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, 2010-2011, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "core.h"
  38 #include "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 tipc_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->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_local = strchr(addr_local, ':');
 191         if (if_local == NULL)
 192                 return 0;
 193         *(if_local++) = 0;
 194         addr_peer = strchr(if_local, '-');
 195         if (addr_peer == NULL)
 196                 return 0;
 197         *(addr_peer++) = 0;
 198         if_local_len = addr_peer - if_local;
 199         if_peer = strchr(addr_peer, ':');
 200         if (if_peer == NULL)
 201                 return 0;
 202         *(if_peer++) = 0;
 203         if_peer_len = strlen(if_peer) + 1;
 204
 205         /* validate component parts of link name */
 206
 207         if ((sscanf(addr_local, "%u.%u.%u%c",
 208                     &z_local, &c_local, &n_local, &dummy) != 3) ||
 209             (sscanf(addr_peer, "%u.%u.%u%c",
 210                     &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
 211             (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
 212             (z_peer  > 255) || (c_peer  > 4095) || (n_peer  > 4095) ||
 213             (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
 214             (if_peer_len  <= 1) || (if_peer_len  > TIPC_MAX_IF_NAME) ||
 215             (strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
 216             (strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
 217                 return 0;
 218
 219         /* return link name components, if necessary */
 220
 221         if (name_parts) {
 222                 name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
 223                 strcpy(name_parts->if_local, if_local);
 224                 name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
 225                 strcpy(name_parts->if_peer, if_peer);
 226         }
 227         return 1;
 228 }
 229
 230 /**
 231  * link_timeout - handle expiration of link timer
 232  * @l_ptr: pointer to link
 233  *
 234  * This routine must not grab "tipc_net_lock" to avoid a potential deadlock conflict
 235  * with tipc_link_delete().  (There is no risk that the node will be deleted by
 236  * another thread because tipc_link_delete() always cancels the link timer before
 237  * tipc_node_delete() is called.)
 238  */
 239
 240 static void link_timeout(struct link *l_ptr)
 241 {
 242         tipc_node_lock(l_ptr->owner);
 243
 244         /* update counters used in statistical profiling of send traffic */
 245
 246         l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
 247         l_ptr->stats.queue_sz_counts++;
 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  * @n_ptr: pointer to associated node
 297  * @b_ptr: pointer to associated bearer
 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 tipc_node *n_ptr,
 304                               struct tipc_bearer *b_ptr,
 305                               const struct tipc_media_addr *media_addr)
 306 {
 307         struct link *l_ptr;
 308         struct tipc_msg *msg;
 309         char *if_name;
 310         char addr_string[16];
 311         u32 peer = n_ptr->addr;
 312
 313         if (n_ptr->link_cnt >= 2) {
 314                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 315                 err("Attempt to establish third link to %s\n", addr_string);
 316                 return NULL;
 317         }
 318
 319         if (n_ptr->links[b_ptr->identity]) {
 320                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 321                 err("Attempt to establish second link on <%s> to %s\n",
 322                     b_ptr->name, addr_string);
 323                 return NULL;
 324         }
 325
 326         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 327         if (!l_ptr) {
 328                 warn("Link creation failed, no memory\n");
 329                 return NULL;
 330         }
 331
 332         l_ptr->addr = peer;
 333         if_name = strchr(b_ptr->name, ':') + 1;
 334         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:",
 335                 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
 336                 tipc_node(tipc_own_addr),
 337                 if_name,
 338                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 339                 /* note: peer i/f is appended to link name by reset/activate */
 340         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 341         l_ptr->owner = n_ptr;
 342         l_ptr->checkpoint = 1;
 343         l_ptr->b_ptr = b_ptr;
 344         link_set_supervision_props(l_ptr, b_ptr->media->tolerance);
 345         l_ptr->state = RESET_UNKNOWN;
 346
 347         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 348         msg = l_ptr->pmsg;
 349         tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
 350         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 351         msg_set_session(msg, (tipc_random & 0xffff));
 352         msg_set_bearer_id(msg, b_ptr->identity);
 353         strcpy((char *)msg_data(msg), if_name);
 354
 355         l_ptr->priority = b_ptr->priority;
 356         tipc_link_set_queue_limits(l_ptr, b_ptr->media->window);
 357
 358         link_init_max_pkt(l_ptr);
 359
 360         l_ptr->next_out_no = 1;
 361         INIT_LIST_HEAD(&l_ptr->waiting_ports);
 362
 363         link_reset_statistics(l_ptr);
 364
 365         tipc_node_attach_link(n_ptr, l_ptr);
 366
 367         k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
 368         list_add_tail(&l_ptr->link_list, &b_ptr->links);
 369         tipc_k_signal((Handler)link_start, (unsigned long)l_ptr);
 370
 371         return l_ptr;
 372 }
 373
 374 /**
 375  * tipc_link_delete - delete a link
 376  * @l_ptr: pointer to link
 377  *
 378  * Note: 'tipc_net_lock' is write_locked, bearer is locked.
 379  * This routine must not grab the node lock until after link timer cancellation
 380  * to avoid a potential deadlock situation.
 381  */
 382
 383 void tipc_link_delete(struct link *l_ptr)
 384 {
 385         if (!l_ptr) {
 386                 err("Attempt to delete non-existent link\n");
 387                 return;
 388         }
 389
 390         k_cancel_timer(&l_ptr->timer);
 391
 392         tipc_node_lock(l_ptr->owner);
 393         tipc_link_reset(l_ptr);
 394         tipc_node_detach_link(l_ptr->owner, l_ptr);
 395         tipc_link_stop(l_ptr);
 396         list_del_init(&l_ptr->link_list);
 397         tipc_node_unlock(l_ptr->owner);
 398         k_term_timer(&l_ptr->timer);
 399         kfree(l_ptr);
 400 }
 401
 402 static void link_start(struct link *l_ptr)
 403 {
 404         tipc_node_lock(l_ptr->owner);
 405         link_state_event(l_ptr, STARTING_EVT);
 406         tipc_node_unlock(l_ptr->owner);
 407 }
 408
 409 /**
 410  * link_schedule_port - schedule port for deferred sending
 411  * @l_ptr: pointer to link
 412  * @origport: reference to sending port
 413  * @sz: amount of data to be sent
 414  *
 415  * Schedules port for renewed sending of messages after link congestion
 416  * has abated.
 417  */
 418
 419 static int link_schedule_port(struct link *l_ptr, u32 origport, u32 sz)
 420 {
 421         struct tipc_port *p_ptr;
 422
 423         spin_lock_bh(&tipc_port_list_lock);
 424         p_ptr = tipc_port_lock(origport);
 425         if (p_ptr) {
 426                 if (!p_ptr->wakeup)
 427                         goto exit;
 428                 if (!list_empty(&p_ptr->wait_list))
 429                         goto exit;
 430                 p_ptr->congested = 1;
 431                 p_ptr->waiting_pkts = 1 + ((sz - 1) / l_ptr->max_pkt);
 432                 list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
 433                 l_ptr->stats.link_congs++;
 434 exit:
 435                 tipc_port_unlock(p_ptr);
 436         }
 437         spin_unlock_bh(&tipc_port_list_lock);
 438         return -ELINKCONG;
 439 }
 440
 441 void tipc_link_wakeup_ports(struct link *l_ptr, int all)
 442 {
 443         struct tipc_port *p_ptr;
 444         struct tipc_port *temp_p_ptr;
 445         int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
 446
 447         if (all)
 448                 win = 100000;
 449         if (win <= 0)
 450                 return;
 451         if (!spin_trylock_bh(&tipc_port_list_lock))
 452                 return;
 453         if (link_congested(l_ptr))
 454                 goto exit;
 455         list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
 456                                  wait_list) {
 457                 if (win <= 0)
 458                         break;
 459                 list_del_init(&p_ptr->wait_list);
 460                 spin_lock_bh(p_ptr->lock);
 461                 p_ptr->congested = 0;
 462                 p_ptr->wakeup(p_ptr);
 463                 win -= p_ptr->waiting_pkts;
 464                 spin_unlock_bh(p_ptr->lock);
 465         }
 466
 467 exit:
 468         spin_unlock_bh(&tipc_port_list_lock);
 469 }
 470
 471 /**
 472  * link_release_outqueue - purge link's outbound message queue
 473  * @l_ptr: pointer to link
 474  */
 475
 476 static void link_release_outqueue(struct link *l_ptr)
 477 {
 478         struct sk_buff *buf = l_ptr->first_out;
 479         struct sk_buff *next;
 480
 481         while (buf) {
 482                 next = buf->next;
 483                 buf_discard(buf);
 484                 buf = next;
 485         }
 486         l_ptr->first_out = NULL;
 487         l_ptr->out_queue_size = 0;
 488 }
 489
 490 /**
 491  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 492  * @l_ptr: pointer to link
 493  */
 494
 495 void tipc_link_reset_fragments(struct link *l_ptr)
 496 {
 497         struct sk_buff *buf = l_ptr->defragm_buf;
 498         struct sk_buff *next;
 499
 500         while (buf) {
 501                 next = buf->next;
 502                 buf_discard(buf);
 503                 buf = next;
 504         }
 505         l_ptr->defragm_buf = NULL;
 506 }
 507
 508 /**
 509  * tipc_link_stop - purge all inbound and outbound messages associated with link
 510  * @l_ptr: pointer to link
 511  */
 512
 513 void tipc_link_stop(struct link *l_ptr)
 514 {
 515         struct sk_buff *buf;
 516         struct sk_buff *next;
 517
 518         buf = l_ptr->oldest_deferred_in;
 519         while (buf) {
 520                 next = buf->next;
 521                 buf_discard(buf);
 522                 buf = next;
 523         }
 524
 525         buf = l_ptr->first_out;
 526         while (buf) {
 527                 next = buf->next;
 528                 buf_discard(buf);
 529                 buf = next;
 530         }
 531
 532         tipc_link_reset_fragments(l_ptr);
 533
 534         buf_discard(l_ptr->proto_msg_queue);
 535         l_ptr->proto_msg_queue = NULL;
 536 }
 537
 538 /* LINK EVENT CODE IS NOT SUPPORTED AT PRESENT */
 539 #define link_send_event(fcn, l_ptr, up) do { } while (0)
 540
 541 void tipc_link_reset(struct link *l_ptr)
 542 {
 543         struct sk_buff *buf;
 544         u32 prev_state = l_ptr->state;
 545         u32 checkpoint = l_ptr->next_in_no;
 546         int was_active_link = tipc_link_is_active(l_ptr);
 547
 548         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 549
 550         /* Link is down, accept any session */
 551         l_ptr->peer_session = INVALID_SESSION;
 552
 553         /* Prepare for max packet size negotiation */
 554         link_init_max_pkt(l_ptr);
 555
 556         l_ptr->state = RESET_UNKNOWN;
 557
 558         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 559                 return;
 560
 561         tipc_node_link_down(l_ptr->owner, l_ptr);
 562         tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
 563
 564         if (was_active_link && tipc_node_active_links(l_ptr->owner) &&
 565             l_ptr->owner->permit_changeover) {
 566                 l_ptr->reset_checkpoint = checkpoint;
 567                 l_ptr->exp_msg_count = START_CHANGEOVER;
 568         }
 569
 570         /* Clean up all queues: */
 571
 572         link_release_outqueue(l_ptr);
 573         buf_discard(l_ptr->proto_msg_queue);
 574         l_ptr->proto_msg_queue = NULL;
 575         buf = l_ptr->oldest_deferred_in;
 576         while (buf) {
 577                 struct sk_buff *next = buf->next;
 578                 buf_discard(buf);
 579                 buf = next;
 580         }
 581         if (!list_empty(&l_ptr->waiting_ports))
 582                 tipc_link_wakeup_ports(l_ptr, 1);
 583
 584         l_ptr->retransm_queue_head = 0;
 585         l_ptr->retransm_queue_size = 0;
 586         l_ptr->last_out = NULL;
 587         l_ptr->first_out = NULL;
 588         l_ptr->next_out = NULL;
 589         l_ptr->unacked_window = 0;
 590         l_ptr->checkpoint = 1;
 591         l_ptr->next_out_no = 1;
 592         l_ptr->deferred_inqueue_sz = 0;
 593         l_ptr->oldest_deferred_in = NULL;
 594         l_ptr->newest_deferred_in = NULL;
 595         l_ptr->fsm_msg_cnt = 0;
 596         l_ptr->stale_count = 0;
 597         link_reset_statistics(l_ptr);
 598
 599         link_send_event(tipc_cfg_link_event, l_ptr, 0);
 600         if (!in_own_cluster(l_ptr->addr))
 601                 link_send_event(tipc_disc_link_event, l_ptr, 0);
 602 }
 603
 604
 605 static void link_activate(struct link *l_ptr)
 606 {
 607         l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
 608         tipc_node_link_up(l_ptr->owner, l_ptr);
 609         tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
 610         link_send_event(tipc_cfg_link_event, l_ptr, 1);
 611         if (!in_own_cluster(l_ptr->addr))
 612                 link_send_event(tipc_disc_link_event, l_ptr, 1);
 613 }
 614
 615 /**
 616  * link_state_event - link finite state machine
 617  * @l_ptr: pointer to link
 618  * @event: state machine event to process
 619  */
 620
 621 static void link_state_event(struct link *l_ptr, unsigned event)
 622 {
 623         struct link *other;
 624         u32 cont_intv = l_ptr->continuity_interval;
 625
 626         if (!l_ptr->started && (event != STARTING_EVT))
 627                 return;         /* Not yet. */
 628
 629         if (link_blocked(l_ptr)) {
 630                 if (event == TIMEOUT_EVT)
 631                         link_set_timer(l_ptr, cont_intv);
 632                 return;   /* Changeover going on */
 633         }
 634
 635         switch (l_ptr->state) {
 636         case WORKING_WORKING:
 637                 switch (event) {
 638                 case TRAFFIC_MSG_EVT:
 639                 case ACTIVATE_MSG:
 640                         break;
 641                 case TIMEOUT_EVT:
 642                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 643                                 l_ptr->checkpoint = l_ptr->next_in_no;
 644                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 645                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 646                                                                  0, 0, 0, 0, 0);
 647                                         l_ptr->fsm_msg_cnt++;
 648                                 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
 649                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 650                                                                  1, 0, 0, 0, 0);
 651                                         l_ptr->fsm_msg_cnt++;
 652                                 }
 653                                 link_set_timer(l_ptr, cont_intv);
 654                                 break;
 655                         }
 656                         l_ptr->state = WORKING_UNKNOWN;
 657                         l_ptr->fsm_msg_cnt = 0;
 658                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 659                         l_ptr->fsm_msg_cnt++;
 660                         link_set_timer(l_ptr, cont_intv / 4);
 661                         break;
 662                 case RESET_MSG:
 663                         info("Resetting link <%s>, requested by peer\n",
 664                              l_ptr->name);
 665                         tipc_link_reset(l_ptr);
 666                         l_ptr->state = RESET_RESET;
 667                         l_ptr->fsm_msg_cnt = 0;
 668                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 669                         l_ptr->fsm_msg_cnt++;
 670                         link_set_timer(l_ptr, cont_intv);
 671                         break;
 672                 default:
 673                         err("Unknown link event %u in WW state\n", event);
 674                 }
 675                 break;
 676         case WORKING_UNKNOWN:
 677                 switch (event) {
 678                 case TRAFFIC_MSG_EVT:
 679                 case ACTIVATE_MSG:
 680                         l_ptr->state = WORKING_WORKING;
 681                         l_ptr->fsm_msg_cnt = 0;
 682                         link_set_timer(l_ptr, cont_intv);
 683                         break;
 684                 case RESET_MSG:
 685                         info("Resetting link <%s>, requested by peer "
 686                              "while probing\n", l_ptr->name);
 687                         tipc_link_reset(l_ptr);
 688                         l_ptr->state = RESET_RESET;
 689                         l_ptr->fsm_msg_cnt = 0;
 690                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 691                         l_ptr->fsm_msg_cnt++;
 692                         link_set_timer(l_ptr, cont_intv);
 693                         break;
 694                 case TIMEOUT_EVT:
 695                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 696                                 l_ptr->state = WORKING_WORKING;
 697                                 l_ptr->fsm_msg_cnt = 0;
 698                                 l_ptr->checkpoint = l_ptr->next_in_no;
 699                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 700                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 701                                                                  0, 0, 0, 0, 0);
 702                                         l_ptr->fsm_msg_cnt++;
 703                                 }
 704                                 link_set_timer(l_ptr, cont_intv);
 705                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 706                                 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 707                                                          1, 0, 0, 0, 0);
 708                                 l_ptr->fsm_msg_cnt++;
 709                                 link_set_timer(l_ptr, cont_intv / 4);
 710                         } else {        /* Link has failed */
 711                                 warn("Resetting link <%s>, peer not responding\n",
 712                                      l_ptr->name);
 713                                 tipc_link_reset(l_ptr);
 714                                 l_ptr->state = RESET_UNKNOWN;
 715                                 l_ptr->fsm_msg_cnt = 0;
 716                                 tipc_link_send_proto_msg(l_ptr, RESET_MSG,
 717                                                          0, 0, 0, 0, 0);
 718                                 l_ptr->fsm_msg_cnt++;
 719                                 link_set_timer(l_ptr, cont_intv);
 720                         }
 721                         break;
 722                 default:
 723                         err("Unknown link event %u in WU state\n", event);
 724                 }
 725                 break;
 726         case RESET_UNKNOWN:
 727                 switch (event) {
 728                 case TRAFFIC_MSG_EVT:
 729                         break;
 730                 case ACTIVATE_MSG:
 731                         other = l_ptr->owner->active_links[0];
 732                         if (other && link_working_unknown(other))
 733                                 break;
 734                         l_ptr->state = WORKING_WORKING;
 735                         l_ptr->fsm_msg_cnt = 0;
 736                         link_activate(l_ptr);
 737                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 738                         l_ptr->fsm_msg_cnt++;
 739                         link_set_timer(l_ptr, cont_intv);
 740                         break;
 741                 case RESET_MSG:
 742                         l_ptr->state = RESET_RESET;
 743                         l_ptr->fsm_msg_cnt = 0;
 744                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
 745                         l_ptr->fsm_msg_cnt++;
 746                         link_set_timer(l_ptr, cont_intv);
 747                         break;
 748                 case STARTING_EVT:
 749                         l_ptr->started = 1;
 750                         /* fall through */
 751                 case TIMEOUT_EVT:
 752                         tipc_link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
 753                         l_ptr->fsm_msg_cnt++;
 754                         link_set_timer(l_ptr, cont_intv);
 755                         break;
 756                 default:
 757                         err("Unknown link event %u in RU state\n", event);
 758                 }
 759                 break;
 760         case RESET_RESET:
 761                 switch (event) {
 762                 case TRAFFIC_MSG_EVT:
 763                 case ACTIVATE_MSG:
 764                         other = l_ptr->owner->active_links[0];
 765                         if (other && link_working_unknown(other))
 766                                 break;
 767                         l_ptr->state = WORKING_WORKING;
 768                         l_ptr->fsm_msg_cnt = 0;
 769                         link_activate(l_ptr);
 770                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 771                         l_ptr->fsm_msg_cnt++;
 772                         link_set_timer(l_ptr, cont_intv);
 773                         break;
 774                 case RESET_MSG:
 775                         break;
 776                 case TIMEOUT_EVT:
 777                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 778                         l_ptr->fsm_msg_cnt++;
 779                         link_set_timer(l_ptr, cont_intv);
 780                         break;
 781                 default:
 782                         err("Unknown link event %u in RR state\n", event);
 783                 }
 784                 break;
 785         default:
 786                 err("Unknown link state %u/%u\n", l_ptr->state, event);
 787         }
 788 }
 789
 790 /*
 791  * link_bundle_buf(): Append contents of a buffer to
 792  * the tail of an existing one.
 793  */
 794
 795 static int link_bundle_buf(struct link *l_ptr,
 796                            struct sk_buff *bundler,
 797                            struct sk_buff *buf)
 798 {
 799         struct tipc_msg *bundler_msg = buf_msg(bundler);
 800         struct tipc_msg *msg = buf_msg(buf);
 801         u32 size = msg_size(msg);
 802         u32 bundle_size = msg_size(bundler_msg);
 803         u32 to_pos = align(bundle_size);
 804         u32 pad = to_pos - bundle_size;
 805
 806         if (msg_user(bundler_msg) != MSG_BUNDLER)
 807                 return 0;
 808         if (msg_type(bundler_msg) != OPEN_MSG)
 809                 return 0;
 810         if (skb_tailroom(bundler) < (pad + size))
 811                 return 0;
 812         if (l_ptr->max_pkt < (to_pos + size))
 813                 return 0;
 814
 815         skb_put(bundler, pad + size);
 816         skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
 817         msg_set_size(bundler_msg, to_pos + size);
 818         msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
 819         buf_discard(buf);
 820         l_ptr->stats.sent_bundled++;
 821         return 1;
 822 }
 823
 824 static void link_add_to_outqueue(struct link *l_ptr,
 825                                  struct sk_buff *buf,
 826                                  struct tipc_msg *msg)
 827 {
 828         u32 ack = mod(l_ptr->next_in_no - 1);
 829         u32 seqno = mod(l_ptr->next_out_no++);
 830
 831         msg_set_word(msg, 2, ((ack << 16) | seqno));
 832         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 833         buf->next = NULL;
 834         if (l_ptr->first_out) {
 835                 l_ptr->last_out->next = buf;
 836                 l_ptr->last_out = buf;
 837         } else
 838                 l_ptr->first_out = l_ptr->last_out = buf;
 839
 840         l_ptr->out_queue_size++;
 841         if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
 842                 l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
 843 }
 844
 845 /*
 846  * tipc_link_send_buf() is the 'full path' for messages, called from
 847  * inside TIPC when the 'fast path' in tipc_send_buf
 848  * has failed, and from link_send()
 849  */
 850
 851 int tipc_link_send_buf(struct link *l_ptr, struct sk_buff *buf)
 852 {
 853         struct tipc_msg *msg = buf_msg(buf);
 854         u32 size = msg_size(msg);
 855         u32 dsz = msg_data_sz(msg);
 856         u32 queue_size = l_ptr->out_queue_size;
 857         u32 imp = tipc_msg_tot_importance(msg);
 858         u32 queue_limit = l_ptr->queue_limit[imp];
 859         u32 max_packet = l_ptr->max_pkt;
 860
 861         msg_set_prevnode(msg, tipc_own_addr);   /* If routed message */
 862
 863         /* Match msg importance against queue limits: */
 864
 865         if (unlikely(queue_size >= queue_limit)) {
 866                 if (imp <= TIPC_CRITICAL_IMPORTANCE) {
 867                         return link_schedule_port(l_ptr, msg_origport(msg),
 868                                                   size);
 869                 }
 870                 buf_discard(buf);
 871                 if (imp > CONN_MANAGER) {
 872                         warn("Resetting link <%s>, send queue full", l_ptr->name);
 873                         tipc_link_reset(l_ptr);
 874                 }
 875                 return dsz;
 876         }
 877
 878         /* Fragmentation needed ? */
 879
 880         if (size > max_packet)
 881                 return link_send_long_buf(l_ptr, buf);
 882
 883         /* Packet can be queued or sent: */
 884
 885         if (likely(!tipc_bearer_congested(l_ptr->b_ptr, l_ptr) &&
 886                    !link_congested(l_ptr))) {
 887                 link_add_to_outqueue(l_ptr, buf, msg);
 888
 889                 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
 890                         l_ptr->unacked_window = 0;
 891                 } else {
 892                         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
 893                         l_ptr->stats.bearer_congs++;
 894                         l_ptr->next_out = buf;
 895                 }
 896                 return dsz;
 897         }
 898         /* Congestion: can message be bundled ?: */
 899
 900         if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
 901             (msg_user(msg) != MSG_FRAGMENTER)) {
 902
 903                 /* Try adding message to an existing bundle */
 904
 905                 if (l_ptr->next_out &&
 906                     link_bundle_buf(l_ptr, l_ptr->last_out, buf)) {
 907                         tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
 908                         return dsz;
 909                 }
 910
 911                 /* Try creating a new bundle */
 912
 913                 if (size <= max_packet * 2 / 3) {
 914                         struct sk_buff *bundler = tipc_buf_acquire(max_packet);
 915                         struct tipc_msg bundler_hdr;
 916
 917                         if (bundler) {
 918                                 tipc_msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
 919                                          INT_H_SIZE, l_ptr->addr);
 920                                 skb_copy_to_linear_data(bundler, &bundler_hdr,
 921                                                         INT_H_SIZE);
 922                                 skb_trim(bundler, INT_H_SIZE);
 923                                 link_bundle_buf(l_ptr, bundler, buf);
 924                                 buf = bundler;
 925                                 msg = buf_msg(buf);
 926                                 l_ptr->stats.sent_bundles++;
 927                         }
 928                 }
 929         }
 930         if (!l_ptr->next_out)
 931                 l_ptr->next_out = buf;
 932         link_add_to_outqueue(l_ptr, buf, msg);
 933         tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
 934         return dsz;
 935 }
 936
 937 /*
 938  * tipc_link_send(): same as tipc_link_send_buf(), but the link to use has
 939  * not been selected yet, and the the owner node is not locked
 940  * Called by TIPC internal users, e.g. the name distributor
 941  */
 942
 943 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector)
 944 {
 945         struct link *l_ptr;
 946         struct tipc_node *n_ptr;
 947         int res = -ELINKCONG;
 948
 949         read_lock_bh(&tipc_net_lock);
 950         n_ptr = tipc_node_find(dest);
 951         if (n_ptr) {
 952                 tipc_node_lock(n_ptr);
 953                 l_ptr = n_ptr->active_links[selector & 1];
 954                 if (l_ptr)
 955                         res = tipc_link_send_buf(l_ptr, buf);
 956                 else
 957                         buf_discard(buf);
 958                 tipc_node_unlock(n_ptr);
 959         } else {
 960                 buf_discard(buf);
 961         }
 962         read_unlock_bh(&tipc_net_lock);
 963         return res;
 964 }
 965
 966 /*
 967  * link_send_buf_fast: Entry for data messages where the
 968  * destination link is known and the header is complete,
 969  * inclusive total message length. Very time critical.
 970  * Link is locked. Returns user data length.
 971  */
 972
 973 static int link_send_buf_fast(struct link *l_ptr, struct sk_buff *buf,
 974                               u32 *used_max_pkt)
 975 {
 976         struct tipc_msg *msg = buf_msg(buf);
 977         int res = msg_data_sz(msg);
 978
 979         if (likely(!link_congested(l_ptr))) {
 980                 if (likely(msg_size(msg) <= l_ptr->max_pkt)) {
 981                         if (likely(list_empty(&l_ptr->b_ptr->cong_links))) {
 982                                 link_add_to_outqueue(l_ptr, buf, msg);
 983                                 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf,
 984                                                             &l_ptr->media_addr))) {
 985                                         l_ptr->unacked_window = 0;
 986                                         return res;
 987                                 }
 988                                 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
 989                                 l_ptr->stats.bearer_congs++;
 990                                 l_ptr->next_out = buf;
 991                                 return res;
 992                         }
 993                 } else
 994                         *used_max_pkt = l_ptr->max_pkt;
 995         }
 996         return tipc_link_send_buf(l_ptr, buf);  /* All other cases */
 997 }
 998
 999 /*
1000  * tipc_send_buf_fast: Entry for data messages where the
1001  * destination node is known and the header is complete,
1002  * inclusive total message length.
1003  * Returns user data length.
1004  */
1005 int tipc_send_buf_fast(struct sk_buff *buf, u32 destnode)
1006 {
1007         struct link *l_ptr;
1008         struct tipc_node *n_ptr;
1009         int res;
1010         u32 selector = msg_origport(buf_msg(buf)) & 1;
1011         u32 dummy;
1012
1013         if (destnode == tipc_own_addr)
1014                 return tipc_port_recv_msg(buf);
1015
1016         read_lock_bh(&tipc_net_lock);
1017         n_ptr = tipc_node_find(destnode);
1018         if (likely(n_ptr)) {
1019                 tipc_node_lock(n_ptr);
1020                 l_ptr = n_ptr->active_links[selector];
1021                 if (likely(l_ptr)) {
1022                         res = link_send_buf_fast(l_ptr, buf, &dummy);
1023                         tipc_node_unlock(n_ptr);
1024                         read_unlock_bh(&tipc_net_lock);
1025                         return res;
1026                 }
1027                 tipc_node_unlock(n_ptr);
1028         }
1029         read_unlock_bh(&tipc_net_lock);
1030         res = msg_data_sz(buf_msg(buf));
1031         tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1032         return res;
1033 }
1034
1035
1036 /*
1037  * tipc_link_send_sections_fast: Entry for messages where the
1038  * destination processor is known and the header is complete,
1039  * except for total message length.
1040  * Returns user data length or errno.
1041  */
1042 int tipc_link_send_sections_fast(struct tipc_port *sender,
1043                                  struct iovec const *msg_sect,
1044                                  const u32 num_sect,
1045                                  u32 destaddr)
1046 {
1047         struct tipc_msg *hdr = &sender->phdr;
1048         struct link *l_ptr;
1049         struct sk_buff *buf;
1050         struct tipc_node *node;
1051         int res;
1052         u32 selector = msg_origport(hdr) & 1;
1053
1054 again:
1055         /*
1056          * Try building message using port's max_pkt hint.
1057          * (Must not hold any locks while building message.)
1058          */
1059
1060         res = tipc_msg_build(hdr, msg_sect, num_sect, sender->max_pkt,
1061                         !sender->user_port, &buf);
1062
1063         read_lock_bh(&tipc_net_lock);
1064         node = tipc_node_find(destaddr);
1065         if (likely(node)) {
1066                 tipc_node_lock(node);
1067                 l_ptr = node->active_links[selector];
1068                 if (likely(l_ptr)) {
1069                         if (likely(buf)) {
1070                                 res = link_send_buf_fast(l_ptr, buf,
1071                                                          &sender->max_pkt);
1072                                 if (unlikely(res < 0))
1073                                         buf_discard(buf);
1074 exit:
1075                                 tipc_node_unlock(node);
1076                                 read_unlock_bh(&tipc_net_lock);
1077                                 return res;
1078                         }
1079
1080                         /* Exit if build request was invalid */
1081
1082                         if (unlikely(res < 0))
1083                                 goto exit;
1084
1085                         /* Exit if link (or bearer) is congested */
1086
1087                         if (link_congested(l_ptr) ||
1088                             !list_empty(&l_ptr->b_ptr->cong_links)) {
1089                                 res = link_schedule_port(l_ptr,
1090                                                          sender->ref, res);
1091                                 goto exit;
1092                         }
1093
1094                         /*
1095                          * Message size exceeds max_pkt hint; update hint,
1096                          * then re-try fast path or fragment the message
1097                          */
1098
1099                         sender->max_pkt = l_ptr->max_pkt;
1100                         tipc_node_unlock(node);
1101                         read_unlock_bh(&tipc_net_lock);
1102
1103
1104                         if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
1105                                 goto again;
1106
1107                         return link_send_sections_long(sender, msg_sect,
1108                                                        num_sect, destaddr);
1109                 }
1110                 tipc_node_unlock(node);
1111         }
1112         read_unlock_bh(&tipc_net_lock);
1113
1114         /* Couldn't find a link to the destination node */
1115
1116         if (buf)
1117                 return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1118         if (res >= 0)
1119                 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1120                                                  TIPC_ERR_NO_NODE);
1121         return res;
1122 }
1123
1124 /*
1125  * link_send_sections_long(): Entry for long messages where the
1126  * destination node is known and the header is complete,
1127  * inclusive total message length.
1128  * Link and bearer congestion status have been checked to be ok,
1129  * and are ignored if they change.
1130  *
1131  * Note that fragments do not use the full link MTU so that they won't have
1132  * to undergo refragmentation if link changeover causes them to be sent
1133  * over another link with an additional tunnel header added as prefix.
1134  * (Refragmentation will still occur if the other link has a smaller MTU.)
1135  *
1136  * Returns user data length or errno.
1137  */
1138 static int link_send_sections_long(struct tipc_port *sender,
1139                                    struct iovec const *msg_sect,
1140                                    u32 num_sect,
1141                                    u32 destaddr)
1142 {
1143         struct link *l_ptr;
1144         struct tipc_node *node;
1145         struct tipc_msg *hdr = &sender->phdr;
1146         u32 dsz = msg_data_sz(hdr);
1147         u32 max_pkt, fragm_sz, rest;
1148         struct tipc_msg fragm_hdr;
1149         struct sk_buff *buf, *buf_chain, *prev;
1150         u32 fragm_crs, fragm_rest, hsz, sect_rest;
1151         const unchar *sect_crs;
1152         int curr_sect;
1153         u32 fragm_no;
1154
1155 again:
1156         fragm_no = 1;
1157         max_pkt = sender->max_pkt - INT_H_SIZE;
1158                 /* leave room for tunnel header in case of link changeover */
1159         fragm_sz = max_pkt - INT_H_SIZE;
1160                 /* leave room for fragmentation header in each fragment */
1161         rest = dsz;
1162         fragm_crs = 0;
1163         fragm_rest = 0;
1164         sect_rest = 0;
1165         sect_crs = NULL;
1166         curr_sect = -1;
1167
1168         /* Prepare reusable fragment header: */
1169
1170         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
1171                  INT_H_SIZE, msg_destnode(hdr));
1172         msg_set_link_selector(&fragm_hdr, sender->ref);
1173         msg_set_size(&fragm_hdr, max_pkt);
1174         msg_set_fragm_no(&fragm_hdr, 1);
1175
1176         /* Prepare header of first fragment: */
1177
1178         buf_chain = buf = tipc_buf_acquire(max_pkt);
1179         if (!buf)
1180                 return -ENOMEM;
1181         buf->next = NULL;
1182         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1183         hsz = msg_hdr_sz(hdr);
1184         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
1185
1186         /* Chop up message: */
1187
1188         fragm_crs = INT_H_SIZE + hsz;
1189         fragm_rest = fragm_sz - hsz;
1190
1191         do {            /* For all sections */
1192                 u32 sz;
1193
1194                 if (!sect_rest) {
1195                         sect_rest = msg_sect[++curr_sect].iov_len;
1196                         sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
1197                 }
1198
1199                 if (sect_rest < fragm_rest)
1200                         sz = sect_rest;
1201                 else
1202                         sz = fragm_rest;
1203
1204                 if (likely(!sender->user_port)) {
1205                         if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
1206 error:
1207                                 for (; buf_chain; buf_chain = buf) {
1208                                         buf = buf_chain->next;
1209                                         buf_discard(buf_chain);
1210                                 }
1211                                 return -EFAULT;
1212                         }
1213                 } else
1214                         skb_copy_to_linear_data_offset(buf, fragm_crs,
1215                                                        sect_crs, sz);
1216                 sect_crs += sz;
1217                 sect_rest -= sz;
1218                 fragm_crs += sz;
1219                 fragm_rest -= sz;
1220                 rest -= sz;
1221
1222                 if (!fragm_rest && rest) {
1223
1224                         /* Initiate new fragment: */
1225                         if (rest <= fragm_sz) {
1226                                 fragm_sz = rest;
1227                                 msg_set_type(&fragm_hdr, LAST_FRAGMENT);
1228                         } else {
1229                                 msg_set_type(&fragm_hdr, FRAGMENT);
1230                         }
1231                         msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
1232                         msg_set_fragm_no(&fragm_hdr, ++fragm_no);
1233                         prev = buf;
1234                         buf = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
1235                         if (!buf)
1236                                 goto error;
1237
1238                         buf->next = NULL;
1239                         prev->next = buf;
1240                         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1241                         fragm_crs = INT_H_SIZE;
1242                         fragm_rest = fragm_sz;
1243                 }
1244         } while (rest > 0);
1245
1246         /*
1247          * Now we have a buffer chain. Select a link and check
1248          * that packet size is still OK
1249          */
1250         node = tipc_node_find(destaddr);
1251         if (likely(node)) {
1252                 tipc_node_lock(node);
1253                 l_ptr = node->active_links[sender->ref & 1];
1254                 if (!l_ptr) {
1255                         tipc_node_unlock(node);
1256                         goto reject;
1257                 }
1258                 if (l_ptr->max_pkt < max_pkt) {
1259                         sender->max_pkt = l_ptr->max_pkt;
1260                         tipc_node_unlock(node);
1261                         for (; buf_chain; buf_chain = buf) {
1262                                 buf = buf_chain->next;
1263                                 buf_discard(buf_chain);
1264                         }
1265                         goto again;
1266                 }
1267         } else {
1268 reject:
1269                 for (; buf_chain; buf_chain = buf) {
1270                         buf = buf_chain->next;
1271                         buf_discard(buf_chain);
1272                 }
1273                 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1274                                                  TIPC_ERR_NO_NODE);
1275         }
1276
1277         /* Append whole chain to send queue: */
1278
1279         buf = buf_chain;
1280         l_ptr->long_msg_seq_no = mod(l_ptr->long_msg_seq_no + 1);
1281         if (!l_ptr->next_out)
1282                 l_ptr->next_out = buf_chain;
1283         l_ptr->stats.sent_fragmented++;
1284         while (buf) {
1285                 struct sk_buff *next = buf->next;
1286                 struct tipc_msg *msg = buf_msg(buf);
1287
1288                 l_ptr->stats.sent_fragments++;
1289                 msg_set_long_msgno(msg, l_ptr->long_msg_seq_no);
1290                 link_add_to_outqueue(l_ptr, buf, msg);
1291                 buf = next;
1292         }
1293
1294         /* Send it, if possible: */
1295
1296         tipc_link_push_queue(l_ptr);
1297         tipc_node_unlock(node);
1298         return dsz;
1299 }
1300
1301 /*
1302  * tipc_link_push_packet: Push one unsent packet to the media
1303  */
1304 u32 tipc_link_push_packet(struct link *l_ptr)
1305 {
1306         struct sk_buff *buf = l_ptr->first_out;
1307         u32 r_q_size = l_ptr->retransm_queue_size;
1308         u32 r_q_head = l_ptr->retransm_queue_head;
1309
1310         /* Step to position where retransmission failed, if any,    */
1311         /* consider that buffers may have been released in meantime */
1312
1313         if (r_q_size && buf) {
1314                 u32 last = lesser(mod(r_q_head + r_q_size),
1315                                   link_last_sent(l_ptr));
1316                 u32 first = msg_seqno(buf_msg(buf));
1317
1318                 while (buf && less(first, r_q_head)) {
1319                         first = mod(first + 1);
1320                         buf = buf->next;
1321                 }
1322                 l_ptr->retransm_queue_head = r_q_head = first;
1323                 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
1324         }
1325
1326         /* Continue retransmission now, if there is anything: */
1327
1328         if (r_q_size && buf) {
1329                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1330                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1331                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1332                         l_ptr->retransm_queue_head = mod(++r_q_head);
1333                         l_ptr->retransm_queue_size = --r_q_size;
1334                         l_ptr->stats.retransmitted++;
1335                         return 0;
1336                 } else {
1337                         l_ptr->stats.bearer_congs++;
1338                         return PUSH_FAILED;
1339                 }
1340         }
1341
1342         /* Send deferred protocol message, if any: */
1343
1344         buf = l_ptr->proto_msg_queue;
1345         if (buf) {
1346                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1347                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1348                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1349                         l_ptr->unacked_window = 0;
1350                         buf_discard(buf);
1351                         l_ptr->proto_msg_queue = NULL;
1352                         return 0;
1353                 } else {
1354                         l_ptr->stats.bearer_congs++;
1355                         return PUSH_FAILED;
1356                 }
1357         }
1358
1359         /* Send one deferred data message, if send window not full: */
1360
1361         buf = l_ptr->next_out;
1362         if (buf) {
1363                 struct tipc_msg *msg = buf_msg(buf);
1364                 u32 next = msg_seqno(msg);
1365                 u32 first = msg_seqno(buf_msg(l_ptr->first_out));
1366
1367                 if (mod(next - first) < l_ptr->queue_limit[0]) {
1368                         msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1369                         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1370                         if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1371                                 if (msg_user(msg) == MSG_BUNDLER)
1372                                         msg_set_type(msg, CLOSED_MSG);
1373                                 l_ptr->next_out = buf->next;
1374                                 return 0;
1375                         } else {
1376                                 l_ptr->stats.bearer_congs++;
1377                                 return PUSH_FAILED;
1378                         }
1379                 }
1380         }
1381         return PUSH_FINISHED;
1382 }
1383
1384 /*
1385  * push_queue(): push out the unsent messages of a link where
1386  *               congestion has abated. Node is locked
1387  */
1388 void tipc_link_push_queue(struct link *l_ptr)
1389 {
1390         u32 res;
1391
1392         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr))
1393                 return;
1394
1395         do {
1396                 res = tipc_link_push_packet(l_ptr);
1397         } while (!res);
1398
1399         if (res == PUSH_FAILED)
1400                 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1401 }
1402
1403 static void link_reset_all(unsigned long addr)
1404 {
1405         struct tipc_node *n_ptr;
1406         char addr_string[16];
1407         u32 i;
1408
1409         read_lock_bh(&tipc_net_lock);
1410         n_ptr = tipc_node_find((u32)addr);
1411         if (!n_ptr) {
1412                 read_unlock_bh(&tipc_net_lock);
1413                 return; /* node no longer exists */
1414         }
1415
1416         tipc_node_lock(n_ptr);
1417
1418         warn("Resetting all links to %s\n",
1419              tipc_addr_string_fill(addr_string, n_ptr->addr));
1420
1421         for (i = 0; i < MAX_BEARERS; i++) {
1422                 if (n_ptr->links[i]) {
1423                         link_print(n_ptr->links[i], "Resetting link\n");
1424                         tipc_link_reset(n_ptr->links[i]);
1425                 }
1426         }
1427
1428         tipc_node_unlock(n_ptr);
1429         read_unlock_bh(&tipc_net_lock);
1430 }
1431
1432 static void link_retransmit_failure(struct link *l_ptr, struct sk_buff *buf)
1433 {
1434         struct tipc_msg *msg = buf_msg(buf);
1435
1436         warn("Retransmission failure on link <%s>\n", l_ptr->name);
1437
1438         if (l_ptr->addr) {
1439
1440                 /* Handle failure on standard link */
1441
1442                 link_print(l_ptr, "Resetting link\n");
1443                 tipc_link_reset(l_ptr);
1444
1445         } else {
1446
1447                 /* Handle failure on broadcast link */
1448
1449                 struct tipc_node *n_ptr;
1450                 char addr_string[16];
1451
1452                 info("Msg seq number: %u,  ", msg_seqno(msg));
1453                 info("Outstanding acks: %lu\n",
1454                      (unsigned long) TIPC_SKB_CB(buf)->handle);
1455
1456                 n_ptr = tipc_bclink_retransmit_to();
1457                 tipc_node_lock(n_ptr);
1458
1459                 tipc_addr_string_fill(addr_string, n_ptr->addr);
1460                 info("Multicast link info for %s\n", addr_string);
1461                 info("Supported: %d,  ", n_ptr->bclink.supported);
1462                 info("Acked: %u\n", n_ptr->bclink.acked);
1463                 info("Last in: %u,  ", n_ptr->bclink.last_in);
1464                 info("Gap after: %u,  ", n_ptr->bclink.gap_after);
1465                 info("Gap to: %u\n", n_ptr->bclink.gap_to);
1466                 info("Nack sync: %u\n\n", n_ptr->bclink.nack_sync);
1467
1468                 tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
1469
1470                 tipc_node_unlock(n_ptr);
1471
1472                 l_ptr->stale_count = 0;
1473         }
1474 }
1475
1476 void tipc_link_retransmit(struct link *l_ptr, struct sk_buff *buf,
1477                           u32 retransmits)
1478 {
1479         struct tipc_msg *msg;
1480
1481         if (!buf)
1482                 return;
1483
1484         msg = buf_msg(buf);
1485
1486         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
1487                 if (l_ptr->retransm_queue_size == 0) {
1488                         l_ptr->retransm_queue_head = msg_seqno(msg);
1489                         l_ptr->retransm_queue_size = retransmits;
1490                 } else {
1491                         err("Unexpected retransmit on link %s (qsize=%d)\n",
1492                             l_ptr->name, l_ptr->retransm_queue_size);
1493                 }
1494                 return;
1495         } else {
1496                 /* Detect repeated retransmit failures on uncongested bearer */
1497
1498                 if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1499                         if (++l_ptr->stale_count > 100) {
1500                                 link_retransmit_failure(l_ptr, buf);
1501                                 return;
1502                         }
1503                 } else {
1504                         l_ptr->last_retransmitted = msg_seqno(msg);
1505                         l_ptr->stale_count = 1;
1506                 }
1507         }
1508
1509         while (retransmits && (buf != l_ptr->next_out) && buf) {
1510                 msg = buf_msg(buf);
1511                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1512                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1513                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1514                         buf = buf->next;
1515                         retransmits--;
1516                         l_ptr->stats.retransmitted++;
1517                 } else {
1518                         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1519                         l_ptr->stats.bearer_congs++;
1520                         l_ptr->retransm_queue_head = msg_seqno(buf_msg(buf));
1521                         l_ptr->retransm_queue_size = retransmits;
1522                         return;
1523                 }
1524         }
1525
1526         l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1527 }
1528
1529 /**
1530  * link_insert_deferred_queue - insert deferred messages back into receive chain
1531  */
1532
1533 static struct sk_buff *link_insert_deferred_queue(struct link *l_ptr,
1534                                                   struct sk_buff *buf)
1535 {
1536         u32 seq_no;
1537
1538         if (l_ptr->oldest_deferred_in == NULL)
1539                 return buf;
1540
1541         seq_no = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
1542         if (seq_no == mod(l_ptr->next_in_no)) {
1543                 l_ptr->newest_deferred_in->next = buf;
1544                 buf = l_ptr->oldest_deferred_in;
1545                 l_ptr->oldest_deferred_in = NULL;
1546                 l_ptr->deferred_inqueue_sz = 0;
1547         }
1548         return buf;
1549 }
1550
1551 /**
1552  * link_recv_buf_validate - validate basic format of received message
1553  *
1554  * This routine ensures a TIPC message has an acceptable header, and at least
1555  * as much data as the header indicates it should.  The routine also ensures
1556  * that the entire message header is stored in the main fragment of the message
1557  * buffer, to simplify future access to message header fields.
1558  *
1559  * Note: Having extra info present in the message header or data areas is OK.
1560  * TIPC will ignore the excess, under the assumption that it is optional info
1561  * introduced by a later release of the protocol.
1562  */
1563
1564 static int link_recv_buf_validate(struct sk_buff *buf)
1565 {
1566         static u32 min_data_hdr_size[8] = {
1567                 SHORT_H_SIZE, MCAST_H_SIZE, LONG_H_SIZE, DIR_MSG_H_SIZE,
1568                 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1569                 };
1570
1571         struct tipc_msg *msg;
1572         u32 tipc_hdr[2];
1573         u32 size;
1574         u32 hdr_size;
1575         u32 min_hdr_size;
1576
1577         if (unlikely(buf->len < MIN_H_SIZE))
1578                 return 0;
1579
1580         msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1581         if (msg == NULL)
1582                 return 0;
1583
1584         if (unlikely(msg_version(msg) != TIPC_VERSION))
1585                 return 0;
1586
1587         size = msg_size(msg);
1588         hdr_size = msg_hdr_sz(msg);
1589         min_hdr_size = msg_isdata(msg) ?
1590                 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1591
1592         if (unlikely((hdr_size < min_hdr_size) ||
1593                      (size < hdr_size) ||
1594                      (buf->len < size) ||
1595                      (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1596                 return 0;
1597
1598         return pskb_may_pull(buf, hdr_size);
1599 }
1600
1601 /**
1602  * tipc_recv_msg - process TIPC messages arriving from off-node
1603  * @head: pointer to message buffer chain
1604  * @tb_ptr: pointer to bearer message arrived on
1605  *
1606  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1607  * structure (i.e. cannot be NULL), but bearer can be inactive.
1608  */
1609
1610 void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
1611 {
1612         read_lock_bh(&tipc_net_lock);
1613         while (head) {
1614                 struct tipc_node *n_ptr;
1615                 struct link *l_ptr;
1616                 struct sk_buff *crs;
1617                 struct sk_buff *buf = head;
1618                 struct tipc_msg *msg;
1619                 u32 seq_no;
1620                 u32 ackd;
1621                 u32 released = 0;
1622                 int type;
1623
1624                 head = head->next;
1625
1626                 /* Ensure bearer is still enabled */
1627
1628                 if (unlikely(!b_ptr->active))
1629                         goto cont;
1630
1631                 /* Ensure message is well-formed */
1632
1633                 if (unlikely(!link_recv_buf_validate(buf)))
1634                         goto cont;
1635
1636                 /* Ensure message data is a single contiguous unit */
1637
1638                 if (unlikely(buf_linearize(buf)))
1639                         goto cont;
1640
1641                 /* Handle arrival of a non-unicast link message */
1642
1643                 msg = buf_msg(buf);
1644
1645                 if (unlikely(msg_non_seq(msg))) {
1646                         if (msg_user(msg) ==  LINK_CONFIG)
1647                                 tipc_disc_recv_msg(buf, b_ptr);
1648                         else
1649                                 tipc_bclink_recv_pkt(buf);
1650                         continue;
1651                 }
1652
1653                 if (unlikely(!msg_short(msg) &&
1654                              (msg_destnode(msg) != tipc_own_addr)))
1655                         goto cont;
1656
1657                 /* Discard non-routeable messages destined for another node */
1658
1659                 if (unlikely(!msg_isdata(msg) &&
1660                              (msg_destnode(msg) != tipc_own_addr))) {
1661                         if ((msg_user(msg) != CONN_MANAGER) &&
1662                             (msg_user(msg) != MSG_FRAGMENTER))
1663                                 goto cont;
1664                 }
1665
1666                 /* Locate neighboring node that sent message */
1667
1668                 n_ptr = tipc_node_find(msg_prevnode(msg));
1669                 if (unlikely(!n_ptr))
1670                         goto cont;
1671                 tipc_node_lock(n_ptr);
1672
1673                 /* Don't talk to neighbor during cleanup after last session */
1674
1675                 if (n_ptr->cleanup_required) {
1676                         tipc_node_unlock(n_ptr);
1677                         goto cont;
1678                 }
1679
1680                 /* Locate unicast link endpoint that should handle message */
1681
1682                 l_ptr = n_ptr->links[b_ptr->identity];
1683                 if (unlikely(!l_ptr)) {
1684                         tipc_node_unlock(n_ptr);
1685                         goto cont;
1686                 }
1687
1688                 /* Validate message sequence number info */
1689
1690                 seq_no = msg_seqno(msg);
1691                 ackd = msg_ack(msg);
1692
1693                 /* Release acked messages */
1694
1695                 if (less(n_ptr->bclink.acked, msg_bcast_ack(msg))) {
1696                         if (tipc_node_is_up(n_ptr) && n_ptr->bclink.supported)
1697                                 tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1698                 }
1699
1700                 crs = l_ptr->first_out;
1701                 while ((crs != l_ptr->next_out) &&
1702                        less_eq(msg_seqno(buf_msg(crs)), ackd)) {
1703                         struct sk_buff *next = crs->next;
1704
1705                         buf_discard(crs);
1706                         crs = next;
1707                         released++;
1708                 }
1709                 if (released) {
1710                         l_ptr->first_out = crs;
1711                         l_ptr->out_queue_size -= released;
1712                 }
1713
1714                 /* Try sending any messages link endpoint has pending */
1715
1716                 if (unlikely(l_ptr->next_out))
1717                         tipc_link_push_queue(l_ptr);
1718                 if (unlikely(!list_empty(&l_ptr->waiting_ports)))
1719                         tipc_link_wakeup_ports(l_ptr, 0);
1720                 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1721                         l_ptr->stats.sent_acks++;
1722                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1723                 }
1724
1725                 /* Now (finally!) process the incoming message */
1726
1727 protocol_check:
1728                 if (likely(link_working_working(l_ptr))) {
1729                         if (likely(seq_no == mod(l_ptr->next_in_no))) {
1730                                 l_ptr->next_in_no++;
1731                                 if (unlikely(l_ptr->oldest_deferred_in))
1732                                         head = link_insert_deferred_queue(l_ptr,
1733                                                                           head);
1734                                 if (likely(msg_is_dest(msg, tipc_own_addr))) {
1735 deliver:
1736                                         if (likely(msg_isdata(msg))) {
1737                                                 tipc_node_unlock(n_ptr);
1738                                                 tipc_port_recv_msg(buf);
1739                                                 continue;
1740                                         }
1741                                         switch (msg_user(msg)) {
1742                                         case MSG_BUNDLER:
1743                                                 l_ptr->stats.recv_bundles++;
1744                                                 l_ptr->stats.recv_bundled +=
1745                                                         msg_msgcnt(msg);
1746                                                 tipc_node_unlock(n_ptr);
1747                                                 tipc_link_recv_bundle(buf);
1748                                                 continue;
1749                                         case NAME_DISTRIBUTOR:
1750                                                 tipc_node_unlock(n_ptr);
1751                                                 tipc_named_recv(buf);
1752                                                 continue;
1753                                         case CONN_MANAGER:
1754                                                 tipc_node_unlock(n_ptr);
1755                                                 tipc_port_recv_proto_msg(buf);
1756                                                 continue;
1757                                         case MSG_FRAGMENTER:
1758                                                 l_ptr->stats.recv_fragments++;
1759                                                 if (tipc_link_recv_fragment(&l_ptr->defragm_buf,
1760                                                                             &buf, &msg)) {
1761                                                         l_ptr->stats.recv_fragmented++;
1762                                                         goto deliver;
1763                                                 }
1764                                                 break;
1765                                         case CHANGEOVER_PROTOCOL:
1766                                                 type = msg_type(msg);
1767                                                 if (link_recv_changeover_msg(&l_ptr, &buf)) {
1768                                                         msg = buf_msg(buf);
1769                                                         seq_no = msg_seqno(msg);
1770                                                         if (type == ORIGINAL_MSG)
1771                                                                 goto deliver;
1772                                                         goto protocol_check;
1773                                                 }
1774                                                 break;
1775                                         default:
1776                                                 buf_discard(buf);
1777                                                 buf = NULL;
1778                                                 break;
1779                                         }
1780                                 }
1781                                 tipc_node_unlock(n_ptr);
1782                                 tipc_net_route_msg(buf);
1783                                 continue;
1784                         }
1785                         link_handle_out_of_seq_msg(l_ptr, buf);
1786                         head = link_insert_deferred_queue(l_ptr, head);
1787                         tipc_node_unlock(n_ptr);
1788                         continue;
1789                 }
1790
1791                 if (msg_user(msg) == LINK_PROTOCOL) {
1792                         link_recv_proto_msg(l_ptr, buf);
1793                         head = link_insert_deferred_queue(l_ptr, head);
1794                         tipc_node_unlock(n_ptr);
1795                         continue;
1796                 }
1797                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1798
1799                 if (link_working_working(l_ptr)) {
1800                         /* Re-insert in front of queue */
1801                         buf->next = head;
1802                         head = buf;
1803                         tipc_node_unlock(n_ptr);
1804                         continue;
1805                 }
1806                 tipc_node_unlock(n_ptr);
1807 cont:
1808                 buf_discard(buf);
1809         }
1810         read_unlock_bh(&tipc_net_lock);
1811 }
1812
1813 /*
1814  * link_defer_buf(): Sort a received out-of-sequence packet
1815  *                   into the deferred reception queue.
1816  * Returns the increase of the queue length,i.e. 0 or 1
1817  */
1818
1819 u32 tipc_link_defer_pkt(struct sk_buff **head,
1820                         struct sk_buff **tail,
1821                         struct sk_buff *buf)
1822 {
1823         struct sk_buff *prev = NULL;
1824         struct sk_buff *crs = *head;
1825         u32 seq_no = msg_seqno(buf_msg(buf));
1826
1827         buf->next = NULL;
1828
1829         /* Empty queue ? */
1830         if (*head == NULL) {
1831                 *head = *tail = buf;
1832                 return 1;
1833         }
1834
1835         /* Last ? */
1836         if (less(msg_seqno(buf_msg(*tail)), seq_no)) {
1837                 (*tail)->next = buf;
1838                 *tail = buf;
1839                 return 1;
1840         }
1841
1842         /* Scan through queue and sort it in */
1843         do {
1844                 struct tipc_msg *msg = buf_msg(crs);
1845
1846                 if (less(seq_no, msg_seqno(msg))) {
1847                         buf->next = crs;
1848                         if (prev)
1849                                 prev->next = buf;
1850                         else
1851                                 *head = buf;
1852                         return 1;
1853                 }
1854                 if (seq_no == msg_seqno(msg))
1855                         break;
1856                 prev = crs;
1857                 crs = crs->next;
1858         } while (crs);
1859
1860         /* Message is a duplicate of an existing message */
1861
1862         buf_discard(buf);
1863         return 0;
1864 }
1865
1866 /**
1867  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1868  */
1869
1870 static void link_handle_out_of_seq_msg(struct link *l_ptr,
1871                                        struct sk_buff *buf)
1872 {
1873         u32 seq_no = msg_seqno(buf_msg(buf));
1874
1875         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1876                 link_recv_proto_msg(l_ptr, buf);
1877                 return;
1878         }
1879
1880         /* Record OOS packet arrival (force mismatch on next timeout) */
1881
1882         l_ptr->checkpoint--;
1883
1884         /*
1885          * Discard packet if a duplicate; otherwise add it to deferred queue
1886          * and notify peer of gap as per protocol specification
1887          */
1888
1889         if (less(seq_no, mod(l_ptr->next_in_no))) {
1890                 l_ptr->stats.duplicates++;
1891                 buf_discard(buf);
1892                 return;
1893         }
1894
1895         if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
1896                                 &l_ptr->newest_deferred_in, buf)) {
1897                 l_ptr->deferred_inqueue_sz++;
1898                 l_ptr->stats.deferred_recv++;
1899                 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
1900                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1901         } else
1902                 l_ptr->stats.duplicates++;
1903 }
1904
1905 /*
1906  * Send protocol message to the other endpoint.
1907  */
1908 void tipc_link_send_proto_msg(struct link *l_ptr, u32 msg_typ, int probe_msg,
1909                               u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
1910 {
1911         struct sk_buff *buf = NULL;
1912         struct tipc_msg *msg = l_ptr->pmsg;
1913         u32 msg_size = sizeof(l_ptr->proto_msg);
1914         int r_flag;
1915
1916         if (link_blocked(l_ptr))
1917                 return;
1918         msg_set_type(msg, msg_typ);
1919         msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
1920         msg_set_bcast_ack(msg, mod(l_ptr->owner->bclink.last_in));
1921         msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
1922
1923         if (msg_typ == STATE_MSG) {
1924                 u32 next_sent = mod(l_ptr->next_out_no);
1925
1926                 if (!tipc_link_is_up(l_ptr))
1927                         return;
1928                 if (l_ptr->next_out)
1929                         next_sent = msg_seqno(buf_msg(l_ptr->next_out));
1930                 msg_set_next_sent(msg, next_sent);
1931                 if (l_ptr->oldest_deferred_in) {
1932                         u32 rec = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
1933                         gap = mod(rec - mod(l_ptr->next_in_no));
1934                 }
1935                 msg_set_seq_gap(msg, gap);
1936                 if (gap)
1937                         l_ptr->stats.sent_nacks++;
1938                 msg_set_link_tolerance(msg, tolerance);
1939                 msg_set_linkprio(msg, priority);
1940                 msg_set_max_pkt(msg, ack_mtu);
1941                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1942                 msg_set_probe(msg, probe_msg != 0);
1943                 if (probe_msg) {
1944                         u32 mtu = l_ptr->max_pkt;
1945
1946                         if ((mtu < l_ptr->max_pkt_target) &&
1947                             link_working_working(l_ptr) &&
1948                             l_ptr->fsm_msg_cnt) {
1949                                 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1950                                 if (l_ptr->max_pkt_probes == 10) {
1951                                         l_ptr->max_pkt_target = (msg_size - 4);
1952                                         l_ptr->max_pkt_probes = 0;
1953                                         msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1954                                 }
1955                                 l_ptr->max_pkt_probes++;
1956                         }
1957
1958                         l_ptr->stats.sent_probes++;
1959                 }
1960                 l_ptr->stats.sent_states++;
1961         } else {                /* RESET_MSG or ACTIVATE_MSG */
1962                 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
1963                 msg_set_seq_gap(msg, 0);
1964                 msg_set_next_sent(msg, 1);
1965                 msg_set_probe(msg, 0);
1966                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1967                 msg_set_linkprio(msg, l_ptr->priority);
1968                 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
1969         }
1970
1971         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1972         msg_set_redundant_link(msg, r_flag);
1973         msg_set_linkprio(msg, l_ptr->priority);
1974
1975         /* Ensure sequence number will not fit : */
1976
1977         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1978
1979         /* Congestion? */
1980
1981         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
1982                 if (!l_ptr->proto_msg_queue) {
1983                         l_ptr->proto_msg_queue =
1984                                 tipc_buf_acquire(sizeof(l_ptr->proto_msg));
1985                 }
1986                 buf = l_ptr->proto_msg_queue;
1987                 if (!buf)
1988                         return;
1989                 skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1990                 return;
1991         }
1992
1993         /* Message can be sent */
1994
1995         buf = tipc_buf_acquire(msg_size);
1996         if (!buf)
1997                 return;
1998
1999         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
2000         msg_set_size(buf_msg(buf), msg_size);
2001
2002         if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
2003                 l_ptr->unacked_window = 0;
2004                 buf_discard(buf);
2005                 return;
2006         }
2007
2008         /* New congestion */
2009         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
2010         l_ptr->proto_msg_queue = buf;
2011         l_ptr->stats.bearer_congs++;
2012 }
2013
2014 /*
2015  * Receive protocol message :
2016  * Note that network plane id propagates through the network, and may
2017  * change at any time. The node with lowest address rules
2018  */
2019
2020 static void link_recv_proto_msg(struct link *l_ptr, struct sk_buff *buf)
2021 {
2022         u32 rec_gap = 0;
2023         u32 max_pkt_info;
2024         u32 max_pkt_ack;
2025         u32 msg_tol;
2026         struct tipc_msg *msg = buf_msg(buf);
2027
2028         if (link_blocked(l_ptr))
2029                 goto exit;
2030
2031         /* record unnumbered packet arrival (force mismatch on next timeout) */
2032
2033         l_ptr->checkpoint--;
2034
2035         if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
2036                 if (tipc_own_addr > msg_prevnode(msg))
2037                         l_ptr->b_ptr->net_plane = msg_net_plane(msg);
2038
2039         l_ptr->owner->permit_changeover = msg_redundant_link(msg);
2040
2041         switch (msg_type(msg)) {
2042
2043         case RESET_MSG:
2044                 if (!link_working_unknown(l_ptr) &&
2045                     (l_ptr->peer_session != INVALID_SESSION)) {
2046                         if (msg_session(msg) == l_ptr->peer_session)
2047                                 break; /* duplicate: ignore */
2048                 }
2049                 /* fall thru' */
2050         case ACTIVATE_MSG:
2051                 /* Update link settings according other endpoint's values */
2052
2053                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
2054
2055                 msg_tol = msg_link_tolerance(msg);
2056                 if (msg_tol > l_ptr->tolerance)
2057                         link_set_supervision_props(l_ptr, msg_tol);
2058
2059                 if (msg_linkprio(msg) > l_ptr->priority)
2060                         l_ptr->priority = msg_linkprio(msg);
2061
2062                 max_pkt_info = msg_max_pkt(msg);
2063                 if (max_pkt_info) {
2064                         if (max_pkt_info < l_ptr->max_pkt_target)
2065                                 l_ptr->max_pkt_target = max_pkt_info;
2066                         if (l_ptr->max_pkt > l_ptr->max_pkt_target)
2067                                 l_ptr->max_pkt = l_ptr->max_pkt_target;
2068                 } else {
2069                         l_ptr->max_pkt = l_ptr->max_pkt_target;
2070                 }
2071                 l_ptr->owner->bclink.supported = (max_pkt_info != 0);
2072
2073                 link_state_event(l_ptr, msg_type(msg));
2074
2075                 l_ptr->peer_session = msg_session(msg);
2076                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
2077
2078                 /* Synchronize broadcast sequence numbers */
2079                 if (!tipc_node_redundant_links(l_ptr->owner))
2080                         l_ptr->owner->bclink.last_in = mod(msg_last_bcast(msg));
2081                 break;
2082         case STATE_MSG:
2083
2084                 msg_tol = msg_link_tolerance(msg);
2085                 if (msg_tol)
2086                         link_set_supervision_props(l_ptr, msg_tol);
2087
2088                 if (msg_linkprio(msg) &&
2089                     (msg_linkprio(msg) != l_ptr->priority)) {
2090                         warn("Resetting link <%s>, priority change %u->%u\n",
2091                              l_ptr->name, l_ptr->priority, msg_linkprio(msg));
2092                         l_ptr->priority = msg_linkprio(msg);
2093                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
2094                         break;
2095                 }
2096                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
2097                 l_ptr->stats.recv_states++;
2098                 if (link_reset_unknown(l_ptr))
2099                         break;
2100
2101                 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
2102                         rec_gap = mod(msg_next_sent(msg) -
2103                                       mod(l_ptr->next_in_no));
2104                 }
2105
2106                 max_pkt_ack = msg_max_pkt(msg);
2107                 if (max_pkt_ack > l_ptr->max_pkt) {
2108                         l_ptr->max_pkt = max_pkt_ack;
2109                         l_ptr->max_pkt_probes = 0;
2110                 }
2111
2112                 max_pkt_ack = 0;
2113                 if (msg_probe(msg)) {
2114                         l_ptr->stats.recv_probes++;
2115                         if (msg_size(msg) > sizeof(l_ptr->proto_msg))
2116                                 max_pkt_ack = msg_size(msg);
2117                 }
2118
2119                 /* Protocol message before retransmits, reduce loss risk */
2120
2121                 tipc_bclink_check_gap(l_ptr->owner, msg_last_bcast(msg));
2122
2123                 if (rec_gap || (msg_probe(msg))) {
2124                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2125                                                  0, rec_gap, 0, 0, max_pkt_ack);
2126                 }
2127                 if (msg_seq_gap(msg)) {
2128                         l_ptr->stats.recv_nacks++;
2129                         tipc_link_retransmit(l_ptr, l_ptr->first_out,
2130                                              msg_seq_gap(msg));
2131                 }
2132                 break;
2133         }
2134 exit:
2135         buf_discard(buf);
2136 }
2137
2138
2139 /*
2140  * tipc_link_tunnel(): Send one message via a link belonging to
2141  * another bearer. Owner node is locked.
2142  */
2143 static void tipc_link_tunnel(struct link *l_ptr,
2144                              struct tipc_msg *tunnel_hdr,
2145                              struct tipc_msg  *msg,
2146                              u32 selector)
2147 {
2148         struct link *tunnel;
2149         struct sk_buff *buf;
2150         u32 length = msg_size(msg);
2151
2152         tunnel = l_ptr->owner->active_links[selector & 1];
2153         if (!tipc_link_is_up(tunnel)) {
2154                 warn("Link changeover error, "
2155                      "tunnel link no longer available\n");
2156                 return;
2157         }
2158         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
2159         buf = tipc_buf_acquire(length + INT_H_SIZE);
2160         if (!buf) {
2161                 warn("Link changeover error, "
2162                      "unable to send tunnel msg\n");
2163                 return;
2164         }
2165         skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
2166         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
2167         tipc_link_send_buf(tunnel, buf);
2168 }
2169
2170
2171
2172 /*
2173  * changeover(): Send whole message queue via the remaining link
2174  *               Owner node is locked.
2175  */
2176
2177 void tipc_link_changeover(struct link *l_ptr)
2178 {
2179         u32 msgcount = l_ptr->out_queue_size;
2180         struct sk_buff *crs = l_ptr->first_out;
2181         struct link *tunnel = l_ptr->owner->active_links[0];
2182         struct tipc_msg tunnel_hdr;
2183         int split_bundles;
2184
2185         if (!tunnel)
2186                 return;
2187
2188         if (!l_ptr->owner->permit_changeover) {
2189                 warn("Link changeover error, "
2190                      "peer did not permit changeover\n");
2191                 return;
2192         }
2193
2194         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2195                  ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
2196         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2197         msg_set_msgcnt(&tunnel_hdr, msgcount);
2198
2199         if (!l_ptr->first_out) {
2200                 struct sk_buff *buf;
2201
2202                 buf = tipc_buf_acquire(INT_H_SIZE);
2203                 if (buf) {
2204                         skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
2205                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
2206                         tipc_link_send_buf(tunnel, buf);
2207                 } else {
2208                         warn("Link changeover error, "
2209                              "unable to send changeover msg\n");
2210                 }
2211                 return;
2212         }
2213
2214         split_bundles = (l_ptr->owner->active_links[0] !=
2215                          l_ptr->owner->active_links[1]);
2216
2217         while (crs) {
2218                 struct tipc_msg *msg = buf_msg(crs);
2219
2220                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
2221                         struct tipc_msg *m = msg_get_wrapped(msg);
2222                         unchar *pos = (unchar *)m;
2223
2224                         msgcount = msg_msgcnt(msg);
2225                         while (msgcount--) {
2226                                 msg_set_seqno(m, msg_seqno(msg));
2227                                 tipc_link_tunnel(l_ptr, &tunnel_hdr, m,
2228                                                  msg_link_selector(m));
2229                                 pos += align(msg_size(m));
2230                                 m = (struct tipc_msg *)pos;
2231                         }
2232                 } else {
2233                         tipc_link_tunnel(l_ptr, &tunnel_hdr, msg,
2234                                          msg_link_selector(msg));
2235                 }
2236                 crs = crs->next;
2237         }
2238 }
2239
2240 void tipc_link_send_duplicate(struct link *l_ptr, struct link *tunnel)
2241 {
2242         struct sk_buff *iter;
2243         struct tipc_msg tunnel_hdr;
2244
2245         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2246                  DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
2247         msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
2248         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2249         iter = l_ptr->first_out;
2250         while (iter) {
2251                 struct sk_buff *outbuf;
2252                 struct tipc_msg *msg = buf_msg(iter);
2253                 u32 length = msg_size(msg);
2254
2255                 if (msg_user(msg) == MSG_BUNDLER)
2256                         msg_set_type(msg, CLOSED_MSG);
2257                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));   /* Update */
2258                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
2259                 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
2260                 outbuf = tipc_buf_acquire(length + INT_H_SIZE);
2261                 if (outbuf == NULL) {
2262                         warn("Link changeover error, "
2263                              "unable to send duplicate msg\n");
2264                         return;
2265                 }
2266                 skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
2267                 skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
2268                                                length);
2269                 tipc_link_send_buf(tunnel, outbuf);
2270                 if (!tipc_link_is_up(l_ptr))
2271                         return;
2272                 iter = iter->next;
2273         }
2274 }
2275
2276
2277
2278 /**
2279  * buf_extract - extracts embedded TIPC message from another message
2280  * @skb: encapsulating message buffer
2281  * @from_pos: offset to extract from
2282  *
2283  * Returns a new message buffer containing an embedded message.  The
2284  * encapsulating message itself is left unchanged.
2285  */
2286
2287 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
2288 {
2289         struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
2290         u32 size = msg_size(msg);
2291         struct sk_buff *eb;
2292
2293         eb = tipc_buf_acquire(size);
2294         if (eb)
2295                 skb_copy_to_linear_data(eb, msg, size);
2296         return eb;
2297 }
2298
2299 /*
2300  *  link_recv_changeover_msg(): Receive tunneled packet sent
2301  *  via other link. Node is locked. Return extracted buffer.
2302  */
2303
2304 static int link_recv_changeover_msg(struct link **l_ptr,
2305                                     struct sk_buff **buf)
2306 {
2307         struct sk_buff *tunnel_buf = *buf;
2308         struct link *dest_link;
2309         struct tipc_msg *msg;
2310         struct tipc_msg *tunnel_msg = buf_msg(tunnel_buf);
2311         u32 msg_typ = msg_type(tunnel_msg);
2312         u32 msg_count = msg_msgcnt(tunnel_msg);
2313
2314         dest_link = (*l_ptr)->owner->links[msg_bearer_id(tunnel_msg)];
2315         if (!dest_link)
2316                 goto exit;
2317         if (dest_link == *l_ptr) {
2318                 err("Unexpected changeover message on link <%s>\n",
2319                     (*l_ptr)->name);
2320                 goto exit;
2321         }
2322         *l_ptr = dest_link;
2323         msg = msg_get_wrapped(tunnel_msg);
2324
2325         if (msg_typ == DUPLICATE_MSG) {
2326                 if (less(msg_seqno(msg), mod(dest_link->next_in_no)))
2327                         goto exit;
2328                 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2329                 if (*buf == NULL) {
2330                         warn("Link changeover error, duplicate msg dropped\n");
2331                         goto exit;
2332                 }
2333                 buf_discard(tunnel_buf);
2334                 return 1;
2335         }
2336
2337         /* First original message ?: */
2338
2339         if (tipc_link_is_up(dest_link)) {
2340                 info("Resetting link <%s>, changeover initiated by peer\n",
2341                      dest_link->name);
2342                 tipc_link_reset(dest_link);
2343                 dest_link->exp_msg_count = msg_count;
2344                 if (!msg_count)
2345                         goto exit;
2346         } else if (dest_link->exp_msg_count == START_CHANGEOVER) {
2347                 dest_link->exp_msg_count = msg_count;
2348                 if (!msg_count)
2349                         goto exit;
2350         }
2351
2352         /* Receive original message */
2353
2354         if (dest_link->exp_msg_count == 0) {
2355                 warn("Link switchover error, "
2356                      "got too many tunnelled messages\n");
2357                 goto exit;
2358         }
2359         dest_link->exp_msg_count--;
2360         if (less(msg_seqno(msg), dest_link->reset_checkpoint)) {
2361                 goto exit;
2362         } else {
2363                 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2364                 if (*buf != NULL) {
2365                         buf_discard(tunnel_buf);
2366                         return 1;
2367                 } else {
2368                         warn("Link changeover error, original msg dropped\n");
2369                 }
2370         }
2371 exit:
2372         *buf = NULL;
2373         buf_discard(tunnel_buf);
2374         return 0;
2375 }
2376
2377 /*
2378  *  Bundler functionality:
2379  */
2380 void tipc_link_recv_bundle(struct sk_buff *buf)
2381 {
2382         u32 msgcount = msg_msgcnt(buf_msg(buf));
2383         u32 pos = INT_H_SIZE;
2384         struct sk_buff *obuf;
2385
2386         while (msgcount--) {
2387                 obuf = buf_extract(buf, pos);
2388                 if (obuf == NULL) {
2389                         warn("Link unable to unbundle message(s)\n");
2390                         break;
2391                 }
2392                 pos += align(msg_size(buf_msg(obuf)));
2393                 tipc_net_route_msg(obuf);
2394         }
2395         buf_discard(buf);
2396 }
2397
2398 /*
2399  *  Fragmentation/defragmentation:
2400  */
2401
2402
2403 /*
2404  * link_send_long_buf: Entry for buffers needing fragmentation.
2405  * The buffer is complete, inclusive total message length.
2406  * Returns user data length.
2407  */
2408 static int link_send_long_buf(struct link *l_ptr, struct sk_buff *buf)
2409 {
2410         struct tipc_msg *inmsg = buf_msg(buf);
2411         struct tipc_msg fragm_hdr;
2412         u32 insize = msg_size(inmsg);
2413         u32 dsz = msg_data_sz(inmsg);
2414         unchar *crs = buf->data;
2415         u32 rest = insize;
2416         u32 pack_sz = l_ptr->max_pkt;
2417         u32 fragm_sz = pack_sz - INT_H_SIZE;
2418         u32 fragm_no = 1;
2419         u32 destaddr;
2420
2421         if (msg_short(inmsg))
2422                 destaddr = l_ptr->addr;
2423         else
2424                 destaddr = msg_destnode(inmsg);
2425
2426         /* Prepare reusable fragment header: */
2427
2428         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
2429                  INT_H_SIZE, destaddr);
2430         msg_set_link_selector(&fragm_hdr, msg_link_selector(inmsg));
2431         msg_set_long_msgno(&fragm_hdr, mod(l_ptr->long_msg_seq_no++));
2432         msg_set_fragm_no(&fragm_hdr, fragm_no);
2433         l_ptr->stats.sent_fragmented++;
2434
2435         /* Chop up message: */
2436
2437         while (rest > 0) {
2438                 struct sk_buff *fragm;
2439
2440                 if (rest <= fragm_sz) {
2441                         fragm_sz = rest;
2442                         msg_set_type(&fragm_hdr, LAST_FRAGMENT);
2443                 }
2444                 fragm = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
2445                 if (fragm == NULL) {
2446                         warn("Link unable to fragment message\n");
2447                         dsz = -ENOMEM;
2448                         goto exit;
2449                 }
2450                 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
2451                 skb_copy_to_linear_data(fragm, &fragm_hdr, INT_H_SIZE);
2452                 skb_copy_to_linear_data_offset(fragm, INT_H_SIZE, crs,
2453                                                fragm_sz);
2454                 /*  Send queued messages first, if any: */
2455
2456                 l_ptr->stats.sent_fragments++;
2457                 tipc_link_send_buf(l_ptr, fragm);
2458                 if (!tipc_link_is_up(l_ptr))
2459                         return dsz;
2460                 msg_set_fragm_no(&fragm_hdr, ++fragm_no);
2461                 rest -= fragm_sz;
2462                 crs += fragm_sz;
2463                 msg_set_type(&fragm_hdr, FRAGMENT);
2464         }
2465 exit:
2466         buf_discard(buf);
2467         return dsz;
2468 }
2469
2470 /*
2471  * A pending message being re-assembled must store certain values
2472  * to handle subsequent fragments correctly. The following functions
2473  * help storing these values in unused, available fields in the
2474  * pending message. This makes dynamic memory allocation unecessary.
2475  */
2476
2477 static void set_long_msg_seqno(struct sk_buff *buf, u32 seqno)
2478 {
2479         msg_set_seqno(buf_msg(buf), seqno);
2480 }
2481
2482 static u32 get_fragm_size(struct sk_buff *buf)
2483 {
2484         return msg_ack(buf_msg(buf));
2485 }
2486
2487 static void set_fragm_size(struct sk_buff *buf, u32 sz)
2488 {
2489         msg_set_ack(buf_msg(buf), sz);
2490 }
2491
2492 static u32 get_expected_frags(struct sk_buff *buf)
2493 {
2494         return msg_bcast_ack(buf_msg(buf));
2495 }
2496
2497 static void set_expected_frags(struct sk_buff *buf, u32 exp)
2498 {
2499         msg_set_bcast_ack(buf_msg(buf), exp);
2500 }
2501
2502 static u32 get_timer_cnt(struct sk_buff *buf)
2503 {
2504         return msg_reroute_cnt(buf_msg(buf));
2505 }
2506
2507 static void incr_timer_cnt(struct sk_buff *buf)
2508 {
2509         msg_incr_reroute_cnt(buf_msg(buf));
2510 }
2511
2512 /*
2513  * tipc_link_recv_fragment(): Called with node lock on. Returns
2514  * the reassembled buffer if message is complete.
2515  */
2516 int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
2517                             struct tipc_msg **m)
2518 {
2519         struct sk_buff *prev = NULL;
2520         struct sk_buff *fbuf = *fb;
2521         struct tipc_msg *fragm = buf_msg(fbuf);
2522         struct sk_buff *pbuf = *pending;
2523         u32 long_msg_seq_no = msg_long_msgno(fragm);
2524
2525         *fb = NULL;
2526
2527         /* Is there an incomplete message waiting for this fragment? */
2528
2529         while (pbuf && ((msg_seqno(buf_msg(pbuf)) != long_msg_seq_no) ||
2530                         (msg_orignode(fragm) != msg_orignode(buf_msg(pbuf))))) {
2531                 prev = pbuf;
2532                 pbuf = pbuf->next;
2533         }
2534
2535         if (!pbuf && (msg_type(fragm) == FIRST_FRAGMENT)) {
2536                 struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
2537                 u32 msg_sz = msg_size(imsg);
2538                 u32 fragm_sz = msg_data_sz(fragm);
2539                 u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
2540                 u32 max =  TIPC_MAX_USER_MSG_SIZE + LONG_H_SIZE;
2541                 if (msg_type(imsg) == TIPC_MCAST_MSG)
2542                         max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
2543                 if (msg_size(imsg) > max) {
2544                         buf_discard(fbuf);
2545                         return 0;
2546                 }
2547                 pbuf = tipc_buf_acquire(msg_size(imsg));
2548                 if (pbuf != NULL) {
2549                         pbuf->next = *pending;
2550                         *pending = pbuf;
2551                         skb_copy_to_linear_data(pbuf, imsg,
2552                                                 msg_data_sz(fragm));
2553                         /*  Prepare buffer for subsequent fragments. */
2554
2555                         set_long_msg_seqno(pbuf, long_msg_seq_no);
2556                         set_fragm_size(pbuf, fragm_sz);
2557                         set_expected_frags(pbuf, exp_fragm_cnt - 1);
2558                 } else {
2559                         warn("Link unable to reassemble fragmented message\n");
2560                 }
2561                 buf_discard(fbuf);
2562                 return 0;
2563         } else if (pbuf && (msg_type(fragm) != FIRST_FRAGMENT)) {
2564                 u32 dsz = msg_data_sz(fragm);
2565                 u32 fsz = get_fragm_size(pbuf);
2566                 u32 crs = ((msg_fragm_no(fragm) - 1) * fsz);
2567                 u32 exp_frags = get_expected_frags(pbuf) - 1;
2568                 skb_copy_to_linear_data_offset(pbuf, crs,
2569                                                msg_data(fragm), dsz);
2570                 buf_discard(fbuf);
2571
2572                 /* Is message complete? */
2573
2574                 if (exp_frags == 0) {
2575                         if (prev)
2576                                 prev->next = pbuf->next;
2577                         else
2578                                 *pending = pbuf->next;
2579                         msg_reset_reroute_cnt(buf_msg(pbuf));
2580                         *fb = pbuf;
2581                         *m = buf_msg(pbuf);
2582                         return 1;
2583                 }
2584                 set_expected_frags(pbuf, exp_frags);
2585                 return 0;
2586         }
2587         buf_discard(fbuf);
2588         return 0;
2589 }
2590
2591 /**
2592  * link_check_defragm_bufs - flush stale incoming message fragments
2593  * @l_ptr: pointer to link
2594  */
2595
2596 static void link_check_defragm_bufs(struct link *l_ptr)
2597 {
2598         struct sk_buff *prev = NULL;
2599         struct sk_buff *next = NULL;
2600         struct sk_buff *buf = l_ptr->defragm_buf;
2601
2602         if (!buf)
2603                 return;
2604         if (!link_working_working(l_ptr))
2605                 return;
2606         while (buf) {
2607                 u32 cnt = get_timer_cnt(buf);
2608
2609                 next = buf->next;
2610                 if (cnt < 4) {
2611                         incr_timer_cnt(buf);
2612                         prev = buf;
2613                 } else {
2614                         if (prev)
2615                                 prev->next = buf->next;
2616                         else
2617                                 l_ptr->defragm_buf = buf->next;
2618                         buf_discard(buf);
2619                 }
2620                 buf = next;
2621         }
2622 }
2623
2624
2625
2626 static void link_set_supervision_props(struct link *l_ptr, u32 tolerance)
2627 {
2628         if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
2629                 return;
2630
2631         l_ptr->tolerance = tolerance;
2632         l_ptr->continuity_interval =
2633                 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
2634         l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
2635 }
2636
2637
2638 void tipc_link_set_queue_limits(struct link *l_ptr, u32 window)
2639 {
2640         /* Data messages from this node, inclusive FIRST_FRAGM */
2641         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
2642         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
2643         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
2644         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
2645         /* Transiting data messages,inclusive FIRST_FRAGM */
2646         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
2647         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
2648         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
2649         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
2650         l_ptr->queue_limit[CONN_MANAGER] = 1200;
2651         l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
2652         l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
2653         /* FRAGMENT and LAST_FRAGMENT packets */
2654         l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
2655 }
2656
2657 /**
2658  * link_find_link - locate link by name
2659  * @name - ptr to link name string
2660  * @node - ptr to area to be filled with ptr to associated node
2661  *
2662  * Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
2663  * this also prevents link deletion.
2664  *
2665  * Returns pointer to link (or 0 if invalid link name).
2666  */
2667
2668 static struct link *link_find_link(const char *name, struct tipc_node **node)
2669 {
2670         struct link_name link_name_parts;
2671         struct tipc_bearer *b_ptr;
2672         struct link *l_ptr;
2673
2674         if (!link_name_validate(name, &link_name_parts))
2675                 return NULL;
2676
2677         b_ptr = tipc_bearer_find_interface(link_name_parts.if_local);
2678         if (!b_ptr)
2679                 return NULL;
2680
2681         *node = tipc_node_find(link_name_parts.addr_peer);
2682         if (!*node)
2683                 return NULL;
2684
2685         l_ptr = (*node)->links[b_ptr->identity];
2686         if (!l_ptr || strcmp(l_ptr->name, name))
2687                 return NULL;
2688
2689         return l_ptr;
2690 }
2691
2692 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2693                                      u16 cmd)
2694 {
2695         struct tipc_link_config *args;
2696         u32 new_value;
2697         struct link *l_ptr;
2698         struct tipc_node *node;
2699         int res;
2700
2701         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2702                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2703
2704         args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2705         new_value = ntohl(args->value);
2706
2707         if (!strcmp(args->name, tipc_bclink_name)) {
2708                 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2709                     (tipc_bclink_set_queue_limits(new_value) == 0))
2710                         return tipc_cfg_reply_none();
2711                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2712                                                    " (cannot change setting on broadcast link)");
2713         }
2714
2715         read_lock_bh(&tipc_net_lock);
2716         l_ptr = link_find_link(args->name, &node);
2717         if (!l_ptr) {
2718                 read_unlock_bh(&tipc_net_lock);
2719                 return tipc_cfg_reply_error_string("link not found");
2720         }
2721
2722         tipc_node_lock(node);
2723         res = -EINVAL;
2724         switch (cmd) {
2725         case TIPC_CMD_SET_LINK_TOL:
2726                 if ((new_value >= TIPC_MIN_LINK_TOL) &&
2727                     (new_value <= TIPC_MAX_LINK_TOL)) {
2728                         link_set_supervision_props(l_ptr, new_value);
2729                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2730                                                  0, 0, new_value, 0, 0);
2731                         res = 0;
2732                 }
2733                 break;
2734         case TIPC_CMD_SET_LINK_PRI:
2735                 if ((new_value >= TIPC_MIN_LINK_PRI) &&
2736                     (new_value <= TIPC_MAX_LINK_PRI)) {
2737                         l_ptr->priority = new_value;
2738                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2739                                                  0, 0, 0, new_value, 0);
2740                         res = 0;
2741                 }
2742                 break;
2743         case TIPC_CMD_SET_LINK_WINDOW:
2744                 if ((new_value >= TIPC_MIN_LINK_WIN) &&
2745                     (new_value <= TIPC_MAX_LINK_WIN)) {
2746                         tipc_link_set_queue_limits(l_ptr, new_value);
2747                         res = 0;
2748                 }
2749                 break;
2750         }
2751         tipc_node_unlock(node);
2752
2753         read_unlock_bh(&tipc_net_lock);
2754         if (res)
2755                 return tipc_cfg_reply_error_string("cannot change link setting");
2756
2757         return tipc_cfg_reply_none();
2758 }
2759
2760 /**
2761  * link_reset_statistics - reset link statistics
2762  * @l_ptr: pointer to link
2763  */
2764
2765 static void link_reset_statistics(struct link *l_ptr)
2766 {
2767         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2768         l_ptr->stats.sent_info = l_ptr->next_out_no;
2769         l_ptr->stats.recv_info = l_ptr->next_in_no;
2770 }
2771
2772 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2773 {
2774         char *link_name;
2775         struct link *l_ptr;
2776         struct tipc_node *node;
2777
2778         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2779                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2780
2781         link_name = (char *)TLV_DATA(req_tlv_area);
2782         if (!strcmp(link_name, tipc_bclink_name)) {
2783                 if (tipc_bclink_reset_stats())
2784                         return tipc_cfg_reply_error_string("link not found");
2785                 return tipc_cfg_reply_none();
2786         }
2787
2788         read_lock_bh(&tipc_net_lock);
2789         l_ptr = link_find_link(link_name, &node);
2790         if (!l_ptr) {
2791                 read_unlock_bh(&tipc_net_lock);
2792                 return tipc_cfg_reply_error_string("link not found");
2793         }
2794
2795         tipc_node_lock(node);
2796         link_reset_statistics(l_ptr);
2797         tipc_node_unlock(node);
2798         read_unlock_bh(&tipc_net_lock);
2799         return tipc_cfg_reply_none();
2800 }
2801
2802 /**
2803  * percent - convert count to a percentage of total (rounding up or down)
2804  */
2805
2806 static u32 percent(u32 count, u32 total)
2807 {
2808         return (count * 100 + (total / 2)) / total;
2809 }
2810
2811 /**
2812  * tipc_link_stats - print link statistics
2813  * @name: link name
2814  * @buf: print buffer area
2815  * @buf_size: size of print buffer area
2816  *
2817  * Returns length of print buffer data string (or 0 if error)
2818  */
2819
2820 static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
2821 {
2822         struct print_buf pb;
2823         struct link *l_ptr;
2824         struct tipc_node *node;
2825         char *status;
2826         u32 profile_total = 0;
2827
2828         if (!strcmp(name, tipc_bclink_name))
2829                 return tipc_bclink_stats(buf, buf_size);
2830
2831         tipc_printbuf_init(&pb, buf, buf_size);
2832
2833         read_lock_bh(&tipc_net_lock);
2834         l_ptr = link_find_link(name, &node);
2835         if (!l_ptr) {
2836                 read_unlock_bh(&tipc_net_lock);
2837                 return 0;
2838         }
2839         tipc_node_lock(node);
2840
2841         if (tipc_link_is_active(l_ptr))
2842                 status = "ACTIVE";
2843         else if (tipc_link_is_up(l_ptr))
2844                 status = "STANDBY";
2845         else
2846                 status = "DEFUNCT";
2847         tipc_printf(&pb, "Link <%s>\n"
2848                          "  %s  MTU:%u  Priority:%u  Tolerance:%u ms"
2849                          "  Window:%u packets\n",
2850                     l_ptr->name, status, l_ptr->max_pkt,
2851                     l_ptr->priority, l_ptr->tolerance, l_ptr->queue_limit[0]);
2852         tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2853                     l_ptr->next_in_no - l_ptr->stats.recv_info,
2854                     l_ptr->stats.recv_fragments,
2855                     l_ptr->stats.recv_fragmented,
2856                     l_ptr->stats.recv_bundles,
2857                     l_ptr->stats.recv_bundled);
2858         tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2859                     l_ptr->next_out_no - l_ptr->stats.sent_info,
2860                     l_ptr->stats.sent_fragments,
2861                     l_ptr->stats.sent_fragmented,
2862                     l_ptr->stats.sent_bundles,
2863                     l_ptr->stats.sent_bundled);
2864         profile_total = l_ptr->stats.msg_length_counts;
2865         if (!profile_total)
2866                 profile_total = 1;
2867         tipc_printf(&pb, "  TX profile sample:%u packets  average:%u octets\n"
2868                          "  0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
2869                          "-16354:%u%% -32768:%u%% -66000:%u%%\n",
2870                     l_ptr->stats.msg_length_counts,
2871                     l_ptr->stats.msg_lengths_total / profile_total,
2872                     percent(l_ptr->stats.msg_length_profile[0], profile_total),
2873                     percent(l_ptr->stats.msg_length_profile[1], profile_total),
2874                     percent(l_ptr->stats.msg_length_profile[2], profile_total),
2875                     percent(l_ptr->stats.msg_length_profile[3], profile_total),
2876                     percent(l_ptr->stats.msg_length_profile[4], profile_total),
2877                     percent(l_ptr->stats.msg_length_profile[5], profile_total),
2878                     percent(l_ptr->stats.msg_length_profile[6], profile_total));
2879         tipc_printf(&pb, "  RX states:%u probes:%u naks:%u defs:%u dups:%u\n",
2880                     l_ptr->stats.recv_states,
2881                     l_ptr->stats.recv_probes,
2882                     l_ptr->stats.recv_nacks,
2883                     l_ptr->stats.deferred_recv,
2884                     l_ptr->stats.duplicates);
2885         tipc_printf(&pb, "  TX states:%u probes:%u naks:%u acks:%u dups:%u\n",
2886                     l_ptr->stats.sent_states,
2887                     l_ptr->stats.sent_probes,
2888                     l_ptr->stats.sent_nacks,
2889                     l_ptr->stats.sent_acks,
2890                     l_ptr->stats.retransmitted);
2891         tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
2892                     l_ptr->stats.bearer_congs,
2893                     l_ptr->stats.link_congs,
2894                     l_ptr->stats.max_queue_sz,
2895                     l_ptr->stats.queue_sz_counts
2896                     ? (l_ptr->stats.accu_queue_sz / l_ptr->stats.queue_sz_counts)
2897                     : 0);
2898
2899         tipc_node_unlock(node);
2900         read_unlock_bh(&tipc_net_lock);
2901         return tipc_printbuf_validate(&pb);
2902 }
2903
2904 #define MAX_LINK_STATS_INFO 2000
2905
2906 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
2907 {
2908         struct sk_buff *buf;
2909         struct tlv_desc *rep_tlv;
2910         int str_len;
2911
2912         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2913                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2914
2915         buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_LINK_STATS_INFO));
2916         if (!buf)
2917                 return NULL;
2918
2919         rep_tlv = (struct tlv_desc *)buf->data;
2920
2921         str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
2922                                   (char *)TLV_DATA(rep_tlv), MAX_LINK_STATS_INFO);
2923         if (!str_len) {
2924                 buf_discard(buf);
2925                 return tipc_cfg_reply_error_string("link not found");
2926         }
2927
2928         skb_put(buf, TLV_SPACE(str_len));
2929         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
2930
2931         return buf;
2932 }
2933
2934 /**
2935  * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
2936  * @dest: network address of destination node
2937  * @selector: used to select from set of active links
2938  *
2939  * If no active link can be found, uses default maximum packet size.
2940  */
2941
2942 u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
2943 {
2944         struct tipc_node *n_ptr;
2945         struct link *l_ptr;
2946         u32 res = MAX_PKT_DEFAULT;
2947
2948         if (dest == tipc_own_addr)
2949                 return MAX_MSG_SIZE;
2950
2951         read_lock_bh(&tipc_net_lock);
2952         n_ptr = tipc_node_find(dest);
2953         if (n_ptr) {
2954                 tipc_node_lock(n_ptr);
2955                 l_ptr = n_ptr->active_links[selector & 1];
2956                 if (l_ptr)
2957                         res = l_ptr->max_pkt;
2958                 tipc_node_unlock(n_ptr);
2959         }
2960         read_unlock_bh(&tipc_net_lock);
2961         return res;
2962 }
2963
2964 static void link_print(struct link *l_ptr, const char *str)
2965 {
2966         char print_area[256];
2967         struct print_buf pb;
2968         struct print_buf *buf = &pb;
2969
2970         tipc_printbuf_init(buf, print_area, sizeof(print_area));
2971
2972         tipc_printf(buf, str);
2973         tipc_printf(buf, "Link %x<%s>:",
2974                     l_ptr->addr, l_ptr->b_ptr->name);
2975
2976 #ifdef CONFIG_TIPC_DEBUG
2977         if (link_reset_reset(l_ptr) || link_reset_unknown(l_ptr))
2978                 goto print_state;
2979
2980         tipc_printf(buf, ": NXO(%u):", mod(l_ptr->next_out_no));
2981         tipc_printf(buf, "NXI(%u):", mod(l_ptr->next_in_no));
2982         tipc_printf(buf, "SQUE");
2983         if (l_ptr->first_out) {
2984                 tipc_printf(buf, "[%u..", msg_seqno(buf_msg(l_ptr->first_out)));
2985                 if (l_ptr->next_out)
2986                         tipc_printf(buf, "%u..",
2987                                     msg_seqno(buf_msg(l_ptr->next_out)));
2988                 tipc_printf(buf, "%u]", msg_seqno(buf_msg(l_ptr->last_out)));
2989                 if ((mod(msg_seqno(buf_msg(l_ptr->last_out)) -
2990                          msg_seqno(buf_msg(l_ptr->first_out)))
2991                      != (l_ptr->out_queue_size - 1)) ||
2992                     (l_ptr->last_out->next != NULL)) {
2993                         tipc_printf(buf, "\nSend queue inconsistency\n");
2994                         tipc_printf(buf, "first_out= %p ", l_ptr->first_out);
2995                         tipc_printf(buf, "next_out= %p ", l_ptr->next_out);
2996                         tipc_printf(buf, "last_out= %p ", l_ptr->last_out);
2997                 }
2998         } else
2999                 tipc_printf(buf, "[]");
3000         tipc_printf(buf, "SQSIZ(%u)", l_ptr->out_queue_size);
3001         if (l_ptr->oldest_deferred_in) {
3002                 u32 o = msg_seqno(buf_msg(l_ptr->oldest_deferred_in));
3003                 u32 n = msg_seqno(buf_msg(l_ptr->newest_deferred_in));
3004                 tipc_printf(buf, ":RQUE[%u..%u]", o, n);
3005                 if (l_ptr->deferred_inqueue_sz != mod((n + 1) - o)) {
3006                         tipc_printf(buf, ":RQSIZ(%u)",
3007                                     l_ptr->deferred_inqueue_sz);
3008                 }
3009         }
3010 print_state:
3011 #endif
3012
3013         if (link_working_unknown(l_ptr))
3014                 tipc_printf(buf, ":WU");
3015         else if (link_reset_reset(l_ptr))
3016                 tipc_printf(buf, ":RR");
3017         else if (link_reset_unknown(l_ptr))
3018                 tipc_printf(buf, ":RU");
3019         else if (link_working_working(l_ptr))
3020                 tipc_printf(buf, ":WW");
3021         tipc_printf(buf, "\n");
3022
3023         tipc_printbuf_validate(buf);
3024         info("%s", print_area);
3025 }
3026