 msg.portid = info->snd_portid; 2362 msg.seq = info->snd_seq; 2363 2364 tipc_node_lock(node); 2365 link = node->links[bearer_id]; 2366 if (!link) { 2367 err = -EINVAL; 2368 goto err_out; 2369 } 2370 2371 err = __tipc_nl_add_link(net, &msg, link); 2372 if (err) 2373 goto err_out; 2374 2375 tipc_node_unlock(node); 2376 2377 return genlmsg_reply(ans_skb, info); 2378 2379 err_out: 2380 tipc_node_unlock(node); 2381 nlmsg_free(ans_skb); 2382 2383 return err; 2384 } 2385 2386 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info) 2387 { 2388 int err; 2389 char *link_name; 2390 unsigned int bearer_id; 2391 struct tipc_link *link; 2392 struct tipc_node *node; 2393 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1]; 2394 struct net *net = sock_net(skb->sk); 2395 2396 if (!info->attrs[TIPC_NLA_LINK]) 2397 return -EINVAL; 2398 2399 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX, 2400 info->attrs[TIPC_NLA_LINK], 2401 tipc_nl_link_policy); 2402 if (err) 2403 return err; 2404 2405 if (!attrs[TIPC_NLA_LINK_NAME]) 2406 return -EINVAL; 2407 2408 link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]); 2409 2410 if (strcmp(link_name, tipc_bclink_name) == 0) { 2411 err = tipc_bclink_reset_stats(net); 2412 if (err) 2413 return err; 2414 return 0; 2415 } 2416 2417 node = tipc_link_find_owner(net, link_name, &bearer_id); 2418 if (!node) 2419 return -EINVAL; 2420 2421 tipc_node_lock(node); 2422 2423 link = node->links[bearer_id]; 2424 if (!link) { 2425 tipc_node_unlock(node); 2426 return -EINVAL; 2427 } 2428 2429 link_reset_statistics(link); 2430 2431 tipc_node_unlock(node); 2432 2433 return 0; 2434 } 2435