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