1 /* 2 * net/tipc/link.c: TIPC link code 3 * 4 * Copyright (c) 1996-2007, 2012-2015, 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 "subscr.h" 39 #include "link.h" 40 #include "bcast.h" 41 #include "socket.h" 42 #include "name_distr.h" 43 #include "discover.h" 44 #include "netlink.h" 45 46 #include <linux/pkt_sched.h> 47 48 /* 49 * Error message prefixes 50 */ 51 static const char *link_co_err = "Link tunneling error, "; 52 static const char *link_rst_msg = "Resetting link "; 53 static const char tipc_bclink_name[] = "broadcast-link"; 54 55 static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = { 56 [TIPC_NLA_LINK_UNSPEC] = { .type = NLA_UNSPEC }, 57 [TIPC_NLA_LINK_NAME] = { 58 .type = NLA_STRING, 59 .len = TIPC_MAX_LINK_NAME 60 }, 61 [TIPC_NLA_LINK_MTU] = { .type = NLA_U32 }, 62 [TIPC_NLA_LINK_BROADCAST] = { .type = NLA_FLAG }, 63 [TIPC_NLA_LINK_UP] = { .type = NLA_FLAG }, 64 [TIPC_NLA_LINK_ACTIVE] = { .type = NLA_FLAG }, 65 [TIPC_NLA_LINK_PROP] = { .type = NLA_NESTED }, 66 [TIPC_NLA_LINK_STATS] = { .type = NLA_NESTED }, 67 [TIPC_NLA_LINK_RX] = { .type = NLA_U32 }, 68 [TIPC_NLA_LINK_TX] = { .type = NLA_U32 } 69 }; 70 71 /* Properties valid for media, bearar and link */ 72 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = { 73 [TIPC_NLA_PROP_UNSPEC] = { .type = NLA_UNSPEC }, 74 [TIPC_NLA_PROP_PRIO] = { .type = NLA_U32 }, 75 [TIPC_NLA_PROP_TOL] = { .type = NLA_U32 }, 76 [TIPC_NLA_PROP_WIN] = { .type = NLA_U32 } 77 }; 78 79 /* Send states for broadcast NACKs 80 */ 81 enum { 82 BC_NACK_SND_CONDITIONAL, 83 BC_NACK_SND_UNCONDITIONAL, 84 BC_NACK_SND_SUPPRESS, 85 }; 86 87 /* 88 * Interval between NACKs when packets arrive out of order 89 */ 90 #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2) 91 /* 92 * Out-of-range value for link session numbers 93 */ 94 #define WILDCARD_SESSION 0x10000 95 96 /* Link FSM states: 97 */ 98 enum { 99 LINK_ESTABLISHED = 0xe, 100 LINK_ESTABLISHING = 0xe << 4, 101 LINK_RESET = 0x1 << 8, 102 LINK_RESETTING = 0x2 << 12, 103 LINK_PEER_RESET = 0xd << 16, 104 LINK_FAILINGOVER = 0xf << 20, 105 LINK_SYNCHING = 0xc << 24 106 }; 107 108 /* Link FSM state checking routines 109 */ 110 static int link_is_up(struct tipc_link *l) 111 { 112 return l->state & (LINK_ESTABLISHED | LINK_SYNCHING); 113 } 114 115 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb, 116 struct sk_buff_head *xmitq); 117 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe, 118 u16 rcvgap, int tolerance, int priority, 119 struct sk_buff_head *xmitq); 120 static void link_reset_statistics(struct tipc_link *l_ptr); 121 static void link_print(struct tipc_link *l_ptr, const char *str); 122 static void tipc_link_build_nack_msg(struct tipc_link *l, 123 struct sk_buff_head *xmitq); 124 static void tipc_link_build_bc_init_msg(struct tipc_link *l, 125 struct sk_buff_head *xmitq); 126 static bool tipc_link_release_pkts(struct tipc_link *l, u16 to); 127 128 /* 129 * Simple non-static link routines (i.e. referenced outside this file) 130 */ 131 bool tipc_link_is_up(struct tipc_link *l) 132 { 133 return link_is_up(l); 134 } 135 136 bool tipc_link_peer_is_down(struct tipc_link *l) 137 { 138 return l->state == LINK_PEER_RESET; 139 } 140 141 bool tipc_link_is_reset(struct tipc_link *l) 142 { 143 return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING); 144 } 145 146 bool tipc_link_is_establishing(struct tipc_link *l) 147 { 148 return l->state == LINK_ESTABLISHING; 149 } 150 151 bool tipc_link_is_synching(struct tipc_link *l) 152 { 153 return l->state == LINK_SYNCHING; 154 } 155 156 bool tipc_link_is_failingover(struct tipc_link *l) 157 { 158 return l->state == LINK_FAILINGOVER; 159 } 160 161 bool tipc_link_is_blocked(struct tipc_link *l) 162 { 163 return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER); 164 } 165 166 static bool link_is_bc_sndlink(struct tipc_link *l) 167 { 168 return !l->bc_sndlink; 169 } 170 171 static bool link_is_bc_rcvlink(struct tipc_link *l) 172 { 173 return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l)); 174 } 175 176 int tipc_link_is_active(struct tipc_link *l) 177 { 178 return l->active; 179 } 180 181 void tipc_link_set_active(struct tipc_link *l, bool active) 182 { 183 l->active = active; 184 } 185 186 void tipc_link_add_bc_peer(struct tipc_link *snd_l, 187 struct tipc_link *uc_l, 188 struct sk_buff_head *xmitq) 189 { 190 struct tipc_link *rcv_l = uc_l->bc_rcvlink; 191 192 snd_l->ackers++; 193 rcv_l->acked = snd_l->snd_nxt - 1; 194 tipc_link_build_bc_init_msg(uc_l, xmitq); 195 } 196 197 void tipc_link_remove_bc_peer(struct tipc_link *snd_l, 198 struct tipc_link *rcv_l, 199 struct sk_buff_head *xmitq) 200 { 201 u16 ack = snd_l->snd_nxt - 1; 202 203 snd_l->ackers--; 204 tipc_link_bc_ack_rcv(rcv_l, ack, xmitq); 205 tipc_link_reset(rcv_l); 206 rcv_l->state = LINK_RESET; 207 if (!snd_l->ackers) { 208 tipc_link_reset(snd_l); 209 __skb_queue_purge(xmitq); 210 } 211 } 212 213 int tipc_link_bc_peers(struct tipc_link *l) 214 { 215 return l->ackers; 216 } 217 218 void tipc_link_set_mtu(struct tipc_link *l, int mtu) 219 { 220 l->mtu = mtu; 221 } 222 223 int tipc_link_mtu(struct tipc_link *l) 224 { 225 return l->mtu; 226 } 227 228 static u32 link_own_addr(struct tipc_link *l) 229 { 230 return msg_prevnode(l->pmsg); 231 } 232 233 /** 234 * tipc_link_create - create a new link 235 * @n: pointer to associated node 236 * @if_name: associated interface name 237 * @bearer_id: id (index) of associated bearer 238 * @tolerance: link tolerance to be used by link 239 * @net_plane: network plane (A,B,c..) this link belongs to 240 * @mtu: mtu to be advertised by link 241 * @priority: priority to be used by link 242 * @window: send window to be used by link 243 * @session: session to be used by link 244 * @ownnode: identity of own node 245 * @peer: node id of peer node 246 * @peer_caps: bitmap describing peer node capabilities 247 * @bc_sndlink: the namespace global link used for broadcast sending 248 * @bc_rcvlink: the peer specific link used for broadcast reception 249 * @inputq: queue to put messages ready for delivery 250 * @namedq: queue to put binding table update messages ready for delivery 251 * @link: return value, pointer to put the created link 252 * 253 * Returns true if link was created, otherwise false 254 */ 255 bool tipc_link_create(struct net *net, char *if_name, int bearer_id, 256 int tolerance, char net_plane, u32 mtu, int priority, 257 int window, u32 session, u32 ownnode, u32 peer, 258 u16 peer_caps, 259 struct tipc_link *bc_sndlink, 260 struct tipc_link *bc_rcvlink, 261 struct sk_buff_head *inputq, 262 struct sk_buff_head *namedq, 263 struct tipc_link **link) 264 { 265 struct tipc_link *l; 266 struct tipc_msg *hdr; 267 268 l = kzalloc(sizeof(*l), GFP_ATOMIC); 269 if (!l) 270 return false; 271 *link = l; 272 l->pmsg = (struct tipc_msg *)&l->proto_msg; 273 hdr = l->pmsg; 274 tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer); 275 msg_set_size(hdr, sizeof(l->proto_msg)); 276 msg_set_session(hdr, session); 277 msg_set_bearer_id(hdr, l->bearer_id); 278 279 /* Note: peer i/f name is completed by reset/activate message */ 280 sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown", 281 tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode), 282 if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer)); 283 strcpy((char *)msg_data(hdr), if_name); 284 285 l->addr = peer; 286 l->peer_caps = peer_caps; 287 l->net = net; 288 l->peer_session = WILDCARD_SESSION; 289 l->bearer_id = bearer_id; 290 l->tolerance = tolerance; 291 l->net_plane = net_plane; 292 l->advertised_mtu = mtu; 293 l->mtu = mtu; 294 l->priority = priority; 295 tipc_link_set_queue_limits(l, window); 296 l->ackers = 1; 297 l->bc_sndlink = bc_sndlink; 298 l->bc_rcvlink = bc_rcvlink; 299 l->inputq = inputq; 300 l->namedq = namedq; 301 l->state = LINK_RESETTING; 302 __skb_queue_head_init(&l->transmq); 303 __skb_queue_head_init(&l->backlogq); 304 __skb_queue_head_init(&l->deferdq); 305 skb_queue_head_init(&l->wakeupq); 306 skb_queue_head_init(l->inputq); 307 return true; 308 } 309 310 /** 311 * tipc_link_bc_create - create new link to be used for broadcast 312 * @n: pointer to associated node 313 * @mtu: mtu to be used 314 * @window: send window to be used 315 * @inputq: queue to put messages ready for delivery 316 * @namedq: queue to put binding table update messages ready for delivery 317 * @link: return value, pointer to put the created link 318 * 319 * Returns true if link was created, otherwise false 320 */ 321 bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, 322 int mtu, int window, u16 peer_caps, 323 struct sk_buff_head *inputq, 324 struct sk_buff_head *namedq, 325 struct tipc_link *bc_sndlink, 326 struct tipc_link **link) 327 { 328 struct tipc_link *l; 329 330 if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window, 331 0, ownnode, peer, peer_caps, bc_sndlink, 332 NULL, inputq, namedq, link)) 333 return false; 334 335 l = *link; 336 strcpy(l->name, tipc_bclink_name); 337 tipc_link_reset(l); 338 l->state = LINK_RESET; 339 l->ackers = 0; 340 l->bc_rcvlink = l; 341 342 /* Broadcast send link is always up */ 343 if (link_is_bc_sndlink(l)) 344 l->state = LINK_ESTABLISHED; 345 346 return true; 347 } 348 349 /** 350 * tipc_link_fsm_evt - link finite state machine 351 * @l: pointer to link 352 * @evt: state machine event to be processed 353 */ 354 int tipc_link_fsm_evt(struct tipc_link *l, int evt) 355 { 356 int rc = 0; 357 358 switch (l->state) { 359 case LINK_RESETTING: 360 switch (evt) { 361 case LINK_PEER_RESET_EVT: 362 l->state = LINK_PEER_RESET; 363 break; 364 case LINK_RESET_EVT: 365 l->state = LINK_RESET; 366 break; 367 case LINK_FAILURE_EVT: 368 case LINK_FAILOVER_BEGIN_EVT: 369 case LINK_ESTABLISH_EVT: 370 case LINK_FAILOVER_END_EVT: 371 case LINK_SYNCH_BEGIN_EVT: 372 case LINK_SYNCH_END_EVT: 373 default: 374 goto illegal_evt; 375 } 376 break; 377 case LINK_RESET: 378 switch (evt) { 379 case LINK_PEER_RESET_EVT: 380 l->state = LINK_ESTABLISHING; 381 break; 382 case LINK_FAILOVER_BEGIN_EVT: 383 l->state = LINK_FAILINGOVER; 384 case LINK_FAILURE_EVT: 385 case LINK_RESET_EVT: 386 case LINK_ESTABLISH_EVT: 387 case LINK_FAILOVER_END_EVT: 388 break; 389 case LINK_SYNCH_BEGIN_EVT: 390 case LINK_SYNCH_END_EVT: 391 default: 392 goto illegal_evt; 393 } 394 break; 395 case LINK_PEER_RESET: 396 switch (evt) { 397 case LINK_RESET_EVT: 398 l->state = LINK_ESTABLISHING; 399 break; 400 case LINK_PEER_RESET_EVT: 401 case LINK_ESTABLISH_EVT: 402 case LINK_FAILURE_EVT: 403 break; 404 case LINK_SYNCH_BEGIN_EVT: 405 case LINK_SYNCH_END_EVT: 406 case LINK_FAILOVER_BEGIN_EVT: 407 case LINK_FAILOVER_END_EVT: 408 default: 409 goto illegal_evt; 410 } 411 break; 412 case LINK_FAILINGOVER: 413 switch (evt) { 414 case LINK_FAILOVER_END_EVT: 415 l->state = LINK_RESET; 416 break; 417 case LINK_PEER_RESET_EVT: 418 case LINK_RESET_EVT: 419 case LINK_ESTABLISH_EVT: 420 case LINK_FAILURE_EVT: 421 break; 422 case LINK_FAILOVER_BEGIN_EVT: 423 case LINK_SYNCH_BEGIN_EVT: 424 case LINK_SYNCH_END_EVT: 425 default: 426 goto illegal_evt; 427 } 428 break; 429 case LINK_ESTABLISHING: 430 switch (evt) { 431 case LINK_ESTABLISH_EVT: 432 l->state = LINK_ESTABLISHED; 433 break; 434 case LINK_FAILOVER_BEGIN_EVT: 435 l->state = LINK_FAILINGOVER; 436 break; 437 case LINK_RESET_EVT: 438 l->state = LINK_RESET; 439 break; 440 case LINK_FAILURE_EVT: 441 case LINK_PEER_RESET_EVT: 442 case LINK_SYNCH_BEGIN_EVT: 443 case LINK_FAILOVER_END_EVT: 444 break; 445 case LINK_SYNCH_END_EVT: 446 default: 447 goto illegal_evt; 448 } 449 break; 450 case LINK_ESTABLISHED: 451 switch (evt) { 452 case LINK_PEER_RESET_EVT: 453 l->state = LINK_PEER_RESET; 454 rc |= TIPC_LINK_DOWN_EVT; 455 break; 456 case LINK_FAILURE_EVT: 457 l->state = LINK_RESETTING; 458 rc |= TIPC_LINK_DOWN_EVT; 459 break; 460 case LINK_RESET_EVT: 461 l->state = LINK_RESET; 462 break; 463 case LINK_ESTABLISH_EVT: 464 case LINK_SYNCH_END_EVT: 465 break; 466 case LINK_SYNCH_BEGIN_EVT: 467 l->state = LINK_SYNCHING; 468 break; 469 case LINK_FAILOVER_BEGIN_EVT: 470 case LINK_FAILOVER_END_EVT: 471 default: 472 goto illegal_evt; 473 } 474 break; 475 case LINK_SYNCHING: 476 switch (evt) { 477 case LINK_PEER_RESET_EVT: 478 l->state = LINK_PEER_RESET; 479 rc |= TIPC_LINK_DOWN_EVT; 480 break; 481 case LINK_FAILURE_EVT: 482 l->state = LINK_RESETTING; 483 rc |= TIPC_LINK_DOWN_EVT; 484 break; 485 case LINK_RESET_EVT: 486 l->state = LINK_RESET; 487 break; 488 case LINK_ESTABLISH_EVT: 489 case LINK_SYNCH_BEGIN_EVT: 490 break; 491 case LINK_SYNCH_END_EVT: 492 l->state = LINK_ESTABLISHED; 493 break; 494 case LINK_FAILOVER_BEGIN_EVT: 495 case LINK_FAILOVER_END_EVT: 496 default: 497 goto illegal_evt; 498 } 499 break; 500 default: 501 pr_err("Unknown FSM state %x in %s\n", l->state, l->name); 502 } 503 return rc; 504 illegal_evt: 505 pr_err("Illegal FSM event %x in state %x on link %s\n", 506 evt, l->state, l->name); 507 return rc; 508 } 509 510 /* link_profile_stats - update statistical profiling of traffic 511 */ 512 static void link_profile_stats(struct tipc_link *l) 513 { 514 struct sk_buff *skb; 515 struct tipc_msg *msg; 516 int length; 517 518 /* Update counters used in statistical profiling of send traffic */ 519 l->stats.accu_queue_sz += skb_queue_len(&l->transmq); 520 l->stats.queue_sz_counts++; 521 522 skb = skb_peek(&l->transmq); 523 if (!skb) 524 return; 525 msg = buf_msg(skb); 526 length = msg_size(msg); 527 528 if (msg_user(msg) == MSG_FRAGMENTER) { 529 if (msg_type(msg) != FIRST_FRAGMENT) 530 return; 531 length = msg_size(msg_get_wrapped(msg)); 532 } 533 l->stats.msg_lengths_total += length; 534 l->stats.msg_length_counts++; 535 if (length <= 64) 536 l->stats.msg_length_profile[0]++; 537 else if (length <= 256) 538 l->stats.msg_length_profile[1]++; 539 else if (length <= 1024) 540 l->stats.msg_length_profile[2]++; 541 else if (length <= 4096) 542 l->stats.msg_length_profile[3]++; 543 else if (length <= 16384) 544 l->stats.msg_length_profile[4]++; 545 else if (length <= 32768) 546 l->stats.msg_length_profile[5]++; 547 else 548 l->stats.msg_length_profile[6]++; 549 } 550 551 /* tipc_link_timeout - perform periodic task as instructed from node timeout 552 */ 553 /* tipc_link_timeout - perform periodic task as instructed from node timeout 554 */ 555 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq) 556 { 557 int rc = 0; 558 int mtyp = STATE_MSG; 559 bool xmit = false; 560 bool prb = false; 561 u16 bc_snt = l->bc_sndlink->snd_nxt - 1; 562 u16 bc_acked = l->bc_rcvlink->acked; 563 bool bc_up = link_is_up(l->bc_rcvlink); 564 565 link_profile_stats(l); 566 567 switch (l->state) { 568 case LINK_ESTABLISHED: 569 case LINK_SYNCHING: 570 if (!l->silent_intv_cnt) { 571 if (bc_up && (bc_acked != bc_snt)) 572 xmit = true; 573 } else if (l->silent_intv_cnt <= l->abort_limit) { 574 xmit = true; 575 prb = true; 576 } else { 577 rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT); 578 } 579 l->silent_intv_cnt++; 580 break; 581 case LINK_RESET: 582 xmit = true; 583 mtyp = RESET_MSG; 584 break; 585 case LINK_ESTABLISHING: 586 xmit = true; 587 mtyp = ACTIVATE_MSG; 588 break; 589 case LINK_PEER_RESET: 590 case LINK_RESETTING: 591 case LINK_FAILINGOVER: 592 break; 593 default: 594 break; 595 } 596 597 if (xmit) 598 tipc_link_build_proto_msg(l, mtyp, prb, 0, 0, 0, xmitq); 599 600 return rc; 601 } 602 603 /** 604 * link_schedule_user - schedule a message sender for wakeup after congestion 605 * @link: congested link 606 * @list: message that was attempted sent 607 * Create pseudo msg to send back to user when congestion abates 608 * Does not consume buffer list 609 */ 610 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list) 611 { 612 struct tipc_msg *msg = buf_msg(skb_peek(list)); 613 int imp = msg_importance(msg); 614 u32 oport = msg_origport(msg); 615 u32 addr = link_own_addr(link); 616 struct sk_buff *skb; 617 618 /* This really cannot happen... */ 619 if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) { 620 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name); 621 return -ENOBUFS; 622 } 623 /* Non-blocking sender: */ 624 if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending) 625 return -ELINKCONG; 626 627 /* Create and schedule wakeup pseudo message */ 628 skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0, 629 addr, addr, oport, 0, 0); 630 if (!skb) 631 return -ENOBUFS; 632 TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list); 633 TIPC_SKB_CB(skb)->chain_imp = imp; 634 skb_queue_tail(&link->wakeupq, skb); 635 link->stats.link_congs++; 636 return -ELINKCONG; 637 } 638 639 /** 640 * link_prepare_wakeup - prepare users for wakeup after congestion 641 * @link: congested link 642 * Move a number of waiting users, as permitted by available space in 643 * the send queue, from link wait queue to node wait queue for wakeup 644 */ 645 void link_prepare_wakeup(struct tipc_link *l) 646 { 647 int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,}; 648 int imp, lim; 649 struct sk_buff *skb, *tmp; 650 651 skb_queue_walk_safe(&l->wakeupq, skb, tmp) { 652 imp = TIPC_SKB_CB(skb)->chain_imp; 653 lim = l->window + l->backlog[imp].limit; 654 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz; 655 if ((pnd[imp] + l->backlog[imp].len) >= lim) 656 break; 657 skb_unlink(skb, &l->wakeupq); 658 skb_queue_tail(l->inputq, skb); 659 } 660 } 661 662 void tipc_link_reset(struct tipc_link *l) 663 { 664 /* Link is down, accept any session */ 665 l->peer_session = WILDCARD_SESSION; 666 667 /* If peer is up, it only accepts an incremented session number */ 668 msg_set_session(l->pmsg, msg_session(l->pmsg) + 1); 669 670 /* Prepare for renewed mtu size negotiation */ 671 l->mtu = l->advertised_mtu; 672 673 /* Clean up all queues and counters: */ 674 __skb_queue_purge(&l->transmq); 675 __skb_queue_purge(&l->deferdq); 676 skb_queue_splice_init(&l->wakeupq, l->inputq); 677 __skb_queue_purge(&l->backlogq); 678 l->backlog[TIPC_LOW_IMPORTANCE].len = 0; 679 l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0; 680 l->backlog[TIPC_HIGH_IMPORTANCE].len = 0; 681 l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0; 682 l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0; 683 kfree_skb(l->reasm_buf); 684 kfree_skb(l->failover_reasm_skb); 685 l->reasm_buf = NULL; 686 l->failover_reasm_skb = NULL; 687 l->rcv_unacked = 0; 688 l->snd_nxt = 1; 689 l->rcv_nxt = 1; 690 l->acked = 0; 691 l->silent_intv_cnt = 0; 692 l->stats.recv_info = 0; 693 l->stale_count = 0; 694 l->bc_peer_is_up = false; 695 link_reset_statistics(l); 696 } 697 698 /** 699 * tipc_link_xmit(): enqueue buffer list according to queue situation 700 * @link: link to use 701 * @list: chain of buffers containing message 702 * @xmitq: returned list of packets to be sent by caller 703 * 704 * Consumes the buffer chain, except when returning -ELINKCONG, 705 * since the caller then may want to make more send attempts. 706 * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS 707 * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted 708 */ 709 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list, 710 struct sk_buff_head *xmitq) 711 { 712 struct tipc_msg *hdr = buf_msg(skb_peek(list)); 713 unsigned int maxwin = l->window; 714 unsigned int i, imp = msg_importance(hdr); 715 unsigned int mtu = l->mtu; 716 u16 ack = l->rcv_nxt - 1; 717 u16 seqno = l->snd_nxt; 718 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1; 719 struct sk_buff_head *transmq = &l->transmq; 720 struct sk_buff_head *backlogq = &l->backlogq; 721 struct sk_buff *skb, *_skb, *bskb; 722 723 /* Match msg importance against this and all higher backlog limits: */ 724 for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) { 725 if (unlikely(l->backlog[i].len >= l->backlog[i].limit)) 726 return link_schedule_user(l, list); 727 } 728 if (unlikely(msg_size(hdr) > mtu)) 729 return -EMSGSIZE; 730 731 /* Prepare each packet for sending, and add to relevant queue: */ 732 while (skb_queue_len(list)) { 733 skb = skb_peek(list); 734 hdr = buf_msg(skb); 735 msg_set_seqno(hdr, seqno); 736 msg_set_ack(hdr, ack); 737 msg_set_bcast_ack(hdr, bc_ack); 738 739 if (likely(skb_queue_len(transmq) < maxwin)) { 740 _skb = skb_clone(skb, GFP_ATOMIC); 741 if (!_skb) 742 return -ENOBUFS; 743 __skb_dequeue(list); 744 __skb_queue_tail(transmq, skb); 745 __skb_queue_tail(xmitq, _skb); 746 TIPC_SKB_CB(skb)->ackers = l->ackers; 747 l->rcv_unacked = 0; 748 seqno++; 749 continue; 750 } 751 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) { 752 kfree_skb(__skb_dequeue(list)); 753 l->stats.sent_bundled++; 754 continue; 755 } 756 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) { 757 kfree_skb(__skb_dequeue(list)); 758 __skb_queue_tail(backlogq, bskb); 759 l->backlog[msg_importance(buf_msg(bskb))].len++; 760 l->stats.sent_bundled++; 761 l->stats.sent_bundles++; 762 continue; 763 } 764 l->backlog[imp].len += skb_queue_len(list); 765 skb_queue_splice_tail_init(list, backlogq); 766 } 767 l->snd_nxt = seqno; 768 return 0; 769 } 770 771 void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq) 772 { 773 struct sk_buff *skb, *_skb; 774 struct tipc_msg *hdr; 775 u16 seqno = l->snd_nxt; 776 u16 ack = l->rcv_nxt - 1; 777 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1; 778 779 while (skb_queue_len(&l->transmq) < l->window) { 780 skb = skb_peek(&l->backlogq); 781 if (!skb) 782 break; 783 _skb = skb_clone(skb, GFP_ATOMIC); 784 if (!_skb) 785 break; 786 __skb_dequeue(&l->backlogq); 787 hdr = buf_msg(skb); 788 l->backlog[msg_importance(hdr)].len--; 789 __skb_queue_tail(&l->transmq, skb); 790 __skb_queue_tail(xmitq, _skb); 791 TIPC_SKB_CB(skb)->ackers = l->ackers; 792 msg_set_seqno(hdr, seqno); 793 msg_set_ack(hdr, ack); 794 msg_set_bcast_ack(hdr, bc_ack); 795 l->rcv_unacked = 0; 796 seqno++; 797 } 798 l->snd_nxt = seqno; 799 } 800 801 static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb) 802 { 803 struct tipc_msg *hdr = buf_msg(skb); 804 805 pr_warn("Retransmission failure on link <%s>\n", l->name); 806 link_print(l, "Resetting link "); 807 pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n", 808 msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr)); 809 pr_info("sqno %u, prev: %x, src: %x\n", 810 msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr)); 811 } 812 813 int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to, 814 struct sk_buff_head *xmitq) 815 { 816 struct sk_buff *_skb, *skb = skb_peek(&l->transmq); 817 struct tipc_msg *hdr; 818 u16 ack = l->rcv_nxt - 1; 819 u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1; 820 821 if (!skb) 822 return 0; 823 824 /* Detect repeated retransmit failures on same packet */ 825 if (likely(l->last_retransm != buf_seqno(skb))) { 826 l->last_retransm = buf_seqno(skb); 827 l->stale_count = 1; 828 } else if (++l->stale_count > 100) { 829 link_retransmit_failure(l, skb); 830 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT); 831 } 832 833 /* Move forward to where retransmission should start */ 834 skb_queue_walk(&l->transmq, skb) { 835 if (!less(buf_seqno(skb), from)) 836 break; 837 } 838 839 skb_queue_walk_from(&l->transmq, skb) { 840 if (more(buf_seqno(skb), to)) 841 break; 842 hdr = buf_msg(skb); 843 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC); 844 if (!_skb) 845 return 0; 846 hdr = buf_msg(_skb); 847 msg_set_ack(hdr, ack); 848 msg_set_bcast_ack(hdr, bc_ack); 849 _skb->priority = TC_PRIO_CONTROL; 850 __skb_queue_tail(xmitq, _skb); 851 l->stats.retransmitted++; 852 } 853 return 0; 854 } 855 856 /* tipc_data_input - deliver data and name distr msgs to upper layer 857 * 858 * Consumes buffer if message is of right type 859 * Node lock must be held 860 */ 861 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb, 862 struct sk_buff_head *inputq) 863 { 864 switch (msg_user(buf_msg(skb))) { 865 case TIPC_LOW_IMPORTANCE: 866 case TIPC_MEDIUM_IMPORTANCE: 867 case TIPC_HIGH_IMPORTANCE: 868 case TIPC_CRITICAL_IMPORTANCE: 869 case CONN_MANAGER: 870 skb_queue_tail(inputq, skb); 871 return true; 872 case NAME_DISTRIBUTOR: 873 l->bc_rcvlink->state = LINK_ESTABLISHED; 874 skb_queue_tail(l->namedq, skb); 875 return true; 876 case MSG_BUNDLER: 877 case TUNNEL_PROTOCOL: 878 case MSG_FRAGMENTER: 879 case BCAST_PROTOCOL: 880 return false; 881 default: 882 pr_warn("Dropping received illegal msg type\n"); 883 kfree_skb(skb); 884 return false; 885 }; 886 } 887 888 /* tipc_link_input - process packet that has passed link protocol check 889 * 890 * Consumes buffer 891 */ 892 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb, 893 struct sk_buff_head *inputq) 894 { 895 struct tipc_msg *hdr = buf_msg(skb); 896 struct sk_buff **reasm_skb = &l->reasm_buf; 897 struct sk_buff *iskb; 898 struct sk_buff_head tmpq; 899 int usr = msg_user(hdr); 900 int rc = 0; 901 int pos = 0; 902 int ipos = 0; 903 904 if (unlikely(usr == TUNNEL_PROTOCOL)) { 905 if (msg_type(hdr) == SYNCH_MSG) { 906 __skb_queue_purge(&l->deferdq); 907 goto drop; 908 } 909 if (!tipc_msg_extract(skb, &iskb, &ipos)) 910 return rc; 911 kfree_skb(skb); 912 skb = iskb; 913 hdr = buf_msg(skb); 914 if (less(msg_seqno(hdr), l->drop_point)) 915 goto drop; 916 if (tipc_data_input(l, skb, inputq)) 917 return rc; 918 usr = msg_user(hdr); 919 reasm_skb = &l->failover_reasm_skb; 920 } 921 922 if (usr == MSG_BUNDLER) { 923 skb_queue_head_init(&tmpq); 924 l->stats.recv_bundles++; 925 l->stats.recv_bundled += msg_msgcnt(hdr); 926 while (tipc_msg_extract(skb, &iskb, &pos)) 927 tipc_data_input(l, iskb, &tmpq); 928 tipc_skb_queue_splice_tail(&tmpq, inputq); 929 return 0; 930 } else if (usr == MSG_FRAGMENTER) { 931 l->stats.recv_fragments++; 932 if (tipc_buf_append(reasm_skb, &skb)) { 933 l->stats.recv_fragmented++; 934 tipc_data_input(l, skb, inputq); 935 } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) { 936 pr_warn_ratelimited("Unable to build fragment list\n"); 937 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT); 938 } 939 return 0; 940 } else if (usr == BCAST_PROTOCOL) { 941 tipc_bcast_lock(l->net); 942 tipc_link_bc_init_rcv(l->bc_rcvlink, hdr); 943 tipc_bcast_unlock(l->net); 944 } 945 drop: 946 kfree_skb(skb); 947 return 0; 948 } 949 950 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked) 951 { 952 bool released = false; 953 struct sk_buff *skb, *tmp; 954 955 skb_queue_walk_safe(&l->transmq, skb, tmp) { 956 if (more(buf_seqno(skb), acked)) 957 break; 958 __skb_unlink(skb, &l->transmq); 959 kfree_skb(skb); 960 released = true; 961 } 962 return released; 963 } 964 965 /* tipc_link_build_ack_msg: prepare link acknowledge message for transmission 966 * 967 * Note that sending of broadcast ack is coordinated among nodes, to reduce 968 * risk of ack storms towards the sender 969 */ 970 int tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq) 971 { 972 if (!l) 973 return 0; 974 975 /* Broadcast ACK must be sent via a unicast link => defer to caller */ 976 if (link_is_bc_rcvlink(l)) { 977 if (((l->rcv_nxt ^ link_own_addr(l)) & 0xf) != 0xf) 978 return 0; 979 l->rcv_unacked = 0; 980 return TIPC_LINK_SND_BC_ACK; 981 } 982 983 /* Unicast ACK */ 984 l->rcv_unacked = 0; 985 l->stats.sent_acks++; 986 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq); 987 return 0; 988 } 989 990 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message 991 */ 992 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq) 993 { 994 int mtyp = RESET_MSG; 995 996 if (l->state == LINK_ESTABLISHING) 997 mtyp = ACTIVATE_MSG; 998 999 tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq); 1000 } 1001 1002 /* tipc_link_build_nack_msg: prepare link nack message for transmission 1003 */ 1004 static void tipc_link_build_nack_msg(struct tipc_link *l, 1005 struct sk_buff_head *xmitq) 1006 { 1007 u32 def_cnt = ++l->stats.deferred_recv; 1008 1009 if (link_is_bc_rcvlink(l)) 1010 return; 1011 1012 if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV)) 1013 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq); 1014 } 1015 1016 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node 1017 * @l: the link that should handle the message 1018 * @skb: TIPC packet 1019 * @xmitq: queue to place packets to be sent after this call 1020 */ 1021 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb, 1022 struct sk_buff_head *xmitq) 1023 { 1024 struct sk_buff_head *defq = &l->deferdq; 1025 struct tipc_msg *hdr; 1026 u16 seqno, rcv_nxt, win_lim; 1027 int rc = 0; 1028 1029 do { 1030 hdr = buf_msg(skb); 1031 seqno = msg_seqno(hdr); 1032 rcv_nxt = l->rcv_nxt; 1033 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN; 1034 1035 /* Verify and update link state */ 1036 if (unlikely(msg_user(hdr) == LINK_PROTOCOL)) 1037 return tipc_link_proto_rcv(l, skb, xmitq); 1038 1039 if (unlikely(!link_is_up(l))) { 1040 if (l->state == LINK_ESTABLISHING) 1041 rc = TIPC_LINK_UP_EVT; 1042 goto drop; 1043 } 1044 1045 /* Don't send probe at next timeout expiration */ 1046 l->silent_intv_cnt = 0; 1047 1048 /* Drop if outside receive window */ 1049 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) { 1050 l->stats.duplicates++; 1051 goto drop; 1052 } 1053 1054 /* Forward queues and wake up waiting users */ 1055 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) { 1056 tipc_link_advance_backlog(l, xmitq); 1057 if (unlikely(!skb_queue_empty(&l->wakeupq))) 1058 link_prepare_wakeup(l); 1059 } 1060 1061 /* Defer delivery if sequence gap */ 1062 if (unlikely(seqno != rcv_nxt)) { 1063 __tipc_skb_queue_sorted(defq, seqno, skb); 1064 tipc_link_build_nack_msg(l, xmitq); 1065 break; 1066 } 1067 1068 /* Deliver packet */ 1069 l->rcv_nxt++; 1070 l->stats.recv_info++; 1071 if (!tipc_data_input(l, skb, l->inputq)) 1072 rc |= tipc_link_input(l, skb, l->inputq); 1073 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN)) 1074 rc |= tipc_link_build_ack_msg(l, xmitq); 1075 if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK)) 1076 break; 1077 } while ((skb = __skb_dequeue(defq))); 1078 1079 return rc; 1080 drop: 1081 kfree_skb(skb); 1082 return rc; 1083 } 1084 1085 /* 1086 * Send protocol message to the other endpoint. 1087 */ 1088 void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg, 1089 u32 gap, u32 tolerance, u32 priority) 1090 { 1091 struct sk_buff *skb = NULL; 1092 struct sk_buff_head xmitq; 1093 1094 __skb_queue_head_init(&xmitq); 1095 tipc_link_build_proto_msg(l, msg_typ, probe_msg, gap, 1096 tolerance, priority, &xmitq); 1097 skb = __skb_dequeue(&xmitq); 1098 if (!skb) 1099 return; 1100 tipc_bearer_xmit_skb(l->net, l->bearer_id, skb, l->media_addr); 1101 l->rcv_unacked = 0; 1102 } 1103 1104 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe, 1105 u16 rcvgap, int tolerance, int priority, 1106 struct sk_buff_head *xmitq) 1107 { 1108 struct sk_buff *skb = NULL; 1109 struct tipc_msg *hdr = l->pmsg; 1110 bool node_up = link_is_up(l->bc_rcvlink); 1111 1112 /* Don't send protocol message during reset or link failover */ 1113 if (tipc_link_is_blocked(l)) 1114 return; 1115 1116 msg_set_type(hdr, mtyp); 1117 msg_set_net_plane(hdr, l->net_plane); 1118 msg_set_next_sent(hdr, l->snd_nxt); 1119 msg_set_ack(hdr, l->rcv_nxt - 1); 1120 msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1); 1121 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1); 1122 msg_set_link_tolerance(hdr, tolerance); 1123 msg_set_linkprio(hdr, priority); 1124 msg_set_redundant_link(hdr, node_up); 1125 msg_set_seq_gap(hdr, 0); 1126 1127 /* Compatibility: created msg must not be in sequence with pkt flow */ 1128 msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2); 1129 1130 if (mtyp == STATE_MSG) { 1131 if (!tipc_link_is_up(l)) 1132 return; 1133 1134 /* Override rcvgap if there are packets in deferred queue */ 1135 if (!skb_queue_empty(&l->deferdq)) 1136 rcvgap = buf_seqno(skb_peek(&l->deferdq)) - l->rcv_nxt; 1137 if (rcvgap) { 1138 msg_set_seq_gap(hdr, rcvgap); 1139 l->stats.sent_nacks++; 1140 } 1141 msg_set_probe(hdr, probe); 1142 if (probe) 1143 l->stats.sent_probes++; 1144 l->stats.sent_states++; 1145 l->rcv_unacked = 0; 1146 } else { 1147 /* RESET_MSG or ACTIVATE_MSG */ 1148 msg_set_max_pkt(hdr, l->advertised_mtu); 1149 msg_set_ack(hdr, l->rcv_nxt - 1); 1150 msg_set_next_sent(hdr, 1); 1151 } 1152 skb = tipc_buf_acquire(msg_size(hdr)); 1153 if (!skb) 1154 return; 1155 skb_copy_to_linear_data(skb, hdr, msg_size(hdr)); 1156 skb->priority = TC_PRIO_CONTROL; 1157 __skb_queue_tail(xmitq, skb); 1158 } 1159 1160 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets 1161 * with contents of the link's transmit and backlog queues. 1162 */ 1163 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl, 1164 int mtyp, struct sk_buff_head *xmitq) 1165 { 1166 struct sk_buff *skb, *tnlskb; 1167 struct tipc_msg *hdr, tnlhdr; 1168 struct sk_buff_head *queue = &l->transmq; 1169 struct sk_buff_head tmpxq, tnlq; 1170 u16 pktlen, pktcnt, seqno = l->snd_nxt; 1171 1172 if (!tnl) 1173 return; 1174 1175 skb_queue_head_init(&tnlq); 1176 skb_queue_head_init(&tmpxq); 1177 1178 /* At least one packet required for safe algorithm => add dummy */ 1179 skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG, 1180 BASIC_H_SIZE, 0, l->addr, link_own_addr(l), 1181 0, 0, TIPC_ERR_NO_PORT); 1182 if (!skb) { 1183 pr_warn("%sunable to create tunnel packet\n", link_co_err); 1184 return; 1185 } 1186 skb_queue_tail(&tnlq, skb); 1187 tipc_link_xmit(l, &tnlq, &tmpxq); 1188 __skb_queue_purge(&tmpxq); 1189 1190 /* Initialize reusable tunnel packet header */ 1191 tipc_msg_init(link_own_addr(l), &tnlhdr, TUNNEL_PROTOCOL, 1192 mtyp, INT_H_SIZE, l->addr); 1193 pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq); 1194 msg_set_msgcnt(&tnlhdr, pktcnt); 1195 msg_set_bearer_id(&tnlhdr, l->peer_bearer_id); 1196 tnl: 1197 /* Wrap each packet into a tunnel packet */ 1198 skb_queue_walk(queue, skb) { 1199 hdr = buf_msg(skb); 1200 if (queue == &l->backlogq) 1201 msg_set_seqno(hdr, seqno++); 1202 pktlen = msg_size(hdr); 1203 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE); 1204 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE); 1205 if (!tnlskb) { 1206 pr_warn("%sunable to send packet\n", link_co_err); 1207 return; 1208 } 1209 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE); 1210 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen); 1211 __skb_queue_tail(&tnlq, tnlskb); 1212 } 1213 if (queue != &l->backlogq) { 1214 queue = &l->backlogq; 1215 goto tnl; 1216 } 1217 1218 tipc_link_xmit(tnl, &tnlq, xmitq); 1219 1220 if (mtyp == FAILOVER_MSG) { 1221 tnl->drop_point = l->rcv_nxt; 1222 tnl->failover_reasm_skb = l->reasm_buf; 1223 l->reasm_buf = NULL; 1224 } 1225 } 1226 1227 /* tipc_link_proto_rcv(): receive link level protocol message : 1228 * Note that network plane id propagates through the network, and may 1229 * change at any time. The node with lowest numerical id determines 1230 * network plane 1231 */ 1232 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb, 1233 struct sk_buff_head *xmitq) 1234 { 1235 struct tipc_msg *hdr = buf_msg(skb); 1236 u16 rcvgap = 0; 1237 u16 ack = msg_ack(hdr); 1238 u16 gap = msg_seq_gap(hdr); 1239 u16 peers_snd_nxt = msg_next_sent(hdr); 1240 u16 peers_tol = msg_link_tolerance(hdr); 1241 u16 peers_prio = msg_linkprio(hdr); 1242 u16 rcv_nxt = l->rcv_nxt; 1243 int mtyp = msg_type(hdr); 1244 char *if_name; 1245 int rc = 0; 1246 1247 if (tipc_link_is_blocked(l) || !xmitq) 1248 goto exit; 1249 1250 if (link_own_addr(l) > msg_prevnode(hdr)) 1251 l->net_plane = msg_net_plane(hdr); 1252 1253 switch (mtyp) { 1254 case RESET_MSG: 1255 1256 /* Ignore duplicate RESET with old session number */ 1257 if ((less_eq(msg_session(hdr), l->peer_session)) && 1258 (l->peer_session != WILDCARD_SESSION)) 1259 break; 1260 /* fall thru' */ 1261 1262 case ACTIVATE_MSG: 1263 1264 /* Complete own link name with peer's interface name */ 1265 if_name = strrchr(l->name, ':') + 1; 1266 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME) 1267 break; 1268 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME) 1269 break; 1270 strncpy(if_name, msg_data(hdr), TIPC_MAX_IF_NAME); 1271 1272 /* Update own tolerance if peer indicates a non-zero value */ 1273 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) 1274 l->tolerance = peers_tol; 1275 1276 /* Update own priority if peer's priority is higher */ 1277 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI)) 1278 l->priority = peers_prio; 1279 1280 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */ 1281 if ((mtyp == RESET_MSG) || !link_is_up(l)) 1282 rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT); 1283 1284 /* ACTIVATE_MSG takes up link if it was already locally reset */ 1285 if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING)) 1286 rc = TIPC_LINK_UP_EVT; 1287 1288 l->peer_session = msg_session(hdr); 1289 l->peer_bearer_id = msg_bearer_id(hdr); 1290 if (l->mtu > msg_max_pkt(hdr)) 1291 l->mtu = msg_max_pkt(hdr); 1292 break; 1293 1294 case STATE_MSG: 1295 1296 /* Update own tolerance if peer indicates a non-zero value */ 1297 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) 1298 l->tolerance = peers_tol; 1299 1300 l->silent_intv_cnt = 0; 1301 l->stats.recv_states++; 1302 if (msg_probe(hdr)) 1303 l->stats.recv_probes++; 1304 1305 if (!link_is_up(l)) { 1306 if (l->state == LINK_ESTABLISHING) 1307 rc = TIPC_LINK_UP_EVT; 1308 break; 1309 } 1310 1311 /* Send NACK if peer has sent pkts we haven't received yet */ 1312 if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l)) 1313 rcvgap = peers_snd_nxt - l->rcv_nxt; 1314 if (rcvgap || (msg_probe(hdr))) 1315 tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap, 1316 0, 0, xmitq); 1317 tipc_link_release_pkts(l, ack); 1318 1319 /* If NACK, retransmit will now start at right position */ 1320 if (gap) { 1321 rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq); 1322 l->stats.recv_nacks++; 1323 } 1324 1325 tipc_link_advance_backlog(l, xmitq); 1326 if (unlikely(!skb_queue_empty(&l->wakeupq))) 1327 link_prepare_wakeup(l); 1328 } 1329 exit: 1330 kfree_skb(skb); 1331 return rc; 1332 } 1333 1334 /* tipc_link_build_bc_proto_msg() - create broadcast protocol message 1335 */ 1336 static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast, 1337 u16 peers_snd_nxt, 1338 struct sk_buff_head *xmitq) 1339 { 1340 struct sk_buff *skb; 1341 struct tipc_msg *hdr; 1342 struct sk_buff *dfrd_skb = skb_peek(&l->deferdq); 1343 u16 ack = l->rcv_nxt - 1; 1344 u16 gap_to = peers_snd_nxt - 1; 1345 1346 skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE, 1347 0, l->addr, link_own_addr(l), 0, 0, 0); 1348 if (!skb) 1349 return false; 1350 hdr = buf_msg(skb); 1351 msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1); 1352 msg_set_bcast_ack(hdr, ack); 1353 msg_set_bcgap_after(hdr, ack); 1354 if (dfrd_skb) 1355 gap_to = buf_seqno(dfrd_skb) - 1; 1356 msg_set_bcgap_to(hdr, gap_to); 1357 msg_set_non_seq(hdr, bcast); 1358 __skb_queue_tail(xmitq, skb); 1359 return true; 1360 } 1361 1362 /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints. 1363 * 1364 * Give a newly added peer node the sequence number where it should 1365 * start receiving and acking broadcast packets. 1366 */ 1367 static void tipc_link_build_bc_init_msg(struct tipc_link *l, 1368 struct sk_buff_head *xmitq) 1369 { 1370 struct sk_buff_head list; 1371 1372 __skb_queue_head_init(&list); 1373 if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list)) 1374 return; 1375 tipc_link_xmit(l, &list, xmitq); 1376 } 1377 1378 /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer 1379 */ 1380 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr) 1381 { 1382 int mtyp = msg_type(hdr); 1383 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr); 1384 1385 if (link_is_up(l)) 1386 return; 1387 1388 if (msg_user(hdr) == BCAST_PROTOCOL) { 1389 l->rcv_nxt = peers_snd_nxt; 1390 l->state = LINK_ESTABLISHED; 1391 return; 1392 } 1393 1394 if (l->peer_caps & TIPC_BCAST_SYNCH) 1395 return; 1396 1397 if (msg_peer_node_is_up(hdr)) 1398 return; 1399 1400 /* Compatibility: accept older, less safe initial synch data */ 1401 if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG)) 1402 l->rcv_nxt = peers_snd_nxt; 1403 } 1404 1405 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state 1406 */ 1407 void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr, 1408 struct sk_buff_head *xmitq) 1409 { 1410 u16 peers_snd_nxt = msg_bc_snd_nxt(hdr); 1411 1412 if (!link_is_up(l)) 1413 return; 1414 1415 if (!msg_peer_node_is_up(hdr)) 1416 return; 1417 1418 l->bc_peer_is_up = true; 1419 1420 /* Ignore if peers_snd_nxt goes beyond receive window */ 1421 if (more(peers_snd_nxt, l->rcv_nxt + l->window)) 1422 return; 1423 1424 if (!more(peers_snd_nxt, l->rcv_nxt)) { 1425 l->nack_state = BC_NACK_SND_CONDITIONAL; 1426 return; 1427 } 1428 1429 /* Don't NACK if one was recently sent or peeked */ 1430 if (l->nack_state == BC_NACK_SND_SUPPRESS) { 1431 l->nack_state = BC_NACK_SND_UNCONDITIONAL; 1432 return; 1433 } 1434 1435 /* Conditionally delay NACK sending until next synch rcv */ 1436 if (l->nack_state == BC_NACK_SND_CONDITIONAL) { 1437 l->nack_state = BC_NACK_SND_UNCONDITIONAL; 1438 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN) 1439 return; 1440 } 1441 1442 /* Send NACK now but suppress next one */ 1443 tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq); 1444 l->nack_state = BC_NACK_SND_SUPPRESS; 1445 } 1446 1447 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked, 1448 struct sk_buff_head *xmitq) 1449 { 1450 struct sk_buff *skb, *tmp; 1451 struct tipc_link *snd_l = l->bc_sndlink; 1452 1453 if (!link_is_up(l) || !l->bc_peer_is_up) 1454 return; 1455 1456 if (!more(acked, l->acked)) 1457 return; 1458 1459 /* Skip over packets peer has already acked */ 1460 skb_queue_walk(&snd_l->transmq, skb) { 1461 if (more(buf_seqno(skb), l->acked)) 1462 break; 1463 } 1464 1465 /* Update/release the packets peer is acking now */ 1466 skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) { 1467 if (more(buf_seqno(skb), acked)) 1468 break; 1469 if (!--TIPC_SKB_CB(skb)->ackers) { 1470 __skb_unlink(skb, &snd_l->transmq); 1471 kfree_skb(skb); 1472 } 1473 } 1474 l->acked = acked; 1475 tipc_link_advance_backlog(snd_l, xmitq); 1476 if (unlikely(!skb_queue_empty(&snd_l->wakeupq))) 1477 link_prepare_wakeup(snd_l); 1478 } 1479 1480 /* tipc_link_bc_nack_rcv(): receive broadcast nack message 1481 */ 1482 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb, 1483 struct sk_buff_head *xmitq) 1484 { 1485 struct tipc_msg *hdr = buf_msg(skb); 1486 u32 dnode = msg_destnode(hdr); 1487 int mtyp = msg_type(hdr); 1488 u16 acked = msg_bcast_ack(hdr); 1489 u16 from = acked + 1; 1490 u16 to = msg_bcgap_to(hdr); 1491 u16 peers_snd_nxt = to + 1; 1492 int rc = 0; 1493 1494 kfree_skb(skb); 1495 1496 if (!tipc_link_is_up(l) || !l->bc_peer_is_up) 1497 return 0; 1498 1499 if (mtyp != STATE_MSG) 1500 return 0; 1501 1502 if (dnode == link_own_addr(l)) { 1503 tipc_link_bc_ack_rcv(l, acked, xmitq); 1504 rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq); 1505 l->stats.recv_nacks++; 1506 return rc; 1507 } 1508 1509 /* Msg for other node => suppress own NACK at next sync if applicable */ 1510 if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from)) 1511 l->nack_state = BC_NACK_SND_SUPPRESS; 1512 1513 return 0; 1514 } 1515 1516 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win) 1517 { 1518 int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE); 1519 1520 l->window = win; 1521 l->backlog[TIPC_LOW_IMPORTANCE].limit = win / 2; 1522 l->backlog[TIPC_MEDIUM_IMPORTANCE].limit = win; 1523 l->backlog[TIPC_HIGH_IMPORTANCE].limit = win / 2 * 3; 1524 l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2; 1525 l->backlog[TIPC_SYSTEM_IMPORTANCE].limit = max_bulk; 1526 } 1527 1528 /* tipc_link_find_owner - locate owner node of link by link's name 1529 * @net: the applicable net namespace 1530 * @name: pointer to link name string 1531 * @bearer_id: pointer to index in 'node->links' array where the link was found. 1532 * 1533 * Returns pointer to node owning the link, or 0 if no matching link is found. 1534 */ 1535 static struct tipc_node *tipc_link_find_owner(struct net *net, 1536 const char *link_name, 1537 unsigned int *bearer_id) 1538 { 1539 struct tipc_net *tn = net_generic(net, tipc_net_id); 1540 struct tipc_link *l_ptr; 1541 struct tipc_node *n_ptr; 1542 struct tipc_node *found_node = NULL; 1543 int i; 1544 1545 *bearer_id = 0; 1546 rcu_read_lock(); 1547 list_for_each_entry_rcu(n_ptr, &tn->node_list, list) { 1548 tipc_node_lock(n_ptr); 1549 for (i = 0; i < MAX_BEARERS; i++) { 1550 l_ptr = n_ptr->links[i].link; 1551 if (l_ptr && !strcmp(l_ptr->name, link_name)) { 1552 *bearer_id = i; 1553 found_node = n_ptr; 1554 break; 1555 } 1556 } 1557 tipc_node_unlock(n_ptr); 1558 if (found_node) 1559 break; 1560 } 1561 rcu_read_unlock(); 1562 1563 return found_node; 1564 } 1565 1566 /** 1567 * link_reset_statistics - reset link statistics 1568 * @l_ptr: pointer to link 1569 */ 1570 static void link_reset_statistics(struct tipc_link *l_ptr) 1571 { 1572 memset(&l_ptr->stats, 0, sizeof(l_ptr->stats)); 1573 l_ptr->stats.sent_info = l_ptr->snd_nxt; 1574 l_ptr->stats.recv_info = l_ptr->rcv_nxt; 1575 } 1576 1577 static void link_print(struct tipc_link *l, const char *str) 1578 { 1579 struct sk_buff *hskb = skb_peek(&l->transmq); 1580 u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1; 1581 u16 tail = l->snd_nxt - 1; 1582 1583 pr_info("%s Link <%s> state %x\n", str, l->name, l->state); 1584 pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n", 1585 skb_queue_len(&l->transmq), head, tail, 1586 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt); 1587 } 1588 1589 /* Parse and validate nested (link) properties valid for media, bearer and link 1590 */ 1591 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[]) 1592 { 1593 int err; 1594 1595 err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop, 1596 tipc_nl_prop_policy); 1597 if (err) 1598 return err; 1599 1600 if (props[TIPC_NLA_PROP_PRIO]) { 1601 u32 prio; 1602 1603 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]); 1604 if (prio > TIPC_MAX_LINK_PRI) 1605 return -EINVAL; 1606 } 1607 1608 if (props[TIPC_NLA_PROP_TOL]) { 1609 u32 tol; 1610 1611 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]); 1612 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL)) 1613 return -EINVAL; 1614 } 1615 1616 if (props[TIPC_NLA_PROP_WIN]) { 1617 u32 win; 1618 1619 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]); 1620 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN)) 1621 return -EINVAL; 1622 } 1623 1624 return 0; 1625 } 1626 1627 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info) 1628 { 1629 int err; 1630 int res = 0; 1631 int bearer_id; 1632 char *name; 1633 struct tipc_link *link; 1634 struct tipc_node *node; 1635 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1]; 1636 struct net *net = sock_net(skb->sk); 1637 1638 if (!info->attrs[TIPC_NLA_LINK]) 1639 return -EINVAL; 1640 1641 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX, 1642 info->attrs[TIPC_NLA_LINK], 1643 tipc_nl_link_policy); 1644 if (err) 1645 return err; 1646 1647 if (!attrs[TIPC_NLA_LINK_NAME]) 1648 return -EINVAL; 1649 1650 name = nla_data(attrs[TIPC_NLA_LINK_NAME]); 1651 1652 if (strcmp(name, tipc_bclink_name) == 0) 1653 return tipc_nl_bc_link_set(net, attrs); 1654 1655 node = tipc_link_find_owner(net, name, &bearer_id); 1656 if (!node) 1657 return -EINVAL; 1658 1659 tipc_node_lock(node); 1660 1661 link = node->links[bearer_id].link; 1662 if (!link) { 1663 res = -EINVAL; 1664 goto out; 1665 } 1666 1667 if (attrs[TIPC_NLA_LINK_PROP]) { 1668 struct nlattr *props[TIPC_NLA_PROP_MAX + 1]; 1669 1670 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], 1671 props); 1672 if (err) { 1673 res = err; 1674 goto out; 1675 } 1676 1677 if (props[TIPC_NLA_PROP_TOL]) { 1678 u32 tol; 1679 1680 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]); 1681 link->tolerance = tol; 1682 tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0); 1683 } 1684 if (props[TIPC_NLA_PROP_PRIO]) { 1685 u32 prio; 1686 1687 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]); 1688 link->priority = prio; 1689 tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio); 1690 } 1691 if (props[TIPC_NLA_PROP_WIN]) { 1692 u32 win; 1693 1694 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]); 1695 tipc_link_set_queue_limits(link, win); 1696 } 1697 } 1698 1699 out: 1700 tipc_node_unlock(node); 1701 1702 return res; 1703 } 1704 1705 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s) 1706 { 1707 int i; 1708 struct nlattr *stats; 1709 1710 struct nla_map { 1711 u32 key; 1712 u32 val; 1713 }; 1714 1715 struct nla_map map[] = { 1716 {TIPC_NLA_STATS_RX_INFO, s->recv_info}, 1717 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments}, 1718 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented}, 1719 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles}, 1720 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled}, 1721 {TIPC_NLA_STATS_TX_INFO, s->sent_info}, 1722 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments}, 1723 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented}, 1724 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles}, 1725 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled}, 1726 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ? 1727 s->msg_length_counts : 1}, 1728 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts}, 1729 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total}, 1730 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]}, 1731 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]}, 1732 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]}, 1733 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]}, 1734 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]}, 1735 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]}, 1736 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]}, 1737 {TIPC_NLA_STATS_RX_STATES, s->recv_states}, 1738 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes}, 1739 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks}, 1740 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv}, 1741 {TIPC_NLA_STATS_TX_STATES, s->sent_states}, 1742 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes}, 1743 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks}, 1744 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks}, 1745 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted}, 1746 {TIPC_NLA_STATS_DUPLICATES, s->duplicates}, 1747 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs}, 1748 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz}, 1749 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ? 1750 (s->accu_queue_sz / s->queue_sz_counts) : 0} 1751 }; 1752 1753 stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS); 1754 if (!stats) 1755 return -EMSGSIZE; 1756 1757 for (i = 0; i < ARRAY_SIZE(map); i++) 1758 if (nla_put_u32(skb, map[i].key, map[i].val)) 1759 goto msg_full; 1760 1761 nla_nest_end(skb, stats); 1762 1763 return 0; 1764 msg_full: 1765 nla_nest_cancel(skb, stats); 1766 1767 return -EMSGSIZE; 1768 } 1769 1770 /* Caller should hold appropriate locks to protect the link */ 1771 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg, 1772 struct tipc_link *link, int nlflags) 1773 { 1774 int err; 1775 void *hdr; 1776 struct nlattr *attrs; 1777 struct nlattr *prop; 1778 struct tipc_net *tn = net_generic(net, tipc_net_id); 1779 1780 hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family, 1781 nlflags, TIPC_NL_LINK_GET); 1782 if (!hdr) 1783 return -EMSGSIZE; 1784 1785 attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK); 1786 if (!attrs) 1787 goto msg_full; 1788 1789 if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name)) 1790 goto attr_msg_full; 1791 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, 1792 tipc_cluster_mask(tn->own_addr))) 1793 goto attr_msg_full; 1794 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu)) 1795 goto attr_msg_full; 1796 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt)) 1797 goto attr_msg_full; 1798 if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt)) 1799 goto attr_msg_full; 1800 1801 if (tipc_link_is_up(link)) 1802 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP)) 1803 goto attr_msg_full; 1804 if (link->active) 1805 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE)) 1806 goto attr_msg_full; 1807 1808 prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP); 1809 if (!prop) 1810 goto attr_msg_full; 1811 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority)) 1812 goto prop_msg_full; 1813 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance)) 1814 goto prop_msg_full; 1815 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, 1816 link->window)) 1817 goto prop_msg_full; 1818 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority)) 1819 goto prop_msg_full; 1820 nla_nest_end(msg->skb, prop); 1821 1822 err = __tipc_nl_add_stats(msg->skb, &link->stats); 1823 if (err) 1824 goto attr_msg_full; 1825 1826 nla_nest_end(msg->skb, attrs); 1827 genlmsg_end(msg->skb, hdr); 1828 1829 return 0; 1830 1831 prop_msg_full: 1832 nla_nest_cancel(msg->skb, prop); 1833 attr_msg_full: 1834 nla_nest_cancel(msg->skb, attrs); 1835 msg_full: 1836 genlmsg_cancel(msg->skb, hdr); 1837 1838 return -EMSGSIZE; 1839 } 1840 1841 /* Caller should hold node lock */ 1842 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg, 1843 struct tipc_node *node, u32 *prev_link) 1844 { 1845 u32 i; 1846 int err; 1847 1848 for (i = *prev_link; i < MAX_BEARERS; i++) { 1849 *prev_link = i; 1850 1851 if (!node->links[i].link) 1852 continue; 1853 1854 err = __tipc_nl_add_link(net, msg, 1855 node->links[i].link, NLM_F_MULTI); 1856 if (err) 1857 return err; 1858 } 1859 *prev_link = 0; 1860 1861 return 0; 1862 } 1863 1864 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb) 1865 { 1866 struct net *net = sock_net(skb->sk); 1867 struct tipc_net *tn = net_generic(net, tipc_net_id); 1868 struct tipc_node *node; 1869 struct tipc_nl_msg msg; 1870 u32 prev_node = cb->args[0]; 1871 u32 prev_link = cb->args[1]; 1872 int done = cb->args[2]; 1873 int err; 1874 1875 if (done) 1876 return 0; 1877 1878 msg.skb = skb; 1879 msg.portid = NETLINK_CB(cb->skb).portid; 1880 msg.seq = cb->nlh->nlmsg_seq; 1881 1882 rcu_read_lock(); 1883 if (prev_node) { 1884 node = tipc_node_find(net, prev_node); 1885 if (!node) { 1886 /* We never set seq or call nl_dump_check_consistent() 1887 * this means that setting prev_seq here will cause the 1888 * consistence check to fail in the netlink callback 1889 * handler. Resulting in the last NLMSG_DONE message 1890 * having the NLM_F_DUMP_INTR flag set. 1891 */ 1892 cb->prev_seq = 1; 1893 goto out; 1894 } 1895 tipc_node_put(node); 1896 1897 list_for_each_entry_continue_rcu(node, &tn->node_list, 1898 list) { 1899 tipc_node_lock(node); 1900 err = __tipc_nl_add_node_links(net, &msg, node, 1901 &prev_link); 1902 tipc_node_unlock(node); 1903 if (err) 1904 goto out; 1905 1906 prev_node = node->addr; 1907 } 1908 } else { 1909 err = tipc_nl_add_bc_link(net, &msg); 1910 if (err) 1911 goto out; 1912 1913 list_for_each_entry_rcu(node, &tn->node_list, list) { 1914 tipc_node_lock(node); 1915 err = __tipc_nl_add_node_links(net, &msg, node, 1916 &prev_link); 1917 tipc_node_unlock(node); 1918 if (err) 1919 goto out; 1920 1921 prev_node = node->addr; 1922 } 1923 } 1924 done = 1; 1925 out: 1926 rcu_read_unlock(); 1927 1928 cb->args[0] = prev_node; 1929 cb->args[1] = prev_link; 1930 cb->args[2] = done; 1931 1932 return skb->len; 1933 } 1934 1935 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info) 1936 { 1937 struct net *net = genl_info_net(info); 1938 struct tipc_nl_msg msg; 1939 char *name; 1940 int err; 1941 1942 msg.portid = info->snd_portid; 1943 msg.seq = info->snd_seq; 1944 1945 if (!info->attrs[TIPC_NLA_LINK_NAME]) 1946 return -EINVAL; 1947 name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]); 1948 1949 msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL); 1950 if (!msg.skb) 1951 return -ENOMEM; 1952 1953 if (strcmp(name, tipc_bclink_name) == 0) { 1954 err = tipc_nl_add_bc_link(net, &msg); 1955 if (err) { 1956 nlmsg_free(msg.skb); 1957 return err; 1958 } 1959 } else { 1960 int bearer_id; 1961 struct tipc_node *node; 1962 struct tipc_link *link; 1963 1964 node = tipc_link_find_owner(net, name, &bearer_id); 1965 if (!node) 1966 return -EINVAL; 1967 1968 tipc_node_lock(node); 1969 link = node->links[bearer_id].link; 1970 if (!link) { 1971 tipc_node_unlock(node); 1972 nlmsg_free(msg.skb); 1973 return -EINVAL; 1974 } 1975 1976 err = __tipc_nl_add_link(net, &msg, link, 0); 1977 tipc_node_unlock(node); 1978 if (err) { 1979 nlmsg_free(msg.skb); 1980 return err; 1981 } 1982 } 1983 1984 return genlmsg_reply(msg.skb, info); 1985 } 1986 1987 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info) 1988 { 1989 int err; 1990 char *link_name; 1991 unsigned int bearer_id; 1992 struct tipc_link *link; 1993 struct tipc_node *node; 1994 struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1]; 1995 struct net *net = sock_net(skb->sk); 1996 1997 if (!info->attrs[TIPC_NLA_LINK]) 1998 return -EINVAL; 1999 2000 err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX, 2001 info->attrs[TIPC_NLA_LINK], 2002 tipc_nl_link_policy); 2003 if (err) 2004 return err; 2005 2006 if (!attrs[TIPC_NLA_LINK_NAME]) 2007 return -EINVAL; 2008 2009 link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]); 2010 2011 if (strcmp(link_name, tipc_bclink_name) == 0) { 2012 err = tipc_bclink_reset_stats(net); 2013 if (err) 2014 return err; 2015 return 0; 2016 } 2017 2018 node = tipc_link_find_owner(net, link_name, &bearer_id); 2019 if (!node) 2020 return -EINVAL; 2021 2022 tipc_node_lock(node); 2023 2024 link = node->links[bearer_id].link; 2025 if (!link) { 2026 tipc_node_unlock(node); 2027 return -EINVAL; 2028 } 2029 2030 link_reset_statistics(link); 2031 2032 tipc_node_unlock(node); 2033 2034 return 0; 2035 } 2036