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  * Error message prefixes
  46  */
  47 static const char *link_co_err = "Link changeover error, ";
  48 static const char *link_rst_msg = "Resetting link ";
  49 static const char *link_unk_evt = "Unknown link event ";
  50
  51 /*
  52  * Out-of-range value for link session numbers
  53  */
  54 #define INVALID_SESSION 0x10000
  55
  56 /*
  57  * Link state events:
  58  */
  59 #define  STARTING_EVT    856384768      /* link processing trigger */
  60 #define  TRAFFIC_MSG_EVT 560815u        /* rx'd ??? */
  61 #define  TIMEOUT_EVT     560817u        /* link timer expired */
  62
  63 /*
  64  * The following two 'message types' is really just implementation
  65  * data conveniently stored in the message header.
  66  * They must not be considered part of the protocol
  67  */
  68 #define OPEN_MSG   0
  69 #define CLOSED_MSG 1
  70
  71 /*
  72  * State value stored in 'exp_msg_count'
  73  */
  74 #define START_CHANGEOVER 100000u
  75
  76 /**
  77  * struct tipc_link_name - deconstructed link name
  78  * @addr_local: network address of node at this end
  79  * @if_local: name of interface at this end
  80  * @addr_peer: network address of node at far end
  81  * @if_peer: name of interface at far end
  82  */
  83 struct tipc_link_name {
  84         u32 addr_local;
  85         char if_local[TIPC_MAX_IF_NAME];
  86         u32 addr_peer;
  87         char if_peer[TIPC_MAX_IF_NAME];
  88 };
  89
  90 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
  91                                        struct sk_buff *buf);
  92 static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf);
  93 static int  link_recv_changeover_msg(struct tipc_link **l_ptr,
  94                                      struct sk_buff **buf);
  95 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance);
  96 static int  link_send_sections_long(struct tipc_port *sender,
  97                                     struct iovec const *msg_sect,
  98                                     u32 num_sect, unsigned int total_len,
  99                                     u32 destnode);
 100 static void link_check_defragm_bufs(struct tipc_link *l_ptr);
 101 static void link_state_event(struct tipc_link *l_ptr, u32 event);
 102 static void link_reset_statistics(struct tipc_link *l_ptr);
 103 static void link_print(struct tipc_link *l_ptr, const char *str);
 104 static void link_start(struct tipc_link *l_ptr);
 105 static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf);
 106
 107 /*
 108  *  Simple link routines
 109  */
 110 static unsigned int align(unsigned int i)
 111 {
 112         return (i + 3) & ~3u;
 113 }
 114
 115 static void link_init_max_pkt(struct tipc_link *l_ptr)
 116 {
 117         u32 max_pkt;
 118
 119         max_pkt = (l_ptr->b_ptr->mtu & ~3);
 120         if (max_pkt > MAX_MSG_SIZE)
 121                 max_pkt = MAX_MSG_SIZE;
 122
 123         l_ptr->max_pkt_target = max_pkt;
 124         if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
 125                 l_ptr->max_pkt = l_ptr->max_pkt_target;
 126         else
 127                 l_ptr->max_pkt = MAX_PKT_DEFAULT;
 128
 129         l_ptr->max_pkt_probes = 0;
 130 }
 131
 132 static u32 link_next_sent(struct tipc_link *l_ptr)
 133 {
 134         if (l_ptr->next_out)
 135                 return buf_seqno(l_ptr->next_out);
 136         return mod(l_ptr->next_out_no);
 137 }
 138
 139 static u32 link_last_sent(struct tipc_link *l_ptr)
 140 {
 141         return mod(link_next_sent(l_ptr) - 1);
 142 }
 143
 144 /*
 145  *  Simple non-static link routines (i.e. referenced outside this file)
 146  */
 147 int tipc_link_is_up(struct tipc_link *l_ptr)
 148 {
 149         if (!l_ptr)
 150                 return 0;
 151         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 152 }
 153
 154 int tipc_link_is_active(struct tipc_link *l_ptr)
 155 {
 156         return  (l_ptr->owner->active_links[0] == l_ptr) ||
 157                 (l_ptr->owner->active_links[1] == l_ptr);
 158 }
 159
 160 /**
 161  * link_name_validate - validate & (optionally) deconstruct tipc_link name
 162  * @name: ptr to link name string
 163  * @name_parts: ptr to area for link name components (or NULL if not needed)
 164  *
 165  * Returns 1 if link name is valid, otherwise 0.
 166  */
 167 static int link_name_validate(const char *name,
 168                                 struct tipc_link_name *name_parts)
 169 {
 170         char name_copy[TIPC_MAX_LINK_NAME];
 171         char *addr_local;
 172         char *if_local;
 173         char *addr_peer;
 174         char *if_peer;
 175         char dummy;
 176         u32 z_local, c_local, n_local;
 177         u32 z_peer, c_peer, n_peer;
 178         u32 if_local_len;
 179         u32 if_peer_len;
 180
 181         /* copy link name & ensure length is OK */
 182         name_copy[TIPC_MAX_LINK_NAME - 1] = 0;
 183         /* need above in case non-Posix strncpy() doesn't pad with nulls */
 184         strncpy(name_copy, name, TIPC_MAX_LINK_NAME);
 185         if (name_copy[TIPC_MAX_LINK_NAME - 1] != 0)
 186                 return 0;
 187
 188         /* ensure all component parts of link name are present */
 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         if ((sscanf(addr_local, "%u.%u.%u%c",
 207                     &z_local, &c_local, &n_local, &dummy) != 3) ||
 208             (sscanf(addr_peer, "%u.%u.%u%c",
 209                     &z_peer, &c_peer, &n_peer, &dummy) != 3) ||
 210             (z_local > 255) || (c_local > 4095) || (n_local > 4095) ||
 211             (z_peer  > 255) || (c_peer  > 4095) || (n_peer  > 4095) ||
 212             (if_local_len <= 1) || (if_local_len > TIPC_MAX_IF_NAME) ||
 213             (if_peer_len  <= 1) || (if_peer_len  > TIPC_MAX_IF_NAME) ||
 214             (strspn(if_local, tipc_alphabet) != (if_local_len - 1)) ||
 215             (strspn(if_peer, tipc_alphabet) != (if_peer_len - 1)))
 216                 return 0;
 217
 218         /* return link name components, if necessary */
 219         if (name_parts) {
 220                 name_parts->addr_local = tipc_addr(z_local, c_local, n_local);
 221                 strcpy(name_parts->if_local, if_local);
 222                 name_parts->addr_peer = tipc_addr(z_peer, c_peer, n_peer);
 223                 strcpy(name_parts->if_peer, if_peer);
 224         }
 225         return 1;
 226 }
 227
 228 /**
 229  * link_timeout - handle expiration of link timer
 230  * @l_ptr: pointer to link
 231  *
 232  * This routine must not grab "tipc_net_lock" to avoid a potential deadlock conflict
 233  * with tipc_link_delete().  (There is no risk that the node will be deleted by
 234  * another thread because tipc_link_delete() always cancels the link timer before
 235  * tipc_node_delete() is called.)
 236  */
 237 static void link_timeout(struct tipc_link *l_ptr)
 238 {
 239         tipc_node_lock(l_ptr->owner);
 240
 241         /* update counters used in statistical profiling of send traffic */
 242         l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
 243         l_ptr->stats.queue_sz_counts++;
 244
 245         if (l_ptr->first_out) {
 246                 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
 247                 u32 length = msg_size(msg);
 248
 249                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 250                     (msg_type(msg) == FIRST_FRAGMENT)) {
 251                         length = msg_size(msg_get_wrapped(msg));
 252                 }
 253                 if (length) {
 254                         l_ptr->stats.msg_lengths_total += length;
 255                         l_ptr->stats.msg_length_counts++;
 256                         if (length <= 64)
 257                                 l_ptr->stats.msg_length_profile[0]++;
 258                         else if (length <= 256)
 259                                 l_ptr->stats.msg_length_profile[1]++;
 260                         else if (length <= 1024)
 261                                 l_ptr->stats.msg_length_profile[2]++;
 262                         else if (length <= 4096)
 263                                 l_ptr->stats.msg_length_profile[3]++;
 264                         else if (length <= 16384)
 265                                 l_ptr->stats.msg_length_profile[4]++;
 266                         else if (length <= 32768)
 267                                 l_ptr->stats.msg_length_profile[5]++;
 268                         else
 269                                 l_ptr->stats.msg_length_profile[6]++;
 270                 }
 271         }
 272
 273         /* do all other link processing performed on a periodic basis */
 274         link_check_defragm_bufs(l_ptr);
 275
 276         link_state_event(l_ptr, TIMEOUT_EVT);
 277
 278         if (l_ptr->next_out)
 279                 tipc_link_push_queue(l_ptr);
 280
 281         tipc_node_unlock(l_ptr->owner);
 282 }
 283
 284 static void link_set_timer(struct tipc_link *l_ptr, u32 time)
 285 {
 286         k_start_timer(&l_ptr->timer, time);
 287 }
 288
 289 /**
 290  * tipc_link_create - create a new link
 291  * @n_ptr: pointer to associated node
 292  * @b_ptr: pointer to associated bearer
 293  * @media_addr: media address to use when sending messages over link
 294  *
 295  * Returns pointer to link.
 296  */
 297 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 298                               struct tipc_bearer *b_ptr,
 299                               const struct tipc_media_addr *media_addr)
 300 {
 301         struct tipc_link *l_ptr;
 302         struct tipc_msg *msg;
 303         char *if_name;
 304         char addr_string[16];
 305         u32 peer = n_ptr->addr;
 306
 307         if (n_ptr->link_cnt >= 2) {
 308                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 309                 pr_err("Attempt to establish third link to %s\n", addr_string);
 310                 return NULL;
 311         }
 312
 313         if (n_ptr->links[b_ptr->identity]) {
 314                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 315                 pr_err("Attempt to establish second link on <%s> to %s\n",
 316                        b_ptr->name, addr_string);
 317                 return NULL;
 318         }
 319
 320         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 321         if (!l_ptr) {
 322                 pr_warn("Link creation failed, no memory\n");
 323                 return NULL;
 324         }
 325
 326         l_ptr->addr = peer;
 327         if_name = strchr(b_ptr->name, ':') + 1;
 328         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 329                 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
 330                 tipc_node(tipc_own_addr),
 331                 if_name,
 332                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 333                 /* note: peer i/f name is updated by reset/activate message */
 334         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 335         l_ptr->owner = n_ptr;
 336         l_ptr->checkpoint = 1;
 337         l_ptr->peer_session = INVALID_SESSION;
 338         l_ptr->b_ptr = b_ptr;
 339         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 340         l_ptr->state = RESET_UNKNOWN;
 341
 342         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 343         msg = l_ptr->pmsg;
 344         tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
 345         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 346         msg_set_session(msg, (tipc_random & 0xffff));
 347         msg_set_bearer_id(msg, b_ptr->identity);
 348         strcpy((char *)msg_data(msg), if_name);
 349
 350         l_ptr->priority = b_ptr->priority;
 351         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 352
 353         link_init_max_pkt(l_ptr);
 354
 355         l_ptr->next_out_no = 1;
 356         INIT_LIST_HEAD(&l_ptr->waiting_ports);
 357
 358         link_reset_statistics(l_ptr);
 359
 360         tipc_node_attach_link(n_ptr, l_ptr);
 361
 362         k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
 363         list_add_tail(&l_ptr->link_list, &b_ptr->links);
 364         tipc_k_signal((Handler)link_start, (unsigned long)l_ptr);
 365
 366         return l_ptr;
 367 }
 368
 369 /**
 370  * tipc_link_delete - delete a link
 371  * @l_ptr: pointer to link
 372  *
 373  * Note: 'tipc_net_lock' is write_locked, bearer is locked.
 374  * This routine must not grab the node lock until after link timer cancellation
 375  * to avoid a potential deadlock situation.
 376  */
 377 void tipc_link_delete(struct tipc_link *l_ptr)
 378 {
 379         if (!l_ptr) {
 380                 pr_err("Attempt to delete non-existent link\n");
 381                 return;
 382         }
 383
 384         k_cancel_timer(&l_ptr->timer);
 385
 386         tipc_node_lock(l_ptr->owner);
 387         tipc_link_reset(l_ptr);
 388         tipc_node_detach_link(l_ptr->owner, l_ptr);
 389         tipc_link_stop(l_ptr);
 390         list_del_init(&l_ptr->link_list);
 391         tipc_node_unlock(l_ptr->owner);
 392         k_term_timer(&l_ptr->timer);
 393         kfree(l_ptr);
 394 }
 395
 396 static void link_start(struct tipc_link *l_ptr)
 397 {
 398         tipc_node_lock(l_ptr->owner);
 399         link_state_event(l_ptr, STARTING_EVT);
 400         tipc_node_unlock(l_ptr->owner);
 401 }
 402
 403 /**
 404  * link_schedule_port - schedule port for deferred sending
 405  * @l_ptr: pointer to link
 406  * @origport: reference to sending port
 407  * @sz: amount of data to be sent
 408  *
 409  * Schedules port for renewed sending of messages after link congestion
 410  * has abated.
 411  */
 412 static int link_schedule_port(struct tipc_link *l_ptr, u32 origport, u32 sz)
 413 {
 414         struct tipc_port *p_ptr;
 415
 416         spin_lock_bh(&tipc_port_list_lock);
 417         p_ptr = tipc_port_lock(origport);
 418         if (p_ptr) {
 419                 if (!p_ptr->wakeup)
 420                         goto exit;
 421                 if (!list_empty(&p_ptr->wait_list))
 422                         goto exit;
 423                 p_ptr->congested = 1;
 424                 p_ptr->waiting_pkts = 1 + ((sz - 1) / l_ptr->max_pkt);
 425                 list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
 426                 l_ptr->stats.link_congs++;
 427 exit:
 428                 tipc_port_unlock(p_ptr);
 429         }
 430         spin_unlock_bh(&tipc_port_list_lock);
 431         return -ELINKCONG;
 432 }
 433
 434 void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all)
 435 {
 436         struct tipc_port *p_ptr;
 437         struct tipc_port *temp_p_ptr;
 438         int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
 439
 440         if (all)
 441                 win = 100000;
 442         if (win <= 0)
 443                 return;
 444         if (!spin_trylock_bh(&tipc_port_list_lock))
 445                 return;
 446         if (link_congested(l_ptr))
 447                 goto exit;
 448         list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
 449                                  wait_list) {
 450                 if (win <= 0)
 451                         break;
 452                 list_del_init(&p_ptr->wait_list);
 453                 spin_lock_bh(p_ptr->lock);
 454                 p_ptr->congested = 0;
 455                 p_ptr->wakeup(p_ptr);
 456                 win -= p_ptr->waiting_pkts;
 457                 spin_unlock_bh(p_ptr->lock);
 458         }
 459
 460 exit:
 461         spin_unlock_bh(&tipc_port_list_lock);
 462 }
 463
 464 /**
 465  * link_release_outqueue - purge link's outbound message queue
 466  * @l_ptr: pointer to link
 467  */
 468 static void link_release_outqueue(struct tipc_link *l_ptr)
 469 {
 470         struct sk_buff *buf = l_ptr->first_out;
 471         struct sk_buff *next;
 472
 473         while (buf) {
 474                 next = buf->next;
 475                 kfree_skb(buf);
 476                 buf = next;
 477         }
 478         l_ptr->first_out = NULL;
 479         l_ptr->out_queue_size = 0;
 480 }
 481
 482 /**
 483  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 484  * @l_ptr: pointer to link
 485  */
 486 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 487 {
 488         struct sk_buff *buf = l_ptr->defragm_buf;
 489         struct sk_buff *next;
 490
 491         while (buf) {
 492                 next = buf->next;
 493                 kfree_skb(buf);
 494                 buf = next;
 495         }
 496         l_ptr->defragm_buf = NULL;
 497 }
 498
 499 /**
 500  * tipc_link_stop - purge all inbound and outbound messages associated with link
 501  * @l_ptr: pointer to link
 502  */
 503 void tipc_link_stop(struct tipc_link *l_ptr)
 504 {
 505         struct sk_buff *buf;
 506         struct sk_buff *next;
 507
 508         buf = l_ptr->oldest_deferred_in;
 509         while (buf) {
 510                 next = buf->next;
 511                 kfree_skb(buf);
 512                 buf = next;
 513         }
 514
 515         buf = l_ptr->first_out;
 516         while (buf) {
 517                 next = buf->next;
 518                 kfree_skb(buf);
 519                 buf = next;
 520         }
 521
 522         tipc_link_reset_fragments(l_ptr);
 523
 524         kfree_skb(l_ptr->proto_msg_queue);
 525         l_ptr->proto_msg_queue = NULL;
 526 }
 527
 528 void tipc_link_reset(struct tipc_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         link_release_outqueue(l_ptr);
 559         kfree_skb(l_ptr->proto_msg_queue);
 560         l_ptr->proto_msg_queue = NULL;
 561         buf = l_ptr->oldest_deferred_in;
 562         while (buf) {
 563                 struct sk_buff *next = buf->next;
 564                 kfree_skb(buf);
 565                 buf = next;
 566         }
 567         if (!list_empty(&l_ptr->waiting_ports))
 568                 tipc_link_wakeup_ports(l_ptr, 1);
 569
 570         l_ptr->retransm_queue_head = 0;
 571         l_ptr->retransm_queue_size = 0;
 572         l_ptr->last_out = NULL;
 573         l_ptr->first_out = NULL;
 574         l_ptr->next_out = NULL;
 575         l_ptr->unacked_window = 0;
 576         l_ptr->checkpoint = 1;
 577         l_ptr->next_out_no = 1;
 578         l_ptr->deferred_inqueue_sz = 0;
 579         l_ptr->oldest_deferred_in = NULL;
 580         l_ptr->newest_deferred_in = NULL;
 581         l_ptr->fsm_msg_cnt = 0;
 582         l_ptr->stale_count = 0;
 583         link_reset_statistics(l_ptr);
 584 }
 585
 586
 587 static void link_activate(struct tipc_link *l_ptr)
 588 {
 589         l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
 590         tipc_node_link_up(l_ptr->owner, l_ptr);
 591         tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
 592 }
 593
 594 /**
 595  * link_state_event - link finite state machine
 596  * @l_ptr: pointer to link
 597  * @event: state machine event to process
 598  */
 599 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 600 {
 601         struct tipc_link *other;
 602         u32 cont_intv = l_ptr->continuity_interval;
 603
 604         if (!l_ptr->started && (event != STARTING_EVT))
 605                 return;         /* Not yet. */
 606
 607         if (link_blocked(l_ptr)) {
 608                 if (event == TIMEOUT_EVT)
 609                         link_set_timer(l_ptr, cont_intv);
 610                 return;   /* Changeover going on */
 611         }
 612
 613         switch (l_ptr->state) {
 614         case WORKING_WORKING:
 615                 switch (event) {
 616                 case TRAFFIC_MSG_EVT:
 617                 case ACTIVATE_MSG:
 618                         break;
 619                 case TIMEOUT_EVT:
 620                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 621                                 l_ptr->checkpoint = l_ptr->next_in_no;
 622                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 623                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 624                                                                  0, 0, 0, 0, 0);
 625                                         l_ptr->fsm_msg_cnt++;
 626                                 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
 627                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 628                                                                  1, 0, 0, 0, 0);
 629                                         l_ptr->fsm_msg_cnt++;
 630                                 }
 631                                 link_set_timer(l_ptr, cont_intv);
 632                                 break;
 633                         }
 634                         l_ptr->state = WORKING_UNKNOWN;
 635                         l_ptr->fsm_msg_cnt = 0;
 636                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 637                         l_ptr->fsm_msg_cnt++;
 638                         link_set_timer(l_ptr, cont_intv / 4);
 639                         break;
 640                 case RESET_MSG:
 641                         pr_info("%s<%s>, requested by peer\n", link_rst_msg,
 642                                 l_ptr->name);
 643                         tipc_link_reset(l_ptr);
 644                         l_ptr->state = RESET_RESET;
 645                         l_ptr->fsm_msg_cnt = 0;
 646                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 647                         l_ptr->fsm_msg_cnt++;
 648                         link_set_timer(l_ptr, cont_intv);
 649                         break;
 650                 default:
 651                         pr_err("%s%u in WW state\n", link_unk_evt, event);
 652                 }
 653                 break;
 654         case WORKING_UNKNOWN:
 655                 switch (event) {
 656                 case TRAFFIC_MSG_EVT:
 657                 case ACTIVATE_MSG:
 658                         l_ptr->state = WORKING_WORKING;
 659                         l_ptr->fsm_msg_cnt = 0;
 660                         link_set_timer(l_ptr, cont_intv);
 661                         break;
 662                 case RESET_MSG:
 663                         pr_info("%s<%s>, requested by peer while probing\n",
 664                                 link_rst_msg, l_ptr->name);
 665                         tipc_link_reset(l_ptr);
 666                         l_ptr->state = RESET_RESET;
 667                         l_ptr->fsm_msg_cnt = 0;
 668                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 669                         l_ptr->fsm_msg_cnt++;
 670                         link_set_timer(l_ptr, cont_intv);
 671                         break;
 672                 case TIMEOUT_EVT:
 673                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 674                                 l_ptr->state = WORKING_WORKING;
 675                                 l_ptr->fsm_msg_cnt = 0;
 676                                 l_ptr->checkpoint = l_ptr->next_in_no;
 677                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 678                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 679                                                                  0, 0, 0, 0, 0);
 680                                         l_ptr->fsm_msg_cnt++;
 681                                 }
 682                                 link_set_timer(l_ptr, cont_intv);
 683                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 684                                 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 685                                                          1, 0, 0, 0, 0);
 686                                 l_ptr->fsm_msg_cnt++;
 687                                 link_set_timer(l_ptr, cont_intv / 4);
 688                         } else {        /* Link has failed */
 689                                 pr_warn("%s<%s>, peer not responding\n",
 690                                         link_rst_msg, l_ptr->name);
 691                                 tipc_link_reset(l_ptr);
 692                                 l_ptr->state = RESET_UNKNOWN;
 693                                 l_ptr->fsm_msg_cnt = 0;
 694                                 tipc_link_send_proto_msg(l_ptr, RESET_MSG,
 695                                                          0, 0, 0, 0, 0);
 696                                 l_ptr->fsm_msg_cnt++;
 697                                 link_set_timer(l_ptr, cont_intv);
 698                         }
 699                         break;
 700                 default:
 701                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 702                 }
 703                 break;
 704         case RESET_UNKNOWN:
 705                 switch (event) {
 706                 case TRAFFIC_MSG_EVT:
 707                         break;
 708                 case ACTIVATE_MSG:
 709                         other = l_ptr->owner->active_links[0];
 710                         if (other && link_working_unknown(other))
 711                                 break;
 712                         l_ptr->state = WORKING_WORKING;
 713                         l_ptr->fsm_msg_cnt = 0;
 714                         link_activate(l_ptr);
 715                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 716                         l_ptr->fsm_msg_cnt++;
 717                         link_set_timer(l_ptr, cont_intv);
 718                         break;
 719                 case RESET_MSG:
 720                         l_ptr->state = RESET_RESET;
 721                         l_ptr->fsm_msg_cnt = 0;
 722                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
 723                         l_ptr->fsm_msg_cnt++;
 724                         link_set_timer(l_ptr, cont_intv);
 725                         break;
 726                 case STARTING_EVT:
 727                         l_ptr->started = 1;
 728                         /* fall through */
 729                 case TIMEOUT_EVT:
 730                         tipc_link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
 731                         l_ptr->fsm_msg_cnt++;
 732                         link_set_timer(l_ptr, cont_intv);
 733                         break;
 734                 default:
 735                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 736                 }
 737                 break;
 738         case RESET_RESET:
 739                 switch (event) {
 740                 case TRAFFIC_MSG_EVT:
 741                 case ACTIVATE_MSG:
 742                         other = l_ptr->owner->active_links[0];
 743                         if (other && link_working_unknown(other))
 744                                 break;
 745                         l_ptr->state = WORKING_WORKING;
 746                         l_ptr->fsm_msg_cnt = 0;
 747                         link_activate(l_ptr);
 748                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 749                         l_ptr->fsm_msg_cnt++;
 750                         link_set_timer(l_ptr, cont_intv);
 751                         break;
 752                 case RESET_MSG:
 753                         break;
 754                 case TIMEOUT_EVT:
 755                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 756                         l_ptr->fsm_msg_cnt++;
 757                         link_set_timer(l_ptr, cont_intv);
 758                         break;
 759                 default:
 760                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 761                 }
 762                 break;
 763         default:
 764                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 765         }
 766 }
 767
 768 /*
 769  * link_bundle_buf(): Append contents of a buffer to
 770  * the tail of an existing one.
 771  */
 772 static int link_bundle_buf(struct tipc_link *l_ptr,
 773                            struct sk_buff *bundler,
 774                            struct sk_buff *buf)
 775 {
 776         struct tipc_msg *bundler_msg = buf_msg(bundler);
 777         struct tipc_msg *msg = buf_msg(buf);
 778         u32 size = msg_size(msg);
 779         u32 bundle_size = msg_size(bundler_msg);
 780         u32 to_pos = align(bundle_size);
 781         u32 pad = to_pos - bundle_size;
 782
 783         if (msg_user(bundler_msg) != MSG_BUNDLER)
 784                 return 0;
 785         if (msg_type(bundler_msg) != OPEN_MSG)
 786                 return 0;
 787         if (skb_tailroom(bundler) < (pad + size))
 788                 return 0;
 789         if (l_ptr->max_pkt < (to_pos + size))
 790                 return 0;
 791
 792         skb_put(bundler, pad + size);
 793         skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
 794         msg_set_size(bundler_msg, to_pos + size);
 795         msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
 796         kfree_skb(buf);
 797         l_ptr->stats.sent_bundled++;
 798         return 1;
 799 }
 800
 801 static void link_add_to_outqueue(struct tipc_link *l_ptr,
 802                                  struct sk_buff *buf,
 803                                  struct tipc_msg *msg)
 804 {
 805         u32 ack = mod(l_ptr->next_in_no - 1);
 806         u32 seqno = mod(l_ptr->next_out_no++);
 807
 808         msg_set_word(msg, 2, ((ack << 16) | seqno));
 809         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 810         buf->next = NULL;
 811         if (l_ptr->first_out) {
 812                 l_ptr->last_out->next = buf;
 813                 l_ptr->last_out = buf;
 814         } else
 815                 l_ptr->first_out = l_ptr->last_out = buf;
 816
 817         l_ptr->out_queue_size++;
 818         if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
 819                 l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
 820 }
 821
 822 static void link_add_chain_to_outqueue(struct tipc_link *l_ptr,
 823                                        struct sk_buff *buf_chain,
 824                                        u32 long_msgno)
 825 {
 826         struct sk_buff *buf;
 827         struct tipc_msg *msg;
 828
 829         if (!l_ptr->next_out)
 830                 l_ptr->next_out = buf_chain;
 831         while (buf_chain) {
 832                 buf = buf_chain;
 833                 buf_chain = buf_chain->next;
 834
 835                 msg = buf_msg(buf);
 836                 msg_set_long_msgno(msg, long_msgno);
 837                 link_add_to_outqueue(l_ptr, buf, msg);
 838         }
 839 }
 840
 841 /*
 842  * tipc_link_send_buf() is the 'full path' for messages, called from
 843  * inside TIPC when the 'fast path' in tipc_send_buf
 844  * has failed, and from link_send()
 845  */
 846 int tipc_link_send_buf(struct tipc_link *l_ptr, struct sk_buff *buf)
 847 {
 848         struct tipc_msg *msg = buf_msg(buf);
 849         u32 size = msg_size(msg);
 850         u32 dsz = msg_data_sz(msg);
 851         u32 queue_size = l_ptr->out_queue_size;
 852         u32 imp = tipc_msg_tot_importance(msg);
 853         u32 queue_limit = l_ptr->queue_limit[imp];
 854         u32 max_packet = l_ptr->max_pkt;
 855
 856         /* Match msg importance against queue limits: */
 857         if (unlikely(queue_size >= queue_limit)) {
 858                 if (imp <= TIPC_CRITICAL_IMPORTANCE) {
 859                         link_schedule_port(l_ptr, msg_origport(msg), size);
 860                         kfree_skb(buf);
 861                         return -ELINKCONG;
 862                 }
 863                 kfree_skb(buf);
 864                 if (imp > CONN_MANAGER) {
 865                         pr_warn("%s<%s>, send queue full", link_rst_msg,
 866                                 l_ptr->name);
 867                         tipc_link_reset(l_ptr);
 868                 }
 869                 return dsz;
 870         }
 871
 872         /* Fragmentation needed ? */
 873         if (size > max_packet)
 874                 return link_send_long_buf(l_ptr, buf);
 875
 876         /* Packet can be queued or sent. */
 877         if (likely(!tipc_bearer_congested(l_ptr->b_ptr, l_ptr) &&
 878                    !link_congested(l_ptr))) {
 879                 link_add_to_outqueue(l_ptr, buf, msg);
 880
 881                 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr))) {
 882                         l_ptr->unacked_window = 0;
 883                 } else {
 884                         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
 885                         l_ptr->stats.bearer_congs++;
 886                         l_ptr->next_out = buf;
 887                 }
 888                 return dsz;
 889         }
 890         /* Congestion: can message be bundled ? */
 891         if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
 892             (msg_user(msg) != MSG_FRAGMENTER)) {
 893
 894                 /* Try adding message to an existing bundle */
 895                 if (l_ptr->next_out &&
 896                     link_bundle_buf(l_ptr, l_ptr->last_out, buf)) {
 897                         tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
 898                         return dsz;
 899                 }
 900
 901                 /* Try creating a new bundle */
 902                 if (size <= max_packet * 2 / 3) {
 903                         struct sk_buff *bundler = tipc_buf_acquire(max_packet);
 904                         struct tipc_msg bundler_hdr;
 905
 906                         if (bundler) {
 907                                 tipc_msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
 908                                          INT_H_SIZE, l_ptr->addr);
 909                                 skb_copy_to_linear_data(bundler, &bundler_hdr,
 910                                                         INT_H_SIZE);
 911                                 skb_trim(bundler, INT_H_SIZE);
 912                                 link_bundle_buf(l_ptr, bundler, buf);
 913                                 buf = bundler;
 914                                 msg = buf_msg(buf);
 915                                 l_ptr->stats.sent_bundles++;
 916                         }
 917                 }
 918         }
 919         if (!l_ptr->next_out)
 920                 l_ptr->next_out = buf;
 921         link_add_to_outqueue(l_ptr, buf, msg);
 922         tipc_bearer_resolve_congestion(l_ptr->b_ptr, l_ptr);
 923         return dsz;
 924 }
 925
 926 /*
 927  * tipc_link_send(): same as tipc_link_send_buf(), but the link to use has
 928  * not been selected yet, and the the owner node is not locked
 929  * Called by TIPC internal users, e.g. the name distributor
 930  */
 931 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector)
 932 {
 933         struct tipc_link *l_ptr;
 934         struct tipc_node *n_ptr;
 935         int res = -ELINKCONG;
 936
 937         read_lock_bh(&tipc_net_lock);
 938         n_ptr = tipc_node_find(dest);
 939         if (n_ptr) {
 940                 tipc_node_lock(n_ptr);
 941                 l_ptr = n_ptr->active_links[selector & 1];
 942                 if (l_ptr)
 943                         res = tipc_link_send_buf(l_ptr, buf);
 944                 else
 945                         kfree_skb(buf);
 946                 tipc_node_unlock(n_ptr);
 947         } else {
 948                 kfree_skb(buf);
 949         }
 950         read_unlock_bh(&tipc_net_lock);
 951         return res;
 952 }
 953
 954 /**
 955  * tipc_link_send_names - send name table entries to new neighbor
 956  *
 957  * Send routine for bulk delivery of name table messages when contact
 958  * with a new neighbor occurs. No link congestion checking is performed
 959  * because name table messages *must* be delivered. The messages must be
 960  * small enough not to require fragmentation.
 961  * Called without any locks held.
 962  */
 963 void tipc_link_send_names(struct list_head *message_list, u32 dest)
 964 {
 965         struct tipc_node *n_ptr;
 966         struct tipc_link *l_ptr;
 967         struct sk_buff *buf;
 968         struct sk_buff *temp_buf;
 969
 970         if (list_empty(message_list))
 971                 return;
 972
 973         read_lock_bh(&tipc_net_lock);
 974         n_ptr = tipc_node_find(dest);
 975         if (n_ptr) {
 976                 tipc_node_lock(n_ptr);
 977                 l_ptr = n_ptr->active_links[0];
 978                 if (l_ptr) {
 979                         /* convert circular list to linear list */
 980                         ((struct sk_buff *)message_list->prev)->next = NULL;
 981                         link_add_chain_to_outqueue(l_ptr,
 982                                 (struct sk_buff *)message_list->next, 0);
 983                         tipc_link_push_queue(l_ptr);
 984                         INIT_LIST_HEAD(message_list);
 985                 }
 986                 tipc_node_unlock(n_ptr);
 987         }
 988         read_unlock_bh(&tipc_net_lock);
 989
 990         /* discard the messages if they couldn't be sent */
 991         list_for_each_safe(buf, temp_buf, ((struct sk_buff *)message_list)) {
 992                 list_del((struct list_head *)buf);
 993                 kfree_skb(buf);
 994         }
 995 }
 996
 997 /*
 998  * link_send_buf_fast: Entry for data messages where the
 999  * destination link is known and the header is complete,
1000  * inclusive total message length. Very time critical.
1001  * Link is locked. Returns user data length.
1002  */
1003 static int link_send_buf_fast(struct tipc_link *l_ptr, struct sk_buff *buf,
1004                               u32 *used_max_pkt)
1005 {
1006         struct tipc_msg *msg = buf_msg(buf);
1007         int res = msg_data_sz(msg);
1008
1009         if (likely(!link_congested(l_ptr))) {
1010                 if (likely(msg_size(msg) <= l_ptr->max_pkt)) {
1011                         if (likely(list_empty(&l_ptr->b_ptr->cong_links))) {
1012                                 link_add_to_outqueue(l_ptr, buf, msg);
1013                                 if (likely(tipc_bearer_send(l_ptr->b_ptr, buf,
1014                                                             &l_ptr->media_addr))) {
1015                                         l_ptr->unacked_window = 0;
1016                                         return res;
1017                                 }
1018                                 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1019                                 l_ptr->stats.bearer_congs++;
1020                                 l_ptr->next_out = buf;
1021                                 return res;
1022                         }
1023                 } else
1024                         *used_max_pkt = l_ptr->max_pkt;
1025         }
1026         return tipc_link_send_buf(l_ptr, buf);  /* All other cases */
1027 }
1028
1029 /*
1030  * tipc_send_buf_fast: Entry for data messages where the
1031  * destination node is known and the header is complete,
1032  * inclusive total message length.
1033  * Returns user data length.
1034  */
1035 int tipc_send_buf_fast(struct sk_buff *buf, u32 destnode)
1036 {
1037         struct tipc_link *l_ptr;
1038         struct tipc_node *n_ptr;
1039         int res;
1040         u32 selector = msg_origport(buf_msg(buf)) & 1;
1041         u32 dummy;
1042
1043         read_lock_bh(&tipc_net_lock);
1044         n_ptr = tipc_node_find(destnode);
1045         if (likely(n_ptr)) {
1046                 tipc_node_lock(n_ptr);
1047                 l_ptr = n_ptr->active_links[selector];
1048                 if (likely(l_ptr)) {
1049                         res = link_send_buf_fast(l_ptr, buf, &dummy);
1050                         tipc_node_unlock(n_ptr);
1051                         read_unlock_bh(&tipc_net_lock);
1052                         return res;
1053                 }
1054                 tipc_node_unlock(n_ptr);
1055         }
1056         read_unlock_bh(&tipc_net_lock);
1057         res = msg_data_sz(buf_msg(buf));
1058         tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1059         return res;
1060 }
1061
1062
1063 /*
1064  * tipc_link_send_sections_fast: Entry for messages where the
1065  * destination processor is known and the header is complete,
1066  * except for total message length.
1067  * Returns user data length or errno.
1068  */
1069 int tipc_link_send_sections_fast(struct tipc_port *sender,
1070                                  struct iovec const *msg_sect,
1071                                  const u32 num_sect,
1072                                  unsigned int total_len,
1073                                  u32 destaddr)
1074 {
1075         struct tipc_msg *hdr = &sender->phdr;
1076         struct tipc_link *l_ptr;
1077         struct sk_buff *buf;
1078         struct tipc_node *node;
1079         int res;
1080         u32 selector = msg_origport(hdr) & 1;
1081
1082 again:
1083         /*
1084          * Try building message using port's max_pkt hint.
1085          * (Must not hold any locks while building message.)
1086          */
1087         res = tipc_msg_build(hdr, msg_sect, num_sect, total_len,
1088                              sender->max_pkt, !sender->user_port, &buf);
1089
1090         read_lock_bh(&tipc_net_lock);
1091         node = tipc_node_find(destaddr);
1092         if (likely(node)) {
1093                 tipc_node_lock(node);
1094                 l_ptr = node->active_links[selector];
1095                 if (likely(l_ptr)) {
1096                         if (likely(buf)) {
1097                                 res = link_send_buf_fast(l_ptr, buf,
1098                                                          &sender->max_pkt);
1099 exit:
1100                                 tipc_node_unlock(node);
1101                                 read_unlock_bh(&tipc_net_lock);
1102                                 return res;
1103                         }
1104
1105                         /* Exit if build request was invalid */
1106                         if (unlikely(res < 0))
1107                                 goto exit;
1108
1109                         /* Exit if link (or bearer) is congested */
1110                         if (link_congested(l_ptr) ||
1111                             !list_empty(&l_ptr->b_ptr->cong_links)) {
1112                                 res = link_schedule_port(l_ptr,
1113                                                          sender->ref, res);
1114                                 goto exit;
1115                         }
1116
1117                         /*
1118                          * Message size exceeds max_pkt hint; update hint,
1119                          * then re-try fast path or fragment the message
1120                          */
1121                         sender->max_pkt = l_ptr->max_pkt;
1122                         tipc_node_unlock(node);
1123                         read_unlock_bh(&tipc_net_lock);
1124
1125
1126                         if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
1127                                 goto again;
1128
1129                         return link_send_sections_long(sender, msg_sect,
1130                                                        num_sect, total_len,
1131                                                        destaddr);
1132                 }
1133                 tipc_node_unlock(node);
1134         }
1135         read_unlock_bh(&tipc_net_lock);
1136
1137         /* Couldn't find a link to the destination node */
1138         if (buf)
1139                 return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1140         if (res >= 0)
1141                 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1142                                                  total_len, TIPC_ERR_NO_NODE);
1143         return res;
1144 }
1145
1146 /*
1147  * link_send_sections_long(): Entry for long messages where the
1148  * destination node is known and the header is complete,
1149  * inclusive total message length.
1150  * Link and bearer congestion status have been checked to be ok,
1151  * and are ignored if they change.
1152  *
1153  * Note that fragments do not use the full link MTU so that they won't have
1154  * to undergo refragmentation if link changeover causes them to be sent
1155  * over another link with an additional tunnel header added as prefix.
1156  * (Refragmentation will still occur if the other link has a smaller MTU.)
1157  *
1158  * Returns user data length or errno.
1159  */
1160 static int link_send_sections_long(struct tipc_port *sender,
1161                                    struct iovec const *msg_sect,
1162                                    u32 num_sect,
1163                                    unsigned int total_len,
1164                                    u32 destaddr)
1165 {
1166         struct tipc_link *l_ptr;
1167         struct tipc_node *node;
1168         struct tipc_msg *hdr = &sender->phdr;
1169         u32 dsz = total_len;
1170         u32 max_pkt, fragm_sz, rest;
1171         struct tipc_msg fragm_hdr;
1172         struct sk_buff *buf, *buf_chain, *prev;
1173         u32 fragm_crs, fragm_rest, hsz, sect_rest;
1174         const unchar *sect_crs;
1175         int curr_sect;
1176         u32 fragm_no;
1177
1178 again:
1179         fragm_no = 1;
1180         max_pkt = sender->max_pkt - INT_H_SIZE;
1181                 /* leave room for tunnel header in case of link changeover */
1182         fragm_sz = max_pkt - INT_H_SIZE;
1183                 /* leave room for fragmentation header in each fragment */
1184         rest = dsz;
1185         fragm_crs = 0;
1186         fragm_rest = 0;
1187         sect_rest = 0;
1188         sect_crs = NULL;
1189         curr_sect = -1;
1190
1191         /* Prepare reusable fragment header */
1192         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
1193                  INT_H_SIZE, msg_destnode(hdr));
1194         msg_set_size(&fragm_hdr, max_pkt);
1195         msg_set_fragm_no(&fragm_hdr, 1);
1196
1197         /* Prepare header of first fragment */
1198         buf_chain = buf = tipc_buf_acquire(max_pkt);
1199         if (!buf)
1200                 return -ENOMEM;
1201         buf->next = NULL;
1202         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1203         hsz = msg_hdr_sz(hdr);
1204         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
1205
1206         /* Chop up message */
1207         fragm_crs = INT_H_SIZE + hsz;
1208         fragm_rest = fragm_sz - hsz;
1209
1210         do {            /* For all sections */
1211                 u32 sz;
1212
1213                 if (!sect_rest) {
1214                         sect_rest = msg_sect[++curr_sect].iov_len;
1215                         sect_crs = (const unchar *)msg_sect[curr_sect].iov_base;
1216                 }
1217
1218                 if (sect_rest < fragm_rest)
1219                         sz = sect_rest;
1220                 else
1221                         sz = fragm_rest;
1222
1223                 if (likely(!sender->user_port)) {
1224                         if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
1225 error:
1226                                 for (; buf_chain; buf_chain = buf) {
1227                                         buf = buf_chain->next;
1228                                         kfree_skb(buf_chain);
1229                                 }
1230                                 return -EFAULT;
1231                         }
1232                 } else
1233                         skb_copy_to_linear_data_offset(buf, fragm_crs,
1234                                                        sect_crs, sz);
1235                 sect_crs += sz;
1236                 sect_rest -= sz;
1237                 fragm_crs += sz;
1238                 fragm_rest -= sz;
1239                 rest -= sz;
1240
1241                 if (!fragm_rest && rest) {
1242
1243                         /* Initiate new fragment: */
1244                         if (rest <= fragm_sz) {
1245                                 fragm_sz = rest;
1246                                 msg_set_type(&fragm_hdr, LAST_FRAGMENT);
1247                         } else {
1248                                 msg_set_type(&fragm_hdr, FRAGMENT);
1249                         }
1250                         msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
1251                         msg_set_fragm_no(&fragm_hdr, ++fragm_no);
1252                         prev = buf;
1253                         buf = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
1254                         if (!buf)
1255                                 goto error;
1256
1257                         buf->next = NULL;
1258                         prev->next = buf;
1259                         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1260                         fragm_crs = INT_H_SIZE;
1261                         fragm_rest = fragm_sz;
1262                 }
1263         } while (rest > 0);
1264
1265         /*
1266          * Now we have a buffer chain. Select a link and check
1267          * that packet size is still OK
1268          */
1269         node = tipc_node_find(destaddr);
1270         if (likely(node)) {
1271                 tipc_node_lock(node);
1272                 l_ptr = node->active_links[sender->ref & 1];
1273                 if (!l_ptr) {
1274                         tipc_node_unlock(node);
1275                         goto reject;
1276                 }
1277                 if (l_ptr->max_pkt < max_pkt) {
1278                         sender->max_pkt = l_ptr->max_pkt;
1279                         tipc_node_unlock(node);
1280                         for (; buf_chain; buf_chain = buf) {
1281                                 buf = buf_chain->next;
1282                                 kfree_skb(buf_chain);
1283                         }
1284                         goto again;
1285                 }
1286         } else {
1287 reject:
1288                 for (; buf_chain; buf_chain = buf) {
1289                         buf = buf_chain->next;
1290                         kfree_skb(buf_chain);
1291                 }
1292                 return tipc_port_reject_sections(sender, hdr, msg_sect, num_sect,
1293                                                  total_len, TIPC_ERR_NO_NODE);
1294         }
1295
1296         /* Append chain of fragments to send queue & send them */
1297         l_ptr->long_msg_seq_no++;
1298         link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
1299         l_ptr->stats.sent_fragments += fragm_no;
1300         l_ptr->stats.sent_fragmented++;
1301         tipc_link_push_queue(l_ptr);
1302         tipc_node_unlock(node);
1303         return dsz;
1304 }
1305
1306 /*
1307  * tipc_link_push_packet: Push one unsent packet to the media
1308  */
1309 u32 tipc_link_push_packet(struct tipc_link *l_ptr)
1310 {
1311         struct sk_buff *buf = l_ptr->first_out;
1312         u32 r_q_size = l_ptr->retransm_queue_size;
1313         u32 r_q_head = l_ptr->retransm_queue_head;
1314
1315         /* Step to position where retransmission failed, if any,    */
1316         /* consider that buffers may have been released in meantime */
1317         if (r_q_size && buf) {
1318                 u32 last = lesser(mod(r_q_head + r_q_size),
1319                                   link_last_sent(l_ptr));
1320                 u32 first = buf_seqno(buf);
1321
1322                 while (buf && less(first, r_q_head)) {
1323                         first = mod(first + 1);
1324                         buf = buf->next;
1325                 }
1326                 l_ptr->retransm_queue_head = r_q_head = first;
1327                 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
1328         }
1329
1330         /* Continue retransmission now, if there is anything: */
1331         if (r_q_size && buf) {
1332                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1333                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1334                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1335                         l_ptr->retransm_queue_head = mod(++r_q_head);
1336                         l_ptr->retransm_queue_size = --r_q_size;
1337                         l_ptr->stats.retransmitted++;
1338                         return 0;
1339                 } else {
1340                         l_ptr->stats.bearer_congs++;
1341                         return PUSH_FAILED;
1342                 }
1343         }
1344
1345         /* Send deferred protocol message, if any: */
1346         buf = l_ptr->proto_msg_queue;
1347         if (buf) {
1348                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1349                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1350                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1351                         l_ptr->unacked_window = 0;
1352                         kfree_skb(buf);
1353                         l_ptr->proto_msg_queue = NULL;
1354                         return 0;
1355                 } else {
1356                         l_ptr->stats.bearer_congs++;
1357                         return PUSH_FAILED;
1358                 }
1359         }
1360
1361         /* Send one deferred data message, if send window not full: */
1362         buf = l_ptr->next_out;
1363         if (buf) {
1364                 struct tipc_msg *msg = buf_msg(buf);
1365                 u32 next = msg_seqno(msg);
1366                 u32 first = buf_seqno(l_ptr->first_out);
1367
1368                 if (mod(next - first) < l_ptr->queue_limit[0]) {
1369                         msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1370                         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1371                         if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1372                                 if (msg_user(msg) == MSG_BUNDLER)
1373                                         msg_set_type(msg, CLOSED_MSG);
1374                                 l_ptr->next_out = buf->next;
1375                                 return 0;
1376                         } else {
1377                                 l_ptr->stats.bearer_congs++;
1378                                 return PUSH_FAILED;
1379                         }
1380                 }
1381         }
1382         return PUSH_FINISHED;
1383 }
1384
1385 /*
1386  * push_queue(): push out the unsent messages of a link where
1387  *               congestion has abated. Node is locked
1388  */
1389 void tipc_link_push_queue(struct tipc_link *l_ptr)
1390 {
1391         u32 res;
1392
1393         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr))
1394                 return;
1395
1396         do {
1397                 res = tipc_link_push_packet(l_ptr);
1398         } while (!res);
1399
1400         if (res == PUSH_FAILED)
1401                 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1402 }
1403
1404 static void link_reset_all(unsigned long addr)
1405 {
1406         struct tipc_node *n_ptr;
1407         char addr_string[16];
1408         u32 i;
1409
1410         read_lock_bh(&tipc_net_lock);
1411         n_ptr = tipc_node_find((u32)addr);
1412         if (!n_ptr) {
1413                 read_unlock_bh(&tipc_net_lock);
1414                 return; /* node no longer exists */
1415         }
1416
1417         tipc_node_lock(n_ptr);
1418
1419         pr_warn("Resetting all links to %s\n",
1420                 tipc_addr_string_fill(addr_string, n_ptr->addr));
1421
1422         for (i = 0; i < MAX_BEARERS; i++) {
1423                 if (n_ptr->links[i]) {
1424                         link_print(n_ptr->links[i], "Resetting link\n");
1425                         tipc_link_reset(n_ptr->links[i]);
1426                 }
1427         }
1428
1429         tipc_node_unlock(n_ptr);
1430         read_unlock_bh(&tipc_net_lock);
1431 }
1432
1433 static void link_retransmit_failure(struct tipc_link *l_ptr,
1434                                         struct sk_buff *buf)
1435 {
1436         struct tipc_msg *msg = buf_msg(buf);
1437
1438         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
1439
1440         if (l_ptr->addr) {
1441                 /* Handle failure on standard link */
1442                 link_print(l_ptr, "Resetting link\n");
1443                 tipc_link_reset(l_ptr);
1444
1445         } else {
1446                 /* Handle failure on broadcast link */
1447                 struct tipc_node *n_ptr;
1448                 char addr_string[16];
1449
1450                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
1451                 pr_cont("Outstanding acks: %lu\n",
1452                         (unsigned long) TIPC_SKB_CB(buf)->handle);
1453
1454                 n_ptr = tipc_bclink_retransmit_to();
1455                 tipc_node_lock(n_ptr);
1456
1457                 tipc_addr_string_fill(addr_string, n_ptr->addr);
1458                 pr_info("Broadcast link info for %s\n", addr_string);
1459                 pr_info("Supportable: %d,  Supported: %d,  Acked: %u\n",
1460                         n_ptr->bclink.supportable,
1461                         n_ptr->bclink.supported,
1462                         n_ptr->bclink.acked);
1463                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
1464                         n_ptr->bclink.last_in,
1465                         n_ptr->bclink.oos_state,
1466                         n_ptr->bclink.last_sent);
1467
1468                 tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
1469
1470                 tipc_node_unlock(n_ptr);
1471
1472                 l_ptr->stale_count = 0;
1473         }
1474 }
1475
1476 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *buf,
1477                           u32 retransmits)
1478 {
1479         struct tipc_msg *msg;
1480
1481         if (!buf)
1482                 return;
1483
1484         msg = buf_msg(buf);
1485
1486         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
1487                 if (l_ptr->retransm_queue_size == 0) {
1488                         l_ptr->retransm_queue_head = msg_seqno(msg);
1489                         l_ptr->retransm_queue_size = retransmits;
1490                 } else {
1491                         pr_err("Unexpected retransmit on link %s (qsize=%d)\n",
1492                                l_ptr->name, l_ptr->retransm_queue_size);
1493                 }
1494                 return;
1495         } else {
1496                 /* Detect repeated retransmit failures on uncongested bearer */
1497                 if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1498                         if (++l_ptr->stale_count > 100) {
1499                                 link_retransmit_failure(l_ptr, buf);
1500                                 return;
1501                         }
1502                 } else {
1503                         l_ptr->last_retransmitted = msg_seqno(msg);
1504                         l_ptr->stale_count = 1;
1505                 }
1506         }
1507
1508         while (retransmits && (buf != l_ptr->next_out) && buf) {
1509                 msg = buf_msg(buf);
1510                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1511                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1512                 if (tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1513                         buf = buf->next;
1514                         retransmits--;
1515                         l_ptr->stats.retransmitted++;
1516                 } else {
1517                         tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1518                         l_ptr->stats.bearer_congs++;
1519                         l_ptr->retransm_queue_head = buf_seqno(buf);
1520                         l_ptr->retransm_queue_size = retransmits;
1521                         return;
1522                 }
1523         }
1524
1525         l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1526 }
1527
1528 /**
1529  * link_insert_deferred_queue - insert deferred messages back into receive chain
1530  */
1531 static struct sk_buff *link_insert_deferred_queue(struct tipc_link *l_ptr,
1532                                                   struct sk_buff *buf)
1533 {
1534         u32 seq_no;
1535
1536         if (l_ptr->oldest_deferred_in == NULL)
1537                 return buf;
1538
1539         seq_no = buf_seqno(l_ptr->oldest_deferred_in);
1540         if (seq_no == mod(l_ptr->next_in_no)) {
1541                 l_ptr->newest_deferred_in->next = buf;
1542                 buf = l_ptr->oldest_deferred_in;
1543                 l_ptr->oldest_deferred_in = NULL;
1544                 l_ptr->deferred_inqueue_sz = 0;
1545         }
1546         return buf;
1547 }
1548
1549 /**
1550  * link_recv_buf_validate - validate basic format of received message
1551  *
1552  * This routine ensures a TIPC message has an acceptable header, and at least
1553  * as much data as the header indicates it should.  The routine also ensures
1554  * that the entire message header is stored in the main fragment of the message
1555  * buffer, to simplify future access to message header fields.
1556  *
1557  * Note: Having extra info present in the message header or data areas is OK.
1558  * TIPC will ignore the excess, under the assumption that it is optional info
1559  * introduced by a later release of the protocol.
1560  */
1561 static int link_recv_buf_validate(struct sk_buff *buf)
1562 {
1563         static u32 min_data_hdr_size[8] = {
1564                 SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
1565                 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1566                 };
1567
1568         struct tipc_msg *msg;
1569         u32 tipc_hdr[2];
1570         u32 size;
1571         u32 hdr_size;
1572         u32 min_hdr_size;
1573
1574         if (unlikely(buf->len < MIN_H_SIZE))
1575                 return 0;
1576
1577         msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1578         if (msg == NULL)
1579                 return 0;
1580
1581         if (unlikely(msg_version(msg) != TIPC_VERSION))
1582                 return 0;
1583
1584         size = msg_size(msg);
1585         hdr_size = msg_hdr_sz(msg);
1586         min_hdr_size = msg_isdata(msg) ?
1587                 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1588
1589         if (unlikely((hdr_size < min_hdr_size) ||
1590                      (size < hdr_size) ||
1591                      (buf->len < size) ||
1592                      (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1593                 return 0;
1594
1595         return pskb_may_pull(buf, hdr_size);
1596 }
1597
1598 /**
1599  * tipc_recv_msg - process TIPC messages arriving from off-node
1600  * @head: pointer to message buffer chain
1601  * @tb_ptr: pointer to bearer message arrived on
1602  *
1603  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1604  * structure (i.e. cannot be NULL), but bearer can be inactive.
1605  */
1606 void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
1607 {
1608         read_lock_bh(&tipc_net_lock);
1609         while (head) {
1610                 struct tipc_node *n_ptr;
1611                 struct tipc_link *l_ptr;
1612                 struct sk_buff *crs;
1613                 struct sk_buff *buf = head;
1614                 struct tipc_msg *msg;
1615                 u32 seq_no;
1616                 u32 ackd;
1617                 u32 released = 0;
1618                 int type;
1619
1620                 head = head->next;
1621
1622                 /* Ensure bearer is still enabled */
1623                 if (unlikely(!b_ptr->active))
1624                         goto cont;
1625
1626                 /* Ensure message is well-formed */
1627                 if (unlikely(!link_recv_buf_validate(buf)))
1628                         goto cont;
1629
1630                 /* Ensure message data is a single contiguous unit */
1631                 if (unlikely(skb_linearize(buf)))
1632                         goto cont;
1633
1634                 /* Handle arrival of a non-unicast link message */
1635                 msg = buf_msg(buf);
1636
1637                 if (unlikely(msg_non_seq(msg))) {
1638                         if (msg_user(msg) ==  LINK_CONFIG)
1639                                 tipc_disc_recv_msg(buf, b_ptr);
1640                         else
1641                                 tipc_bclink_recv_pkt(buf);
1642                         continue;
1643                 }
1644
1645                 /* Discard unicast link messages destined for another node */
1646                 if (unlikely(!msg_short(msg) &&
1647                              (msg_destnode(msg) != tipc_own_addr)))
1648                         goto cont;
1649
1650                 /* Locate neighboring node that sent message */
1651                 n_ptr = tipc_node_find(msg_prevnode(msg));
1652                 if (unlikely(!n_ptr))
1653                         goto cont;
1654                 tipc_node_lock(n_ptr);
1655
1656                 /* Locate unicast link endpoint that should handle message */
1657                 l_ptr = n_ptr->links[b_ptr->identity];
1658                 if (unlikely(!l_ptr)) {
1659                         tipc_node_unlock(n_ptr);
1660                         goto cont;
1661                 }
1662
1663                 /* Verify that communication with node is currently allowed */
1664                 if ((n_ptr->block_setup & WAIT_PEER_DOWN) &&
1665                         msg_user(msg) == LINK_PROTOCOL &&
1666                         (msg_type(msg) == RESET_MSG ||
1667                                         msg_type(msg) == ACTIVATE_MSG) &&
1668                         !msg_redundant_link(msg))
1669                         n_ptr->block_setup &= ~WAIT_PEER_DOWN;
1670
1671                 if (n_ptr->block_setup) {
1672                         tipc_node_unlock(n_ptr);
1673                         goto cont;
1674                 }
1675
1676                 /* Validate message sequence number info */
1677                 seq_no = msg_seqno(msg);
1678                 ackd = msg_ack(msg);
1679
1680                 /* Release acked messages */
1681                 if (n_ptr->bclink.supported)
1682                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1683
1684                 crs = l_ptr->first_out;
1685                 while ((crs != l_ptr->next_out) &&
1686                        less_eq(buf_seqno(crs), ackd)) {
1687                         struct sk_buff *next = crs->next;
1688
1689                         kfree_skb(crs);
1690                         crs = next;
1691                         released++;
1692                 }
1693                 if (released) {
1694                         l_ptr->first_out = crs;
1695                         l_ptr->out_queue_size -= released;
1696                 }
1697
1698                 /* Try sending any messages link endpoint has pending */
1699                 if (unlikely(l_ptr->next_out))
1700                         tipc_link_push_queue(l_ptr);
1701                 if (unlikely(!list_empty(&l_ptr->waiting_ports)))
1702                         tipc_link_wakeup_ports(l_ptr, 0);
1703                 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1704                         l_ptr->stats.sent_acks++;
1705                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1706                 }
1707
1708                 /* Now (finally!) process the incoming message */
1709 protocol_check:
1710                 if (likely(link_working_working(l_ptr))) {
1711                         if (likely(seq_no == mod(l_ptr->next_in_no))) {
1712                                 l_ptr->next_in_no++;
1713                                 if (unlikely(l_ptr->oldest_deferred_in))
1714                                         head = link_insert_deferred_queue(l_ptr,
1715                                                                           head);
1716 deliver:
1717                                 if (likely(msg_isdata(msg))) {
1718                                         tipc_node_unlock(n_ptr);
1719                                         tipc_port_recv_msg(buf);
1720                                         continue;
1721                                 }
1722                                 switch (msg_user(msg)) {
1723                                         int ret;
1724                                 case MSG_BUNDLER:
1725                                         l_ptr->stats.recv_bundles++;
1726                                         l_ptr->stats.recv_bundled +=
1727                                                 msg_msgcnt(msg);
1728                                         tipc_node_unlock(n_ptr);
1729                                         tipc_link_recv_bundle(buf);
1730                                         continue;
1731                                 case NAME_DISTRIBUTOR:
1732                                         tipc_node_unlock(n_ptr);
1733                                         tipc_named_recv(buf);
1734                                         continue;
1735                                 case CONN_MANAGER:
1736                                         tipc_node_unlock(n_ptr);
1737                                         tipc_port_recv_proto_msg(buf);
1738                                         continue;
1739                                 case MSG_FRAGMENTER:
1740                                         l_ptr->stats.recv_fragments++;
1741                                         ret = tipc_link_recv_fragment(
1742                                                 &l_ptr->defragm_buf,
1743                                                 &buf, &msg);
1744                                         if (ret == 1) {
1745                                                 l_ptr->stats.recv_fragmented++;
1746                                                 goto deliver;
1747                                         }
1748                                         if (ret == -1)
1749                                                 l_ptr->next_in_no--;
1750                                         break;
1751                                 case CHANGEOVER_PROTOCOL:
1752                                         type = msg_type(msg);
1753                                         if (link_recv_changeover_msg(&l_ptr,
1754                                                                      &buf)) {
1755                                                 msg = buf_msg(buf);
1756                                                 seq_no = msg_seqno(msg);
1757                                                 if (type == ORIGINAL_MSG)
1758                                                         goto deliver;
1759                                                 goto protocol_check;
1760                                         }
1761                                         break;
1762                                 default:
1763                                         kfree_skb(buf);
1764                                         buf = NULL;
1765                                         break;
1766                                 }
1767                                 tipc_node_unlock(n_ptr);
1768                                 tipc_net_route_msg(buf);
1769                                 continue;
1770                         }
1771                         link_handle_out_of_seq_msg(l_ptr, buf);
1772                         head = link_insert_deferred_queue(l_ptr, head);
1773                         tipc_node_unlock(n_ptr);
1774                         continue;
1775                 }
1776
1777                 if (msg_user(msg) == LINK_PROTOCOL) {
1778                         link_recv_proto_msg(l_ptr, buf);
1779                         head = link_insert_deferred_queue(l_ptr, head);
1780                         tipc_node_unlock(n_ptr);
1781                         continue;
1782                 }
1783                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1784
1785                 if (link_working_working(l_ptr)) {
1786                         /* Re-insert in front of queue */
1787                         buf->next = head;
1788                         head = buf;
1789                         tipc_node_unlock(n_ptr);
1790                         continue;
1791                 }
1792                 tipc_node_unlock(n_ptr);
1793 cont:
1794                 kfree_skb(buf);
1795         }
1796         read_unlock_bh(&tipc_net_lock);
1797 }
1798
1799 /**
1800  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1801  *
1802  * Returns increase in queue length (i.e. 0 or 1)
1803  */
1804 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
1805                         struct sk_buff *buf)
1806 {
1807         struct sk_buff *queue_buf;
1808         struct sk_buff **prev;
1809         u32 seq_no = buf_seqno(buf);
1810
1811         buf->next = NULL;
1812
1813         /* Empty queue ? */
1814         if (*head == NULL) {
1815                 *head = *tail = buf;
1816                 return 1;
1817         }
1818
1819         /* Last ? */
1820         if (less(buf_seqno(*tail), seq_no)) {
1821                 (*tail)->next = buf;
1822                 *tail = buf;
1823                 return 1;
1824         }
1825
1826         /* Locate insertion point in queue, then insert; discard if duplicate */
1827         prev = head;
1828         queue_buf = *head;
1829         for (;;) {
1830                 u32 curr_seqno = buf_seqno(queue_buf);
1831
1832                 if (seq_no == curr_seqno) {
1833                         kfree_skb(buf);
1834                         return 0;
1835                 }
1836
1837                 if (less(seq_no, curr_seqno))
1838                         break;
1839
1840                 prev = &queue_buf->next;
1841                 queue_buf = queue_buf->next;
1842         }
1843
1844         buf->next = queue_buf;
1845         *prev = buf;
1846         return 1;
1847 }
1848
1849 /*
1850  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1851  */
1852 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1853                                        struct sk_buff *buf)
1854 {
1855         u32 seq_no = buf_seqno(buf);
1856
1857         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1858                 link_recv_proto_msg(l_ptr, buf);
1859                 return;
1860         }
1861
1862         /* Record OOS packet arrival (force mismatch on next timeout) */
1863         l_ptr->checkpoint--;
1864
1865         /*
1866          * Discard packet if a duplicate; otherwise add it to deferred queue
1867          * and notify peer of gap as per protocol specification
1868          */
1869         if (less(seq_no, mod(l_ptr->next_in_no))) {
1870                 l_ptr->stats.duplicates++;
1871                 kfree_skb(buf);
1872                 return;
1873         }
1874
1875         if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
1876                                 &l_ptr->newest_deferred_in, buf)) {
1877                 l_ptr->deferred_inqueue_sz++;
1878                 l_ptr->stats.deferred_recv++;
1879                 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
1880                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1881         } else
1882                 l_ptr->stats.duplicates++;
1883 }
1884
1885 /*
1886  * Send protocol message to the other endpoint.
1887  */
1888 void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ,
1889                                 int probe_msg, u32 gap, u32 tolerance,
1890                                 u32 priority, u32 ack_mtu)
1891 {
1892         struct sk_buff *buf = NULL;
1893         struct tipc_msg *msg = l_ptr->pmsg;
1894         u32 msg_size = sizeof(l_ptr->proto_msg);
1895         int r_flag;
1896
1897         /* Discard any previous message that was deferred due to congestion */
1898         if (l_ptr->proto_msg_queue) {
1899                 kfree_skb(l_ptr->proto_msg_queue);
1900                 l_ptr->proto_msg_queue = NULL;
1901         }
1902
1903         if (link_blocked(l_ptr))
1904                 return;
1905
1906         /* Abort non-RESET send if communication with node is prohibited */
1907         if ((l_ptr->owner->block_setup) && (msg_typ != RESET_MSG))
1908                 return;
1909
1910         /* Create protocol message with "out-of-sequence" sequence number */
1911         msg_set_type(msg, msg_typ);
1912         msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
1913         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1914         msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
1915
1916         if (msg_typ == STATE_MSG) {
1917                 u32 next_sent = mod(l_ptr->next_out_no);
1918
1919                 if (!tipc_link_is_up(l_ptr))
1920                         return;
1921                 if (l_ptr->next_out)
1922                         next_sent = buf_seqno(l_ptr->next_out);
1923                 msg_set_next_sent(msg, next_sent);
1924                 if (l_ptr->oldest_deferred_in) {
1925                         u32 rec = buf_seqno(l_ptr->oldest_deferred_in);
1926                         gap = mod(rec - mod(l_ptr->next_in_no));
1927                 }
1928                 msg_set_seq_gap(msg, gap);
1929                 if (gap)
1930                         l_ptr->stats.sent_nacks++;
1931                 msg_set_link_tolerance(msg, tolerance);
1932                 msg_set_linkprio(msg, priority);
1933                 msg_set_max_pkt(msg, ack_mtu);
1934                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1935                 msg_set_probe(msg, probe_msg != 0);
1936                 if (probe_msg) {
1937                         u32 mtu = l_ptr->max_pkt;
1938
1939                         if ((mtu < l_ptr->max_pkt_target) &&
1940                             link_working_working(l_ptr) &&
1941                             l_ptr->fsm_msg_cnt) {
1942                                 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1943                                 if (l_ptr->max_pkt_probes == 10) {
1944                                         l_ptr->max_pkt_target = (msg_size - 4);
1945                                         l_ptr->max_pkt_probes = 0;
1946                                         msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1947                                 }
1948                                 l_ptr->max_pkt_probes++;
1949                         }
1950
1951                         l_ptr->stats.sent_probes++;
1952                 }
1953                 l_ptr->stats.sent_states++;
1954         } else {                /* RESET_MSG or ACTIVATE_MSG */
1955                 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
1956                 msg_set_seq_gap(msg, 0);
1957                 msg_set_next_sent(msg, 1);
1958                 msg_set_probe(msg, 0);
1959                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1960                 msg_set_linkprio(msg, l_ptr->priority);
1961                 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
1962         }
1963
1964         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1965         msg_set_redundant_link(msg, r_flag);
1966         msg_set_linkprio(msg, l_ptr->priority);
1967         msg_set_size(msg, msg_size);
1968
1969         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1970
1971         buf = tipc_buf_acquire(msg_size);
1972         if (!buf)
1973                 return;
1974
1975         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1976
1977         /* Defer message if bearer is already congested */
1978         if (tipc_bearer_congested(l_ptr->b_ptr, l_ptr)) {
1979                 l_ptr->proto_msg_queue = buf;
1980                 return;
1981         }
1982
1983         /* Defer message if attempting to send results in bearer congestion */
1984         if (!tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr)) {
1985                 tipc_bearer_schedule(l_ptr->b_ptr, l_ptr);
1986                 l_ptr->proto_msg_queue = buf;
1987                 l_ptr->stats.bearer_congs++;
1988                 return;
1989         }
1990
1991         /* Discard message if it was sent successfully */
1992         l_ptr->unacked_window = 0;
1993         kfree_skb(buf);
1994 }
1995
1996 /*
1997  * Receive protocol message :
1998  * Note that network plane id propagates through the network, and may
1999  * change at any time. The node with lowest address rules
2000  */
2001 static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
2002 {
2003         u32 rec_gap = 0;
2004         u32 max_pkt_info;
2005         u32 max_pkt_ack;
2006         u32 msg_tol;
2007         struct tipc_msg *msg = buf_msg(buf);
2008
2009         if (link_blocked(l_ptr))
2010                 goto exit;
2011
2012         /* record unnumbered packet arrival (force mismatch on next timeout) */
2013         l_ptr->checkpoint--;
2014
2015         if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
2016                 if (tipc_own_addr > msg_prevnode(msg))
2017                         l_ptr->b_ptr->net_plane = msg_net_plane(msg);
2018
2019         l_ptr->owner->permit_changeover = msg_redundant_link(msg);
2020
2021         switch (msg_type(msg)) {
2022
2023         case RESET_MSG:
2024                 if (!link_working_unknown(l_ptr) &&
2025                     (l_ptr->peer_session != INVALID_SESSION)) {
2026                         if (less_eq(msg_session(msg), l_ptr->peer_session))
2027                                 break; /* duplicate or old reset: ignore */
2028                 }
2029
2030                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
2031                                 link_working_unknown(l_ptr))) {
2032                         /*
2033                          * peer has lost contact -- don't allow peer's links
2034                          * to reactivate before we recognize loss & clean up
2035                          */
2036                         l_ptr->owner->block_setup = WAIT_NODE_DOWN;
2037                 }
2038
2039                 link_state_event(l_ptr, RESET_MSG);
2040
2041                 /* fall thru' */
2042         case ACTIVATE_MSG:
2043                 /* Update link settings according other endpoint's values */
2044                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
2045
2046                 msg_tol = msg_link_tolerance(msg);
2047                 if (msg_tol > l_ptr->tolerance)
2048                         link_set_supervision_props(l_ptr, msg_tol);
2049
2050                 if (msg_linkprio(msg) > l_ptr->priority)
2051                         l_ptr->priority = msg_linkprio(msg);
2052
2053                 max_pkt_info = msg_max_pkt(msg);
2054                 if (max_pkt_info) {
2055                         if (max_pkt_info < l_ptr->max_pkt_target)
2056                                 l_ptr->max_pkt_target = max_pkt_info;
2057                         if (l_ptr->max_pkt > l_ptr->max_pkt_target)
2058                                 l_ptr->max_pkt = l_ptr->max_pkt_target;
2059                 } else {
2060                         l_ptr->max_pkt = l_ptr->max_pkt_target;
2061                 }
2062                 l_ptr->owner->bclink.supportable = (max_pkt_info != 0);
2063
2064                 /* Synchronize broadcast link info, if not done previously */
2065                 if (!tipc_node_is_up(l_ptr->owner)) {
2066                         l_ptr->owner->bclink.last_sent =
2067                                 l_ptr->owner->bclink.last_in =
2068                                 msg_last_bcast(msg);
2069                         l_ptr->owner->bclink.oos_state = 0;
2070                 }
2071
2072                 l_ptr->peer_session = msg_session(msg);
2073                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
2074
2075                 if (msg_type(msg) == ACTIVATE_MSG)
2076                         link_state_event(l_ptr, ACTIVATE_MSG);
2077                 break;
2078         case STATE_MSG:
2079
2080                 msg_tol = msg_link_tolerance(msg);
2081                 if (msg_tol)
2082                         link_set_supervision_props(l_ptr, msg_tol);
2083
2084                 if (msg_linkprio(msg) &&
2085                     (msg_linkprio(msg) != l_ptr->priority)) {
2086                         pr_warn("%s<%s>, priority change %u->%u\n",
2087                                 link_rst_msg, l_ptr->name, l_ptr->priority,
2088                                 msg_linkprio(msg));
2089                         l_ptr->priority = msg_linkprio(msg);
2090                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
2091                         break;
2092                 }
2093                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
2094                 l_ptr->stats.recv_states++;
2095                 if (link_reset_unknown(l_ptr))
2096                         break;
2097
2098                 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
2099                         rec_gap = mod(msg_next_sent(msg) -
2100                                       mod(l_ptr->next_in_no));
2101                 }
2102
2103                 max_pkt_ack = msg_max_pkt(msg);
2104                 if (max_pkt_ack > l_ptr->max_pkt) {
2105                         l_ptr->max_pkt = max_pkt_ack;
2106                         l_ptr->max_pkt_probes = 0;
2107                 }
2108
2109                 max_pkt_ack = 0;
2110                 if (msg_probe(msg)) {
2111                         l_ptr->stats.recv_probes++;
2112                         if (msg_size(msg) > sizeof(l_ptr->proto_msg))
2113                                 max_pkt_ack = msg_size(msg);
2114                 }
2115
2116                 /* Protocol message before retransmits, reduce loss risk */
2117                 if (l_ptr->owner->bclink.supported)
2118                         tipc_bclink_update_link_state(l_ptr->owner,
2119                                                       msg_last_bcast(msg));
2120
2121                 if (rec_gap || (msg_probe(msg))) {
2122                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
2123                                                  0, rec_gap, 0, 0, max_pkt_ack);
2124                 }
2125                 if (msg_seq_gap(msg)) {
2126                         l_ptr->stats.recv_nacks++;
2127                         tipc_link_retransmit(l_ptr, l_ptr->first_out,
2128                                              msg_seq_gap(msg));
2129                 }
2130                 break;
2131         }
2132 exit:
2133         kfree_skb(buf);
2134 }
2135
2136
2137 /*
2138  * tipc_link_tunnel(): Send one message via a link belonging to
2139  * another bearer. Owner node is locked.
2140  */
2141 static void tipc_link_tunnel(struct tipc_link *l_ptr,
2142                              struct tipc_msg *tunnel_hdr,
2143                              struct tipc_msg  *msg,
2144                              u32 selector)
2145 {
2146         struct tipc_link *tunnel;
2147         struct sk_buff *buf;
2148         u32 length = msg_size(msg);
2149
2150         tunnel = l_ptr->owner->active_links[selector & 1];
2151         if (!tipc_link_is_up(tunnel)) {
2152                 pr_warn("%stunnel link no longer available\n", link_co_err);
2153                 return;
2154         }
2155         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
2156         buf = tipc_buf_acquire(length + INT_H_SIZE);
2157         if (!buf) {
2158                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
2159                 return;
2160         }
2161         skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
2162         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
2163         tipc_link_send_buf(tunnel, buf);
2164 }
2165
2166
2167
2168 /*
2169  * changeover(): Send whole message queue via the remaining link
2170  *               Owner node is locked.
2171  */
2172 void tipc_link_changeover(struct tipc_link *l_ptr)
2173 {
2174         u32 msgcount = l_ptr->out_queue_size;
2175         struct sk_buff *crs = l_ptr->first_out;
2176         struct tipc_link *tunnel = l_ptr->owner->active_links[0];
2177         struct tipc_msg tunnel_hdr;
2178         int split_bundles;
2179
2180         if (!tunnel)
2181                 return;
2182
2183         if (!l_ptr->owner->permit_changeover) {
2184                 pr_warn("%speer did not permit changeover\n", link_co_err);
2185                 return;
2186         }
2187
2188         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2189                  ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
2190         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2191         msg_set_msgcnt(&tunnel_hdr, msgcount);
2192
2193         if (!l_ptr->first_out) {
2194                 struct sk_buff *buf;
2195
2196                 buf = tipc_buf_acquire(INT_H_SIZE);
2197                 if (buf) {
2198                         skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
2199                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
2200                         tipc_link_send_buf(tunnel, buf);
2201                 } else {
2202                         pr_warn("%sunable to send changeover msg\n",
2203                                 link_co_err);
2204                 }
2205                 return;
2206         }
2207
2208         split_bundles = (l_ptr->owner->active_links[0] !=
2209                          l_ptr->owner->active_links[1]);
2210
2211         while (crs) {
2212                 struct tipc_msg *msg = buf_msg(crs);
2213
2214                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
2215                         struct tipc_msg *m = msg_get_wrapped(msg);
2216                         unchar *pos = (unchar *)m;
2217
2218                         msgcount = msg_msgcnt(msg);
2219                         while (msgcount--) {
2220                                 msg_set_seqno(m, msg_seqno(msg));
2221                                 tipc_link_tunnel(l_ptr, &tunnel_hdr, m,
2222                                                  msg_link_selector(m));
2223                                 pos += align(msg_size(m));
2224                                 m = (struct tipc_msg *)pos;
2225                         }
2226                 } else {
2227                         tipc_link_tunnel(l_ptr, &tunnel_hdr, msg,
2228                                          msg_link_selector(msg));
2229                 }
2230                 crs = crs->next;
2231         }
2232 }
2233
2234 void tipc_link_send_duplicate(struct tipc_link *l_ptr, struct tipc_link *tunnel)
2235 {
2236         struct sk_buff *iter;
2237         struct tipc_msg tunnel_hdr;
2238
2239         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2240                  DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
2241         msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
2242         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2243         iter = l_ptr->first_out;
2244         while (iter) {
2245                 struct sk_buff *outbuf;
2246                 struct tipc_msg *msg = buf_msg(iter);
2247                 u32 length = msg_size(msg);
2248
2249                 if (msg_user(msg) == MSG_BUNDLER)
2250                         msg_set_type(msg, CLOSED_MSG);
2251                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));   /* Update */
2252                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
2253                 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
2254                 outbuf = tipc_buf_acquire(length + INT_H_SIZE);
2255                 if (outbuf == NULL) {
2256                         pr_warn("%sunable to send duplicate msg\n",
2257                                 link_co_err);
2258                         return;
2259                 }
2260                 skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
2261                 skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
2262                                                length);
2263                 tipc_link_send_buf(tunnel, outbuf);
2264                 if (!tipc_link_is_up(l_ptr))
2265                         return;
2266                 iter = iter->next;
2267         }
2268 }
2269
2270 /**
2271  * buf_extract - extracts embedded TIPC message from another message
2272  * @skb: encapsulating message buffer
2273  * @from_pos: offset to extract from
2274  *
2275  * Returns a new message buffer containing an embedded message.  The
2276  * encapsulating message itself is left unchanged.
2277  */
2278 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
2279 {
2280         struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
2281         u32 size = msg_size(msg);
2282         struct sk_buff *eb;
2283
2284         eb = tipc_buf_acquire(size);
2285         if (eb)
2286                 skb_copy_to_linear_data(eb, msg, size);
2287         return eb;
2288 }
2289
2290 /*
2291  *  link_recv_changeover_msg(): Receive tunneled packet sent
2292  *  via other link. Node is locked. Return extracted buffer.
2293  */
2294 static int link_recv_changeover_msg(struct tipc_link **l_ptr,
2295                                     struct sk_buff **buf)
2296 {
2297         struct sk_buff *tunnel_buf = *buf;
2298         struct tipc_link *dest_link;
2299         struct tipc_msg *msg;
2300         struct tipc_msg *tunnel_msg = buf_msg(tunnel_buf);
2301         u32 msg_typ = msg_type(tunnel_msg);
2302         u32 msg_count = msg_msgcnt(tunnel_msg);
2303
2304         dest_link = (*l_ptr)->owner->links[msg_bearer_id(tunnel_msg)];
2305         if (!dest_link)
2306                 goto exit;
2307         if (dest_link == *l_ptr) {
2308                 pr_err("Unexpected changeover message on link <%s>\n",
2309                        (*l_ptr)->name);
2310                 goto exit;
2311         }
2312         *l_ptr = dest_link;
2313         msg = msg_get_wrapped(tunnel_msg);
2314
2315         if (msg_typ == DUPLICATE_MSG) {
2316                 if (less(msg_seqno(msg), mod(dest_link->next_in_no)))
2317                         goto exit;
2318                 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2319                 if (*buf == NULL) {
2320                         pr_warn("%sduplicate msg dropped\n", link_co_err);
2321                         goto exit;
2322                 }
2323                 kfree_skb(tunnel_buf);
2324                 return 1;
2325         }
2326
2327         /* First original message ?: */
2328         if (tipc_link_is_up(dest_link)) {
2329                 pr_info("%s<%s>, changeover initiated by peer\n", link_rst_msg,
2330                         dest_link->name);
2331                 tipc_link_reset(dest_link);
2332                 dest_link->exp_msg_count = msg_count;
2333                 if (!msg_count)
2334                         goto exit;
2335         } else if (dest_link->exp_msg_count == START_CHANGEOVER) {
2336                 dest_link->exp_msg_count = msg_count;
2337                 if (!msg_count)
2338                         goto exit;
2339         }
2340
2341         /* Receive original message */
2342         if (dest_link->exp_msg_count == 0) {
2343                 pr_warn("%sgot too many tunnelled messages\n", link_co_err);
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                         kfree_skb(tunnel_buf);
2353                         return 1;
2354                 } else {
2355                         pr_warn("%soriginal msg dropped\n", link_co_err);
2356                 }
2357         }
2358 exit:
2359         *buf = NULL;
2360         kfree_skb(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                         pr_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         kfree_skb(buf);
2383 }
2384
2385 /*
2386  *  Fragmentation/defragmentation:
2387  */
2388
2389 /*
2390  * link_send_long_buf: Entry for buffers needing fragmentation.
2391  * The buffer is complete, inclusive total message length.
2392  * Returns user data length.
2393  */
2394 static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf)
2395 {
2396         struct sk_buff *buf_chain = NULL;
2397         struct sk_buff *buf_chain_tail = (struct sk_buff *)&buf_chain;
2398         struct tipc_msg *inmsg = buf_msg(buf);
2399         struct tipc_msg fragm_hdr;
2400         u32 insize = msg_size(inmsg);
2401         u32 dsz = msg_data_sz(inmsg);
2402         unchar *crs = buf->data;
2403         u32 rest = insize;
2404         u32 pack_sz = l_ptr->max_pkt;
2405         u32 fragm_sz = pack_sz - INT_H_SIZE;
2406         u32 fragm_no = 0;
2407         u32 destaddr;
2408
2409         if (msg_short(inmsg))
2410                 destaddr = l_ptr->addr;
2411         else
2412                 destaddr = msg_destnode(inmsg);
2413
2414         /* Prepare reusable fragment header: */
2415         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
2416                  INT_H_SIZE, destaddr);
2417
2418         /* Chop up message: */
2419         while (rest > 0) {
2420                 struct sk_buff *fragm;
2421
2422                 if (rest <= fragm_sz) {
2423                         fragm_sz = rest;
2424                         msg_set_type(&fragm_hdr, LAST_FRAGMENT);
2425                 }
2426                 fragm = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
2427                 if (fragm == NULL) {
2428                         kfree_skb(buf);
2429                         while (buf_chain) {
2430                                 buf = buf_chain;
2431                                 buf_chain = buf_chain->next;
2432                                 kfree_skb(buf);
2433                         }
2434                         return -ENOMEM;
2435                 }
2436                 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
2437                 fragm_no++;
2438                 msg_set_fragm_no(&fragm_hdr, fragm_no);
2439                 skb_copy_to_linear_data(fragm, &fragm_hdr, INT_H_SIZE);
2440                 skb_copy_to_linear_data_offset(fragm, INT_H_SIZE, crs,
2441                                                fragm_sz);
2442                 buf_chain_tail->next = fragm;
2443                 buf_chain_tail = fragm;
2444
2445                 rest -= fragm_sz;
2446                 crs += fragm_sz;
2447                 msg_set_type(&fragm_hdr, FRAGMENT);
2448         }
2449         kfree_skb(buf);
2450
2451         /* Append chain of fragments to send queue & send them */
2452         l_ptr->long_msg_seq_no++;
2453         link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
2454         l_ptr->stats.sent_fragments += fragm_no;
2455         l_ptr->stats.sent_fragmented++;
2456         tipc_link_push_queue(l_ptr);
2457
2458         return dsz;
2459 }
2460
2461 /*
2462  * A pending message being re-assembled must store certain values
2463  * to handle subsequent fragments correctly. The following functions
2464  * help storing these values in unused, available fields in the
2465  * pending message. This makes dynamic memory allocation unnecessary.
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         while (pbuf && ((buf_seqno(pbuf) != long_msg_seq_no) ||
2519                         (msg_orignode(fragm) != msg_orignode(buf_msg(pbuf))))) {
2520                 prev = pbuf;
2521                 pbuf = pbuf->next;
2522         }
2523
2524         if (!pbuf && (msg_type(fragm) == FIRST_FRAGMENT)) {
2525                 struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
2526                 u32 msg_sz = msg_size(imsg);
2527                 u32 fragm_sz = msg_data_sz(fragm);
2528                 u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
2529                 u32 max =  TIPC_MAX_USER_MSG_SIZE + NAMED_H_SIZE;
2530                 if (msg_type(imsg) == TIPC_MCAST_MSG)
2531                         max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
2532                 if (msg_size(imsg) > max) {
2533                         kfree_skb(fbuf);
2534                         return 0;
2535                 }
2536                 pbuf = tipc_buf_acquire(msg_size(imsg));
2537                 if (pbuf != NULL) {
2538                         pbuf->next = *pending;
2539                         *pending = pbuf;
2540                         skb_copy_to_linear_data(pbuf, imsg,
2541                                                 msg_data_sz(fragm));
2542                         /*  Prepare buffer for subsequent fragments. */
2543                         set_long_msg_seqno(pbuf, long_msg_seq_no);
2544                         set_fragm_size(pbuf, fragm_sz);
2545                         set_expected_frags(pbuf, exp_fragm_cnt - 1);
2546                 } else {
2547                         pr_debug("Link unable to reassemble fragmented message\n");
2548                         kfree_skb(fbuf);
2549                         return -1;
2550                 }
2551                 kfree_skb(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                 kfree_skb(fbuf);
2561
2562                 /* Is message complete? */
2563                 if (exp_frags == 0) {
2564                         if (prev)
2565                                 prev->next = pbuf->next;
2566                         else
2567                                 *pending = pbuf->next;
2568                         msg_reset_reroute_cnt(buf_msg(pbuf));
2569                         *fb = pbuf;
2570                         *m = buf_msg(pbuf);
2571                         return 1;
2572                 }
2573                 set_expected_frags(pbuf, exp_frags);
2574                 return 0;
2575         }
2576         kfree_skb(fbuf);
2577         return 0;
2578 }
2579
2580 /**
2581  * link_check_defragm_bufs - flush stale incoming message fragments
2582  * @l_ptr: pointer to link
2583  */
2584 static void link_check_defragm_bufs(struct tipc_link *l_ptr)
2585 {
2586         struct sk_buff *prev = NULL;
2587         struct sk_buff *next = NULL;
2588         struct sk_buff *buf = l_ptr->defragm_buf;
2589
2590         if (!buf)
2591                 return;
2592         if (!link_working_working(l_ptr))
2593                 return;
2594         while (buf) {
2595                 u32 cnt = get_timer_cnt(buf);
2596
2597                 next = buf->next;
2598                 if (cnt < 4) {
2599                         incr_timer_cnt(buf);
2600                         prev = buf;
2601                 } else {
2602                         if (prev)
2603                                 prev->next = buf->next;
2604                         else
2605                                 l_ptr->defragm_buf = buf->next;
2606                         kfree_skb(buf);
2607                 }
2608                 buf = next;
2609         }
2610 }
2611
2612 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
2613 {
2614         if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
2615                 return;
2616
2617         l_ptr->tolerance = tolerance;
2618         l_ptr->continuity_interval =
2619                 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
2620         l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
2621 }
2622
2623 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
2624 {
2625         /* Data messages from this node, inclusive FIRST_FRAGM */
2626         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
2627         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
2628         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
2629         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
2630         /* Transiting data messages,inclusive FIRST_FRAGM */
2631         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
2632         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
2633         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
2634         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
2635         l_ptr->queue_limit[CONN_MANAGER] = 1200;
2636         l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
2637         l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
2638         /* FRAGMENT and LAST_FRAGMENT packets */
2639         l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
2640 }
2641
2642 /**
2643  * link_find_link - locate link by name
2644  * @name: ptr to link name string
2645  * @node: ptr to area to be filled with ptr to associated node
2646  *
2647  * Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
2648  * this also prevents link deletion.
2649  *
2650  * Returns pointer to link (or 0 if invalid link name).
2651  */
2652 static struct tipc_link *link_find_link(const char *name,
2653                                         struct tipc_node **node)
2654 {
2655         struct tipc_link_name link_name_parts;
2656         struct tipc_bearer *b_ptr;
2657         struct tipc_link *l_ptr;
2658
2659         if (!link_name_validate(name, &link_name_parts))
2660                 return NULL;
2661
2662         b_ptr = tipc_bearer_find_interface(link_name_parts.if_local);
2663         if (!b_ptr)
2664                 return NULL;
2665
2666         *node = tipc_node_find(link_name_parts.addr_peer);
2667         if (!*node)
2668                 return NULL;
2669
2670         l_ptr = (*node)->links[b_ptr->identity];
2671         if (!l_ptr || strcmp(l_ptr->name, name))
2672                 return NULL;
2673
2674         return l_ptr;
2675 }
2676
2677 /**
2678  * link_value_is_valid -- validate proposed link tolerance/priority/window
2679  *
2680  * @cmd: value type (TIPC_CMD_SET_LINK_*)
2681  * @new_value: the new value
2682  *
2683  * Returns 1 if value is within range, 0 if not.
2684  */
2685 static int link_value_is_valid(u16 cmd, u32 new_value)
2686 {
2687         switch (cmd) {
2688         case TIPC_CMD_SET_LINK_TOL:
2689                 return (new_value >= TIPC_MIN_LINK_TOL) &&
2690                         (new_value <= TIPC_MAX_LINK_TOL);
2691         case TIPC_CMD_SET_LINK_PRI:
2692                 return (new_value <= TIPC_MAX_LINK_PRI);
2693         case TIPC_CMD_SET_LINK_WINDOW:
2694                 return (new_value >= TIPC_MIN_LINK_WIN) &&
2695                         (new_value <= TIPC_MAX_LINK_WIN);
2696         }
2697         return 0;
2698 }
2699
2700 /**
2701  * link_cmd_set_value - change priority/tolerance/window for link/bearer/media
2702  * @name: ptr to link, bearer, or media name
2703  * @new_value: new value of link, bearer, or media setting
2704  * @cmd: which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*)
2705  *
2706  * Caller must hold 'tipc_net_lock' to ensure link/bearer/media is not deleted.
2707  *
2708  * Returns 0 if value updated and negative value on error.
2709  */
2710 static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
2711 {
2712         struct tipc_node *node;
2713         struct tipc_link *l_ptr;
2714         struct tipc_bearer *b_ptr;
2715         struct tipc_media *m_ptr;
2716
2717         l_ptr = link_find_link(name, &node);
2718         if (l_ptr) {
2719                 /*
2720                  * acquire node lock for tipc_link_send_proto_msg().
2721                  * see "TIPC locking policy" in net.c.
2722                  */
2723                 tipc_node_lock(node);
2724                 switch (cmd) {
2725                 case TIPC_CMD_SET_LINK_TOL:
2726                         link_set_supervision_props(l_ptr, new_value);
2727                         tipc_link_send_proto_msg(l_ptr,
2728                                 STATE_MSG, 0, 0, new_value, 0, 0);
2729                         break;
2730                 case TIPC_CMD_SET_LINK_PRI:
2731                         l_ptr->priority = new_value;
2732                         tipc_link_send_proto_msg(l_ptr,
2733                                 STATE_MSG, 0, 0, 0, new_value, 0);
2734                         break;
2735                 case TIPC_CMD_SET_LINK_WINDOW:
2736                         tipc_link_set_queue_limits(l_ptr, new_value);
2737                         break;
2738                 }
2739                 tipc_node_unlock(node);
2740                 return 0;
2741         }
2742
2743         b_ptr = tipc_bearer_find(name);
2744         if (b_ptr) {
2745                 switch (cmd) {
2746                 case TIPC_CMD_SET_LINK_TOL:
2747                         b_ptr->tolerance = new_value;
2748                         return 0;
2749                 case TIPC_CMD_SET_LINK_PRI:
2750                         b_ptr->priority = new_value;
2751                         return 0;
2752                 case TIPC_CMD_SET_LINK_WINDOW:
2753                         b_ptr->window = new_value;
2754                         return 0;
2755                 }
2756                 return -EINVAL;
2757         }
2758
2759         m_ptr = tipc_media_find(name);
2760         if (!m_ptr)
2761                 return -ENODEV;
2762         switch (cmd) {
2763         case TIPC_CMD_SET_LINK_TOL:
2764                 m_ptr->tolerance = new_value;
2765                 return 0;
2766         case TIPC_CMD_SET_LINK_PRI:
2767                 m_ptr->priority = new_value;
2768                 return 0;
2769         case TIPC_CMD_SET_LINK_WINDOW:
2770                 m_ptr->window = new_value;
2771                 return 0;
2772         }
2773         return -EINVAL;
2774 }
2775
2776 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2777                                      u16 cmd)
2778 {
2779         struct tipc_link_config *args;
2780         u32 new_value;
2781         int res;
2782
2783         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2784                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2785
2786         args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2787         new_value = ntohl(args->value);
2788
2789         if (!link_value_is_valid(cmd, new_value))
2790                 return tipc_cfg_reply_error_string(
2791                         "cannot change, value invalid");
2792
2793         if (!strcmp(args->name, tipc_bclink_name)) {
2794                 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2795                     (tipc_bclink_set_queue_limits(new_value) == 0))
2796                         return tipc_cfg_reply_none();
2797                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2798                                                    " (cannot change setting on broadcast link)");
2799         }
2800
2801         read_lock_bh(&tipc_net_lock);
2802         res = link_cmd_set_value(args->name, new_value, cmd);
2803         read_unlock_bh(&tipc_net_lock);
2804         if (res)
2805                 return tipc_cfg_reply_error_string("cannot change link setting");
2806
2807         return tipc_cfg_reply_none();
2808 }
2809
2810 /**
2811  * link_reset_statistics - reset link statistics
2812  * @l_ptr: pointer to link
2813  */
2814 static void link_reset_statistics(struct tipc_link *l_ptr)
2815 {
2816         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2817         l_ptr->stats.sent_info = l_ptr->next_out_no;
2818         l_ptr->stats.recv_info = l_ptr->next_in_no;
2819 }
2820
2821 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2822 {
2823         char *link_name;
2824         struct tipc_link *l_ptr;
2825         struct tipc_node *node;
2826
2827         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2828                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2829
2830         link_name = (char *)TLV_DATA(req_tlv_area);
2831         if (!strcmp(link_name, tipc_bclink_name)) {
2832                 if (tipc_bclink_reset_stats())
2833                         return tipc_cfg_reply_error_string("link not found");
2834                 return tipc_cfg_reply_none();
2835         }
2836
2837         read_lock_bh(&tipc_net_lock);
2838         l_ptr = link_find_link(link_name, &node);
2839         if (!l_ptr) {
2840                 read_unlock_bh(&tipc_net_lock);
2841                 return tipc_cfg_reply_error_string("link not found");
2842         }
2843
2844         tipc_node_lock(node);
2845         link_reset_statistics(l_ptr);
2846         tipc_node_unlock(node);
2847         read_unlock_bh(&tipc_net_lock);
2848         return tipc_cfg_reply_none();
2849 }
2850
2851 /**
2852  * percent - convert count to a percentage of total (rounding up or down)
2853  */
2854 static u32 percent(u32 count, u32 total)
2855 {
2856         return (count * 100 + (total / 2)) / total;
2857 }
2858
2859 /**
2860  * tipc_link_stats - print link statistics
2861  * @name: link name
2862  * @buf: print buffer area
2863  * @buf_size: size of print buffer area
2864  *
2865  * Returns length of print buffer data string (or 0 if error)
2866  */
2867 static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
2868 {
2869         struct tipc_link *l;
2870         struct tipc_stats *s;
2871         struct tipc_node *node;
2872         char *status;
2873         u32 profile_total = 0;
2874         int ret;
2875
2876         if (!strcmp(name, tipc_bclink_name))
2877                 return tipc_bclink_stats(buf, buf_size);
2878
2879         read_lock_bh(&tipc_net_lock);
2880         l = link_find_link(name, &node);
2881         if (!l) {
2882                 read_unlock_bh(&tipc_net_lock);
2883                 return 0;
2884         }
2885         tipc_node_lock(node);
2886         s = &l->stats;
2887
2888         if (tipc_link_is_active(l))
2889                 status = "ACTIVE";
2890         else if (tipc_link_is_up(l))
2891                 status = "STANDBY";
2892         else
2893                 status = "DEFUNCT";
2894
2895         ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
2896                             "  %s  MTU:%u  Priority:%u  Tolerance:%u ms"
2897                             "  Window:%u packets\n",
2898                             l->name, status, l->max_pkt, l->priority,
2899                             l->tolerance, l->queue_limit[0]);
2900
2901         ret += tipc_snprintf(buf + ret, buf_size - ret,
2902                              "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2903                              l->next_in_no - s->recv_info, s->recv_fragments,
2904                              s->recv_fragmented, s->recv_bundles,
2905                              s->recv_bundled);
2906
2907         ret += tipc_snprintf(buf + ret, buf_size - ret,
2908                              "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2909                              l->next_out_no - s->sent_info, s->sent_fragments,
2910                              s->sent_fragmented, s->sent_bundles,
2911                              s->sent_bundled);
2912
2913         profile_total = s->msg_length_counts;
2914         if (!profile_total)
2915                 profile_total = 1;
2916
2917         ret += tipc_snprintf(buf + ret, buf_size - ret,
2918                              "  TX profile sample:%u packets  average:%u octets\n"
2919                              "  0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
2920                              "-16384:%u%% -32768:%u%% -66000:%u%%\n",
2921                              s->msg_length_counts,
2922                              s->msg_lengths_total / profile_total,
2923                              percent(s->msg_length_profile[0], profile_total),
2924                              percent(s->msg_length_profile[1], profile_total),
2925                              percent(s->msg_length_profile[2], profile_total),
2926                              percent(s->msg_length_profile[3], profile_total),
2927                              percent(s->msg_length_profile[4], profile_total),
2928                              percent(s->msg_length_profile[5], profile_total),
2929                              percent(s->msg_length_profile[6], profile_total));
2930
2931         ret += tipc_snprintf(buf + ret, buf_size - ret,
2932                              "  RX states:%u probes:%u naks:%u defs:%u"
2933                              " dups:%u\n", s->recv_states, s->recv_probes,
2934                              s->recv_nacks, s->deferred_recv, s->duplicates);
2935
2936         ret += tipc_snprintf(buf + ret, buf_size - ret,
2937                              "  TX states:%u probes:%u naks:%u acks:%u"
2938                              " dups:%u\n", s->sent_states, s->sent_probes,
2939                              s->sent_nacks, s->sent_acks, s->retransmitted);
2940
2941         ret += tipc_snprintf(buf + ret, buf_size - ret,
2942                              "  Congestion bearer:%u link:%u  Send queue"
2943                              " max:%u avg:%u\n", s->bearer_congs, s->link_congs,
2944                              s->max_queue_sz, s->queue_sz_counts ?
2945                              (s->accu_queue_sz / s->queue_sz_counts) : 0);
2946
2947         tipc_node_unlock(node);
2948         read_unlock_bh(&tipc_net_lock);
2949         return ret;
2950 }
2951
2952 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
2953 {
2954         struct sk_buff *buf;
2955         struct tlv_desc *rep_tlv;
2956         int str_len;
2957         int pb_len;
2958         char *pb;
2959
2960         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2961                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2962
2963         buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
2964         if (!buf)
2965                 return NULL;
2966
2967         rep_tlv = (struct tlv_desc *)buf->data;
2968         pb = TLV_DATA(rep_tlv);
2969         pb_len = ULTRA_STRING_MAX_LEN;
2970         str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
2971                                   pb, pb_len);
2972         if (!str_len) {
2973                 kfree_skb(buf);
2974                 return tipc_cfg_reply_error_string("link not found");
2975         }
2976         str_len += 1;   /* for "\0" */
2977         skb_put(buf, TLV_SPACE(str_len));
2978         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
2979
2980         return buf;
2981 }
2982
2983 /**
2984  * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
2985  * @dest: network address of destination node
2986  * @selector: used to select from set of active links
2987  *
2988  * If no active link can be found, uses default maximum packet size.
2989  */
2990 u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
2991 {
2992         struct tipc_node *n_ptr;
2993         struct tipc_link *l_ptr;
2994         u32 res = MAX_PKT_DEFAULT;
2995
2996         if (dest == tipc_own_addr)
2997                 return MAX_MSG_SIZE;
2998
2999         read_lock_bh(&tipc_net_lock);
3000         n_ptr = tipc_node_find(dest);
3001         if (n_ptr) {
3002                 tipc_node_lock(n_ptr);
3003                 l_ptr = n_ptr->active_links[selector & 1];
3004                 if (l_ptr)
3005                         res = l_ptr->max_pkt;
3006                 tipc_node_unlock(n_ptr);
3007         }
3008         read_unlock_bh(&tipc_net_lock);
3009         return res;
3010 }
3011
3012 static void link_print(struct tipc_link *l_ptr, const char *str)
3013 {
3014         pr_info("%s Link %x<%s>:", str, l_ptr->addr, l_ptr->b_ptr->name);
3015
3016         if (link_working_unknown(l_ptr))
3017                 pr_cont(":WU\n");
3018         else if (link_reset_reset(l_ptr))
3019                 pr_cont(":RR\n");
3020         else if (link_reset_unknown(l_ptr))
3021                 pr_cont(":RU\n");
3022         else if (link_working_working(l_ptr))
3023                 pr_cont(":WW\n");
3024         else
3025                 pr_cont("\n");
3026 }