net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, Ericsson AB
   5  * Copyright (c) 2004-2007, 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 "port.h"
  40 #include "name_distr.h"
  41 #include "discover.h"
  42 #include "config.h"
  43
  44
  45 /*
  46  * Out-of-range value for link session numbers
  47  */
  48
  49 #define INVALID_SESSION 0x10000
  50
  51 /*
  52  * Link state events:
  53  */
  54
  55 #define  STARTING_EVT    856384768      /* link processing trigger */
  56 #define  TRAFFIC_MSG_EVT 560815u        /* rx'd ??? */
  57 #define  TIMEOUT_EVT     560817u        /* link timer expired */
  58
  59 /*
  60  * The following two 'message types' is really just implementation
  61  * data conveniently stored in the message header.
  62  * They must not be considered part of the protocol
  63  */
  64 #define OPEN_MSG   0
  65 #define CLOSED_MSG 1
  66
  67 /*
  68  * State value stored in 'exp_msg_count'
  69  */
  70
  71 #define START_CHANGEOVER 100000u
  72
  73 /**
  74  * struct link_name - deconstructed link name
  75  * @addr_local: network address of node at this end
  76  * @if_local: name of interface at this end
  77  * @addr_peer: network address of node at far end
  78  * @if_peer: name of interface at far end
  79  */
  80
  81 struct link_name {
  82         u32 addr_local;
  83         char if_local[TIPC_MAX_IF_NAME];
  84         u32 addr_peer;
  85         char if_peer[TIPC_MAX_IF_NAME];
  86 };
  87
  88 static void link_handle_out_of_seq_msg(struct link *l_ptr,
  89                                        struct sk_buff *buf);
  90 static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf);
  91 static int  link_recv_changeover_msg(struct link **l_ptr, struct sk_buff **buf);
  92 static void link_set_supervision_props(struct link *l_ptr, u32 tolerance);
  93 static int  link_send_sections_long(struct port *sender,
  94                                     struct iovec const *msg_sect,
  95                                     u32 num_sect, u32 destnode);
  96 static void link_check_defragm_bufs(struct link *l_ptr);
  97 static void link_state_event(struct link *l_ptr, u32 event);
  98 static void link_reset_statistics(struct link *l_ptr);
  99 static void link_print(struct link *l_ptr, const char *str);
 100 static void link_start(struct link *l_ptr);
 101 static int link_send_long_buf(struct link *l_ptr, struct sk_buff *buf);
 102
 103 /*
 104  *  Simple link routines
 105  */
 106
 107 static unsigned int align(unsigned int i)
 108 {
 109         return (i + 3) & ~3u;
 110 }
 111
 112 static void link_init_max_pkt(struct link *l_ptr)
 113 {
 114         u32 max_pkt;
 115
 116         max_pkt = (l_ptr->b_ptr->publ.mtu & ~3);
 117         if (max_pkt > MAX_MSG_SIZE)
 118                 max_pkt = MAX_MSG_SIZE;
 119
 120         l_ptr->max_pkt_target = max_pkt;
 121         if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
 122                 l_ptr->max_pkt = l_ptr->max_pkt_target;
 123         else
 124                 l_ptr->max_pkt = MAX_PKT_DEFAULT;
 125
 126         l_ptr->max_pkt_probes = 0;
 127 }
 128
 129 static u32 link_next_sent(struct link *l_ptr)
 130 {
 131         if (l_ptr->next_out)
 132                 return msg_seqno(buf_msg(l_ptr->next_out));
 133         return mod(l_ptr->next_out_no);
 134 }
 135
 136 static u32 link_last_sent(struct link *l_ptr)
 137 {
 138         return mod(link_next_sent(l_ptr) - 1);
 139 }
 140
 141 /*
 142  *  Simple non-static link routines (i.e. referenced outside this file)
 143  */
 144
 145 int tipc_link_is_up(struct link *l_ptr)
 146 {
 147         if (!l_ptr)
 148                 return 0;
 149         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 150 }
 151
 152 int tipc_link_is_active(struct link *l_ptr)
 153 {
 154         return  (l_ptr->owner->active_links[0] == l_ptr) ||
 155                 (l_ptr->owner->active_links[1] == l_ptr);
 156 }
 157
 158 /**
 159  * link_name_validate - validate & (optionally) deconstruct link name
 160  * @name - ptr to link name string
 161  * @name_parts - ptr to area for link name components (or NULL if not needed)
 162  *
 163  * Returns 1 if link name is valid, otherwise 0.
 164  */
 165
 166 static int link_name_validate(const char *name, struct link_name *name_parts)
 167 {
 168         char name_copy[TIPC_MAX_LINK_NAME];
 169         char *addr_local;
 170         char *if_local;
 171         char *addr_peer;
 172         char *if_peer;
 173         char dummy;
 174         u32 z_local, c_local, n_local;
 175         u32 z_peer, c_peer, n_peer;
 176         u32 if_local_len;
 177         u32 if_peer_len;
 178
 179         /* copy link name & ensure length is OK */
 180
 181         name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
 182         /* need above in case non-Posix strncpy() doesn't pad with nulls */
 183         strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
 184         if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
 185                 return 0;
 186
 187         /* ensure all component parts of link name are present */
 188
 189         addr_local = name_copy;
 190         if ((if_local = strchr(addr_local, ':')) == NULL)
 191                 return 0;
 192         *(if_local++) = 0;
 193         if ((addr_peer = strchr(if_local, '-')) == NULL)
 194                 return 0;
 195         *(addr_peer++) = 0;
 196         if_local_len = addr_peer - if_local;
 197         if ((if_peer = strchr(addr_peer, ':')) == NULL)
 198                 return 0;
 199         *(if_peer++) = 0;
 200         if_peer_len = strlen(if_peer) + 1;
 201
 202         /* validate component parts of link name */
 203
 204         if ((sscanf(addr_local, "%u.%u.%u%c",
 205                     &z_local, &c_local, &n_local, &dummy) != 3) ||
 206             (sscanf(addr_peer, "%u.%u.%u%c",
 207                     &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
 208             (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
 209             (z_peer  > 255) || (c_peer  > 4095) || (n_peer  > 4095) ||
 210             (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
 211             (if_peer_len  <= 1) || (if_peer_len  > TIPC_MAX_IF_NAME) ||
 212             (strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
 213             (strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
 214                 return 0;
 215
 216         /* return link name components, if necessary */
 217
 218         if (name_parts) {
 219                 name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
 220                 strcpy(name_parts->if_local, if_local);
 221                 name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
 222                 strcpy(name_parts->if_peer, if_peer);
 223         }
 224         return 1;
 225 }
 226
 227 /**
 228  * link_timeout - handle expiration of link timer
 229  * @l_ptr: pointer to link
 230  *
 231  * This routine must not grab "tipc_net_lock" to avoid a potential deadlock conflict
 232  * with tipc_link_delete().  (There is no risk that the node will be deleted by
 233  * another thread because tipc_link_delete() always cancels the link timer before
 234  * tipc_node_delete() is called.)
 235  */
 236
 237 static void link_timeout(struct link *l_ptr)
 238 {
 239         tipc_node_lock(l_ptr->owner);
 240
 241         /* update counters used in statistical profiling of send traffic */
 242
 243         l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
 244         l_ptr->stats.queue_sz_counts++;
 245
 246         if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
 247                 l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
 248
 249         if (l_ptr->first_out) {
 250                 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
 251                 u32 length = msg_size(msg);
 252
 253                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 254                     (msg_type(msg) == FIRST_FRAGMENT)) {
 255                         length = msg_size(msg_get_wrapped(msg));
 256                 }
 257                 if (length) {
 258                         l_ptr->stats.msg_lengths_total += length;
 259                         l_ptr->stats.msg_length_counts++;
 260                         if (length <= 64)
 261                                 l_ptr->stats.msg_length_profile[0]++;
 262                         else if (length <= 256)
 263                                 l_ptr->stats.msg_length_profile[1]++;
 264                         else if (length <= 1024)
 265                                 l_ptr->stats.msg_length_profile[2]++;
 266                         else if (length <= 4096)
 267                                 l_ptr->stats.msg_length_profile[3]++;
 268                         else if (length <= 16384)
 269                                 l_ptr->stats.msg_length_profile[4]++;
 270                         else if (length <= 32768)
 271                                 l_ptr->stats.msg_length_profile[5]++;
 272                         else
 273                                 l_ptr->stats.msg_length_profile[6]++;
 274                 }
 275         }
 276
 277         /* do all other link processing performed on a periodic basis */
 278
 279         link_check_defragm_bufs(l_ptr);
 280
 281         link_state_event(l_ptr, TIMEOUT_EVT);
 282
 283         if (l_ptr->next_out)
 284                 tipc_link_push_queue(l_ptr);
 285
 286         tipc_node_unlock(l_ptr->owner);
 287 }
 288
 289 static void link_set_timer(struct link *l_ptr, u32 time)
 290 {
 291         k_start_timer(&l_ptr->timer, time);
 292 }
 293
 294 /**
 295  * tipc_link_create - create a new link
 296  * @b_ptr: pointer to associated bearer
 297  * @peer: network address of node at other end of link
 298  * @media_addr: media address to use when sending messages over link
 299  *
 300  * Returns pointer to link.
 301  */
 302
 303 struct link *tipc_link_create(struct bearer *b_ptr, const u32 peer,
 304                               const struct tipc_media_addr *media_addr)
 305 {
 306         struct link *l_ptr;
 307         struct tipc_msg *msg;
 308         char *if_name;
 309
 310         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 311         if (!l_ptr) {
 312                 warn("Link creation failed, no memory\n");
 313                 return NULL;
 314         }
 315
 316         l_ptr->addr = peer;
 317         if_name = strchr(b_ptr->publ.name, ':') + 1;
 318         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:",
 319                 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
 320                 tipc_node(tipc_own_addr),
 321                 if_name,
 322                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 323                 /* note: peer i/f is appended to link name by reset/activate */
 324         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 325         l_ptr->checkpoint = 1;
 326         l_ptr->b_ptr = b_ptr;
 327         link_set_supervision_props(l_ptr, b_ptr->media->tolerance);
 328         l_ptr->state = RESET_UNKNOWN;
 329
 330         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 331         msg = l_ptr->pmsg;
 332         tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
 333         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 334         msg_set_session(msg, (tipc_random & 0xffff));
 335         msg_set_bearer_id(msg, b_ptr->identity);
 336         strcpy((char *)msg_data(msg), if_name);
 337
 338         l_ptr->priority = b_ptr->priority;
 339         tipc_link_set_queue_limits(l_ptr, b_ptr->media->window);
 340
 341         link_init_max_pkt(l_ptr);
 342
 343         l_ptr->next_out_no = 1;
 344         INIT_LIST_HEAD(&l_ptr->waiting_ports);
 345
 346         link_reset_statistics(l_ptr);
 347
 348         l_ptr->owner = tipc_node_attach_link(l_ptr);
 349         if (!l_ptr->owner) {
 350                 kfree(l_ptr);
 351                 return NULL;
 352         }
 353
 354         k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
 355         list_add_tail(&l_ptr->link_list, &b_ptr->links);
 356         tipc_k_signal((Handler)link_start, (unsigned long)l_ptr);
 357
 358         return l_ptr;
 359 }
 360
 361 /**
 362  * tipc_link_delete - delete a link
 363  * @l_ptr: pointer to link
 364  *
 365  * Note: 'tipc_net_lock' is write_locked, bearer is locked.
 366  * This routine must not grab the node lock until after link timer cancellation
 367  * to avoid a potential deadlock situation.
 368  */
 369
 370 void tipc_link_delete(struct link *l_ptr)
 371 {
 372         if (!l_ptr) {
 373                 err("Attempt to delete non-existent link\n");
 374                 return;
 375         }
 376
 377         k_cancel_timer(&l_ptr->timer);
 378
 379         tipc_node_lock(l_ptr->owner);
 380         tipc_link_reset(l_ptr);
 381         tipc_node_detach_link(l_ptr->owner, l_ptr);
 382         tipc_link_stop(l_ptr);
 383         list_del_init(&l_ptr->link_list);
 384         tipc_node_unlock(l_ptr->owner);
 385         k_term_timer(&l_ptr->timer);
 386         kfree(l_ptr);
 387 }
 388
 389 static void link_start(struct link *l_ptr)
 390 {
 391         link_state_event(l_ptr, STARTING_EVT);
 392 }
 393
 394 /**
 395  * link_schedule_port - schedule port for deferred sending
 396  * @l_ptr: pointer to link
 397  * @origport: reference to sending port
 398  * @sz: amount of data to be sent
 399  *
 400  * Schedules port for renewed sending of messages after link congestion
 401  * has abated.
 402  */
 403
 404 static int link_schedule_port(struct link *l_ptr, u32 origport, u32 sz)
 405 {
 406         struct port *p_ptr;
 407
 408         spin_lock_bh(&tipc_port_list_lock);
 409         p_ptr = tipc_port_lock(origport);
 410         if (p_ptr) {
 411                 if (!p_ptr->wakeup)
 412                         goto exit;
 413                 if (!list_empty(&p_ptr->wait_list))
 414                         goto exit;
 415                 p_ptr->publ.congested = 1;
 416                 p_ptr->waiting_pkts = 1 + ((sz - 1) / l_ptr->max_pkt);
 417                 list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
 418                 l_ptr->stats.link_congs++;
 419 exit:
 420                 tipc_port_unlock(p_ptr);
 421         }
 422         spin_unlock_bh(&tipc_port_list_lock);
 423         return -ELINKCONG;
 424 }
 425
 426 void tipc_link_wakeup_ports(struct link *l_ptr, int all)
 427 {
 428         struct port *p_ptr;
 429         struct port *temp_p_ptr;
 430         int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
 431
 432         if (all)
 433                 win = 100000;
 434         if (win <= 0)
 435                 return;
 436         if (!spin_trylock_bh(&tipc_port_list_lock))
 437                 return;
 438         if (link_congested(l_ptr))
 439                 goto exit;
 440         list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
 441                                  wait_list) {
 442                 if (win <= 0)
 443                         break;
 444                 list_del_init(&p_ptr->wait_list);
 445                 spin_lock_bh(p_ptr->publ.lock);
 446                 p_ptr->publ.congested = 0;
 447                 p_ptr->wakeup(&p_ptr->publ);
 448                 win -= p_ptr->waiting_pkts;
 449                 spin_unlock_bh(p_ptr->publ.lock);
 450         }
 451
 452 exit:
 453         spin_unlock_bh(&tipc_port_list_lock);
 454 }
 455
 456 /**
 457  * link_release_outqueue - purge link's outbound message queue
 458  * @l_ptr: pointer to link
 459  */
 460
 461 static void link_release_outqueue(struct link *l_ptr)
 462 {
 463         struct sk_buff *buf = l_ptr->first_out;
 464         struct sk_buff *next;
 465
 466         while (buf) {
 467                 next = buf->next;
 468                 buf_discard(buf);
 469                 buf = next;
 470         }
 471         l_ptr->first_out = NULL;
 472         l_ptr->out_queue_size = 0;
 473 }
 474
 475 /**
 476  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 477  * @l_ptr: pointer to link
 478  */
 479
 480 void tipc_link_reset_fragments(struct link *l_ptr)
 481 {
 482         struct sk_buff *buf = l_ptr->defragm_buf;
 483         struct sk_buff *next;
 484
 485         while (buf) {
 486                 next = buf->next;
 487                 buf_discard(buf);
 488                 buf = next;
 489         }
 490         l_ptr->defragm_buf = NULL;
 491 }
 492
 493 /**
 494  * tipc_link_stop - purge all inbound and outbound messages associated with link
 495  * @l_ptr: pointer to link
 496  */
 497
 498 void tipc_link_stop(struct link *l_ptr)
 499 {
 500         struct sk_buff *buf;
 501         struct sk_buff *next;
 502
 503         buf = l_ptr->oldest_deferred_in;
 504         while (buf) {
 505                 next = buf->next;
 506                 buf_discard(buf);
 507                 buf = next;
 508         }
 509
 510         buf = l_ptr->first_out;
 511         while (buf) {
 512                 next = buf->next;
 513                 buf_discard(buf);
 514                 buf = next;
 515         }
 516
 517         tipc_link_reset_fragments(l_ptr);
 518
 519         buf_discard(l_ptr->proto_msg_queue);
 520         l_ptr->proto_msg_queue = NULL;
 521 }
 522
 523 /* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
 524 #define link_send_event(fcn, l_ptr, up) do { } while (0)
 525
 526 void tipc_link_reset(struct link *l_ptr)
 527 {
 528         struct sk_buff *buf;
 529         u32 prev_state = l_ptr->state;
 530         u32 checkpoint = l_ptr->next_in_no;
 531         int was_active_link = tipc_link_is_active(l_ptr);
 532
 533         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 534
 535         /* Link is down, accept any session */
 536         l_ptr->peer_session = INVALID_SESSION;
 537
 538         /* Prepare for max packet size negotiation */
 539         link_init_max_pkt(l_ptr);
 540
 541         l_ptr->state = RESET_UNKNOWN;
 542
 543         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 544                 return;
 545
 546         tipc_node_link_down(l_ptr->owner, l_ptr);
 547         tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
 548
 549         if (was_active_link && tipc_node_has_active_links(l_ptr->owner) &&
 550             l_ptr->owner->permit_changeover) {
 551                 l_ptr->reset_checkpoint = checkpoint;
 552                 l_ptr->exp_msg_count = START_CHANGEOVER;
 553         }
 554
 555         /* Clean up all queues: */
 556
 557         link_release_outqueue(l_ptr);
 558         buf_discard(l_ptr->proto_msg_queue);
 559         l_ptr->proto_msg_queue = NULL;
 560         buf = l_ptr->oldest_deferred_in;
 561         while (buf) {
 562                 struct sk_buff *next = buf->next;
 563                 buf_discard(buf);
 564                 buf = next;
 565         }
 566         if (!list_empty(&l_ptr->waiting_ports))
 567                 tipc_link_wakeup_ports(l_ptr, 1);
 568
 569         l_ptr->retransm_queue_head = 0;
 570         l_ptr->retransm_queue_size = 0;
 571         l_ptr->last_out = NULL;
 572         l_ptr->first_out = NULL;
 573         l_ptr->next_out = NULL;
 574         l_ptr->unacked_window = 0;
 575         l_ptr->checkpoint = 1;
 576         l_ptr->next_out_no = 1;
 577         l_ptr->deferred_inqueue_sz = 0;
 578         l_ptr->oldest_deferred_in = NULL;
 579         l_ptr->newest_deferred_in = NULL;
 580         l_ptr->fsm_msg_cnt = 0;
 581         l_ptr->stale_count = 0;
 582         link_reset_statistics(l_ptr);
 583
 584         link_send_event(tipc_cfg_link_event, l_ptr, 0);
 585         if (!in_own_cluster(l_ptr->addr))
 586                 link_send_event(tipc_disc_link_event, l_ptr, 0);
 587 }
 588
 589
 590 static void link_activate(struct link *l_ptr)
 591 {
 592         l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
 593         tipc_node_link_up(l_ptr->owner, l_ptr);
 594         tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
 595         link_send_event(tipc_cfg_link_event, l_ptr, 1);
 596         if (!in_own_cluster(l_ptr->addr))
 597                 link_send_event(tipc_disc_link_event, l_ptr, 1);
 598 }
 599
 600 /**
 601  * link_state_event - link finite state machine
 602  * @l_ptr: pointer to link
 603  * @event: state machine event to process
 604  */
 605
 606 static void link_state_event(struct link *l_ptr, unsigned event)
 607 {
 608         struct link *other;
 609         u32 cont_intv = l_ptr->continuity_interval;
 610
 611         if (!l_ptr->started && (event != STARTING_EVT))
 612                 return;         /* Not yet. */
 613
 614         if (link_blocked(l_ptr)) {
 615                 if (event == TIMEOUT_EVT) {
 616                         link_set_timer(l_ptr, cont_intv);
 617                 }
 618                 return;   /* Changeover going on */
 619         }
 620
 621         switch (l_ptr->state) {
 622         case WORKING_WORKING:
 623                 switch (event) {
 624                 case TRAFFIC_MSG_EVT:
 625                 case ACTIVATE_MSG:
 626                         break;
 627                 case TIMEOUT_EVT:
 628                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 629                                 l_ptr->checkpoint = l_ptr->next_in_no;
 630                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 631                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 632                                                                  0, 0, 0, 0, 0);
 633                                         l_ptr->fsm_msg_cnt++;
 634                                 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
 635                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 636                                                                  1, 0, 0, 0, 0);
 637                                         l_ptr->fsm_msg_cnt++;
 638                                 }
 639                                 link_set_timer(l_ptr, cont_intv);
 640                                 break;
 641                         }
 642                         l_ptr->state = WORKING_UNKNOWN;
 643                         l_ptr->fsm_msg_cnt = 0;
 644                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 645                         l_ptr->fsm_msg_cnt++;
 646                         link_set_timer(l_ptr, cont_intv / 4);
 647                         break;
 648                 case RESET_MSG:
 649                         info("Resetting link <%s>, requested by peer\n",
 650                              l_ptr->name);
 651                         tipc_link_reset(l_ptr);
 652                         l_ptr->state = RESET_RESET;
 653                         l_ptr->fsm_msg_cnt = 0;
 654                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 655                         l_ptr->fsm_msg_cnt++;
 656                         link_set_timer(l_ptr, cont_intv);
 657                         break;
 658                 default:
 659                         err("Unknown link event %u in WW state\n", event);
 660                 }
 661                 break;
 662         case WORKING_UNKNOWN:
 663                 switch (event) {
 664                 case TRAFFIC_MSG_EVT:
 665                 case ACTIVATE_MSG:
 666                         l_ptr->state = WORKING_WORKING;
 667                         l_ptr->fsm_msg_cnt = 0;
 668                         link_set_timer(l_ptr, cont_intv);
 669                         break;
 670                 case RESET_MSG:
 671                         info("Resetting link <%s>, requested by peer "
 672                              "while probing\n", l_ptr->name);
 673                         tipc_link_reset(l_ptr);
 674                         l_ptr->state = RESET_RESET;
 675                         l_ptr->fsm_msg_cnt = 0;
 676                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 677                         l_ptr->fsm_msg_cnt++;
 678                         link_set_timer(l_ptr, cont_intv);
 679                         break;
 680                 case TIMEOUT_EVT:
 681                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 682                                 l_ptr->state = WORKING_WORKING;
 683                                 l_ptr->fsm_msg_cnt = 0;
 684                                 l_ptr->checkpoint = l_ptr->next_in_no;
 685                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 686                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 687                                                                  0, 0, 0, 0, 0);
 688                                         l_ptr->fsm_msg_cnt++;
 689                                 }
 690                                 link_set_timer(l_ptr, cont_intv);
 691                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 692                                 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 693                                                          1, 0, 0, 0, 0);
 694                                 l_ptr->fsm_msg_cnt++;
 695                                 link_set_timer(l_ptr, cont_intv / 4);
 696                         } else {        /* Link has failed */
 697                                 warn("Resetting link <%s>, peer not responding\n",
 698                                      l_ptr->name);
 699                                 tipc_link_reset(l_ptr);
 700                                 l_ptr->state = RESET_UNKNOWN;
 701                                 l_ptr->fsm_msg_cnt = 0;
 702                                 tipc_link_send_proto_msg(l_ptr, RESET_MSG,
 703                                                          0, 0, 0, 0, 0);
 704                                 l_ptr->fsm_msg_cnt++;
 705                                 link_set_timer(l_ptr, cont_intv);
 706                         }
 707                         break;
 708                 default:
 709                         err("Unknown link event %u in WU state\n", event);
 710                 }
 711                 break;
 712         case RESET_UNKNOWN:
 713                 switch (event) {
 714                 case TRAFFIC_MSG_EVT:
 715                         break;
 716                 case ACTIVATE_MSG:
 717                         other = l_ptr->owner->active_links[0];
 718                         if (other && link_working_unknown(other))
 719                                 break;
 720                         l_ptr->state = WORKING_WORKING;
 721                         l_ptr->fsm_msg_cnt = 0;
 722                         link_activate(l_ptr);
 723                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 724                         l_ptr->fsm_msg_cnt++;
 725                         link_set_timer(l_ptr, cont_intv);
 726                         break;
 727                 case RESET_MSG:
 728                         l_ptr->state = RESET_RESET;
 729                         l_ptr->fsm_msg_cnt = 0;
 730                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
 731                         l_ptr->fsm_msg_cnt++;
 732                         link_set_timer(l_ptr, cont_intv);
 733                         break;
 734                 case STARTING_EVT:
 735                         l_ptr->started = 1;
 736                         /* fall through */
 737                 case TIMEOUT_EVT:
 738                         tipc_link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
 739                         l_ptr->fsm_msg_cnt++;
 740                         link_set_timer(l_ptr, cont_intv);
 741                         break;
 742                 default:
 743                         err("Unknown link event %u in RU state\n", event);
 744                 }
 745                 break;
 746         case RESET_RESET:
 747                 switch (event) {
 748                 case TRAFFIC_MSG_EVT:
 749                 case ACTIVATE_MSG:
 750                         other = l_ptr->owner->active_links[0];
 751                         if (other && link_working_unknown(other))
 752                                 break;
 753                         l_ptr->state = WORKING_WORKING;
 754                         l_ptr->fsm_msg_cnt = 0;
 755                         link_activate(l_ptr);
 756                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 757                         l_ptr->fsm_msg_cnt++;
 758                         link_set_timer(l_ptr, cont_intv);
 759                         break;
 760                 case RESET_MSG:
 761                         break;
 762                 case TIMEOUT_EVT:
 763                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 764                         l_ptr->fsm_msg_cnt++;
 765                         link_set_timer(l_ptr, cont_intv);
 766                         break;
 767                 default:
 768                         err("Unknown link event %u in RR state\n", event);
 769                 }
 770                 break;
 771         default:
 772                 err("Unknown link state %u/%u\n", l_ptr->state, event);
 773         }
 774 }
 775
 776 /*
 777  * link_bundle_buf(): Append contents of a buffer to
 778  * the tail of an existing one.
 779  */
 780
 781 static int link_bundle_buf(struct link *l_ptr,
 782                            struct sk_buff *bundler,
 783                            struct sk_buff *buf)
 784 {
 785         struct tipc_msg *bundler_msg = buf_msg(bundler);
 786         struct tipc_msg *msg = buf_msg(buf);
 787         u32 size = msg_size(msg);
 788         u32 bundle_size = msg_size(bundler_msg);
 789         u32 to_pos = align(bundle_size);
 790         u32 pad = to_pos - bundle_size;
 791
 792         if (msg_user(bundler_msg) != MSG_BUNDLER)
 793                 return 0;
 794         if (msg_type(bundler_msg) != OPEN_MSG)
 795                 return 0;
 796         if (skb_tailroom(bundler) < (pad + size))
 797                 return 0;
 798         if (l_ptr->max_pkt < (to_pos + size))
 799                 return 0;
 800
 801         skb_put(bundler, pad + size);
 802         skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
 803         msg_set_size(bundler_msg, to_pos + size);
 804         msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
 805         buf_discard(buf);
 806         l_ptr->stats.sent_bundled++;
 807         return 1;
 808 }
 809
 810 static void link_add_to_outqueue(struct link *l_ptr,
 811                                  struct sk_buff *buf,
 812                                  struct tipc_msg *msg)
 813 {
 814         u32 ack = mod(l_ptr->next_in_no - 1);
 815         u32 seqno = mod(l_ptr->next_out_no++);
 816
 817         msg_set_word(msg, 2, ((ack << 16) | seqno));
 818         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 819         buf->next = NULL;
 820         if (l_ptr->first_out) {
 821                 l_ptr->last_out->next = buf;
 822                 l_ptr->last_out = buf;
 823         } else
 824                 l_ptr->first_out = l_ptr->last_out = buf;
 825         l_ptr->out_queue_size++;
 826 }
 827
 828 /*
 829  * tipc_link_send_buf() is the 'full path' for messages, called from
 830  * inside TIPC when the 'fast path' in tipc_send_buf
 831  * has failed, and from link_send()
 832  */
 833
 834 int tipc_link_send_buf(struct link *l_ptr, struct sk_buff *buf)
 835 {
 836         struct tipc_msg *msg = buf_msg(buf);
 837         u32 size = msg_size(msg);
 838         u32 dsz = msg_data_sz(msg);
 839         u32 queue_size = l_ptr->out_queue_size;
 840         u32 imp = tipc_msg_tot_importance(msg);
 841         u32 queue_limit = l_ptr->queue_limit[imp];
 842         u32 max_packet = l_ptr->max_pkt;
 843
 844         msg_set_prevnode(msg, tipc_own_addr);   /* If routed message */
 845
 846         /* Match msg importance against queue limits: */
 847
 848         if (unlikely(queue_size >= queue_limit)) {
 849                 if (imp <= TIPC_CRITICAL_IMPORTANCE) {
 850                         return link_schedule_port(l_ptr, msg_origport(msg),
 851                                                   size);
 852                 }
 853                 buf_discard(buf);
 854                 if (imp > CONN_MANAGER) {
 855                         warn("Resetting link <%s>, send queue full", l_ptr->name);
 856                         tipc_link_reset(l_ptr);
 857                 }
 858                 return dsz;
 859         }
 860
 861         /* Fragmentation needed ? */
 862
 863         if (size > max_packet)
 864                 return link_send_long_buf(l_ptr, buf);
 865
 866         /* Packet can be queued or sent: */
 867
 868         if (queue_size > l_ptr->stats.max_queue_sz)
 869                 l_ptr->stats.max_queue_sz = queue_size;
 870
 871         if (likely(!tipc_bearer_congested(l_ptr->b_ptr, l_ptr) &&
 872                    !link_congested(l_ptr))) {
 873                 link_add_to_outqueue(l_ptr, buf, msg);
 874
 875                 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
 876                         l_ptr->unacked_window = 0;
 877                 } else {
 878                         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
 879                         l_ptr->stats.bearer_congs++;
 880                         l_ptr->next_out = buf;
 881                 }
 882                 return dsz;
 883         }
 884         /* Congestion: can message be bundled ?: */
 885
 886         if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
 887             (msg_user(msg) != MSG_FRAGMENTER)) {
 888
 889                 /* Try adding message to an existing bundle */
 890
 891                 if (l_ptr->next_out &&
 892                     link_bundle_buf(l_ptr, l_ptr->last_out, buf)) {
 893                         tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
 894                         return dsz;
 895                 }
 896
 897                 /* Try creating a new bundle */
 898
 899                 if (size <= max_packet * 2 / 3) {
 900                         struct sk_buff *bundler = tipc_buf_acquire(max_packet);
 901                         struct tipc_msg bundler_hdr;
 902
 903                         if (bundler) {
 904                                 tipc_msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
 905                                          INT_H_SIZE, l_ptr->addr);
 906                                 skb_copy_to_linear_data(bundler, &bundler_hdr,
 907                                                         INT_H_SIZE);
 908                                 skb_trim(bundler, INT_H_SIZE);
 909                                 link_bundle_buf(l_ptr, bundler, buf);
 910                                 buf = bundler;
 911                                 msg = buf_msg(buf);
 912                                 l_ptr->stats.sent_bundles++;
 913                         }
 914                 }
 915         }
 916         if (!l_ptr->next_out)
 917                 l_ptr->next_out = buf;
 918         link_add_to_outqueue(l_ptr, buf, msg);
 919         tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
 920         return dsz;
 921 }
 922
 923 /*
 924  * tipc_link_send(): same as tipc_link_send_buf(), but the link to use has
 925  * not been selected yet, and the the owner node is not locked
 926  * Called by TIPC internal users, e.g. the name distributor
 927  */
 928
 929 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector)
 930 {
 931         struct link *l_ptr;
 932         struct tipc_node *n_ptr;
 933         int res = -ELINKCONG;
 934
 935         read_lock_bh(&tipc_net_lock);
 936         n_ptr = tipc_node_find(dest);
 937         if (n_ptr) {
 938                 tipc_node_lock(n_ptr);
 939                 l_ptr = n_ptr->active_links[selector & 1];
 940                 if (l_ptr) {
 941                         res = tipc_link_send_buf(l_ptr, buf);
 942                 } else {
 943                         buf_discard(buf);
 944                 }
 945                 tipc_node_unlock(n_ptr);
 946         } else {
 947                 buf_discard(buf);
 948         }
 949         read_unlock_bh(&tipc_net_lock);
 950         return res;
 951 }
 952
 953 /*
 954  * link_send_buf_fast: Entry for data messages where the
 955  * destination link is known and the header is complete,
 956  * inclusive total message length. Very time critical.
 957  * Link is locked. Returns user data length.
 958  */
 959
 960 static int link_send_buf_fast(struct link *l_ptr, struct sk_buff *buf,
 961                               u32 *used_max_pkt)
 962 {
 963         struct tipc_msg *msg = buf_msg(buf);
 964         int res = msg_data_sz(msg);
 965
 966         if (likely(!link_congested(l_ptr))) {
 967                 if (likely(msg_size(msg) <= l_ptr->max_pkt)) {
 968                         if (likely(list_empty(&l_ptr->b_ptr->cong_links))) {
 969                                 link_add_to_outqueue(l_ptr, buf, msg);
 970                                 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf,
 971                                                             &l_ptr->media_addr))) {
 972                                         l_ptr->unacked_window = 0;
 973                                         return res;
 974                                 }
 975                                 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
 976                                 l_ptr->stats.bearer_congs++;
 977                                 l_ptr->next_out = buf;
 978                                 return res;
 979                         }
 980                 } else
 981                         *used_max_pkt = l_ptr->max_pkt;
 982         }
 983         return tipc_link_send_buf(l_ptr, buf);  /* All other cases */
 984 }
 985
 986 /*
 987  * tipc_send_buf_fast: Entry for data messages where the
 988  * destination node is known and the header is complete,
 989  * inclusive total message length.
 990  * Returns user data length.
 991  */
 992 int tipc_send_buf_fast(struct sk_buff *buf, u32 destnode)
 993 {
 994         struct link *l_ptr;
 995         struct tipc_node *n_ptr;
 996         int res;
 997         u32 selector = msg_origport(buf_msg(buf)) & 1;
 998         u32 dummy;
 999
1000         if (destnode == tipc_own_addr)
1001                 return tipc_port_recv_msg(buf);
1002
1003         read_lock_bh(&tipc_net_lock);
1004         n_ptr = tipc_node_find(destnode);
1005         if (likely(n_ptr)) {
1006                 tipc_node_lock(n_ptr);
1007                 l_ptr = n_ptr->active_links[selector];
1008                 if (likely(l_ptr)) {
1009                         res = link_send_buf_fast(l_ptr, buf, &dummy);
1010                         tipc_node_unlock(n_ptr);
1011                         read_unlock_bh(&tipc_net_lock);
1012                         return res;
1013                 }
1014                 tipc_node_unlock(n_ptr);
1015         }
1016         read_unlock_bh(&tipc_net_lock);
1017         res = msg_data_sz(buf_msg(buf));
1018         tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1019         return res;
1020 }
1021
1022
1023 /*
1024  * tipc_link_send_sections_fast: Entry for messages where the
1025  * destination processor is known and the header is complete,
1026  * except for total message length.
1027  * Returns user data length or errno.
1028  */
1029 int tipc_link_send_sections_fast(struct port *sender,
1030                                  struct iovec const *msg_sect,
1031                                  const u32 num_sect,
1032                                  u32 destaddr)
1033 {
1034         struct tipc_msg *hdr = &sender->publ.phdr;
1035         struct link *l_ptr;
1036         struct sk_buff *buf;
1037         struct tipc_node *node;
1038         int res;
1039         u32 selector = msg_origport(hdr) & 1;
1040
1041 again:
1042         /*
1043          * Try building message using port's max_pkt hint.
1044          * (Must not hold any locks while building message.)
1045          */
1046
1047         res = tipc_msg_build(hdr, msg_sect, num_sect, sender->publ.max_pkt,
1048                         !sender->user_port, &buf);
1049
1050         read_lock_bh(&tipc_net_lock);
1051         node = tipc_node_find(destaddr);
1052         if (likely(node)) {
1053                 tipc_node_lock(node);
1054                 l_ptr = node->active_links[selector];
1055                 if (likely(l_ptr)) {
1056                         if (likely(buf)) {
1057                                 res = link_send_buf_fast(l_ptr, buf,
1058                                                          &sender->publ.max_pkt);
1059                                 if (unlikely(res < 0))
1060                                         buf_discard(buf);
1061 exit:
1062                                 tipc_node_unlock(node);
1063                                 read_unlock_bh(&tipc_net_lock);
1064                                 return res;
1065                         }
1066
1067                         /* Exit if build request was invalid */
1068
1069                         if (unlikely(res < 0))
1070                                 goto exit;
1071
1072                         /* Exit if link (or bearer) is congested */
1073
1074                         if (link_congested(l_ptr) ||
1075                             !list_empty(&l_ptr->b_ptr->cong_links)) {
1076                                 res = link_schedule_port(l_ptr,
1077                                                          sender->publ.ref, res);
1078                                 goto exit;
1079                         }
1080
1081                         /*
1082                          * Message size exceeds max_pkt hint; update hint,
1083                          * then re-try fast path or fragment the message
1084                          */
1085
1086                         sender->publ.max_pkt = l_ptr->max_pkt;
1087                         tipc_node_unlock(node);
1088                         read_unlock_bh(&tipc_net_lock);
1089
1090
1091                         if ((msg_hdr_sz(hdr) + res) <= sender->publ.max_pkt)
1092                                 goto again;
1093
1094                         return link_send_sections_long(sender, msg_sect,
1095                                                        num_sect, destaddr);
1096                 }
1097                 tipc_node_unlock(node);
1098         }
1099         read_unlock_bh(&tipc_net_lock);
1100
1101         /* Couldn't find a link to the destination node */
1102
1103         if (buf)
1104                 return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1105         if (res >= 0)
1106                 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1107                                                  TIPC_ERR_NO_NODE);
1108         return res;
1109 }
1110
1111 /*
1112  * link_send_sections_long(): Entry for long messages where the
1113  * destination node is known and the header is complete,
1114  * inclusive total message length.
1115  * Link and bearer congestion status have been checked to be ok,
1116  * and are ignored if they change.
1117  *
1118  * Note that fragments do not use the full link MTU so that they won't have
1119  * to undergo refragmentation if link changeover causes them to be sent
1120  * over another link with an additional tunnel header added as prefix.
1121  * (Refragmentation will still occur if the other link has a smaller MTU.)
1122  *
1123  * Returns user data length or errno.
1124  */
1125 static int link_send_sections_long(struct port *sender,
1126                                    struct iovec const *msg_sect,
1127                                    u32 num_sect,
1128                                    u32 destaddr)
1129 {
1130         struct link *l_ptr;
1131         struct tipc_node *node;
1132         struct tipc_msg *hdr = &sender->publ.phdr;
1133         u32 dsz = msg_data_sz(hdr);
1134         u32 max_pkt, fragm_sz, rest;
1135         struct tipc_msg fragm_hdr;
1136         struct sk_buff *buf, *buf_chain, *prev;
1137         u32 fragm_crs, fragm_rest, hsz, sect_rest;
1138         const unchar *sect_crs;
1139         int curr_sect;
1140         u32 fragm_no;
1141
1142 again:
1143         fragm_no = 1;
1144         max_pkt = sender->publ.max_pkt - INT_H_SIZE;
1145                 /* leave room for tunnel header in case of link changeover */
1146         fragm_sz = max_pkt - INT_H_SIZE;
1147                 /* leave room for fragmentation header in each fragment */
1148         rest = dsz;
1149         fragm_crs = 0;
1150         fragm_rest = 0;
1151         sect_rest = 0;
1152         sect_crs = NULL;
1153         curr_sect = -1;
1154
1155         /* Prepare reusable fragment header: */
1156
1157         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
1158                  INT_H_SIZE, msg_destnode(hdr));
1159         msg_set_link_selector(&fragm_hdr, sender->publ.ref);
1160         msg_set_size(&fragm_hdr, max_pkt);
1161         msg_set_fragm_no(&fragm_hdr, 1);
1162
1163         /* Prepare header of first fragment: */
1164
1165         buf_chain = buf = tipc_buf_acquire(max_pkt);
1166         if (!buf)
1167                 return -ENOMEM;
1168         buf->next = NULL;
1169         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1170         hsz = msg_hdr_sz(hdr);
1171         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
1172
1173         /* Chop up message: */
1174
1175         fragm_crs = INT_H_SIZE + hsz;
1176         fragm_rest = fragm_sz - hsz;
1177
1178         do {            /* For all sections */
1179                 u32 sz;
1180
1181                 if (!sect_rest) {
1182                         sect_rest = msg_sect[++curr_sect].iov_len;
1183                         sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
1184                 }
1185
1186                 if (sect_rest < fragm_rest)
1187                         sz = sect_rest;
1188                 else
1189                         sz = fragm_rest;
1190
1191                 if (likely(!sender->user_port)) {
1192                         if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
1193 error:
1194                                 for (; buf_chain; buf_chain = buf) {
1195                                         buf = buf_chain->next;
1196                                         buf_discard(buf_chain);
1197                                 }
1198                                 return -EFAULT;
1199                         }
1200                 } else
1201                         skb_copy_to_linear_data_offset(buf, fragm_crs,
1202                                                        sect_crs, sz);
1203                 sect_crs += sz;
1204                 sect_rest -= sz;
1205                 fragm_crs += sz;
1206                 fragm_rest -= sz;
1207                 rest -= sz;
1208
1209                 if (!fragm_rest && rest) {
1210
1211                         /* Initiate new fragment: */
1212                         if (rest <= fragm_sz) {
1213                                 fragm_sz = rest;
1214                                 msg_set_type(&fragm_hdr, LAST_FRAGMENT);
1215                         } else {
1216                                 msg_set_type(&fragm_hdr, FRAGMENT);
1217                         }
1218                         msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
1219                         msg_set_fragm_no(&fragm_hdr, ++fragm_no);
1220                         prev = buf;
1221                         buf = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
1222                         if (!buf)
1223                                 goto error;
1224
1225                         buf->next = NULL;
1226                         prev->next = buf;
1227                         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1228                         fragm_crs = INT_H_SIZE;
1229                         fragm_rest = fragm_sz;
1230                 }
1231         } while (rest > 0);
1232
1233         /*
1234          * Now we have a buffer chain. Select a link and check
1235          * that packet size is still OK
1236          */
1237         node = tipc_node_find(destaddr);
1238         if (likely(node)) {
1239                 tipc_node_lock(node);
1240                 l_ptr = node->active_links[sender->publ.ref & 1];
1241                 if (!l_ptr) {
1242                         tipc_node_unlock(node);
1243                         goto reject;
1244                 }
1245                 if (l_ptr->max_pkt < max_pkt) {
1246                         sender->publ.max_pkt = l_ptr->max_pkt;
1247                         tipc_node_unlock(node);
1248                         for (; buf_chain; buf_chain = buf) {
1249                                 buf = buf_chain->next;
1250                                 buf_discard(buf_chain);
1251                         }
1252                         goto again;
1253                 }
1254         } else {
1255 reject:
1256                 for (; buf_chain; buf_chain = buf) {
1257                         buf = buf_chain->next;
1258                         buf_discard(buf_chain);
1259                 }
1260                 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1261                                                  TIPC_ERR_NO_NODE);
1262         }
1263
1264         /* Append whole chain to send queue: */
1265
1266         buf = buf_chain;
1267         l_ptr->long_msg_seq_no = mod(l_ptr->long_msg_seq_no + 1);
1268         if (!l_ptr->next_out)
1269                 l_ptr->next_out = buf_chain;
1270         l_ptr->stats.sent_fragmented++;
1271         while (buf) {
1272                 struct sk_buff *next = buf->next;
1273                 struct tipc_msg *msg = buf_msg(buf);
1274
1275                 l_ptr->stats.sent_fragments++;
1276                 msg_set_long_msgno(msg, l_ptr->long_msg_seq_no);
1277                 link_add_to_outqueue(l_ptr, buf, msg);
1278                 buf = next;
1279         }
1280
1281         /* Send it, if possible: */
1282
1283         tipc_link_push_queue(l_ptr);
1284         tipc_node_unlock(node);
1285         return dsz;
1286 }
1287
1288 /*
1289  * tipc_link_push_packet: Push one unsent packet to the media
1290  */
1291 u32 tipc_link_push_packet(struct link *l_ptr)
1292 {
1293         struct sk_buff *buf = l_ptr->first_out;
1294         u32 r_q_size = l_ptr->retransm_queue_size;
1295         u32 r_q_head = l_ptr->retransm_queue_head;
1296
1297         /* Step to position where retransmission failed, if any,    */
1298         /* consider that buffers may have been released in meantime */
1299
1300         if (r_q_size && buf) {
1301                 u32 last = lesser(mod(r_q_head + r_q_size),
1302                                   link_last_sent(l_ptr));
1303                 u32 first = msg_seqno(buf_msg(buf));
1304
1305                 while (buf && less(first, r_q_head)) {
1306                         first = mod(first + 1);
1307                         buf = buf->next;
1308                 }
1309                 l_ptr->retransm_queue_head = r_q_head = first;
1310                 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
1311         }
1312
1313         /* Continue retransmission now, if there is anything: */
1314
1315         if (r_q_size && buf) {
1316                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1317                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1318                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1319                         l_ptr->retransm_queue_head = mod(++r_q_head);
1320                         l_ptr->retransm_queue_size = --r_q_size;
1321                         l_ptr->stats.retransmitted++;
1322                         return 0;
1323                 } else {
1324                         l_ptr->stats.bearer_congs++;
1325                         return PUSH_FAILED;
1326                 }
1327         }
1328
1329         /* Send deferred protocol message, if any: */
1330
1331         buf = l_ptr->proto_msg_queue;
1332         if (buf) {
1333                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1334                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1335                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1336                         l_ptr->unacked_window = 0;
1337                         buf_discard(buf);
1338                         l_ptr->proto_msg_queue = NULL;
1339                         return 0;
1340                 } else {
1341                         l_ptr->stats.bearer_congs++;
1342                         return PUSH_FAILED;
1343                 }
1344         }
1345
1346         /* Send one deferred data message, if send window not full: */
1347
1348         buf = l_ptr->next_out;
1349         if (buf) {
1350                 struct tipc_msg *msg = buf_msg(buf);
1351                 u32 next = msg_seqno(msg);
1352                 u32 first = msg_seqno(buf_msg(l_ptr->first_out));
1353
1354                 if (mod(next - first) < l_ptr->queue_limit[0]) {
1355                         msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1356                         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1357                         if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1358                                 if (msg_user(msg) == MSG_BUNDLER)
1359                                         msg_set_type(msg, CLOSED_MSG);
1360                                 l_ptr->next_out = buf->next;
1361                                 return 0;
1362                         } else {
1363                                 l_ptr->stats.bearer_congs++;
1364                                 return PUSH_FAILED;
1365                         }
1366                 }
1367         }
1368         return PUSH_FINISHED;
1369 }
1370
1371 /*
1372  * push_queue(): push out the unsent messages of a link where
1373  *               congestion has abated. Node is locked
1374  */
1375 void tipc_link_push_queue(struct link *l_ptr)
1376 {
1377         u32 res;
1378
1379         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr))
1380                 return;
1381
1382         do {
1383                 res = tipc_link_push_packet(l_ptr);
1384         } while (!res);
1385
1386         if (res == PUSH_FAILED)
1387                 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1388 }
1389
1390 static void link_reset_all(unsigned long addr)
1391 {
1392         struct tipc_node *n_ptr;
1393         char addr_string[16];
1394         u32 i;
1395
1396         read_lock_bh(&tipc_net_lock);
1397         n_ptr = tipc_node_find((u32)addr);
1398         if (!n_ptr) {
1399                 read_unlock_bh(&tipc_net_lock);
1400                 return; /* node no longer exists */
1401         }
1402
1403         tipc_node_lock(n_ptr);
1404
1405         warn("Resetting all links to %s\n",
1406              tipc_addr_string_fill(addr_string, n_ptr->addr));
1407
1408         for (i = 0; i < MAX_BEARERS; i++) {
1409                 if (n_ptr->links[i]) {
1410                         link_print(n_ptr->links[i], "Resetting link\n");
1411                         tipc_link_reset(n_ptr->links[i]);
1412                 }
1413         }
1414
1415         tipc_node_unlock(n_ptr);
1416         read_unlock_bh(&tipc_net_lock);
1417 }
1418
1419 static void link_retransmit_failure(struct link *l_ptr, struct sk_buff *buf)
1420 {
1421         struct tipc_msg *msg = buf_msg(buf);
1422
1423         warn("Retransmission failure on link <%s>\n", l_ptr->name);
1424
1425         if (l_ptr->addr) {
1426
1427                 /* Handle failure on standard link */
1428
1429                 link_print(l_ptr, "Resetting link\n");
1430                 tipc_link_reset(l_ptr);
1431
1432         } else {
1433
1434                 /* Handle failure on broadcast link */
1435
1436                 struct tipc_node *n_ptr;
1437                 char addr_string[16];
1438
1439                 info("Msg seq number: %u,  ", msg_seqno(msg));
1440                 info("Outstanding acks: %lu\n",
1441                      (unsigned long) TIPC_SKB_CB(buf)->handle);
1442
1443                 n_ptr = l_ptr->owner->next;
1444                 tipc_node_lock(n_ptr);
1445
1446                 tipc_addr_string_fill(addr_string, n_ptr->addr);
1447                 info("Multicast link info for %s\n", addr_string);
1448                 info("Supported: %d,  ", n_ptr->bclink.supported);
1449                 info("Acked: %u\n", n_ptr->bclink.acked);
1450                 info("Last in: %u,  ", n_ptr->bclink.last_in);
1451                 info("Gap after: %u,  ", n_ptr->bclink.gap_after);
1452                 info("Gap to: %u\n", n_ptr->bclink.gap_to);
1453                 info("Nack sync: %u\n\n", n_ptr->bclink.nack_sync);
1454
1455                 tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
1456
1457                 tipc_node_unlock(n_ptr);
1458
1459                 l_ptr->stale_count = 0;
1460         }
1461 }
1462
1463 void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *buf,
1464                           u32 retransmits)
1465 {
1466         struct tipc_msg *msg;
1467
1468         if (!buf)
1469                 return;
1470
1471         msg = buf_msg(buf);
1472
1473         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
1474                 if (l_ptr->retransm_queue_size == 0) {
1475                         l_ptr->retransm_queue_head = msg_seqno(msg);
1476                         l_ptr->retransm_queue_size = retransmits;
1477                 } else {
1478                         err("Unexpected retransmit on link %s (qsize=%d)\n",
1479                             l_ptr->name, l_ptr->retransm_queue_size);
1480                 }
1481                 return;
1482         } else {
1483                 /* Detect repeated retransmit failures on uncongested bearer */
1484
1485                 if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1486                         if (++l_ptr->stale_count > 100) {
1487                                 link_retransmit_failure(l_ptr, buf);
1488                                 return;
1489                         }
1490                 } else {
1491                         l_ptr->last_retransmitted = msg_seqno(msg);
1492                         l_ptr->stale_count = 1;
1493                 }
1494         }
1495
1496         while (retransmits && (buf != l_ptr->next_out) && buf) {
1497                 msg = buf_msg(buf);
1498                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1499                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1500                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1501                         buf = buf->next;
1502                         retransmits--;
1503                         l_ptr->stats.retransmitted++;
1504                 } else {
1505                         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1506                         l_ptr->stats.bearer_congs++;
1507                         l_ptr->retransm_queue_head = msg_seqno(buf_msg(buf));
1508                         l_ptr->retransm_queue_size = retransmits;
1509                         return;
1510                 }
1511         }
1512
1513         l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1514 }
1515
1516 /**
1517  * link_insert_deferred_queue - insert deferred messages back into receive chain
1518  */
1519
1520 static struct sk_buff *link_insert_deferred_queue(struct link *l_ptr,
1521                                                   struct sk_buff *buf)
1522 {
1523         u32 seq_no;
1524
1525         if (l_ptr->oldest_deferred_in == NULL)
1526                 return buf;
1527
1528         seq_no = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
1529         if (seq_no == mod(l_ptr->next_in_no)) {
1530                 l_ptr->newest_deferred_in->next = buf;
1531                 buf = l_ptr->oldest_deferred_in;
1532                 l_ptr->oldest_deferred_in = NULL;
1533                 l_ptr->deferred_inqueue_sz = 0;
1534         }
1535         return buf;
1536 }
1537
1538 /**
1539  * link_recv_buf_validate - validate basic format of received message
1540  *
1541  * This routine ensures a TIPC message has an acceptable header, and at least
1542  * as much data as the header indicates it should.  The routine also ensures
1543  * that the entire message header is stored in the main fragment of the message
1544  * buffer, to simplify future access to message header fields.
1545  *
1546  * Note: Having extra info present in the message header or data areas is OK.
1547  * TIPC will ignore the excess, under the assumption that it is optional info
1548  * introduced by a later release of the protocol.
1549  */
1550
1551 static int link_recv_buf_validate(struct sk_buff *buf)
1552 {
1553         static u32 min_data_hdr_size[8] = {
1554                 SHORT_H_SIZE, MCAST_H_SIZE, LONG_H_SIZE, DIR_MSG_H_SIZE,
1555                 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1556                 };
1557
1558         struct tipc_msg *msg;
1559         u32 tipc_hdr[2];
1560         u32 size;
1561         u32 hdr_size;
1562         u32 min_hdr_size;
1563
1564         if (unlikely(buf->len < MIN_H_SIZE))
1565                 return 0;
1566
1567         msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1568         if (msg == NULL)
1569                 return 0;
1570
1571         if (unlikely(msg_version(msg) != TIPC_VERSION))
1572                 return 0;
1573
1574         size = msg_size(msg);
1575         hdr_size = msg_hdr_sz(msg);
1576         min_hdr_size = msg_isdata(msg) ?
1577                 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1578
1579         if (unlikely((hdr_size < min_hdr_size) ||
1580                      (size < hdr_size) ||
1581                      (buf->len < size) ||
1582                      (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1583                 return 0;
1584
1585         return pskb_may_pull(buf, hdr_size);
1586 }
1587
1588 /**
1589  * tipc_recv_msg - process TIPC messages arriving from off-node
1590  * @head: pointer to message buffer chain
1591  * @tb_ptr: pointer to bearer message arrived on
1592  *
1593  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1594  * structure (i.e. cannot be NULL), but bearer can be inactive.
1595  */
1596
1597 void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *tb_ptr)
1598 {
1599         read_lock_bh(&tipc_net_lock);
1600         while (head) {
1601                 struct bearer *b_ptr = (struct bearer *)tb_ptr;
1602                 struct tipc_node *n_ptr;
1603                 struct link *l_ptr;
1604                 struct sk_buff *crs;
1605                 struct sk_buff *buf = head;
1606                 struct tipc_msg *msg;
1607                 u32 seq_no;
1608                 u32 ackd;
1609                 u32 released = 0;
1610                 int type;
1611
1612                 head = head->next;
1613
1614                 /* Ensure bearer is still enabled */
1615
1616                 if (unlikely(!b_ptr->active))
1617                         goto cont;
1618
1619                 /* Ensure message is well-formed */
1620
1621                 if (unlikely(!link_recv_buf_validate(buf)))
1622                         goto cont;
1623
1624                 /* Ensure message data is a single contiguous unit */
1625
1626                 if (unlikely(buf_linearize(buf))) {
1627                         goto cont;
1628                 }
1629
1630                 /* Handle arrival of a non-unicast link message */
1631
1632                 msg = buf_msg(buf);
1633
1634                 if (unlikely(msg_non_seq(msg))) {
1635                         if (msg_user(msg) ==  LINK_CONFIG)
1636                                 tipc_disc_recv_msg(buf, b_ptr);
1637                         else
1638                                 tipc_bclink_recv_pkt(buf);
1639                         continue;
1640                 }
1641
1642                 if (unlikely(!msg_short(msg) &&
1643                              (msg_destnode(msg) != tipc_own_addr)))
1644                         goto cont;
1645
1646                 /* Discard non-routeable messages destined for another node */
1647
1648                 if (unlikely(!msg_isdata(msg) &&
1649                              (msg_destnode(msg) != tipc_own_addr))) {
1650                         if ((msg_user(msg) != CONN_MANAGER) &&
1651                             (msg_user(msg) != MSG_FRAGMENTER))
1652                                 goto cont;
1653                 }
1654
1655                 /* Locate neighboring node that sent message */
1656
1657                 n_ptr = tipc_node_find(msg_prevnode(msg));
1658                 if (unlikely(!n_ptr))
1659                         goto cont;
1660                 tipc_node_lock(n_ptr);
1661
1662                 /* Don't talk to neighbor during cleanup after last session */
1663
1664                 if (n_ptr->cleanup_required) {
1665                         tipc_node_unlock(n_ptr);
1666                         goto cont;
1667                 }
1668
1669                 /* Locate unicast link endpoint that should handle message */
1670
1671                 l_ptr = n_ptr->links[b_ptr->identity];
1672                 if (unlikely(!l_ptr)) {
1673                         tipc_node_unlock(n_ptr);
1674                         goto cont;
1675                 }
1676
1677                 /* Validate message sequence number info */
1678
1679                 seq_no = msg_seqno(msg);
1680                 ackd = msg_ack(msg);
1681
1682                 /* Release acked messages */
1683
1684                 if (less(n_ptr->bclink.acked, msg_bcast_ack(msg))) {
1685                         if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
1686                                 tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1687                 }
1688
1689                 crs = l_ptr->first_out;
1690                 while ((crs != l_ptr->next_out) &&
1691                        less_eq(msg_seqno(buf_msg(crs)), ackd)) {
1692                         struct sk_buff *next = crs->next;
1693
1694                         buf_discard(crs);
1695                         crs = next;
1696                         released++;
1697                 }
1698                 if (released) {
1699                         l_ptr->first_out = crs;
1700                         l_ptr->out_queue_size -= released;
1701                 }
1702
1703                 /* Try sending any messages link endpoint has pending */
1704
1705                 if (unlikely(l_ptr->next_out))
1706                         tipc_link_push_queue(l_ptr);
1707                 if (unlikely(!list_empty(&l_ptr->waiting_ports)))
1708                         tipc_link_wakeup_ports(l_ptr, 0);
1709                 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1710                         l_ptr->stats.sent_acks++;
1711                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1712                 }
1713
1714                 /* Now (finally!) process the incoming message */
1715
1716 protocol_check:
1717                 if (likely(link_working_working(l_ptr))) {
1718                         if (likely(seq_no == mod(l_ptr->next_in_no))) {
1719                                 l_ptr->next_in_no++;
1720                                 if (unlikely(l_ptr->oldest_deferred_in))
1721                                         head = link_insert_deferred_queue(l_ptr,
1722                                                                           head);
1723                                 if (likely(msg_is_dest(msg, tipc_own_addr))) {
1724 deliver:
1725                                         if (likely(msg_isdata(msg))) {
1726                                                 tipc_node_unlock(n_ptr);
1727                                                 tipc_port_recv_msg(buf);
1728                                                 continue;
1729                                         }
1730                                         switch (msg_user(msg)) {
1731                                         case MSG_BUNDLER:
1732                                                 l_ptr->stats.recv_bundles++;
1733                                                 l_ptr->stats.recv_bundled +=
1734                                                         msg_msgcnt(msg);
1735                                                 tipc_node_unlock(n_ptr);
1736                                                 tipc_link_recv_bundle(buf);
1737                                                 continue;
1738                                         case ROUTE_DISTRIBUTOR:
1739                                                 tipc_node_unlock(n_ptr);
1740                                                 buf_discard(buf);
1741                                                 continue;
1742                                         case NAME_DISTRIBUTOR:
1743                                                 tipc_node_unlock(n_ptr);
1744                                                 tipc_named_recv(buf);
1745                                                 continue;
1746                                         case CONN_MANAGER:
1747                                                 tipc_node_unlock(n_ptr);
1748                                                 tipc_port_recv_proto_msg(buf);
1749                                                 continue;
1750                                         case MSG_FRAGMENTER:
1751                                                 l_ptr->stats.recv_fragments++;
1752                                                 if (tipc_link_recv_fragment(&l_ptr->defragm_buf,
1753                                                                             &buf, &msg)) {
1754                                                         l_ptr->stats.recv_fragmented++;
1755                                                         goto deliver;
1756                                                 }
1757                                                 break;
1758                                         case CHANGEOVER_PROTOCOL:
1759                                                 type = msg_type(msg);
1760                                                 if (link_recv_changeover_msg(&l_ptr, &buf)) {
1761                                                         msg = buf_msg(buf);
1762                                                         seq_no = msg_seqno(msg);
1763                                                         if (type == ORIGINAL_MSG)
1764                                                                 goto deliver;
1765                                                         goto protocol_check;
1766                                                 }
1767                                                 break;
1768                                         }
1769                                 }
1770                                 tipc_node_unlock(n_ptr);
1771                                 tipc_net_route_msg(buf);
1772                                 continue;
1773                         }
1774                         link_handle_out_of_seq_msg(l_ptr, buf);
1775                         head = link_insert_deferred_queue(l_ptr, head);
1776                         tipc_node_unlock(n_ptr);
1777                         continue;
1778                 }
1779
1780                 if (msg_user(msg) == LINK_PROTOCOL) {
1781                         link_recv_proto_msg(l_ptr, buf);
1782                         head = link_insert_deferred_queue(l_ptr, head);
1783                         tipc_node_unlock(n_ptr);
1784                         continue;
1785                 }
1786                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1787
1788                 if (link_working_working(l_ptr)) {
1789                         /* Re-insert in front of queue */
1790                         buf->next = head;
1791                         head = buf;
1792                         tipc_node_unlock(n_ptr);
1793                         continue;
1794                 }
1795                 tipc_node_unlock(n_ptr);
1796 cont:
1797                 buf_discard(buf);
1798         }
1799         read_unlock_bh(&tipc_net_lock);
1800 }
1801
1802 /*
1803  * link_defer_buf(): Sort a received out-of-sequence packet
1804  *                   into the deferred reception queue.
1805  * Returns the increase of the queue length,i.e. 0 or 1
1806  */
1807
1808 u32 tipc_link_defer_pkt(struct sk_buff **head,
1809                         struct sk_buff **tail,
1810                         struct sk_buff *buf)
1811 {
1812         struct sk_buff *prev = NULL;
1813         struct sk_buff *crs = *head;
1814         u32 seq_no = msg_seqno(buf_msg(buf));
1815
1816         buf->next = NULL;
1817
1818         /* Empty queue ? */
1819         if (*head == NULL) {
1820                 *head = *tail = buf;
1821                 return 1;
1822         }
1823
1824         /* Last ? */
1825         if (less(msg_seqno(buf_msg(*tail)), seq_no)) {
1826                 (*tail)->next = buf;
1827                 *tail = buf;
1828                 return 1;
1829         }
1830
1831         /* Scan through queue and sort it in */
1832         do {
1833                 struct tipc_msg *msg = buf_msg(crs);
1834
1835                 if (less(seq_no, msg_seqno(msg))) {
1836                         buf->next = crs;
1837                         if (prev)
1838                                 prev->next = buf;
1839                         else
1840                                 *head = buf;
1841                         return 1;
1842                 }
1843                 if (seq_no == msg_seqno(msg)) {
1844                         break;
1845                 }
1846                 prev = crs;
1847                 crs = crs->next;
1848         } while (crs);
1849
1850         /* Message is a duplicate of an existing message */
1851
1852         buf_discard(buf);
1853         return 0;
1854 }
1855
1856 /**
1857  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1858  */
1859
1860 static void link_handle_out_of_seq_msg(struct link *l_ptr,
1861                                        struct sk_buff *buf)
1862 {
1863         u32 seq_no = msg_seqno(buf_msg(buf));
1864
1865         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1866                 link_recv_proto_msg(l_ptr, buf);
1867                 return;
1868         }
1869
1870         /* Record OOS packet arrival (force mismatch on next timeout) */
1871
1872         l_ptr->checkpoint--;
1873
1874         /*
1875          * Discard packet if a duplicate; otherwise add it to deferred queue
1876          * and notify peer of gap as per protocol specification
1877          */
1878
1879         if (less(seq_no, mod(l_ptr->next_in_no))) {
1880                 l_ptr->stats.duplicates++;
1881                 buf_discard(buf);
1882                 return;
1883         }
1884
1885         if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
1886                                 &l_ptr->newest_deferred_in, buf)) {
1887                 l_ptr->deferred_inqueue_sz++;
1888                 l_ptr->stats.deferred_recv++;
1889                 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
1890                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1891         } else
1892                 l_ptr->stats.duplicates++;
1893 }
1894
1895 /*
1896  * Send protocol message to the other endpoint.
1897  */
1898 void tipc_link_send_proto_msg(struct link *l_ptr, u32 msg_typ, int probe_msg,
1899                               u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
1900 {
1901         struct sk_buff *buf = NULL;
1902         struct tipc_msg *msg = l_ptr->pmsg;
1903         u32 msg_size = sizeof(l_ptr->proto_msg);
1904
1905         if (link_blocked(l_ptr))
1906                 return;
1907         msg_set_type(msg, msg_typ);
1908         msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
1909         msg_set_bcast_ack(msg, mod(l_ptr->owner->bclink.last_in));
1910         msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
1911
1912         if (msg_typ == STATE_MSG) {
1913                 u32 next_sent = mod(l_ptr->next_out_no);
1914
1915                 if (!tipc_link_is_up(l_ptr))
1916                         return;
1917                 if (l_ptr->next_out)
1918                         next_sent = msg_seqno(buf_msg(l_ptr->next_out));
1919                 msg_set_next_sent(msg, next_sent);
1920                 if (l_ptr->oldest_deferred_in) {
1921                         u32 rec = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
1922                         gap = mod(rec - mod(l_ptr->next_in_no));
1923                 }
1924                 msg_set_seq_gap(msg, gap);
1925                 if (gap)
1926                         l_ptr->stats.sent_nacks++;
1927                 msg_set_link_tolerance(msg, tolerance);
1928                 msg_set_linkprio(msg, priority);
1929                 msg_set_max_pkt(msg, ack_mtu);
1930                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1931                 msg_set_probe(msg, probe_msg != 0);
1932                 if (probe_msg) {
1933                         u32 mtu = l_ptr->max_pkt;
1934
1935                         if ((mtu < l_ptr->max_pkt_target) &&
1936                             link_working_working(l_ptr) &&
1937                             l_ptr->fsm_msg_cnt) {
1938                                 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1939                                 if (l_ptr->max_pkt_probes == 10) {
1940                                         l_ptr->max_pkt_target = (msg_size - 4);
1941                                         l_ptr->max_pkt_probes = 0;
1942                                         msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1943                                 }
1944                                 l_ptr->max_pkt_probes++;
1945                         }
1946
1947                         l_ptr->stats.sent_probes++;
1948                 }
1949                 l_ptr->stats.sent_states++;
1950         } else {                /* RESET_MSG or ACTIVATE_MSG */
1951                 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
1952                 msg_set_seq_gap(msg, 0);
1953                 msg_set_next_sent(msg, 1);
1954                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1955                 msg_set_linkprio(msg, l_ptr->priority);
1956                 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
1957         }
1958
1959         if (tipc_node_has_redundant_links(l_ptr->owner)) {
1960                 msg_set_redundant_link(msg);
1961         } else {
1962                 msg_clear_redundant_link(msg);
1963         }
1964         msg_set_linkprio(msg, l_ptr->priority);
1965
1966         /* Ensure sequence number will not fit : */
1967
1968         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1969
1970         /* Congestion? */
1971
1972         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
1973                 if (!l_ptr->proto_msg_queue) {
1974                         l_ptr->proto_msg_queue =
1975                                 tipc_buf_acquire(sizeof(l_ptr->proto_msg));
1976                 }
1977                 buf = l_ptr->proto_msg_queue;
1978                 if (!buf)
1979                         return;
1980                 skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1981                 return;
1982         }
1983         msg_set_timestamp(msg, jiffies_to_msecs(jiffies));
1984
1985         /* Message can be sent */
1986
1987         buf = tipc_buf_acquire(msg_size);
1988         if (!buf)
1989                 return;
1990
1991         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1992         msg_set_size(buf_msg(buf), msg_size);
1993
1994         if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1995                 l_ptr->unacked_window = 0;
1996                 buf_discard(buf);
1997                 return;
1998         }
1999
2000         /* New congestion */
2001         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
2002         l_ptr->proto_msg_queue = buf;
2003         l_ptr->stats.bearer_congs++;
2004 }
2005
2006 /*
2007  * Receive protocol message :
2008  * Note that network plane id propagates through the network, and may
2009  * change at any time. The node with lowest address rules
2010  */
2011
2012 static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf)
2013 {
2014         u32 rec_gap = 0;
2015         u32 max_pkt_info;
2016         u32 max_pkt_ack;
2017         u32 msg_tol;
2018         struct tipc_msg *msg = buf_msg(buf);
2019
2020         if (link_blocked(l_ptr))
2021                 goto exit;
2022
2023         /* record unnumbered packet arrival (force mismatch on next timeout) */
2024
2025         l_ptr->checkpoint--;
2026
2027         if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
2028                 if (tipc_own_addr > msg_prevnode(msg))
2029                         l_ptr->b_ptr->net_plane = msg_net_plane(msg);
2030
2031         l_ptr->owner->permit_changeover = msg_redundant_link(msg);
2032
2033         switch (msg_type(msg)) {
2034
2035         case RESET_MSG:
2036                 if (!link_working_unknown(l_ptr) &&
2037                     (l_ptr->peer_session != INVALID_SESSION)) {
2038                         if (msg_session(msg) == l_ptr->peer_session)
2039                                 break; /* duplicate: ignore */
2040                 }
2041                 /* fall thru' */
2042         case ACTIVATE_MSG:
2043                 /* Update link settings according other endpoint's values */
2044
2045                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
2046
2047                 if ((msg_tol = msg_link_tolerance(msg)) &&
2048                     (msg_tol > l_ptr->tolerance))
2049                         link_set_supervision_props(l_ptr, msg_tol);
2050
2051                 if (msg_linkprio(msg) > l_ptr->priority)
2052                         l_ptr->priority = msg_linkprio(msg);
2053
2054                 max_pkt_info = msg_max_pkt(msg);
2055                 if (max_pkt_info) {
2056                         if (max_pkt_info < l_ptr->max_pkt_target)
2057                                 l_ptr->max_pkt_target = max_pkt_info;
2058                         if (l_ptr->max_pkt > l_ptr->max_pkt_target)
2059                                 l_ptr->max_pkt = l_ptr->max_pkt_target;
2060                 } else {
2061                         l_ptr->max_pkt = l_ptr->max_pkt_target;
2062                 }
2063                 l_ptr->owner->bclink.supported = (max_pkt_info != 0);
2064
2065                 link_state_event(l_ptr, msg_type(msg));
2066
2067                 l_ptr->peer_session = msg_session(msg);
2068                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
2069
2070                 /* Synchronize broadcast sequence numbers */
2071                 if (!tipc_node_has_redundant_links(l_ptr->owner)) {
2072                         l_ptr->owner->bclink.last_in = mod(msg_last_bcast(msg));
2073                 }
2074                 break;
2075         case STATE_MSG:
2076
2077                 if ((msg_tol = msg_link_tolerance(msg)))
2078                         link_set_supervision_props(l_ptr, msg_tol);
2079
2080                 if (msg_linkprio(msg) &&
2081                     (msg_linkprio(msg) != l_ptr->priority)) {
2082                         warn("Resetting link <%s>, priority change %u->%u\n",
2083                              l_ptr->name, l_ptr->priority, msg_linkprio(msg));
2084                         l_ptr->priority = msg_linkprio(msg);
2085                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
2086                         break;
2087                 }
2088                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
2089                 l_ptr->stats.recv_states++;
2090                 if (link_reset_unknown(l_ptr))
2091                         break;
2092
2093                 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
2094                         rec_gap = mod(msg_next_sent(msg) -
2095                                       mod(l_ptr->next_in_no));
2096                 }
2097
2098                 max_pkt_ack = msg_max_pkt(msg);
2099                 if (max_pkt_ack > l_ptr->max_pkt) {
2100                         l_ptr->max_pkt = max_pkt_ack;
2101                         l_ptr->max_pkt_probes = 0;
2102                 }
2103
2104                 max_pkt_ack = 0;
2105                 if (msg_probe(msg)) {
2106                         l_ptr->stats.recv_probes++;
2107                         if (msg_size(msg) > sizeof(l_ptr->proto_msg)) {
2108                                 max_pkt_ack = msg_size(msg);
2109                         }
2110                 }
2111
2112                 /* Protocol message before retransmits, reduce loss risk */
2113
2114                 tipc_bclink_check_gap(l_ptr->owner, msg_last_bcast(msg));
2115
2116                 if (rec_gap || (msg_probe(msg))) {
2117                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2118                                                  0, rec_gap, 0, 0, max_pkt_ack);
2119                 }
2120                 if (msg_seq_gap(msg)) {
2121                         l_ptr->stats.recv_nacks++;
2122                         tipc_link_retransmit(l_ptr, l_ptr->first_out,
2123                                              msg_seq_gap(msg));
2124                 }
2125                 break;
2126         }
2127 exit:
2128         buf_discard(buf);
2129 }
2130
2131
2132 /*
2133  * tipc_link_tunnel(): Send one message via a link belonging to
2134  * another bearer. Owner node is locked.
2135  */
2136 static void tipc_link_tunnel(struct link *l_ptr,
2137                              struct tipc_msg *tunnel_hdr,
2138                              struct tipc_msg  *msg,
2139                              u32 selector)
2140 {
2141         struct link *tunnel;
2142         struct sk_buff *buf;
2143         u32 length = msg_size(msg);
2144
2145         tunnel = l_ptr->owner->active_links[selector & 1];
2146         if (!tipc_link_is_up(tunnel)) {
2147                 warn("Link changeover error, "
2148                      "tunnel link no longer available\n");
2149                 return;
2150         }
2151         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
2152         buf = tipc_buf_acquire(length + INT_H_SIZE);
2153         if (!buf) {
2154                 warn("Link changeover error, "
2155                      "unable to send tunnel msg\n");
2156                 return;
2157         }
2158         skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
2159         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
2160         tipc_link_send_buf(tunnel, buf);
2161 }
2162
2163
2164
2165 /*
2166  * changeover(): Send whole message queue via the remaining link
2167  *               Owner node is locked.
2168  */
2169
2170 void tipc_link_changeover(struct link *l_ptr)
2171 {
2172         u32 msgcount = l_ptr->out_queue_size;
2173         struct sk_buff *crs = l_ptr->first_out;
2174         struct link *tunnel = l_ptr->owner->active_links[0];
2175         struct tipc_msg tunnel_hdr;
2176         int split_bundles;
2177
2178         if (!tunnel)
2179                 return;
2180
2181         if (!l_ptr->owner->permit_changeover) {
2182                 warn("Link changeover error, "
2183                      "peer did not permit changeover\n");
2184                 return;
2185         }
2186
2187         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2188                  ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
2189         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2190         msg_set_msgcnt(&tunnel_hdr, msgcount);
2191
2192         if (!l_ptr->first_out) {
2193                 struct sk_buff *buf;
2194
2195                 buf = tipc_buf_acquire(INT_H_SIZE);
2196                 if (buf) {
2197                         skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
2198                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
2199                         tipc_link_send_buf(tunnel, buf);
2200                 } else {
2201                         warn("Link changeover error, "
2202                              "unable to send changeover msg\n");
2203                 }
2204                 return;
2205         }
2206
2207         split_bundles = (l_ptr->owner->active_links[0] !=
2208                          l_ptr->owner->active_links[1]);
2209
2210         while (crs) {
2211                 struct tipc_msg *msg = buf_msg(crs);
2212
2213                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
2214                         struct tipc_msg *m = msg_get_wrapped(msg);
2215                         unchar *pos = (unchar *)m;
2216
2217                         msgcount = msg_msgcnt(msg);
2218                         while (msgcount--) {
2219                                 msg_set_seqno(m, msg_seqno(msg));
2220                                 tipc_link_tunnel(l_ptr, &tunnel_hdr, m,
2221                                                  msg_link_selector(m));
2222                                 pos += align(msg_size(m));
2223                                 m = (struct tipc_msg *)pos;
2224                         }
2225                 } else {
2226                         tipc_link_tunnel(l_ptr, &tunnel_hdr, msg,
2227                                          msg_link_selector(msg));
2228                 }
2229                 crs = crs->next;
2230         }
2231 }
2232
2233 void tipc_link_send_duplicate(struct link *l_ptr, struct link *tunnel)
2234 {
2235         struct sk_buff *iter;
2236         struct tipc_msg tunnel_hdr;
2237
2238         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2239                  DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
2240         msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
2241         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2242         iter = l_ptr->first_out;
2243         while (iter) {
2244                 struct sk_buff *outbuf;
2245                 struct tipc_msg *msg = buf_msg(iter);
2246                 u32 length = msg_size(msg);
2247
2248                 if (msg_user(msg) == MSG_BUNDLER)
2249                         msg_set_type(msg, CLOSED_MSG);
2250                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));   /* Update */
2251                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
2252                 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
2253                 outbuf = tipc_buf_acquire(length + INT_H_SIZE);
2254                 if (outbuf == NULL) {
2255                         warn("Link changeover error, "
2256                              "unable to send duplicate msg\n");
2257                         return;
2258                 }
2259                 skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
2260                 skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
2261                                                length);
2262                 tipc_link_send_buf(tunnel, outbuf);
2263                 if (!tipc_link_is_up(l_ptr))
2264                         return;
2265                 iter = iter->next;
2266         }
2267 }
2268
2269
2270
2271 /**
2272  * buf_extract - extracts embedded TIPC message from another message
2273  * @skb: encapsulating message buffer
2274  * @from_pos: offset to extract from
2275  *
2276  * Returns a new message buffer containing an embedded message.  The
2277  * encapsulating message itself is left unchanged.
2278  */
2279
2280 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
2281 {
2282         struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
2283         u32 size = msg_size(msg);
2284         struct sk_buff *eb;
2285
2286         eb = tipc_buf_acquire(size);
2287         if (eb)
2288                 skb_copy_to_linear_data(eb, msg, size);
2289         return eb;
2290 }
2291
2292 /*
2293  *  link_recv_changeover_msg(): Receive tunneled packet sent
2294  *  via other link. Node is locked. Return extracted buffer.
2295  */
2296
2297 static int link_recv_changeover_msg(struct link **l_ptr,
2298                                     struct sk_buff **buf)
2299 {
2300         struct sk_buff *tunnel_buf = *buf;
2301         struct link *dest_link;
2302         struct tipc_msg *msg;
2303         struct tipc_msg *tunnel_msg = buf_msg(tunnel_buf);
2304         u32 msg_typ = msg_type(tunnel_msg);
2305         u32 msg_count = msg_msgcnt(tunnel_msg);
2306
2307         dest_link = (*l_ptr)->owner->links[msg_bearer_id(tunnel_msg)];
2308         if (!dest_link)
2309                 goto exit;
2310         if (dest_link == *l_ptr) {
2311                 err("Unexpected changeover message on link <%s>\n",
2312                     (*l_ptr)->name);
2313                 goto exit;
2314         }
2315         *l_ptr = dest_link;
2316         msg = msg_get_wrapped(tunnel_msg);
2317
2318         if (msg_typ == DUPLICATE_MSG) {
2319                 if (less(msg_seqno(msg), mod(dest_link->next_in_no)))
2320                         goto exit;
2321                 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2322                 if (*buf == NULL) {
2323                         warn("Link changeover error, duplicate msg dropped\n");
2324                         goto exit;
2325                 }
2326                 buf_discard(tunnel_buf);
2327                 return 1;
2328         }
2329
2330         /* First original message ?: */
2331
2332         if (tipc_link_is_up(dest_link)) {
2333                 info("Resetting link <%s>, changeover initiated by peer\n",
2334                      dest_link->name);
2335                 tipc_link_reset(dest_link);
2336                 dest_link->exp_msg_count = msg_count;
2337                 if (!msg_count)
2338                         goto exit;
2339         } else if (dest_link->exp_msg_count == START_CHANGEOVER) {
2340                 dest_link->exp_msg_count = msg_count;
2341                 if (!msg_count)
2342                         goto exit;
2343         }
2344
2345         /* Receive original message */
2346
2347         if (dest_link->exp_msg_count == 0) {
2348                 warn("Link switchover error, "
2349                      "got too many tunnelled messages\n");
2350                 goto exit;
2351         }
2352         dest_link->exp_msg_count--;
2353         if (less(msg_seqno(msg), dest_link->reset_checkpoint)) {
2354                 goto exit;
2355         } else {
2356                 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2357                 if (*buf != NULL) {
2358                         buf_discard(tunnel_buf);
2359                         return 1;
2360                 } else {
2361                         warn("Link changeover error, original msg dropped\n");
2362                 }
2363         }
2364 exit:
2365         *buf = NULL;
2366         buf_discard(tunnel_buf);
2367         return 0;
2368 }
2369
2370 /*
2371  *  Bundler functionality:
2372  */
2373 void tipc_link_recv_bundle(struct sk_buff *buf)
2374 {
2375         u32 msgcount = msg_msgcnt(buf_msg(buf));
2376         u32 pos = INT_H_SIZE;
2377         struct sk_buff *obuf;
2378
2379         while (msgcount--) {
2380                 obuf = buf_extract(buf, pos);
2381                 if (obuf == NULL) {
2382                         warn("Link unable to unbundle message(s)\n");
2383                         break;
2384                 }
2385                 pos += align(msg_size(buf_msg(obuf)));
2386                 tipc_net_route_msg(obuf);
2387         }
2388         buf_discard(buf);
2389 }
2390
2391 /*
2392  *  Fragmentation/defragmentation:
2393  */
2394
2395
2396 /*
2397  * link_send_long_buf: Entry for buffers needing fragmentation.
2398  * The buffer is complete, inclusive total message length.
2399  * Returns user data length.
2400  */
2401 static int link_send_long_buf(struct link *l_ptr, struct sk_buff *buf)
2402 {
2403         struct tipc_msg *inmsg = buf_msg(buf);
2404         struct tipc_msg fragm_hdr;
2405         u32 insize = msg_size(inmsg);
2406         u32 dsz = msg_data_sz(inmsg);
2407         unchar *crs = buf->data;
2408         u32 rest = insize;
2409         u32 pack_sz = l_ptr->max_pkt;
2410         u32 fragm_sz = pack_sz - INT_H_SIZE;
2411         u32 fragm_no = 1;
2412         u32 destaddr;
2413
2414         if (msg_short(inmsg))
2415                 destaddr = l_ptr->addr;
2416         else
2417                 destaddr = msg_destnode(inmsg);
2418
2419         if (msg_routed(inmsg))
2420                 msg_set_prevnode(inmsg, tipc_own_addr);
2421
2422         /* Prepare reusable fragment header: */
2423
2424         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
2425                  INT_H_SIZE, destaddr);
2426         msg_set_link_selector(&fragm_hdr, msg_link_selector(inmsg));
2427         msg_set_long_msgno(&fragm_hdr, mod(l_ptr->long_msg_seq_no++));
2428         msg_set_fragm_no(&fragm_hdr, fragm_no);
2429         l_ptr->stats.sent_fragmented++;
2430
2431         /* Chop up message: */
2432
2433         while (rest > 0) {
2434                 struct sk_buff *fragm;
2435
2436                 if (rest <= fragm_sz) {
2437                         fragm_sz = rest;
2438                         msg_set_type(&fragm_hdr, LAST_FRAGMENT);
2439                 }
2440                 fragm = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
2441                 if (fragm == NULL) {
2442                         warn("Link unable to fragment message\n");
2443                         dsz = -ENOMEM;
2444                         goto exit;
2445                 }
2446                 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
2447                 skb_copy_to_linear_data(fragm, &fragm_hdr, INT_H_SIZE);
2448                 skb_copy_to_linear_data_offset(fragm, INT_H_SIZE, crs,
2449                                                fragm_sz);
2450                 /*  Send queued messages first, if any: */
2451
2452                 l_ptr->stats.sent_fragments++;
2453                 tipc_link_send_buf(l_ptr, fragm);
2454                 if (!tipc_link_is_up(l_ptr))
2455                         return dsz;
2456                 msg_set_fragm_no(&fragm_hdr, ++fragm_no);
2457                 rest -= fragm_sz;
2458                 crs += fragm_sz;
2459                 msg_set_type(&fragm_hdr, FRAGMENT);
2460         }
2461 exit:
2462         buf_discard(buf);
2463         return dsz;
2464 }
2465
2466 /*
2467  * A pending message being re-assembled must store certain values
2468  * to handle subsequent fragments correctly. The following functions
2469  * help storing these values in unused, available fields in the
2470  * pending message. This makes dynamic memory allocation unecessary.
2471  */
2472
2473 static void set_long_msg_seqno(struct sk_buff *buf, u32 seqno)
2474 {
2475         msg_set_seqno(buf_msg(buf), seqno);
2476 }
2477
2478 static u32 get_fragm_size(struct sk_buff *buf)
2479 {
2480         return msg_ack(buf_msg(buf));
2481 }
2482
2483 static void set_fragm_size(struct sk_buff *buf, u32 sz)
2484 {
2485         msg_set_ack(buf_msg(buf), sz);
2486 }
2487
2488 static u32 get_expected_frags(struct sk_buff *buf)
2489 {
2490         return msg_bcast_ack(buf_msg(buf));
2491 }
2492
2493 static void set_expected_frags(struct sk_buff *buf, u32 exp)
2494 {
2495         msg_set_bcast_ack(buf_msg(buf), exp);
2496 }
2497
2498 static u32 get_timer_cnt(struct sk_buff *buf)
2499 {
2500         return msg_reroute_cnt(buf_msg(buf));
2501 }
2502
2503 static void incr_timer_cnt(struct sk_buff *buf)
2504 {
2505         msg_incr_reroute_cnt(buf_msg(buf));
2506 }
2507
2508 /*
2509  * tipc_link_recv_fragment(): Called with node lock on. Returns
2510  * the reassembled buffer if message is complete.
2511  */
2512 int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
2513                             struct tipc_msg **m)
2514 {
2515         struct sk_buff *prev = NULL;
2516         struct sk_buff *fbuf = *fb;
2517         struct tipc_msg *fragm = buf_msg(fbuf);
2518         struct sk_buff *pbuf = *pending;
2519         u32 long_msg_seq_no = msg_long_msgno(fragm);
2520
2521         *fb = NULL;
2522
2523         /* Is there an incomplete message waiting for this fragment? */
2524
2525         while (pbuf && ((msg_seqno(buf_msg(pbuf)) != long_msg_seq_no) ||
2526                         (msg_orignode(fragm) != msg_orignode(buf_msg(pbuf))))) {
2527                 prev = pbuf;
2528                 pbuf = pbuf->next;
2529         }
2530
2531         if (!pbuf && (msg_type(fragm) == FIRST_FRAGMENT)) {
2532                 struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
2533                 u32 msg_sz = msg_size(imsg);
2534                 u32 fragm_sz = msg_data_sz(fragm);
2535                 u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
2536                 u32 max =  TIPC_MAX_USER_MSG_SIZE + LONG_H_SIZE;
2537                 if (msg_type(imsg) == TIPC_MCAST_MSG)
2538                         max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
2539                 if (msg_size(imsg) > max) {
2540                         buf_discard(fbuf);
2541                         return 0;
2542                 }
2543                 pbuf = tipc_buf_acquire(msg_size(imsg));
2544                 if (pbuf != NULL) {
2545                         pbuf->next = *pending;
2546                         *pending = pbuf;
2547                         skb_copy_to_linear_data(pbuf, imsg,
2548                                                 msg_data_sz(fragm));
2549                         /*  Prepare buffer for subsequent fragments. */
2550
2551                         set_long_msg_seqno(pbuf, long_msg_seq_no);
2552                         set_fragm_size(pbuf, fragm_sz);
2553                         set_expected_frags(pbuf, exp_fragm_cnt - 1);
2554                 } else {
2555                         warn("Link unable to reassemble fragmented message\n");
2556                 }
2557                 buf_discard(fbuf);
2558                 return 0;
2559         } else if (pbuf && (msg_type(fragm) != FIRST_FRAGMENT)) {
2560                 u32 dsz = msg_data_sz(fragm);
2561                 u32 fsz = get_fragm_size(pbuf);
2562                 u32 crs = ((msg_fragm_no(fragm) - 1) * fsz);
2563                 u32 exp_frags = get_expected_frags(pbuf) - 1;
2564                 skb_copy_to_linear_data_offset(pbuf, crs,
2565                                                msg_data(fragm), dsz);
2566                 buf_discard(fbuf);
2567
2568                 /* Is message complete? */
2569
2570                 if (exp_frags == 0) {
2571                         if (prev)
2572                                 prev->next = pbuf->next;
2573                         else
2574                                 *pending = pbuf->next;
2575                         msg_reset_reroute_cnt(buf_msg(pbuf));
2576                         *fb = pbuf;
2577                         *m = buf_msg(pbuf);
2578                         return 1;
2579                 }
2580                 set_expected_frags(pbuf, exp_frags);
2581                 return 0;
2582         }
2583         buf_discard(fbuf);
2584         return 0;
2585 }
2586
2587 /**
2588  * link_check_defragm_bufs - flush stale incoming message fragments
2589  * @l_ptr: pointer to link
2590  */
2591
2592 static void link_check_defragm_bufs(struct link *l_ptr)
2593 {
2594         struct sk_buff *prev = NULL;
2595         struct sk_buff *next = NULL;
2596         struct sk_buff *buf = l_ptr->defragm_buf;
2597
2598         if (!buf)
2599                 return;
2600         if (!link_working_working(l_ptr))
2601                 return;
2602         while (buf) {
2603                 u32 cnt = get_timer_cnt(buf);
2604
2605                 next = buf->next;
2606                 if (cnt < 4) {
2607                         incr_timer_cnt(buf);
2608                         prev = buf;
2609                 } else {
2610                         if (prev)
2611                                 prev->next = buf->next;
2612                         else
2613                                 l_ptr->defragm_buf = buf->next;
2614                         buf_discard(buf);
2615                 }
2616                 buf = next;
2617         }
2618 }
2619
2620
2621
2622 static void link_set_supervision_props(struct link *l_ptr, u32 tolerance)
2623 {
2624         l_ptr->tolerance = tolerance;
2625         l_ptr->continuity_interval =
2626                 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
2627         l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
2628 }
2629
2630
2631 void tipc_link_set_queue_limits(struct link *l_ptr, u32 window)
2632 {
2633         /* Data messages from this node, inclusive FIRST_FRAGM */
2634         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
2635         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
2636         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
2637         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
2638         /* Transiting data messages,inclusive FIRST_FRAGM */
2639         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
2640         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
2641         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
2642         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
2643         l_ptr->queue_limit[CONN_MANAGER] = 1200;
2644         l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
2645         l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
2646         /* FRAGMENT and LAST_FRAGMENT packets */
2647         l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
2648 }
2649
2650 /**
2651  * link_find_link - locate link by name
2652  * @name - ptr to link name string
2653  * @node - ptr to area to be filled with ptr to associated node
2654  *
2655  * Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
2656  * this also prevents link deletion.
2657  *
2658  * Returns pointer to link (or 0 if invalid link name).
2659  */
2660
2661 static struct link *link_find_link(const char *name, struct tipc_node **node)
2662 {
2663         struct link_name link_name_parts;
2664         struct bearer *b_ptr;
2665         struct link *l_ptr;
2666
2667         if (!link_name_validate(name, &link_name_parts))
2668                 return NULL;
2669
2670         b_ptr = tipc_bearer_find_interface(link_name_parts.if_local);
2671         if (!b_ptr)
2672                 return NULL;
2673
2674         *node = tipc_node_find(link_name_parts.addr_peer);
2675         if (!*node)
2676                 return NULL;
2677
2678         l_ptr = (*node)->links[b_ptr->identity];
2679         if (!l_ptr || strcmp(l_ptr->name, name))
2680                 return NULL;
2681
2682         return l_ptr;
2683 }
2684
2685 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2686                                      u16 cmd)
2687 {
2688         struct tipc_link_config *args;
2689         u32 new_value;
2690         struct link *l_ptr;
2691         struct tipc_node *node;
2692         int res;
2693
2694         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2695                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2696
2697         args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2698         new_value = ntohl(args->value);
2699
2700         if (!strcmp(args->name, tipc_bclink_name)) {
2701                 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2702                     (tipc_bclink_set_queue_limits(new_value) == 0))
2703                         return tipc_cfg_reply_none();
2704                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2705                                                    " (cannot change setting on broadcast link)");
2706         }
2707
2708         read_lock_bh(&tipc_net_lock);
2709         l_ptr = link_find_link(args->name, &node);
2710         if (!l_ptr) {
2711                 read_unlock_bh(&tipc_net_lock);
2712                 return tipc_cfg_reply_error_string("link not found");
2713         }
2714
2715         tipc_node_lock(node);
2716         res = -EINVAL;
2717         switch (cmd) {
2718         case TIPC_CMD_SET_LINK_TOL:
2719                 if ((new_value >= TIPC_MIN_LINK_TOL) &&
2720                     (new_value <= TIPC_MAX_LINK_TOL)) {
2721                         link_set_supervision_props(l_ptr, new_value);
2722                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2723                                                  0, 0, new_value, 0, 0);
2724                         res = 0;
2725                 }
2726                 break;
2727         case TIPC_CMD_SET_LINK_PRI:
2728                 if ((new_value >= TIPC_MIN_LINK_PRI) &&
2729                     (new_value <= TIPC_MAX_LINK_PRI)) {
2730                         l_ptr->priority = new_value;
2731                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2732                                                  0, 0, 0, new_value, 0);
2733                         res = 0;
2734                 }
2735                 break;
2736         case TIPC_CMD_SET_LINK_WINDOW:
2737                 if ((new_value >= TIPC_MIN_LINK_WIN) &&
2738                     (new_value <= TIPC_MAX_LINK_WIN)) {
2739                         tipc_link_set_queue_limits(l_ptr, new_value);
2740                         res = 0;
2741                 }
2742                 break;
2743         }
2744         tipc_node_unlock(node);
2745
2746         read_unlock_bh(&tipc_net_lock);
2747         if (res)
2748                 return tipc_cfg_reply_error_string("cannot change link setting");
2749
2750         return tipc_cfg_reply_none();
2751 }
2752
2753 /**
2754  * link_reset_statistics - reset link statistics
2755  * @l_ptr: pointer to link
2756  */
2757
2758 static void link_reset_statistics(struct link *l_ptr)
2759 {
2760         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2761         l_ptr->stats.sent_info = l_ptr->next_out_no;
2762         l_ptr->stats.recv_info = l_ptr->next_in_no;
2763 }
2764
2765 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2766 {
2767         char *link_name;
2768         struct link *l_ptr;
2769         struct tipc_node *node;
2770
2771         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2772                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2773
2774         link_name = (char *)TLV_DATA(req_tlv_area);
2775         if (!strcmp(link_name, tipc_bclink_name)) {
2776                 if (tipc_bclink_reset_stats())
2777                         return tipc_cfg_reply_error_string("link not found");
2778                 return tipc_cfg_reply_none();
2779         }
2780
2781         read_lock_bh(&tipc_net_lock);
2782         l_ptr = link_find_link(link_name, &node);
2783         if (!l_ptr) {
2784                 read_unlock_bh(&tipc_net_lock);
2785                 return tipc_cfg_reply_error_string("link not found");
2786         }
2787
2788         tipc_node_lock(node);
2789         link_reset_statistics(l_ptr);
2790         tipc_node_unlock(node);
2791         read_unlock_bh(&tipc_net_lock);
2792         return tipc_cfg_reply_none();
2793 }
2794
2795 /**
2796  * percent - convert count to a percentage of total (rounding up or down)
2797  */
2798
2799 static u32 percent(u32 count, u32 total)
2800 {
2801         return (count * 100 + (total / 2)) / total;
2802 }
2803
2804 /**
2805  * tipc_link_stats - print link statistics
2806  * @name: link name
2807  * @buf: print buffer area
2808  * @buf_size: size of print buffer area
2809  *
2810  * Returns length of print buffer data string (or 0 if error)
2811  */
2812
2813 static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
2814 {
2815         struct print_buf pb;
2816         struct link *l_ptr;
2817         struct tipc_node *node;
2818         char *status;
2819         u32 profile_total = 0;
2820
2821         if (!strcmp(name, tipc_bclink_name))
2822                 return tipc_bclink_stats(buf, buf_size);
2823
2824         tipc_printbuf_init(&pb, buf, buf_size);
2825
2826         read_lock_bh(&tipc_net_lock);
2827         l_ptr = link_find_link(name, &node);
2828         if (!l_ptr) {
2829                 read_unlock_bh(&tipc_net_lock);
2830                 return 0;
2831         }
2832         tipc_node_lock(node);
2833
2834         if (tipc_link_is_active(l_ptr))
2835                 status = "ACTIVE";
2836         else if (tipc_link_is_up(l_ptr))
2837                 status = "STANDBY";
2838         else
2839                 status = "DEFUNCT";
2840         tipc_printf(&pb, "Link <%s>\n"
2841                          "  %s  MTU:%u  Priority:%u  Tolerance:%u ms"
2842                          "  Window:%u packets\n",
2843                     l_ptr->name, status, l_ptr->max_pkt,
2844                     l_ptr->priority, l_ptr->tolerance, l_ptr->queue_limit[0]);
2845         tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2846                     l_ptr->next_in_no - l_ptr->stats.recv_info,
2847                     l_ptr->stats.recv_fragments,
2848                     l_ptr->stats.recv_fragmented,
2849                     l_ptr->stats.recv_bundles,
2850                     l_ptr->stats.recv_bundled);
2851         tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2852                     l_ptr->next_out_no - l_ptr->stats.sent_info,
2853                     l_ptr->stats.sent_fragments,
2854                     l_ptr->stats.sent_fragmented,
2855                     l_ptr->stats.sent_bundles,
2856                     l_ptr->stats.sent_bundled);
2857         profile_total = l_ptr->stats.msg_length_counts;
2858         if (!profile_total)
2859                 profile_total = 1;
2860         tipc_printf(&pb, "  TX profile sample:%u packets  average:%u octets\n"
2861                          "  0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
2862                          "-16354:%u%% -32768:%u%% -66000:%u%%\n",
2863                     l_ptr->stats.msg_length_counts,
2864                     l_ptr->stats.msg_lengths_total / profile_total,
2865                     percent(l_ptr->stats.msg_length_profile[0], profile_total),
2866                     percent(l_ptr->stats.msg_length_profile[1], profile_total),
2867                     percent(l_ptr->stats.msg_length_profile[2], profile_total),
2868                     percent(l_ptr->stats.msg_length_profile[3], profile_total),
2869                     percent(l_ptr->stats.msg_length_profile[4], profile_total),
2870                     percent(l_ptr->stats.msg_length_profile[5], profile_total),
2871                     percent(l_ptr->stats.msg_length_profile[6], profile_total));
2872         tipc_printf(&pb, "  RX states:%u probes:%u naks:%u defs:%u dups:%u\n",
2873                     l_ptr->stats.recv_states,
2874                     l_ptr->stats.recv_probes,
2875                     l_ptr->stats.recv_nacks,
2876                     l_ptr->stats.deferred_recv,
2877                     l_ptr->stats.duplicates);
2878         tipc_printf(&pb, "  TX states:%u probes:%u naks:%u acks:%u dups:%u\n",
2879                     l_ptr->stats.sent_states,
2880                     l_ptr->stats.sent_probes,
2881                     l_ptr->stats.sent_nacks,
2882                     l_ptr->stats.sent_acks,
2883                     l_ptr->stats.retransmitted);
2884         tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
2885                     l_ptr->stats.bearer_congs,
2886                     l_ptr->stats.link_congs,
2887                     l_ptr->stats.max_queue_sz,
2888                     l_ptr->stats.queue_sz_counts
2889                     ? (l_ptr->stats.accu_queue_sz / l_ptr->stats.queue_sz_counts)
2890                     : 0);
2891
2892         tipc_node_unlock(node);
2893         read_unlock_bh(&tipc_net_lock);
2894         return tipc_printbuf_validate(&pb);
2895 }
2896
2897 #define MAX_LINK_STATS_INFO 2000
2898
2899 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
2900 {
2901         struct sk_buff *buf;
2902         struct tlv_desc *rep_tlv;
2903         int str_len;
2904
2905         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2906                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2907
2908         buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_LINK_STATS_INFO));
2909         if (!buf)
2910                 return NULL;
2911
2912         rep_tlv = (struct tlv_desc *)buf->data;
2913
2914         str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
2915                                   (char *)TLV_DATA(rep_tlv), MAX_LINK_STATS_INFO);
2916         if (!str_len) {
2917                 buf_discard(buf);
2918                 return tipc_cfg_reply_error_string("link not found");
2919         }
2920
2921         skb_put(buf, TLV_SPACE(str_len));
2922         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
2923
2924         return buf;
2925 }
2926
2927 /**
2928  * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
2929  * @dest: network address of destination node
2930  * @selector: used to select from set of active links
2931  *
2932  * If no active link can be found, uses default maximum packet size.
2933  */
2934
2935 u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
2936 {
2937         struct tipc_node *n_ptr;
2938         struct link *l_ptr;
2939         u32 res = MAX_PKT_DEFAULT;
2940
2941         if (dest == tipc_own_addr)
2942                 return MAX_MSG_SIZE;
2943
2944         read_lock_bh(&tipc_net_lock);
2945         n_ptr = tipc_node_find(dest);
2946         if (n_ptr) {
2947                 tipc_node_lock(n_ptr);
2948                 l_ptr = n_ptr->active_links[selector & 1];
2949                 if (l_ptr)
2950                         res = l_ptr->max_pkt;
2951                 tipc_node_unlock(n_ptr);
2952         }
2953         read_unlock_bh(&tipc_net_lock);
2954         return res;
2955 }
2956
2957 static void link_print(struct link *l_ptr, const char *str)
2958 {
2959         char print_area[256];
2960         struct print_buf pb;
2961         struct print_buf *buf = &pb;
2962
2963         tipc_printbuf_init(buf, print_area, sizeof(print_area));
2964
2965         tipc_printf(buf, str);
2966         tipc_printf(buf, "Link %x<%s>:",
2967                     l_ptr->addr, l_ptr->b_ptr->publ.name);
2968
2969 #ifdef CONFIG_TIPC_DEBUG
2970         if (link_reset_reset(l_ptr) || link_reset_unknown(l_ptr))
2971                 goto print_state;
2972
2973         tipc_printf(buf, ": NXO(%u):", mod(l_ptr->next_out_no));
2974         tipc_printf(buf, "NXI(%u):", mod(l_ptr->next_in_no));
2975         tipc_printf(buf, "SQUE");
2976         if (l_ptr->first_out) {
2977                 tipc_printf(buf, "[%u..", msg_seqno(buf_msg(l_ptr->first_out)));
2978                 if (l_ptr->next_out)
2979                         tipc_printf(buf, "%u..",
2980                                     msg_seqno(buf_msg(l_ptr->next_out)));
2981                 tipc_printf(buf, "%u]", msg_seqno(buf_msg(l_ptr->last_out)));
2982                 if ((mod(msg_seqno(buf_msg(l_ptr->last_out)) -
2983                          msg_seqno(buf_msg(l_ptr->first_out)))
2984                      != (l_ptr->out_queue_size - 1)) ||
2985                     (l_ptr->last_out->next != NULL)) {
2986                         tipc_printf(buf, "\nSend queue inconsistency\n");
2987                         tipc_printf(buf, "first_out= %x ", l_ptr->first_out);
2988                         tipc_printf(buf, "next_out= %x ", l_ptr->next_out);
2989                         tipc_printf(buf, "last_out= %x ", l_ptr->last_out);
2990                 }
2991         } else
2992                 tipc_printf(buf, "[]");
2993         tipc_printf(buf, "SQSIZ(%u)", l_ptr->out_queue_size);
2994         if (l_ptr->oldest_deferred_in) {
2995                 u32 o = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
2996                 u32 n = msg_seqno(buf_msg(l_ptr->newest_deferred_in));
2997                 tipc_printf(buf, ":RQUE[%u..%u]", o, n);
2998                 if (l_ptr->deferred_inqueue_sz != mod((n + 1) - o)) {
2999                         tipc_printf(buf, ":RQSIZ(%u)",
3000                                     l_ptr->deferred_inqueue_sz);
3001                 }
3002         }
3003 print_state:
3004 #endif
3005
3006         if (link_working_unknown(l_ptr))
3007                 tipc_printf(buf, ":WU");
3008         else if (link_reset_reset(l_ptr))
3009                 tipc_printf(buf, ":RR");
3010         else if (link_reset_unknown(l_ptr))
3011                 tipc_printf(buf, ":RU");
3012         else if (link_working_working(l_ptr))
3013                 tipc_printf(buf, ":WW");
3014         tipc_printf(buf, "\n");
3015
3016         tipc_printbuf_validate(buf);
3017         info("%s", print_area);
3018 }
3019