net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, 2012, Ericsson AB
   5  * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "core.h"
  38 #include "link.h"
  39 #include "port.h"
  40 #include "name_distr.h"
  41 #include "discover.h"
  42 #include "config.h"
  43
  44 #include <linux/pkt_sched.h>
  45
  46 /*
  47  * Error message prefixes
  48  */
  49 static const char *link_co_err = "Link changeover error, ";
  50 static const char *link_rst_msg = "Resetting link ";
  51 static const char *link_unk_evt = "Unknown link event ";
  52
  53 /*
  54  * Out-of-range value for link session numbers
  55  */
  56 #define INVALID_SESSION 0x10000
  57
  58 /*
  59  * Link state events:
  60  */
  61 #define  STARTING_EVT    856384768      /* link processing trigger */
  62 #define  TRAFFIC_MSG_EVT 560815u        /* rx'd ??? */
  63 #define  TIMEOUT_EVT     560817u        /* link timer expired */
  64
  65 /*
  66  * The following two 'message types' is really just implementation
  67  * data conveniently stored in the message header.
  68  * They must not be considered part of the protocol
  69  */
  70 #define OPEN_MSG   0
  71 #define CLOSED_MSG 1
  72
  73 /*
  74  * State value stored in 'exp_msg_count'
  75  */
  76 #define START_CHANGEOVER 100000u
  77
  78 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
  79                                        struct sk_buff *buf);
  80 static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf);
  81 static int  link_recv_changeover_msg(struct tipc_link **l_ptr,
  82                                      struct sk_buff **buf);
  83 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance);
  84 static int  link_send_sections_long(struct tipc_port *sender,
  85                                     struct iovec const *msg_sect,
  86                                     unsigned int len, u32 destnode);
  87 static void link_state_event(struct tipc_link *l_ptr, u32 event);
  88 static void link_reset_statistics(struct tipc_link *l_ptr);
  89 static void link_print(struct tipc_link *l_ptr, const char *str);
  90 static void link_start(struct tipc_link *l_ptr);
  91 static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf);
  92 static void tipc_link_send_sync(struct tipc_link *l);
  93 static void tipc_link_recv_sync(struct tipc_node *n, struct sk_buff *buf);
  94
  95 /*
  96  *  Simple link routines
  97  */
  98 static unsigned int align(unsigned int i)
  99 {
 100         return (i + 3) & ~3u;
 101 }
 102
 103 static void link_init_max_pkt(struct tipc_link *l_ptr)
 104 {
 105         u32 max_pkt;
 106
 107         max_pkt = (l_ptr->b_ptr->mtu & ~3);
 108         if (max_pkt > MAX_MSG_SIZE)
 109                 max_pkt = MAX_MSG_SIZE;
 110
 111         l_ptr->max_pkt_target = max_pkt;
 112         if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
 113                 l_ptr->max_pkt = l_ptr->max_pkt_target;
 114         else
 115                 l_ptr->max_pkt = MAX_PKT_DEFAULT;
 116
 117         l_ptr->max_pkt_probes = 0;
 118 }
 119
 120 static u32 link_next_sent(struct tipc_link *l_ptr)
 121 {
 122         if (l_ptr->next_out)
 123                 return buf_seqno(l_ptr->next_out);
 124         return mod(l_ptr->next_out_no);
 125 }
 126
 127 static u32 link_last_sent(struct tipc_link *l_ptr)
 128 {
 129         return mod(link_next_sent(l_ptr) - 1);
 130 }
 131
 132 /*
 133  *  Simple non-static link routines (i.e. referenced outside this file)
 134  */
 135 int tipc_link_is_up(struct tipc_link *l_ptr)
 136 {
 137         if (!l_ptr)
 138                 return 0;
 139         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 140 }
 141
 142 int tipc_link_is_active(struct tipc_link *l_ptr)
 143 {
 144         return  (l_ptr->owner->active_links[0] == l_ptr) ||
 145                 (l_ptr->owner->active_links[1] == l_ptr);
 146 }
 147
 148 /**
 149  * link_timeout - handle expiration of link timer
 150  * @l_ptr: pointer to link
 151  *
 152  * This routine must not grab "tipc_net_lock" to avoid a potential deadlock conflict
 153  * with tipc_link_delete().  (There is no risk that the node will be deleted by
 154  * another thread because tipc_link_delete() always cancels the link timer before
 155  * tipc_node_delete() is called.)
 156  */
 157 static void link_timeout(struct tipc_link *l_ptr)
 158 {
 159         tipc_node_lock(l_ptr->owner);
 160
 161         /* update counters used in statistical profiling of send traffic */
 162         l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
 163         l_ptr->stats.queue_sz_counts++;
 164
 165         if (l_ptr->first_out) {
 166                 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
 167                 u32 length = msg_size(msg);
 168
 169                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 170                     (msg_type(msg) == FIRST_FRAGMENT)) {
 171                         length = msg_size(msg_get_wrapped(msg));
 172                 }
 173                 if (length) {
 174                         l_ptr->stats.msg_lengths_total += length;
 175                         l_ptr->stats.msg_length_counts++;
 176                         if (length <= 64)
 177                                 l_ptr->stats.msg_length_profile[0]++;
 178                         else if (length <= 256)
 179                                 l_ptr->stats.msg_length_profile[1]++;
 180                         else if (length <= 1024)
 181                                 l_ptr->stats.msg_length_profile[2]++;
 182                         else if (length <= 4096)
 183                                 l_ptr->stats.msg_length_profile[3]++;
 184                         else if (length <= 16384)
 185                                 l_ptr->stats.msg_length_profile[4]++;
 186                         else if (length <= 32768)
 187                                 l_ptr->stats.msg_length_profile[5]++;
 188                         else
 189                                 l_ptr->stats.msg_length_profile[6]++;
 190                 }
 191         }
 192
 193         /* do all other link processing performed on a periodic basis */
 194
 195         link_state_event(l_ptr, TIMEOUT_EVT);
 196
 197         if (l_ptr->next_out)
 198                 tipc_link_push_queue(l_ptr);
 199
 200         tipc_node_unlock(l_ptr->owner);
 201 }
 202
 203 static void link_set_timer(struct tipc_link *l_ptr, u32 time)
 204 {
 205         k_start_timer(&l_ptr->timer, time);
 206 }
 207
 208 /**
 209  * tipc_link_create - create a new link
 210  * @n_ptr: pointer to associated node
 211  * @b_ptr: pointer to associated bearer
 212  * @media_addr: media address to use when sending messages over link
 213  *
 214  * Returns pointer to link.
 215  */
 216 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 217                               struct tipc_bearer *b_ptr,
 218                               const struct tipc_media_addr *media_addr)
 219 {
 220         struct tipc_link *l_ptr;
 221         struct tipc_msg *msg;
 222         char *if_name;
 223         char addr_string[16];
 224         u32 peer = n_ptr->addr;
 225
 226         if (n_ptr->link_cnt >= 2) {
 227                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 228                 pr_err("Attempt to establish third link to %s\n", addr_string);
 229                 return NULL;
 230         }
 231
 232         if (n_ptr->links[b_ptr->identity]) {
 233                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 234                 pr_err("Attempt to establish second link on <%s> to %s\n",
 235                        b_ptr->name, addr_string);
 236                 return NULL;
 237         }
 238
 239         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 240         if (!l_ptr) {
 241                 pr_warn("Link creation failed, no memory\n");
 242                 return NULL;
 243         }
 244
 245         l_ptr->addr = peer;
 246         if_name = strchr(b_ptr->name, ':') + 1;
 247         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 248                 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
 249                 tipc_node(tipc_own_addr),
 250                 if_name,
 251                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 252                 /* note: peer i/f name is updated by reset/activate message */
 253         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 254         l_ptr->owner = n_ptr;
 255         l_ptr->checkpoint = 1;
 256         l_ptr->peer_session = INVALID_SESSION;
 257         l_ptr->b_ptr = b_ptr;
 258         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 259         l_ptr->state = RESET_UNKNOWN;
 260
 261         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 262         msg = l_ptr->pmsg;
 263         tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
 264         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 265         msg_set_session(msg, (tipc_random & 0xffff));
 266         msg_set_bearer_id(msg, b_ptr->identity);
 267         strcpy((char *)msg_data(msg), if_name);
 268
 269         l_ptr->priority = b_ptr->priority;
 270         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 271
 272         link_init_max_pkt(l_ptr);
 273
 274         l_ptr->next_out_no = 1;
 275         INIT_LIST_HEAD(&l_ptr->waiting_ports);
 276
 277         link_reset_statistics(l_ptr);
 278
 279         tipc_node_attach_link(n_ptr, l_ptr);
 280
 281         k_init_timer(&l_ptr->timer, (Handler)link_timeout, (unsigned long)l_ptr);
 282         list_add_tail(&l_ptr->link_list, &b_ptr->links);
 283         tipc_k_signal((Handler)link_start, (unsigned long)l_ptr);
 284
 285         return l_ptr;
 286 }
 287
 288 /**
 289  * tipc_link_delete - delete a link
 290  * @l_ptr: pointer to link
 291  *
 292  * Note: 'tipc_net_lock' is write_locked, bearer is locked.
 293  * This routine must not grab the node lock until after link timer cancellation
 294  * to avoid a potential deadlock situation.
 295  */
 296 void tipc_link_delete(struct tipc_link *l_ptr)
 297 {
 298         if (!l_ptr) {
 299                 pr_err("Attempt to delete non-existent link\n");
 300                 return;
 301         }
 302
 303         k_cancel_timer(&l_ptr->timer);
 304
 305         tipc_node_lock(l_ptr->owner);
 306         tipc_link_reset(l_ptr);
 307         tipc_node_detach_link(l_ptr->owner, l_ptr);
 308         tipc_link_stop(l_ptr);
 309         list_del_init(&l_ptr->link_list);
 310         tipc_node_unlock(l_ptr->owner);
 311         k_term_timer(&l_ptr->timer);
 312         kfree(l_ptr);
 313 }
 314
 315 static void link_start(struct tipc_link *l_ptr)
 316 {
 317         tipc_node_lock(l_ptr->owner);
 318         link_state_event(l_ptr, STARTING_EVT);
 319         tipc_node_unlock(l_ptr->owner);
 320 }
 321
 322 /**
 323  * link_schedule_port - schedule port for deferred sending
 324  * @l_ptr: pointer to link
 325  * @origport: reference to sending port
 326  * @sz: amount of data to be sent
 327  *
 328  * Schedules port for renewed sending of messages after link congestion
 329  * has abated.
 330  */
 331 static int link_schedule_port(struct tipc_link *l_ptr, u32 origport, u32 sz)
 332 {
 333         struct tipc_port *p_ptr;
 334
 335         spin_lock_bh(&tipc_port_list_lock);
 336         p_ptr = tipc_port_lock(origport);
 337         if (p_ptr) {
 338                 if (!p_ptr->wakeup)
 339                         goto exit;
 340                 if (!list_empty(&p_ptr->wait_list))
 341                         goto exit;
 342                 p_ptr->congested = 1;
 343                 p_ptr->waiting_pkts = 1 + ((sz - 1) / l_ptr->max_pkt);
 344                 list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
 345                 l_ptr->stats.link_congs++;
 346 exit:
 347                 tipc_port_unlock(p_ptr);
 348         }
 349         spin_unlock_bh(&tipc_port_list_lock);
 350         return -ELINKCONG;
 351 }
 352
 353 void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all)
 354 {
 355         struct tipc_port *p_ptr;
 356         struct tipc_port *temp_p_ptr;
 357         int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
 358
 359         if (all)
 360                 win = 100000;
 361         if (win <= 0)
 362                 return;
 363         if (!spin_trylock_bh(&tipc_port_list_lock))
 364                 return;
 365         if (link_congested(l_ptr))
 366                 goto exit;
 367         list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
 368                                  wait_list) {
 369                 if (win <= 0)
 370                         break;
 371                 list_del_init(&p_ptr->wait_list);
 372                 spin_lock_bh(p_ptr->lock);
 373                 p_ptr->congested = 0;
 374                 p_ptr->wakeup(p_ptr);
 375                 win -= p_ptr->waiting_pkts;
 376                 spin_unlock_bh(p_ptr->lock);
 377         }
 378
 379 exit:
 380         spin_unlock_bh(&tipc_port_list_lock);
 381 }
 382
 383 /**
 384  * link_release_outqueue - purge link's outbound message queue
 385  * @l_ptr: pointer to link
 386  */
 387 static void link_release_outqueue(struct tipc_link *l_ptr)
 388 {
 389         kfree_skb_list(l_ptr->first_out);
 390         l_ptr->first_out = NULL;
 391         l_ptr->out_queue_size = 0;
 392 }
 393
 394 /**
 395  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 396  * @l_ptr: pointer to link
 397  */
 398 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 399 {
 400         kfree_skb(l_ptr->reasm_head);
 401         l_ptr->reasm_head = NULL;
 402         l_ptr->reasm_tail = NULL;
 403 }
 404
 405 /**
 406  * tipc_link_stop - purge all inbound and outbound messages associated with link
 407  * @l_ptr: pointer to link
 408  */
 409 void tipc_link_stop(struct tipc_link *l_ptr)
 410 {
 411         kfree_skb_list(l_ptr->oldest_deferred_in);
 412         kfree_skb_list(l_ptr->first_out);
 413         tipc_link_reset_fragments(l_ptr);
 414         kfree_skb(l_ptr->proto_msg_queue);
 415         l_ptr->proto_msg_queue = NULL;
 416 }
 417
 418 void tipc_link_reset(struct tipc_link *l_ptr)
 419 {
 420         u32 prev_state = l_ptr->state;
 421         u32 checkpoint = l_ptr->next_in_no;
 422         int was_active_link = tipc_link_is_active(l_ptr);
 423
 424         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 425
 426         /* Link is down, accept any session */
 427         l_ptr->peer_session = INVALID_SESSION;
 428
 429         /* Prepare for max packet size negotiation */
 430         link_init_max_pkt(l_ptr);
 431
 432         l_ptr->state = RESET_UNKNOWN;
 433
 434         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 435                 return;
 436
 437         tipc_node_link_down(l_ptr->owner, l_ptr);
 438         tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
 439
 440         if (was_active_link && tipc_node_active_links(l_ptr->owner) &&
 441             l_ptr->owner->permit_changeover) {
 442                 l_ptr->reset_checkpoint = checkpoint;
 443                 l_ptr->exp_msg_count = START_CHANGEOVER;
 444         }
 445
 446         /* Clean up all queues: */
 447         link_release_outqueue(l_ptr);
 448         kfree_skb(l_ptr->proto_msg_queue);
 449         l_ptr->proto_msg_queue = NULL;
 450         kfree_skb_list(l_ptr->oldest_deferred_in);
 451         if (!list_empty(&l_ptr->waiting_ports))
 452                 tipc_link_wakeup_ports(l_ptr, 1);
 453
 454         l_ptr->retransm_queue_head = 0;
 455         l_ptr->retransm_queue_size = 0;
 456         l_ptr->last_out = NULL;
 457         l_ptr->first_out = NULL;
 458         l_ptr->next_out = NULL;
 459         l_ptr->unacked_window = 0;
 460         l_ptr->checkpoint = 1;
 461         l_ptr->next_out_no = 1;
 462         l_ptr->deferred_inqueue_sz = 0;
 463         l_ptr->oldest_deferred_in = NULL;
 464         l_ptr->newest_deferred_in = NULL;
 465         l_ptr->fsm_msg_cnt = 0;
 466         l_ptr->stale_count = 0;
 467         link_reset_statistics(l_ptr);
 468 }
 469
 470
 471 static void link_activate(struct tipc_link *l_ptr)
 472 {
 473         l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
 474         tipc_node_link_up(l_ptr->owner, l_ptr);
 475         tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
 476 }
 477
 478 /**
 479  * link_state_event - link finite state machine
 480  * @l_ptr: pointer to link
 481  * @event: state machine event to process
 482  */
 483 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 484 {
 485         struct tipc_link *other;
 486         u32 cont_intv = l_ptr->continuity_interval;
 487
 488         if (!l_ptr->started && (event != STARTING_EVT))
 489                 return;         /* Not yet. */
 490
 491         if (link_blocked(l_ptr)) {
 492                 if (event == TIMEOUT_EVT)
 493                         link_set_timer(l_ptr, cont_intv);
 494                 return;   /* Changeover going on */
 495         }
 496
 497         switch (l_ptr->state) {
 498         case WORKING_WORKING:
 499                 switch (event) {
 500                 case TRAFFIC_MSG_EVT:
 501                 case ACTIVATE_MSG:
 502                         break;
 503                 case TIMEOUT_EVT:
 504                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 505                                 l_ptr->checkpoint = l_ptr->next_in_no;
 506                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 507                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 508                                                                  0, 0, 0, 0, 0);
 509                                         l_ptr->fsm_msg_cnt++;
 510                                 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
 511                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 512                                                                  1, 0, 0, 0, 0);
 513                                         l_ptr->fsm_msg_cnt++;
 514                                 }
 515                                 link_set_timer(l_ptr, cont_intv);
 516                                 break;
 517                         }
 518                         l_ptr->state = WORKING_UNKNOWN;
 519                         l_ptr->fsm_msg_cnt = 0;
 520                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 521                         l_ptr->fsm_msg_cnt++;
 522                         link_set_timer(l_ptr, cont_intv / 4);
 523                         break;
 524                 case RESET_MSG:
 525                         pr_info("%s<%s>, requested by peer\n", link_rst_msg,
 526                                 l_ptr->name);
 527                         tipc_link_reset(l_ptr);
 528                         l_ptr->state = RESET_RESET;
 529                         l_ptr->fsm_msg_cnt = 0;
 530                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 531                         l_ptr->fsm_msg_cnt++;
 532                         link_set_timer(l_ptr, cont_intv);
 533                         break;
 534                 default:
 535                         pr_err("%s%u in WW state\n", link_unk_evt, event);
 536                 }
 537                 break;
 538         case WORKING_UNKNOWN:
 539                 switch (event) {
 540                 case TRAFFIC_MSG_EVT:
 541                 case ACTIVATE_MSG:
 542                         l_ptr->state = WORKING_WORKING;
 543                         l_ptr->fsm_msg_cnt = 0;
 544                         link_set_timer(l_ptr, cont_intv);
 545                         break;
 546                 case RESET_MSG:
 547                         pr_info("%s<%s>, requested by peer while probing\n",
 548                                 link_rst_msg, l_ptr->name);
 549                         tipc_link_reset(l_ptr);
 550                         l_ptr->state = RESET_RESET;
 551                         l_ptr->fsm_msg_cnt = 0;
 552                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 553                         l_ptr->fsm_msg_cnt++;
 554                         link_set_timer(l_ptr, cont_intv);
 555                         break;
 556                 case TIMEOUT_EVT:
 557                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 558                                 l_ptr->state = WORKING_WORKING;
 559                                 l_ptr->fsm_msg_cnt = 0;
 560                                 l_ptr->checkpoint = l_ptr->next_in_no;
 561                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 562                                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 563                                                                  0, 0, 0, 0, 0);
 564                                         l_ptr->fsm_msg_cnt++;
 565                                 }
 566                                 link_set_timer(l_ptr, cont_intv);
 567                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 568                                 tipc_link_send_proto_msg(l_ptr, STATE_MSG,
 569                                                          1, 0, 0, 0, 0);
 570                                 l_ptr->fsm_msg_cnt++;
 571                                 link_set_timer(l_ptr, cont_intv / 4);
 572                         } else {        /* Link has failed */
 573                                 pr_warn("%s<%s>, peer not responding\n",
 574                                         link_rst_msg, l_ptr->name);
 575                                 tipc_link_reset(l_ptr);
 576                                 l_ptr->state = RESET_UNKNOWN;
 577                                 l_ptr->fsm_msg_cnt = 0;
 578                                 tipc_link_send_proto_msg(l_ptr, RESET_MSG,
 579                                                          0, 0, 0, 0, 0);
 580                                 l_ptr->fsm_msg_cnt++;
 581                                 link_set_timer(l_ptr, cont_intv);
 582                         }
 583                         break;
 584                 default:
 585                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 586                 }
 587                 break;
 588         case RESET_UNKNOWN:
 589                 switch (event) {
 590                 case TRAFFIC_MSG_EVT:
 591                         break;
 592                 case ACTIVATE_MSG:
 593                         other = l_ptr->owner->active_links[0];
 594                         if (other && link_working_unknown(other))
 595                                 break;
 596                         l_ptr->state = WORKING_WORKING;
 597                         l_ptr->fsm_msg_cnt = 0;
 598                         link_activate(l_ptr);
 599                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 600                         l_ptr->fsm_msg_cnt++;
 601                         if (l_ptr->owner->working_links == 1)
 602                                 tipc_link_send_sync(l_ptr);
 603                         link_set_timer(l_ptr, cont_intv);
 604                         break;
 605                 case RESET_MSG:
 606                         l_ptr->state = RESET_RESET;
 607                         l_ptr->fsm_msg_cnt = 0;
 608                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 1, 0, 0, 0, 0);
 609                         l_ptr->fsm_msg_cnt++;
 610                         link_set_timer(l_ptr, cont_intv);
 611                         break;
 612                 case STARTING_EVT:
 613                         l_ptr->started = 1;
 614                         /* fall through */
 615                 case TIMEOUT_EVT:
 616                         tipc_link_send_proto_msg(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
 617                         l_ptr->fsm_msg_cnt++;
 618                         link_set_timer(l_ptr, cont_intv);
 619                         break;
 620                 default:
 621                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 622                 }
 623                 break;
 624         case RESET_RESET:
 625                 switch (event) {
 626                 case TRAFFIC_MSG_EVT:
 627                 case ACTIVATE_MSG:
 628                         other = l_ptr->owner->active_links[0];
 629                         if (other && link_working_unknown(other))
 630                                 break;
 631                         l_ptr->state = WORKING_WORKING;
 632                         l_ptr->fsm_msg_cnt = 0;
 633                         link_activate(l_ptr);
 634                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 635                         l_ptr->fsm_msg_cnt++;
 636                         if (l_ptr->owner->working_links == 1)
 637                                 tipc_link_send_sync(l_ptr);
 638                         link_set_timer(l_ptr, cont_intv);
 639                         break;
 640                 case RESET_MSG:
 641                         break;
 642                 case TIMEOUT_EVT:
 643                         tipc_link_send_proto_msg(l_ptr, ACTIVATE_MSG, 0, 0, 0, 0, 0);
 644                         l_ptr->fsm_msg_cnt++;
 645                         link_set_timer(l_ptr, cont_intv);
 646                         break;
 647                 default:
 648                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 649                 }
 650                 break;
 651         default:
 652                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 653         }
 654 }
 655
 656 /*
 657  * link_bundle_buf(): Append contents of a buffer to
 658  * the tail of an existing one.
 659  */
 660 static int link_bundle_buf(struct tipc_link *l_ptr, struct sk_buff *bundler,
 661                            struct sk_buff *buf)
 662 {
 663         struct tipc_msg *bundler_msg = buf_msg(bundler);
 664         struct tipc_msg *msg = buf_msg(buf);
 665         u32 size = msg_size(msg);
 666         u32 bundle_size = msg_size(bundler_msg);
 667         u32 to_pos = align(bundle_size);
 668         u32 pad = to_pos - bundle_size;
 669
 670         if (msg_user(bundler_msg) != MSG_BUNDLER)
 671                 return 0;
 672         if (msg_type(bundler_msg) != OPEN_MSG)
 673                 return 0;
 674         if (skb_tailroom(bundler) < (pad + size))
 675                 return 0;
 676         if (l_ptr->max_pkt < (to_pos + size))
 677                 return 0;
 678
 679         skb_put(bundler, pad + size);
 680         skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
 681         msg_set_size(bundler_msg, to_pos + size);
 682         msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
 683         kfree_skb(buf);
 684         l_ptr->stats.sent_bundled++;
 685         return 1;
 686 }
 687
 688 static void link_add_to_outqueue(struct tipc_link *l_ptr,
 689                                  struct sk_buff *buf,
 690                                  struct tipc_msg *msg)
 691 {
 692         u32 ack = mod(l_ptr->next_in_no - 1);
 693         u32 seqno = mod(l_ptr->next_out_no++);
 694
 695         msg_set_word(msg, 2, ((ack << 16) | seqno));
 696         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 697         buf->next = NULL;
 698         if (l_ptr->first_out) {
 699                 l_ptr->last_out->next = buf;
 700                 l_ptr->last_out = buf;
 701         } else
 702                 l_ptr->first_out = l_ptr->last_out = buf;
 703
 704         l_ptr->out_queue_size++;
 705         if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
 706                 l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
 707 }
 708
 709 static void link_add_chain_to_outqueue(struct tipc_link *l_ptr,
 710                                        struct sk_buff *buf_chain,
 711                                        u32 long_msgno)
 712 {
 713         struct sk_buff *buf;
 714         struct tipc_msg *msg;
 715
 716         if (!l_ptr->next_out)
 717                 l_ptr->next_out = buf_chain;
 718         while (buf_chain) {
 719                 buf = buf_chain;
 720                 buf_chain = buf_chain->next;
 721
 722                 msg = buf_msg(buf);
 723                 msg_set_long_msgno(msg, long_msgno);
 724                 link_add_to_outqueue(l_ptr, buf, msg);
 725         }
 726 }
 727
 728 /*
 729  * tipc_link_send_buf() is the 'full path' for messages, called from
 730  * inside TIPC when the 'fast path' in tipc_send_buf
 731  * has failed, and from link_send()
 732  */
 733 int tipc_link_send_buf(struct tipc_link *l_ptr, struct sk_buff *buf)
 734 {
 735         struct tipc_msg *msg = buf_msg(buf);
 736         u32 size = msg_size(msg);
 737         u32 dsz = msg_data_sz(msg);
 738         u32 queue_size = l_ptr->out_queue_size;
 739         u32 imp = tipc_msg_tot_importance(msg);
 740         u32 queue_limit = l_ptr->queue_limit[imp];
 741         u32 max_packet = l_ptr->max_pkt;
 742
 743         /* Match msg importance against queue limits: */
 744         if (unlikely(queue_size >= queue_limit)) {
 745                 if (imp <= TIPC_CRITICAL_IMPORTANCE) {
 746                         link_schedule_port(l_ptr, msg_origport(msg), size);
 747                         kfree_skb(buf);
 748                         return -ELINKCONG;
 749                 }
 750                 kfree_skb(buf);
 751                 if (imp > CONN_MANAGER) {
 752                         pr_warn("%s<%s>, send queue full", link_rst_msg,
 753                                 l_ptr->name);
 754                         tipc_link_reset(l_ptr);
 755                 }
 756                 return dsz;
 757         }
 758
 759         /* Fragmentation needed ? */
 760         if (size > max_packet)
 761                 return link_send_long_buf(l_ptr, buf);
 762
 763         /* Packet can be queued or sent. */
 764         if (likely(!link_congested(l_ptr))) {
 765                 link_add_to_outqueue(l_ptr, buf, msg);
 766
 767                 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
 768                 l_ptr->unacked_window = 0;
 769                 return dsz;
 770         }
 771         /* Congestion: can message be bundled ? */
 772         if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
 773             (msg_user(msg) != MSG_FRAGMENTER)) {
 774
 775                 /* Try adding message to an existing bundle */
 776                 if (l_ptr->next_out &&
 777                     link_bundle_buf(l_ptr, l_ptr->last_out, buf))
 778                         return dsz;
 779
 780                 /* Try creating a new bundle */
 781                 if (size <= max_packet * 2 / 3) {
 782                         struct sk_buff *bundler = tipc_buf_acquire(max_packet);
 783                         struct tipc_msg bundler_hdr;
 784
 785                         if (bundler) {
 786                                 tipc_msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
 787                                          INT_H_SIZE, l_ptr->addr);
 788                                 skb_copy_to_linear_data(bundler, &bundler_hdr,
 789                                                         INT_H_SIZE);
 790                                 skb_trim(bundler, INT_H_SIZE);
 791                                 link_bundle_buf(l_ptr, bundler, buf);
 792                                 buf = bundler;
 793                                 msg = buf_msg(buf);
 794                                 l_ptr->stats.sent_bundles++;
 795                         }
 796                 }
 797         }
 798         if (!l_ptr->next_out)
 799                 l_ptr->next_out = buf;
 800         link_add_to_outqueue(l_ptr, buf, msg);
 801         return dsz;
 802 }
 803
 804 /*
 805  * tipc_link_send(): same as tipc_link_send_buf(), but the link to use has
 806  * not been selected yet, and the the owner node is not locked
 807  * Called by TIPC internal users, e.g. the name distributor
 808  */
 809 int tipc_link_send(struct sk_buff *buf, u32 dest, u32 selector)
 810 {
 811         struct tipc_link *l_ptr;
 812         struct tipc_node *n_ptr;
 813         int res = -ELINKCONG;
 814
 815         read_lock_bh(&tipc_net_lock);
 816         n_ptr = tipc_node_find(dest);
 817         if (n_ptr) {
 818                 tipc_node_lock(n_ptr);
 819                 l_ptr = n_ptr->active_links[selector & 1];
 820                 if (l_ptr)
 821                         res = tipc_link_send_buf(l_ptr, buf);
 822                 else
 823                         kfree_skb(buf);
 824                 tipc_node_unlock(n_ptr);
 825         } else {
 826                 kfree_skb(buf);
 827         }
 828         read_unlock_bh(&tipc_net_lock);
 829         return res;
 830 }
 831
 832 /*
 833  * tipc_link_send_sync - synchronize broadcast link endpoints.
 834  *
 835  * Give a newly added peer node the sequence number where it should
 836  * start receiving and acking broadcast packets.
 837  *
 838  * Called with node locked
 839  */
 840 static void tipc_link_send_sync(struct tipc_link *l)
 841 {
 842         struct sk_buff *buf;
 843         struct tipc_msg *msg;
 844
 845         buf = tipc_buf_acquire(INT_H_SIZE);
 846         if (!buf)
 847                 return;
 848
 849         msg = buf_msg(buf);
 850         tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE, l->addr);
 851         msg_set_last_bcast(msg, l->owner->bclink.acked);
 852         link_add_chain_to_outqueue(l, buf, 0);
 853         tipc_link_push_queue(l);
 854 }
 855
 856 /*
 857  * tipc_link_recv_sync - synchronize broadcast link endpoints.
 858  * Receive the sequence number where we should start receiving and
 859  * acking broadcast packets from a newly added peer node, and open
 860  * up for reception of such packets.
 861  *
 862  * Called with node locked
 863  */
 864 static void tipc_link_recv_sync(struct tipc_node *n, struct sk_buff *buf)
 865 {
 866         struct tipc_msg *msg = buf_msg(buf);
 867
 868         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 869         n->bclink.recv_permitted = true;
 870         kfree_skb(buf);
 871 }
 872
 873 /*
 874  * tipc_link_send_names - send name table entries to new neighbor
 875  *
 876  * Send routine for bulk delivery of name table messages when contact
 877  * with a new neighbor occurs. No link congestion checking is performed
 878  * because name table messages *must* be delivered. The messages must be
 879  * small enough not to require fragmentation.
 880  * Called without any locks held.
 881  */
 882 void tipc_link_send_names(struct list_head *message_list, u32 dest)
 883 {
 884         struct tipc_node *n_ptr;
 885         struct tipc_link *l_ptr;
 886         struct sk_buff *buf;
 887         struct sk_buff *temp_buf;
 888
 889         if (list_empty(message_list))
 890                 return;
 891
 892         read_lock_bh(&tipc_net_lock);
 893         n_ptr = tipc_node_find(dest);
 894         if (n_ptr) {
 895                 tipc_node_lock(n_ptr);
 896                 l_ptr = n_ptr->active_links[0];
 897                 if (l_ptr) {
 898                         /* convert circular list to linear list */
 899                         ((struct sk_buff *)message_list->prev)->next = NULL;
 900                         link_add_chain_to_outqueue(l_ptr,
 901                                 (struct sk_buff *)message_list->next, 0);
 902                         tipc_link_push_queue(l_ptr);
 903                         INIT_LIST_HEAD(message_list);
 904                 }
 905                 tipc_node_unlock(n_ptr);
 906         }
 907         read_unlock_bh(&tipc_net_lock);
 908
 909         /* discard the messages if they couldn't be sent */
 910         list_for_each_safe(buf, temp_buf, ((struct sk_buff *)message_list)) {
 911                 list_del((struct list_head *)buf);
 912                 kfree_skb(buf);
 913         }
 914 }
 915
 916 /*
 917  * link_send_buf_fast: Entry for data messages where the
 918  * destination link is known and the header is complete,
 919  * inclusive total message length. Very time critical.
 920  * Link is locked. Returns user data length.
 921  */
 922 static int link_send_buf_fast(struct tipc_link *l_ptr, struct sk_buff *buf,
 923                               u32 *used_max_pkt)
 924 {
 925         struct tipc_msg *msg = buf_msg(buf);
 926         int res = msg_data_sz(msg);
 927
 928         if (likely(!link_congested(l_ptr))) {
 929                 if (likely(msg_size(msg) <= l_ptr->max_pkt)) {
 930                         link_add_to_outqueue(l_ptr, buf, msg);
 931                         tipc_bearer_send(l_ptr->b_ptr, buf,
 932                                          &l_ptr->media_addr);
 933                         l_ptr->unacked_window = 0;
 934                         return res;
 935                 }
 936                 else
 937                         *used_max_pkt = l_ptr->max_pkt;
 938         }
 939         return tipc_link_send_buf(l_ptr, buf);  /* All other cases */
 940 }
 941
 942 /*
 943  * tipc_link_send_sections_fast: Entry for messages where the
 944  * destination processor is known and the header is complete,
 945  * except for total message length.
 946  * Returns user data length or errno.
 947  */
 948 int tipc_link_send_sections_fast(struct tipc_port *sender,
 949                                  struct iovec const *msg_sect,
 950                                  unsigned int len, u32 destaddr)
 951 {
 952         struct tipc_msg *hdr = &sender->phdr;
 953         struct tipc_link *l_ptr;
 954         struct sk_buff *buf;
 955         struct tipc_node *node;
 956         int res;
 957         u32 selector = msg_origport(hdr) & 1;
 958
 959 again:
 960         /*
 961          * Try building message using port's max_pkt hint.
 962          * (Must not hold any locks while building message.)
 963          */
 964         res = tipc_msg_build(hdr, msg_sect, len, sender->max_pkt, &buf);
 965         /* Exit if build request was invalid */
 966         if (unlikely(res < 0))
 967                 return res;
 968
 969         read_lock_bh(&tipc_net_lock);
 970         node = tipc_node_find(destaddr);
 971         if (likely(node)) {
 972                 tipc_node_lock(node);
 973                 l_ptr = node->active_links[selector];
 974                 if (likely(l_ptr)) {
 975                         if (likely(buf)) {
 976                                 res = link_send_buf_fast(l_ptr, buf,
 977                                                          &sender->max_pkt);
 978 exit:
 979                                 tipc_node_unlock(node);
 980                                 read_unlock_bh(&tipc_net_lock);
 981                                 return res;
 982                         }
 983
 984                         /* Exit if link (or bearer) is congested */
 985                         if (link_congested(l_ptr)) {
 986                                 res = link_schedule_port(l_ptr,
 987                                                          sender->ref, res);
 988                                 goto exit;
 989                         }
 990
 991                         /*
 992                          * Message size exceeds max_pkt hint; update hint,
 993                          * then re-try fast path or fragment the message
 994                          */
 995                         sender->max_pkt = l_ptr->max_pkt;
 996                         tipc_node_unlock(node);
 997                         read_unlock_bh(&tipc_net_lock);
 998
 999
1000                         if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
1001                                 goto again;
1002
1003                         return link_send_sections_long(sender, msg_sect, len,
1004                                                        destaddr);
1005                 }
1006                 tipc_node_unlock(node);
1007         }
1008         read_unlock_bh(&tipc_net_lock);
1009
1010         /* Couldn't find a link to the destination node */
1011         if (buf)
1012                 return tipc_reject_msg(buf, TIPC_ERR_NO_NODE);
1013         if (res >= 0)
1014                 return tipc_port_reject_sections(sender, hdr, msg_sect,
1015                                                  len, TIPC_ERR_NO_NODE);
1016         return res;
1017 }
1018
1019 /*
1020  * link_send_sections_long(): Entry for long messages where the
1021  * destination node is known and the header is complete,
1022  * inclusive total message length.
1023  * Link and bearer congestion status have been checked to be ok,
1024  * and are ignored if they change.
1025  *
1026  * Note that fragments do not use the full link MTU so that they won't have
1027  * to undergo refragmentation if link changeover causes them to be sent
1028  * over another link with an additional tunnel header added as prefix.
1029  * (Refragmentation will still occur if the other link has a smaller MTU.)
1030  *
1031  * Returns user data length or errno.
1032  */
1033 static int link_send_sections_long(struct tipc_port *sender,
1034                                    struct iovec const *msg_sect,
1035                                    unsigned int len, u32 destaddr)
1036 {
1037         struct tipc_link *l_ptr;
1038         struct tipc_node *node;
1039         struct tipc_msg *hdr = &sender->phdr;
1040         u32 dsz = len;
1041         u32 max_pkt, fragm_sz, rest;
1042         struct tipc_msg fragm_hdr;
1043         struct sk_buff *buf, *buf_chain, *prev;
1044         u32 fragm_crs, fragm_rest, hsz, sect_rest;
1045         const unchar __user *sect_crs;
1046         int curr_sect;
1047         u32 fragm_no;
1048         int res = 0;
1049
1050 again:
1051         fragm_no = 1;
1052         max_pkt = sender->max_pkt - INT_H_SIZE;
1053                 /* leave room for tunnel header in case of link changeover */
1054         fragm_sz = max_pkt - INT_H_SIZE;
1055                 /* leave room for fragmentation header in each fragment */
1056         rest = dsz;
1057         fragm_crs = 0;
1058         fragm_rest = 0;
1059         sect_rest = 0;
1060         sect_crs = NULL;
1061         curr_sect = -1;
1062
1063         /* Prepare reusable fragment header */
1064         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
1065                  INT_H_SIZE, msg_destnode(hdr));
1066         msg_set_size(&fragm_hdr, max_pkt);
1067         msg_set_fragm_no(&fragm_hdr, 1);
1068
1069         /* Prepare header of first fragment */
1070         buf_chain = buf = tipc_buf_acquire(max_pkt);
1071         if (!buf)
1072                 return -ENOMEM;
1073         buf->next = NULL;
1074         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1075         hsz = msg_hdr_sz(hdr);
1076         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
1077
1078         /* Chop up message */
1079         fragm_crs = INT_H_SIZE + hsz;
1080         fragm_rest = fragm_sz - hsz;
1081
1082         do {            /* For all sections */
1083                 u32 sz;
1084
1085                 if (!sect_rest) {
1086                         sect_rest = msg_sect[++curr_sect].iov_len;
1087                         sect_crs = msg_sect[curr_sect].iov_base;
1088                 }
1089
1090                 if (sect_rest < fragm_rest)
1091                         sz = sect_rest;
1092                 else
1093                         sz = fragm_rest;
1094
1095                 if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
1096                         res = -EFAULT;
1097 error:
1098                         kfree_skb_list(buf_chain);
1099                         return res;
1100                 }
1101                 sect_crs += sz;
1102                 sect_rest -= sz;
1103                 fragm_crs += sz;
1104                 fragm_rest -= sz;
1105                 rest -= sz;
1106
1107                 if (!fragm_rest && rest) {
1108
1109                         /* Initiate new fragment: */
1110                         if (rest <= fragm_sz) {
1111                                 fragm_sz = rest;
1112                                 msg_set_type(&fragm_hdr, LAST_FRAGMENT);
1113                         } else {
1114                                 msg_set_type(&fragm_hdr, FRAGMENT);
1115                         }
1116                         msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
1117                         msg_set_fragm_no(&fragm_hdr, ++fragm_no);
1118                         prev = buf;
1119                         buf = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
1120                         if (!buf) {
1121                                 res = -ENOMEM;
1122                                 goto error;
1123                         }
1124
1125                         buf->next = NULL;
1126                         prev->next = buf;
1127                         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1128                         fragm_crs = INT_H_SIZE;
1129                         fragm_rest = fragm_sz;
1130                 }
1131         } while (rest > 0);
1132
1133         /*
1134          * Now we have a buffer chain. Select a link and check
1135          * that packet size is still OK
1136          */
1137         node = tipc_node_find(destaddr);
1138         if (likely(node)) {
1139                 tipc_node_lock(node);
1140                 l_ptr = node->active_links[sender->ref & 1];
1141                 if (!l_ptr) {
1142                         tipc_node_unlock(node);
1143                         goto reject;
1144                 }
1145                 if (l_ptr->max_pkt < max_pkt) {
1146                         sender->max_pkt = l_ptr->max_pkt;
1147                         tipc_node_unlock(node);
1148                         kfree_skb_list(buf_chain);
1149                         goto again;
1150                 }
1151         } else {
1152 reject:
1153                 kfree_skb_list(buf_chain);
1154                 return tipc_port_reject_sections(sender, hdr, msg_sect,
1155                                                  len, TIPC_ERR_NO_NODE);
1156         }
1157
1158         /* Append chain of fragments to send queue & send them */
1159         l_ptr->long_msg_seq_no++;
1160         link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
1161         l_ptr->stats.sent_fragments += fragm_no;
1162         l_ptr->stats.sent_fragmented++;
1163         tipc_link_push_queue(l_ptr);
1164         tipc_node_unlock(node);
1165         return dsz;
1166 }
1167
1168 /*
1169  * tipc_link_push_packet: Push one unsent packet to the media
1170  */
1171 u32 tipc_link_push_packet(struct tipc_link *l_ptr)
1172 {
1173         struct sk_buff *buf = l_ptr->first_out;
1174         u32 r_q_size = l_ptr->retransm_queue_size;
1175         u32 r_q_head = l_ptr->retransm_queue_head;
1176
1177         /* Step to position where retransmission failed, if any,    */
1178         /* consider that buffers may have been released in meantime */
1179         if (r_q_size && buf) {
1180                 u32 last = lesser(mod(r_q_head + r_q_size),
1181                                   link_last_sent(l_ptr));
1182                 u32 first = buf_seqno(buf);
1183
1184                 while (buf && less(first, r_q_head)) {
1185                         first = mod(first + 1);
1186                         buf = buf->next;
1187                 }
1188                 l_ptr->retransm_queue_head = r_q_head = first;
1189                 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
1190         }
1191
1192         /* Continue retransmission now, if there is anything: */
1193         if (r_q_size && buf) {
1194                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1195                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1196                 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1197                 l_ptr->retransm_queue_head = mod(++r_q_head);
1198                 l_ptr->retransm_queue_size = --r_q_size;
1199                 l_ptr->stats.retransmitted++;
1200                 return 0;
1201         }
1202
1203         /* Send deferred protocol message, if any: */
1204         buf = l_ptr->proto_msg_queue;
1205         if (buf) {
1206                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1207                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1208                 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1209                 l_ptr->unacked_window = 0;
1210                 kfree_skb(buf);
1211                 l_ptr->proto_msg_queue = NULL;
1212                 return 0;
1213         }
1214
1215         /* Send one deferred data message, if send window not full: */
1216         buf = l_ptr->next_out;
1217         if (buf) {
1218                 struct tipc_msg *msg = buf_msg(buf);
1219                 u32 next = msg_seqno(msg);
1220                 u32 first = buf_seqno(l_ptr->first_out);
1221
1222                 if (mod(next - first) < l_ptr->queue_limit[0]) {
1223                         msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1224                         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1225                         tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1226                         if (msg_user(msg) == MSG_BUNDLER)
1227                                 msg_set_type(msg, CLOSED_MSG);
1228                         l_ptr->next_out = buf->next;
1229                         return 0;
1230                 }
1231         }
1232         return 1;
1233 }
1234
1235 /*
1236  * push_queue(): push out the unsent messages of a link where
1237  *               congestion has abated. Node is locked
1238  */
1239 void tipc_link_push_queue(struct tipc_link *l_ptr)
1240 {
1241         u32 res;
1242
1243         do {
1244                 res = tipc_link_push_packet(l_ptr);
1245         } while (!res);
1246 }
1247
1248 static void link_reset_all(unsigned long addr)
1249 {
1250         struct tipc_node *n_ptr;
1251         char addr_string[16];
1252         u32 i;
1253
1254         read_lock_bh(&tipc_net_lock);
1255         n_ptr = tipc_node_find((u32)addr);
1256         if (!n_ptr) {
1257                 read_unlock_bh(&tipc_net_lock);
1258                 return; /* node no longer exists */
1259         }
1260
1261         tipc_node_lock(n_ptr);
1262
1263         pr_warn("Resetting all links to %s\n",
1264                 tipc_addr_string_fill(addr_string, n_ptr->addr));
1265
1266         for (i = 0; i < MAX_BEARERS; i++) {
1267                 if (n_ptr->links[i]) {
1268                         link_print(n_ptr->links[i], "Resetting link\n");
1269                         tipc_link_reset(n_ptr->links[i]);
1270                 }
1271         }
1272
1273         tipc_node_unlock(n_ptr);
1274         read_unlock_bh(&tipc_net_lock);
1275 }
1276
1277 static void link_retransmit_failure(struct tipc_link *l_ptr,
1278                                     struct sk_buff *buf)
1279 {
1280         struct tipc_msg *msg = buf_msg(buf);
1281
1282         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
1283
1284         if (l_ptr->addr) {
1285                 /* Handle failure on standard link */
1286                 link_print(l_ptr, "Resetting link\n");
1287                 tipc_link_reset(l_ptr);
1288
1289         } else {
1290                 /* Handle failure on broadcast link */
1291                 struct tipc_node *n_ptr;
1292                 char addr_string[16];
1293
1294                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
1295                 pr_cont("Outstanding acks: %lu\n",
1296                         (unsigned long) TIPC_SKB_CB(buf)->handle);
1297
1298                 n_ptr = tipc_bclink_retransmit_to();
1299                 tipc_node_lock(n_ptr);
1300
1301                 tipc_addr_string_fill(addr_string, n_ptr->addr);
1302                 pr_info("Broadcast link info for %s\n", addr_string);
1303                 pr_info("Reception permitted: %d,  Acked: %u\n",
1304                         n_ptr->bclink.recv_permitted,
1305                         n_ptr->bclink.acked);
1306                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
1307                         n_ptr->bclink.last_in,
1308                         n_ptr->bclink.oos_state,
1309                         n_ptr->bclink.last_sent);
1310
1311                 tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
1312
1313                 tipc_node_unlock(n_ptr);
1314
1315                 l_ptr->stale_count = 0;
1316         }
1317 }
1318
1319 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *buf,
1320                           u32 retransmits)
1321 {
1322         struct tipc_msg *msg;
1323
1324         if (!buf)
1325                 return;
1326
1327         msg = buf_msg(buf);
1328
1329         /* Detect repeated retransmit failures */
1330         if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1331                 if (++l_ptr->stale_count > 100) {
1332                         link_retransmit_failure(l_ptr, buf);
1333                         return;
1334                 }
1335         } else {
1336                 l_ptr->last_retransmitted = msg_seqno(msg);
1337                 l_ptr->stale_count = 1;
1338         }
1339
1340         while (retransmits && (buf != l_ptr->next_out) && buf) {
1341                 msg = buf_msg(buf);
1342                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1343                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1344                 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1345                 buf = buf->next;
1346                 retransmits--;
1347                 l_ptr->stats.retransmitted++;
1348         }
1349
1350         l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1351 }
1352
1353 /**
1354  * link_insert_deferred_queue - insert deferred messages back into receive chain
1355  */
1356 static struct sk_buff *link_insert_deferred_queue(struct tipc_link *l_ptr,
1357                                                   struct sk_buff *buf)
1358 {
1359         u32 seq_no;
1360
1361         if (l_ptr->oldest_deferred_in == NULL)
1362                 return buf;
1363
1364         seq_no = buf_seqno(l_ptr->oldest_deferred_in);
1365         if (seq_no == mod(l_ptr->next_in_no)) {
1366                 l_ptr->newest_deferred_in->next = buf;
1367                 buf = l_ptr->oldest_deferred_in;
1368                 l_ptr->oldest_deferred_in = NULL;
1369                 l_ptr->deferred_inqueue_sz = 0;
1370         }
1371         return buf;
1372 }
1373
1374 /**
1375  * link_recv_buf_validate - validate basic format of received message
1376  *
1377  * This routine ensures a TIPC message has an acceptable header, and at least
1378  * as much data as the header indicates it should.  The routine also ensures
1379  * that the entire message header is stored in the main fragment of the message
1380  * buffer, to simplify future access to message header fields.
1381  *
1382  * Note: Having extra info present in the message header or data areas is OK.
1383  * TIPC will ignore the excess, under the assumption that it is optional info
1384  * introduced by a later release of the protocol.
1385  */
1386 static int link_recv_buf_validate(struct sk_buff *buf)
1387 {
1388         static u32 min_data_hdr_size[8] = {
1389                 SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
1390                 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1391                 };
1392
1393         struct tipc_msg *msg;
1394         u32 tipc_hdr[2];
1395         u32 size;
1396         u32 hdr_size;
1397         u32 min_hdr_size;
1398
1399         if (unlikely(buf->len < MIN_H_SIZE))
1400                 return 0;
1401
1402         msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1403         if (msg == NULL)
1404                 return 0;
1405
1406         if (unlikely(msg_version(msg) != TIPC_VERSION))
1407                 return 0;
1408
1409         size = msg_size(msg);
1410         hdr_size = msg_hdr_sz(msg);
1411         min_hdr_size = msg_isdata(msg) ?
1412                 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1413
1414         if (unlikely((hdr_size < min_hdr_size) ||
1415                      (size < hdr_size) ||
1416                      (buf->len < size) ||
1417                      (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1418                 return 0;
1419
1420         return pskb_may_pull(buf, hdr_size);
1421 }
1422
1423 /**
1424  * tipc_recv_msg - process TIPC messages arriving from off-node
1425  * @head: pointer to message buffer chain
1426  * @tb_ptr: pointer to bearer message arrived on
1427  *
1428  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1429  * structure (i.e. cannot be NULL), but bearer can be inactive.
1430  */
1431 void tipc_recv_msg(struct sk_buff *head, struct tipc_bearer *b_ptr)
1432 {
1433         read_lock_bh(&tipc_net_lock);
1434         while (head) {
1435                 struct tipc_node *n_ptr;
1436                 struct tipc_link *l_ptr;
1437                 struct sk_buff *crs;
1438                 struct sk_buff *buf = head;
1439                 struct tipc_msg *msg;
1440                 u32 seq_no;
1441                 u32 ackd;
1442                 u32 released = 0;
1443                 int type;
1444
1445                 head = head->next;
1446
1447                 /* Ensure bearer is still enabled */
1448                 if (unlikely(!b_ptr->active))
1449                         goto discard;
1450
1451                 /* Ensure message is well-formed */
1452                 if (unlikely(!link_recv_buf_validate(buf)))
1453                         goto discard;
1454
1455                 /* Ensure message data is a single contiguous unit */
1456                 if (unlikely(skb_linearize(buf)))
1457                         goto discard;
1458
1459                 /* Handle arrival of a non-unicast link message */
1460                 msg = buf_msg(buf);
1461
1462                 if (unlikely(msg_non_seq(msg))) {
1463                         if (msg_user(msg) ==  LINK_CONFIG)
1464                                 tipc_disc_recv_msg(buf, b_ptr);
1465                         else
1466                                 tipc_bclink_recv_pkt(buf);
1467                         continue;
1468                 }
1469
1470                 /* Discard unicast link messages destined for another node */
1471                 if (unlikely(!msg_short(msg) &&
1472                              (msg_destnode(msg) != tipc_own_addr)))
1473                         goto discard;
1474
1475                 /* Locate neighboring node that sent message */
1476                 n_ptr = tipc_node_find(msg_prevnode(msg));
1477                 if (unlikely(!n_ptr))
1478                         goto discard;
1479                 tipc_node_lock(n_ptr);
1480
1481                 /* Locate unicast link endpoint that should handle message */
1482                 l_ptr = n_ptr->links[b_ptr->identity];
1483                 if (unlikely(!l_ptr))
1484                         goto unlock_discard;
1485
1486                 /* Verify that communication with node is currently allowed */
1487                 if ((n_ptr->block_setup & WAIT_PEER_DOWN) &&
1488                         msg_user(msg) == LINK_PROTOCOL &&
1489                         (msg_type(msg) == RESET_MSG ||
1490                                         msg_type(msg) == ACTIVATE_MSG) &&
1491                         !msg_redundant_link(msg))
1492                         n_ptr->block_setup &= ~WAIT_PEER_DOWN;
1493
1494                 if (n_ptr->block_setup)
1495                         goto unlock_discard;
1496
1497                 /* Validate message sequence number info */
1498                 seq_no = msg_seqno(msg);
1499                 ackd = msg_ack(msg);
1500
1501                 /* Release acked messages */
1502                 if (n_ptr->bclink.recv_permitted)
1503                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1504
1505                 crs = l_ptr->first_out;
1506                 while ((crs != l_ptr->next_out) &&
1507                        less_eq(buf_seqno(crs), ackd)) {
1508                         struct sk_buff *next = crs->next;
1509
1510                         kfree_skb(crs);
1511                         crs = next;
1512                         released++;
1513                 }
1514                 if (released) {
1515                         l_ptr->first_out = crs;
1516                         l_ptr->out_queue_size -= released;
1517                 }
1518
1519                 /* Try sending any messages link endpoint has pending */
1520                 if (unlikely(l_ptr->next_out))
1521                         tipc_link_push_queue(l_ptr);
1522                 if (unlikely(!list_empty(&l_ptr->waiting_ports)))
1523                         tipc_link_wakeup_ports(l_ptr, 0);
1524                 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1525                         l_ptr->stats.sent_acks++;
1526                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1527                 }
1528
1529                 /* Now (finally!) process the incoming message */
1530 protocol_check:
1531                 if (unlikely(!link_working_working(l_ptr))) {
1532                         if (msg_user(msg) == LINK_PROTOCOL) {
1533                                 link_recv_proto_msg(l_ptr, buf);
1534                                 head = link_insert_deferred_queue(l_ptr, head);
1535                                 tipc_node_unlock(n_ptr);
1536                                 continue;
1537                         }
1538
1539                         /* Traffic message. Conditionally activate link */
1540                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1541
1542                         if (link_working_working(l_ptr)) {
1543                                 /* Re-insert buffer in front of queue */
1544                                 buf->next = head;
1545                                 head = buf;
1546                                 tipc_node_unlock(n_ptr);
1547                                 continue;
1548                         }
1549                         goto unlock_discard;
1550                 }
1551
1552                 /* Link is now in state WORKING_WORKING */
1553                 if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
1554                         link_handle_out_of_seq_msg(l_ptr, buf);
1555                         head = link_insert_deferred_queue(l_ptr, head);
1556                         tipc_node_unlock(n_ptr);
1557                         continue;
1558                 }
1559                 l_ptr->next_in_no++;
1560                 if (unlikely(l_ptr->oldest_deferred_in))
1561                         head = link_insert_deferred_queue(l_ptr, head);
1562 deliver:
1563                 if (likely(msg_isdata(msg))) {
1564                         tipc_node_unlock(n_ptr);
1565                         tipc_port_recv_msg(buf);
1566                         continue;
1567                 }
1568                 switch (msg_user(msg)) {
1569                         int ret;
1570                 case MSG_BUNDLER:
1571                         l_ptr->stats.recv_bundles++;
1572                         l_ptr->stats.recv_bundled += msg_msgcnt(msg);
1573                         tipc_node_unlock(n_ptr);
1574                         tipc_link_recv_bundle(buf);
1575                         continue;
1576                 case NAME_DISTRIBUTOR:
1577                         n_ptr->bclink.recv_permitted = true;
1578                         tipc_node_unlock(n_ptr);
1579                         tipc_named_recv(buf);
1580                         continue;
1581                 case BCAST_PROTOCOL:
1582                         tipc_link_recv_sync(n_ptr, buf);
1583                         tipc_node_unlock(n_ptr);
1584                         continue;
1585                 case CONN_MANAGER:
1586                         tipc_node_unlock(n_ptr);
1587                         tipc_port_recv_proto_msg(buf);
1588                         continue;
1589                 case MSG_FRAGMENTER:
1590                         l_ptr->stats.recv_fragments++;
1591                         ret = tipc_link_recv_fragment(&l_ptr->reasm_head,
1592                                                       &l_ptr->reasm_tail,
1593                                                       &buf);
1594                         if (ret == LINK_REASM_COMPLETE) {
1595                                 l_ptr->stats.recv_fragmented++;
1596                                 msg = buf_msg(buf);
1597                                 goto deliver;
1598                         }
1599                         if (ret == LINK_REASM_ERROR)
1600                                 tipc_link_reset(l_ptr);
1601                         tipc_node_unlock(n_ptr);
1602                         continue;
1603                 case CHANGEOVER_PROTOCOL:
1604                         type = msg_type(msg);
1605                         if (link_recv_changeover_msg(&l_ptr, &buf)) {
1606                                 msg = buf_msg(buf);
1607                                 seq_no = msg_seqno(msg);
1608                                 if (type == ORIGINAL_MSG)
1609                                         goto deliver;
1610                                 goto protocol_check;
1611                         }
1612                         break;
1613                 default:
1614                         kfree_skb(buf);
1615                         buf = NULL;
1616                         break;
1617                 }
1618                 tipc_node_unlock(n_ptr);
1619                 tipc_net_route_msg(buf);
1620                 continue;
1621 unlock_discard:
1622
1623                 tipc_node_unlock(n_ptr);
1624 discard:
1625                 kfree_skb(buf);
1626         }
1627         read_unlock_bh(&tipc_net_lock);
1628 }
1629
1630 /**
1631  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1632  *
1633  * Returns increase in queue length (i.e. 0 or 1)
1634  */
1635 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
1636                         struct sk_buff *buf)
1637 {
1638         struct sk_buff *queue_buf;
1639         struct sk_buff **prev;
1640         u32 seq_no = buf_seqno(buf);
1641
1642         buf->next = NULL;
1643
1644         /* Empty queue ? */
1645         if (*head == NULL) {
1646                 *head = *tail = buf;
1647                 return 1;
1648         }
1649
1650         /* Last ? */
1651         if (less(buf_seqno(*tail), seq_no)) {
1652                 (*tail)->next = buf;
1653                 *tail = buf;
1654                 return 1;
1655         }
1656
1657         /* Locate insertion point in queue, then insert; discard if duplicate */
1658         prev = head;
1659         queue_buf = *head;
1660         for (;;) {
1661                 u32 curr_seqno = buf_seqno(queue_buf);
1662
1663                 if (seq_no == curr_seqno) {
1664                         kfree_skb(buf);
1665                         return 0;
1666                 }
1667
1668                 if (less(seq_no, curr_seqno))
1669                         break;
1670
1671                 prev = &queue_buf->next;
1672                 queue_buf = queue_buf->next;
1673         }
1674
1675         buf->next = queue_buf;
1676         *prev = buf;
1677         return 1;
1678 }
1679
1680 /*
1681  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1682  */
1683 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1684                                        struct sk_buff *buf)
1685 {
1686         u32 seq_no = buf_seqno(buf);
1687
1688         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1689                 link_recv_proto_msg(l_ptr, buf);
1690                 return;
1691         }
1692
1693         /* Record OOS packet arrival (force mismatch on next timeout) */
1694         l_ptr->checkpoint--;
1695
1696         /*
1697          * Discard packet if a duplicate; otherwise add it to deferred queue
1698          * and notify peer of gap as per protocol specification
1699          */
1700         if (less(seq_no, mod(l_ptr->next_in_no))) {
1701                 l_ptr->stats.duplicates++;
1702                 kfree_skb(buf);
1703                 return;
1704         }
1705
1706         if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
1707                                 &l_ptr->newest_deferred_in, buf)) {
1708                 l_ptr->deferred_inqueue_sz++;
1709                 l_ptr->stats.deferred_recv++;
1710                 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
1711                         tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1712         } else
1713                 l_ptr->stats.duplicates++;
1714 }
1715
1716 /*
1717  * Send protocol message to the other endpoint.
1718  */
1719 void tipc_link_send_proto_msg(struct tipc_link *l_ptr, u32 msg_typ,
1720                               int probe_msg, u32 gap, u32 tolerance,
1721                               u32 priority, u32 ack_mtu)
1722 {
1723         struct sk_buff *buf = NULL;
1724         struct tipc_msg *msg = l_ptr->pmsg;
1725         u32 msg_size = sizeof(l_ptr->proto_msg);
1726         int r_flag;
1727
1728         /* Discard any previous message that was deferred due to congestion */
1729         if (l_ptr->proto_msg_queue) {
1730                 kfree_skb(l_ptr->proto_msg_queue);
1731                 l_ptr->proto_msg_queue = NULL;
1732         }
1733
1734         if (link_blocked(l_ptr))
1735                 return;
1736
1737         /* Abort non-RESET send if communication with node is prohibited */
1738         if ((l_ptr->owner->block_setup) && (msg_typ != RESET_MSG))
1739                 return;
1740
1741         /* Create protocol message with "out-of-sequence" sequence number */
1742         msg_set_type(msg, msg_typ);
1743         msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
1744         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1745         msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
1746
1747         if (msg_typ == STATE_MSG) {
1748                 u32 next_sent = mod(l_ptr->next_out_no);
1749
1750                 if (!tipc_link_is_up(l_ptr))
1751                         return;
1752                 if (l_ptr->next_out)
1753                         next_sent = buf_seqno(l_ptr->next_out);
1754                 msg_set_next_sent(msg, next_sent);
1755                 if (l_ptr->oldest_deferred_in) {
1756                         u32 rec = buf_seqno(l_ptr->oldest_deferred_in);
1757                         gap = mod(rec - mod(l_ptr->next_in_no));
1758                 }
1759                 msg_set_seq_gap(msg, gap);
1760                 if (gap)
1761                         l_ptr->stats.sent_nacks++;
1762                 msg_set_link_tolerance(msg, tolerance);
1763                 msg_set_linkprio(msg, priority);
1764                 msg_set_max_pkt(msg, ack_mtu);
1765                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1766                 msg_set_probe(msg, probe_msg != 0);
1767                 if (probe_msg) {
1768                         u32 mtu = l_ptr->max_pkt;
1769
1770                         if ((mtu < l_ptr->max_pkt_target) &&
1771                             link_working_working(l_ptr) &&
1772                             l_ptr->fsm_msg_cnt) {
1773                                 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1774                                 if (l_ptr->max_pkt_probes == 10) {
1775                                         l_ptr->max_pkt_target = (msg_size - 4);
1776                                         l_ptr->max_pkt_probes = 0;
1777                                         msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1778                                 }
1779                                 l_ptr->max_pkt_probes++;
1780                         }
1781
1782                         l_ptr->stats.sent_probes++;
1783                 }
1784                 l_ptr->stats.sent_states++;
1785         } else {                /* RESET_MSG or ACTIVATE_MSG */
1786                 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
1787                 msg_set_seq_gap(msg, 0);
1788                 msg_set_next_sent(msg, 1);
1789                 msg_set_probe(msg, 0);
1790                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1791                 msg_set_linkprio(msg, l_ptr->priority);
1792                 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
1793         }
1794
1795         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1796         msg_set_redundant_link(msg, r_flag);
1797         msg_set_linkprio(msg, l_ptr->priority);
1798         msg_set_size(msg, msg_size);
1799
1800         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1801
1802         buf = tipc_buf_acquire(msg_size);
1803         if (!buf)
1804                 return;
1805
1806         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1807         buf->priority = TC_PRIO_CONTROL;
1808
1809         tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1810         l_ptr->unacked_window = 0;
1811         kfree_skb(buf);
1812 }
1813
1814 /*
1815  * Receive protocol message :
1816  * Note that network plane id propagates through the network, and may
1817  * change at any time. The node with lowest address rules
1818  */
1819 static void link_recv_proto_msg(struct tipc_link *l_ptr, struct sk_buff *buf)
1820 {
1821         u32 rec_gap = 0;
1822         u32 max_pkt_info;
1823         u32 max_pkt_ack;
1824         u32 msg_tol;
1825         struct tipc_msg *msg = buf_msg(buf);
1826
1827         if (link_blocked(l_ptr))
1828                 goto exit;
1829
1830         /* record unnumbered packet arrival (force mismatch on next timeout) */
1831         l_ptr->checkpoint--;
1832
1833         if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
1834                 if (tipc_own_addr > msg_prevnode(msg))
1835                         l_ptr->b_ptr->net_plane = msg_net_plane(msg);
1836
1837         l_ptr->owner->permit_changeover = msg_redundant_link(msg);
1838
1839         switch (msg_type(msg)) {
1840
1841         case RESET_MSG:
1842                 if (!link_working_unknown(l_ptr) &&
1843                     (l_ptr->peer_session != INVALID_SESSION)) {
1844                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1845                                 break; /* duplicate or old reset: ignore */
1846                 }
1847
1848                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1849                                 link_working_unknown(l_ptr))) {
1850                         /*
1851                          * peer has lost contact -- don't allow peer's links
1852                          * to reactivate before we recognize loss & clean up
1853                          */
1854                         l_ptr->owner->block_setup = WAIT_NODE_DOWN;
1855                 }
1856
1857                 link_state_event(l_ptr, RESET_MSG);
1858
1859                 /* fall thru' */
1860         case ACTIVATE_MSG:
1861                 /* Update link settings according other endpoint's values */
1862                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1863
1864                 msg_tol = msg_link_tolerance(msg);
1865                 if (msg_tol > l_ptr->tolerance)
1866                         link_set_supervision_props(l_ptr, msg_tol);
1867
1868                 if (msg_linkprio(msg) > l_ptr->priority)
1869                         l_ptr->priority = msg_linkprio(msg);
1870
1871                 max_pkt_info = msg_max_pkt(msg);
1872                 if (max_pkt_info) {
1873                         if (max_pkt_info < l_ptr->max_pkt_target)
1874                                 l_ptr->max_pkt_target = max_pkt_info;
1875                         if (l_ptr->max_pkt > l_ptr->max_pkt_target)
1876                                 l_ptr->max_pkt = l_ptr->max_pkt_target;
1877                 } else {
1878                         l_ptr->max_pkt = l_ptr->max_pkt_target;
1879                 }
1880
1881                 /* Synchronize broadcast link info, if not done previously */
1882                 if (!tipc_node_is_up(l_ptr->owner)) {
1883                         l_ptr->owner->bclink.last_sent =
1884                                 l_ptr->owner->bclink.last_in =
1885                                 msg_last_bcast(msg);
1886                         l_ptr->owner->bclink.oos_state = 0;
1887                 }
1888
1889                 l_ptr->peer_session = msg_session(msg);
1890                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1891
1892                 if (msg_type(msg) == ACTIVATE_MSG)
1893                         link_state_event(l_ptr, ACTIVATE_MSG);
1894                 break;
1895         case STATE_MSG:
1896
1897                 msg_tol = msg_link_tolerance(msg);
1898                 if (msg_tol)
1899                         link_set_supervision_props(l_ptr, msg_tol);
1900
1901                 if (msg_linkprio(msg) &&
1902                     (msg_linkprio(msg) != l_ptr->priority)) {
1903                         pr_warn("%s<%s>, priority change %u->%u\n",
1904                                 link_rst_msg, l_ptr->name, l_ptr->priority,
1905                                 msg_linkprio(msg));
1906                         l_ptr->priority = msg_linkprio(msg);
1907                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1908                         break;
1909                 }
1910                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1911                 l_ptr->stats.recv_states++;
1912                 if (link_reset_unknown(l_ptr))
1913                         break;
1914
1915                 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
1916                         rec_gap = mod(msg_next_sent(msg) -
1917                                       mod(l_ptr->next_in_no));
1918                 }
1919
1920                 max_pkt_ack = msg_max_pkt(msg);
1921                 if (max_pkt_ack > l_ptr->max_pkt) {
1922                         l_ptr->max_pkt = max_pkt_ack;
1923                         l_ptr->max_pkt_probes = 0;
1924                 }
1925
1926                 max_pkt_ack = 0;
1927                 if (msg_probe(msg)) {
1928                         l_ptr->stats.recv_probes++;
1929                         if (msg_size(msg) > sizeof(l_ptr->proto_msg))
1930                                 max_pkt_ack = msg_size(msg);
1931                 }
1932
1933                 /* Protocol message before retransmits, reduce loss risk */
1934                 if (l_ptr->owner->bclink.recv_permitted)
1935                         tipc_bclink_update_link_state(l_ptr->owner,
1936                                                       msg_last_bcast(msg));
1937
1938                 if (rec_gap || (msg_probe(msg))) {
1939                         tipc_link_send_proto_msg(l_ptr, STATE_MSG,
1940                                                  0, rec_gap, 0, 0, max_pkt_ack);
1941                 }
1942                 if (msg_seq_gap(msg)) {
1943                         l_ptr->stats.recv_nacks++;
1944                         tipc_link_retransmit(l_ptr, l_ptr->first_out,
1945                                              msg_seq_gap(msg));
1946                 }
1947                 break;
1948         }
1949 exit:
1950         kfree_skb(buf);
1951 }
1952
1953
1954 /*
1955  * tipc_link_tunnel(): Send one message via a link belonging to
1956  * another bearer. Owner node is locked.
1957  */
1958 static void tipc_link_tunnel(struct tipc_link *l_ptr,
1959                              struct tipc_msg *tunnel_hdr, struct tipc_msg *msg,
1960                              u32 selector)
1961 {
1962         struct tipc_link *tunnel;
1963         struct sk_buff *buf;
1964         u32 length = msg_size(msg);
1965
1966         tunnel = l_ptr->owner->active_links[selector & 1];
1967         if (!tipc_link_is_up(tunnel)) {
1968                 pr_warn("%stunnel link no longer available\n", link_co_err);
1969                 return;
1970         }
1971         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1972         buf = tipc_buf_acquire(length + INT_H_SIZE);
1973         if (!buf) {
1974                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1975                 return;
1976         }
1977         skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
1978         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
1979         tipc_link_send_buf(tunnel, buf);
1980 }
1981
1982
1983
1984 /*
1985  * changeover(): Send whole message queue via the remaining link
1986  *               Owner node is locked.
1987  */
1988 void tipc_link_changeover(struct tipc_link *l_ptr)
1989 {
1990         u32 msgcount = l_ptr->out_queue_size;
1991         struct sk_buff *crs = l_ptr->first_out;
1992         struct tipc_link *tunnel = l_ptr->owner->active_links[0];
1993         struct tipc_msg tunnel_hdr;
1994         int split_bundles;
1995
1996         if (!tunnel)
1997                 return;
1998
1999         if (!l_ptr->owner->permit_changeover) {
2000                 pr_warn("%speer did not permit changeover\n", link_co_err);
2001                 return;
2002         }
2003
2004         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2005                  ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
2006         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2007         msg_set_msgcnt(&tunnel_hdr, msgcount);
2008
2009         if (!l_ptr->first_out) {
2010                 struct sk_buff *buf;
2011
2012                 buf = tipc_buf_acquire(INT_H_SIZE);
2013                 if (buf) {
2014                         skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
2015                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
2016                         tipc_link_send_buf(tunnel, buf);
2017                 } else {
2018                         pr_warn("%sunable to send changeover msg\n",
2019                                 link_co_err);
2020                 }
2021                 return;
2022         }
2023
2024         split_bundles = (l_ptr->owner->active_links[0] !=
2025                          l_ptr->owner->active_links[1]);
2026
2027         while (crs) {
2028                 struct tipc_msg *msg = buf_msg(crs);
2029
2030                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
2031                         struct tipc_msg *m = msg_get_wrapped(msg);
2032                         unchar *pos = (unchar *)m;
2033
2034                         msgcount = msg_msgcnt(msg);
2035                         while (msgcount--) {
2036                                 msg_set_seqno(m, msg_seqno(msg));
2037                                 tipc_link_tunnel(l_ptr, &tunnel_hdr, m,
2038                                                  msg_link_selector(m));
2039                                 pos += align(msg_size(m));
2040                                 m = (struct tipc_msg *)pos;
2041                         }
2042                 } else {
2043                         tipc_link_tunnel(l_ptr, &tunnel_hdr, msg,
2044                                          msg_link_selector(msg));
2045                 }
2046                 crs = crs->next;
2047         }
2048 }
2049
2050 void tipc_link_send_duplicate(struct tipc_link *l_ptr, struct tipc_link *tunnel)
2051 {
2052         struct sk_buff *iter;
2053         struct tipc_msg tunnel_hdr;
2054
2055         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2056                  DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
2057         msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
2058         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2059         iter = l_ptr->first_out;
2060         while (iter) {
2061                 struct sk_buff *outbuf;
2062                 struct tipc_msg *msg = buf_msg(iter);
2063                 u32 length = msg_size(msg);
2064
2065                 if (msg_user(msg) == MSG_BUNDLER)
2066                         msg_set_type(msg, CLOSED_MSG);
2067                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));   /* Update */
2068                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
2069                 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
2070                 outbuf = tipc_buf_acquire(length + INT_H_SIZE);
2071                 if (outbuf == NULL) {
2072                         pr_warn("%sunable to send duplicate msg\n",
2073                                 link_co_err);
2074                         return;
2075                 }
2076                 skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
2077                 skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
2078                                                length);
2079                 tipc_link_send_buf(tunnel, outbuf);
2080                 if (!tipc_link_is_up(l_ptr))
2081                         return;
2082                 iter = iter->next;
2083         }
2084 }
2085
2086 /**
2087  * buf_extract - extracts embedded TIPC message from another message
2088  * @skb: encapsulating message buffer
2089  * @from_pos: offset to extract from
2090  *
2091  * Returns a new message buffer containing an embedded message.  The
2092  * encapsulating message itself is left unchanged.
2093  */
2094 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
2095 {
2096         struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
2097         u32 size = msg_size(msg);
2098         struct sk_buff *eb;
2099
2100         eb = tipc_buf_acquire(size);
2101         if (eb)
2102                 skb_copy_to_linear_data(eb, msg, size);
2103         return eb;
2104 }
2105
2106 /*
2107  *  link_recv_changeover_msg(): Receive tunneled packet sent
2108  *  via other link. Node is locked. Return extracted buffer.
2109  */
2110 static int link_recv_changeover_msg(struct tipc_link **l_ptr,
2111                                     struct sk_buff **buf)
2112 {
2113         struct sk_buff *tunnel_buf = *buf;
2114         struct tipc_link *dest_link;
2115         struct tipc_msg *msg;
2116         struct tipc_msg *tunnel_msg = buf_msg(tunnel_buf);
2117         u32 msg_typ = msg_type(tunnel_msg);
2118         u32 msg_count = msg_msgcnt(tunnel_msg);
2119         u32 bearer_id = msg_bearer_id(tunnel_msg);
2120
2121         if (bearer_id >= MAX_BEARERS)
2122                 goto exit;
2123         dest_link = (*l_ptr)->owner->links[bearer_id];
2124         if (!dest_link)
2125                 goto exit;
2126         if (dest_link == *l_ptr) {
2127                 pr_err("Unexpected changeover message on link <%s>\n",
2128                        (*l_ptr)->name);
2129                 goto exit;
2130         }
2131         *l_ptr = dest_link;
2132         msg = msg_get_wrapped(tunnel_msg);
2133
2134         if (msg_typ == DUPLICATE_MSG) {
2135                 if (less(msg_seqno(msg), mod(dest_link->next_in_no)))
2136                         goto exit;
2137                 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2138                 if (*buf == NULL) {
2139                         pr_warn("%sduplicate msg dropped\n", link_co_err);
2140                         goto exit;
2141                 }
2142                 kfree_skb(tunnel_buf);
2143                 return 1;
2144         }
2145
2146         /* First original message ?: */
2147         if (tipc_link_is_up(dest_link)) {
2148                 pr_info("%s<%s>, changeover initiated by peer\n", link_rst_msg,
2149                         dest_link->name);
2150                 tipc_link_reset(dest_link);
2151                 dest_link->exp_msg_count = msg_count;
2152                 if (!msg_count)
2153                         goto exit;
2154         } else if (dest_link->exp_msg_count == START_CHANGEOVER) {
2155                 dest_link->exp_msg_count = msg_count;
2156                 if (!msg_count)
2157                         goto exit;
2158         }
2159
2160         /* Receive original message */
2161         if (dest_link->exp_msg_count == 0) {
2162                 pr_warn("%sgot too many tunnelled messages\n", link_co_err);
2163                 goto exit;
2164         }
2165         dest_link->exp_msg_count--;
2166         if (less(msg_seqno(msg), dest_link->reset_checkpoint)) {
2167                 goto exit;
2168         } else {
2169                 *buf = buf_extract(tunnel_buf, INT_H_SIZE);
2170                 if (*buf != NULL) {
2171                         kfree_skb(tunnel_buf);
2172                         return 1;
2173                 } else {
2174                         pr_warn("%soriginal msg dropped\n", link_co_err);
2175                 }
2176         }
2177 exit:
2178         *buf = NULL;
2179         kfree_skb(tunnel_buf);
2180         return 0;
2181 }
2182
2183 /*
2184  *  Bundler functionality:
2185  */
2186 void tipc_link_recv_bundle(struct sk_buff *buf)
2187 {
2188         u32 msgcount = msg_msgcnt(buf_msg(buf));
2189         u32 pos = INT_H_SIZE;
2190         struct sk_buff *obuf;
2191
2192         while (msgcount--) {
2193                 obuf = buf_extract(buf, pos);
2194                 if (obuf == NULL) {
2195                         pr_warn("Link unable to unbundle message(s)\n");
2196                         break;
2197                 }
2198                 pos += align(msg_size(buf_msg(obuf)));
2199                 tipc_net_route_msg(obuf);
2200         }
2201         kfree_skb(buf);
2202 }
2203
2204 /*
2205  *  Fragmentation/defragmentation:
2206  */
2207
2208 /*
2209  * link_send_long_buf: Entry for buffers needing fragmentation.
2210  * The buffer is complete, inclusive total message length.
2211  * Returns user data length.
2212  */
2213 static int link_send_long_buf(struct tipc_link *l_ptr, struct sk_buff *buf)
2214 {
2215         struct sk_buff *buf_chain = NULL;
2216         struct sk_buff *buf_chain_tail = (struct sk_buff *)&buf_chain;
2217         struct tipc_msg *inmsg = buf_msg(buf);
2218         struct tipc_msg fragm_hdr;
2219         u32 insize = msg_size(inmsg);
2220         u32 dsz = msg_data_sz(inmsg);
2221         unchar *crs = buf->data;
2222         u32 rest = insize;
2223         u32 pack_sz = l_ptr->max_pkt;
2224         u32 fragm_sz = pack_sz - INT_H_SIZE;
2225         u32 fragm_no = 0;
2226         u32 destaddr;
2227
2228         if (msg_short(inmsg))
2229                 destaddr = l_ptr->addr;
2230         else
2231                 destaddr = msg_destnode(inmsg);
2232
2233         /* Prepare reusable fragment header: */
2234         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
2235                  INT_H_SIZE, destaddr);
2236
2237         /* Chop up message: */
2238         while (rest > 0) {
2239                 struct sk_buff *fragm;
2240
2241                 if (rest <= fragm_sz) {
2242                         fragm_sz = rest;
2243                         msg_set_type(&fragm_hdr, LAST_FRAGMENT);
2244                 }
2245                 fragm = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
2246                 if (fragm == NULL) {
2247                         kfree_skb(buf);
2248                         kfree_skb_list(buf_chain);
2249                         return -ENOMEM;
2250                 }
2251                 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
2252                 fragm_no++;
2253                 msg_set_fragm_no(&fragm_hdr, fragm_no);
2254                 skb_copy_to_linear_data(fragm, &fragm_hdr, INT_H_SIZE);
2255                 skb_copy_to_linear_data_offset(fragm, INT_H_SIZE, crs,
2256                                                fragm_sz);
2257                 buf_chain_tail->next = fragm;
2258                 buf_chain_tail = fragm;
2259
2260                 rest -= fragm_sz;
2261                 crs += fragm_sz;
2262                 msg_set_type(&fragm_hdr, FRAGMENT);
2263         }
2264         kfree_skb(buf);
2265
2266         /* Append chain of fragments to send queue & send them */
2267         l_ptr->long_msg_seq_no++;
2268         link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
2269         l_ptr->stats.sent_fragments += fragm_no;
2270         l_ptr->stats.sent_fragmented++;
2271         tipc_link_push_queue(l_ptr);
2272
2273         return dsz;
2274 }
2275
2276 /*
2277  * tipc_link_recv_fragment(): Called with node lock on. Returns
2278  * the reassembled buffer if message is complete.
2279  */
2280 int tipc_link_recv_fragment(struct sk_buff **head, struct sk_buff **tail,
2281                             struct sk_buff **fbuf)
2282 {
2283         struct sk_buff *frag = *fbuf;
2284         struct tipc_msg *msg = buf_msg(frag);
2285         u32 fragid = msg_type(msg);
2286         bool headstolen;
2287         int delta;
2288
2289         skb_pull(frag, msg_hdr_sz(msg));
2290         if (fragid == FIRST_FRAGMENT) {
2291                 if (*head || skb_unclone(frag, GFP_ATOMIC))
2292                         goto out_free;
2293                 *head = frag;
2294                 skb_frag_list_init(*head);
2295                 return 0;
2296         } else if (*head &&
2297                    skb_try_coalesce(*head, frag, &headstolen, &delta)) {
2298                 kfree_skb_partial(frag, headstolen);
2299         } else {
2300                 if (!*head)
2301                         goto out_free;
2302                 if (!skb_has_frag_list(*head))
2303                         skb_shinfo(*head)->frag_list = frag;
2304                 else
2305                         (*tail)->next = frag;
2306                 *tail = frag;
2307                 (*head)->truesize += frag->truesize;
2308         }
2309         if (fragid == LAST_FRAGMENT) {
2310                 *fbuf = *head;
2311                 *tail = *head = NULL;
2312                 return LINK_REASM_COMPLETE;
2313         }
2314         return 0;
2315 out_free:
2316         pr_warn_ratelimited("Link unable to reassemble fragmented message\n");
2317         kfree_skb(*fbuf);
2318         return LINK_REASM_ERROR;
2319 }
2320
2321 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
2322 {
2323         if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
2324                 return;
2325
2326         l_ptr->tolerance = tolerance;
2327         l_ptr->continuity_interval =
2328                 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
2329         l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
2330 }
2331
2332 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
2333 {
2334         /* Data messages from this node, inclusive FIRST_FRAGM */
2335         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
2336         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
2337         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
2338         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
2339         /* Transiting data messages,inclusive FIRST_FRAGM */
2340         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
2341         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
2342         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
2343         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
2344         l_ptr->queue_limit[CONN_MANAGER] = 1200;
2345         l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
2346         l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
2347         /* FRAGMENT and LAST_FRAGMENT packets */
2348         l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
2349 }
2350
2351 /**
2352  * link_find_link - locate link by name
2353  * @name: ptr to link name string
2354  * @node: ptr to area to be filled with ptr to associated node
2355  *
2356  * Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
2357  * this also prevents link deletion.
2358  *
2359  * Returns pointer to link (or 0 if invalid link name).
2360  */
2361 static struct tipc_link *link_find_link(const char *name,
2362                                         struct tipc_node **node)
2363 {
2364         struct tipc_link *l_ptr;
2365         struct tipc_node *n_ptr;
2366         int i;
2367
2368         list_for_each_entry(n_ptr, &tipc_node_list, list) {
2369                 for (i = 0; i < MAX_BEARERS; i++) {
2370                         l_ptr = n_ptr->links[i];
2371                         if (l_ptr && !strcmp(l_ptr->name, name))
2372                                 goto found;
2373                 }
2374         }
2375         l_ptr = NULL;
2376         n_ptr = NULL;
2377 found:
2378         *node = n_ptr;
2379         return l_ptr;
2380 }
2381
2382 /**
2383  * link_value_is_valid -- validate proposed link tolerance/priority/window
2384  *
2385  * @cmd: value type (TIPC_CMD_SET_LINK_*)
2386  * @new_value: the new value
2387  *
2388  * Returns 1 if value is within range, 0 if not.
2389  */
2390 static int link_value_is_valid(u16 cmd, u32 new_value)
2391 {
2392         switch (cmd) {
2393         case TIPC_CMD_SET_LINK_TOL:
2394                 return (new_value >= TIPC_MIN_LINK_TOL) &&
2395                         (new_value <= TIPC_MAX_LINK_TOL);
2396         case TIPC_CMD_SET_LINK_PRI:
2397                 return (new_value <= TIPC_MAX_LINK_PRI);
2398         case TIPC_CMD_SET_LINK_WINDOW:
2399                 return (new_value >= TIPC_MIN_LINK_WIN) &&
2400                         (new_value <= TIPC_MAX_LINK_WIN);
2401         }
2402         return 0;
2403 }
2404
2405 /**
2406  * link_cmd_set_value - change priority/tolerance/window for link/bearer/media
2407  * @name: ptr to link, bearer, or media name
2408  * @new_value: new value of link, bearer, or media setting
2409  * @cmd: which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*)
2410  *
2411  * Caller must hold 'tipc_net_lock' to ensure link/bearer/media is not deleted.
2412  *
2413  * Returns 0 if value updated and negative value on error.
2414  */
2415 static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
2416 {
2417         struct tipc_node *node;
2418         struct tipc_link *l_ptr;
2419         struct tipc_bearer *b_ptr;
2420         struct tipc_media *m_ptr;
2421         int res = 0;
2422
2423         l_ptr = link_find_link(name, &node);
2424         if (l_ptr) {
2425                 /*
2426                  * acquire node lock for tipc_link_send_proto_msg().
2427                  * see "TIPC locking policy" in net.c.
2428                  */
2429                 tipc_node_lock(node);
2430                 switch (cmd) {
2431                 case TIPC_CMD_SET_LINK_TOL:
2432                         link_set_supervision_props(l_ptr, new_value);
2433                         tipc_link_send_proto_msg(l_ptr,
2434                                 STATE_MSG, 0, 0, new_value, 0, 0);
2435                         break;
2436                 case TIPC_CMD_SET_LINK_PRI:
2437                         l_ptr->priority = new_value;
2438                         tipc_link_send_proto_msg(l_ptr,
2439                                 STATE_MSG, 0, 0, 0, new_value, 0);
2440                         break;
2441                 case TIPC_CMD_SET_LINK_WINDOW:
2442                         tipc_link_set_queue_limits(l_ptr, new_value);
2443                         break;
2444                 default:
2445                         res = -EINVAL;
2446                         break;
2447                 }
2448                 tipc_node_unlock(node);
2449                 return res;
2450         }
2451
2452         b_ptr = tipc_bearer_find(name);
2453         if (b_ptr) {
2454                 switch (cmd) {
2455                 case TIPC_CMD_SET_LINK_TOL:
2456                         b_ptr->tolerance = new_value;
2457                         break;
2458                 case TIPC_CMD_SET_LINK_PRI:
2459                         b_ptr->priority = new_value;
2460                         break;
2461                 case TIPC_CMD_SET_LINK_WINDOW:
2462                         b_ptr->window = new_value;
2463                         break;
2464                 default:
2465                         res = -EINVAL;
2466                         break;
2467                 }
2468                 return res;
2469         }
2470
2471         m_ptr = tipc_media_find(name);
2472         if (!m_ptr)
2473                 return -ENODEV;
2474         switch (cmd) {
2475         case TIPC_CMD_SET_LINK_TOL:
2476                 m_ptr->tolerance = new_value;
2477                 break;
2478         case TIPC_CMD_SET_LINK_PRI:
2479                 m_ptr->priority = new_value;
2480                 break;
2481         case TIPC_CMD_SET_LINK_WINDOW:
2482                 m_ptr->window = new_value;
2483                 break;
2484         default:
2485                 res = -EINVAL;
2486                 break;
2487         }
2488         return res;
2489 }
2490
2491 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2492                                      u16 cmd)
2493 {
2494         struct tipc_link_config *args;
2495         u32 new_value;
2496         int res;
2497
2498         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2499                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2500
2501         args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2502         new_value = ntohl(args->value);
2503
2504         if (!link_value_is_valid(cmd, new_value))
2505                 return tipc_cfg_reply_error_string(
2506                         "cannot change, value invalid");
2507
2508         if (!strcmp(args->name, tipc_bclink_name)) {
2509                 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2510                     (tipc_bclink_set_queue_limits(new_value) == 0))
2511                         return tipc_cfg_reply_none();
2512                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2513                                                    " (cannot change setting on broadcast link)");
2514         }
2515
2516         read_lock_bh(&tipc_net_lock);
2517         res = link_cmd_set_value(args->name, new_value, cmd);
2518         read_unlock_bh(&tipc_net_lock);
2519         if (res)
2520                 return tipc_cfg_reply_error_string("cannot change link setting");
2521
2522         return tipc_cfg_reply_none();
2523 }
2524
2525 /**
2526  * link_reset_statistics - reset link statistics
2527  * @l_ptr: pointer to link
2528  */
2529 static void link_reset_statistics(struct tipc_link *l_ptr)
2530 {
2531         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2532         l_ptr->stats.sent_info = l_ptr->next_out_no;
2533         l_ptr->stats.recv_info = l_ptr->next_in_no;
2534 }
2535
2536 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2537 {
2538         char *link_name;
2539         struct tipc_link *l_ptr;
2540         struct tipc_node *node;
2541
2542         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2543                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2544
2545         link_name = (char *)TLV_DATA(req_tlv_area);
2546         if (!strcmp(link_name, tipc_bclink_name)) {
2547                 if (tipc_bclink_reset_stats())
2548                         return tipc_cfg_reply_error_string("link not found");
2549                 return tipc_cfg_reply_none();
2550         }
2551
2552         read_lock_bh(&tipc_net_lock);
2553         l_ptr = link_find_link(link_name, &node);
2554         if (!l_ptr) {
2555                 read_unlock_bh(&tipc_net_lock);
2556                 return tipc_cfg_reply_error_string("link not found");
2557         }
2558
2559         tipc_node_lock(node);
2560         link_reset_statistics(l_ptr);
2561         tipc_node_unlock(node);
2562         read_unlock_bh(&tipc_net_lock);
2563         return tipc_cfg_reply_none();
2564 }
2565
2566 /**
2567  * percent - convert count to a percentage of total (rounding up or down)
2568  */
2569 static u32 percent(u32 count, u32 total)
2570 {
2571         return (count * 100 + (total / 2)) / total;
2572 }
2573
2574 /**
2575  * tipc_link_stats - print link statistics
2576  * @name: link name
2577  * @buf: print buffer area
2578  * @buf_size: size of print buffer area
2579  *
2580  * Returns length of print buffer data string (or 0 if error)
2581  */
2582 static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
2583 {
2584         struct tipc_link *l;
2585         struct tipc_stats *s;
2586         struct tipc_node *node;
2587         char *status;
2588         u32 profile_total = 0;
2589         int ret;
2590
2591         if (!strcmp(name, tipc_bclink_name))
2592                 return tipc_bclink_stats(buf, buf_size);
2593
2594         read_lock_bh(&tipc_net_lock);
2595         l = link_find_link(name, &node);
2596         if (!l) {
2597                 read_unlock_bh(&tipc_net_lock);
2598                 return 0;
2599         }
2600         tipc_node_lock(node);
2601         s = &l->stats;
2602
2603         if (tipc_link_is_active(l))
2604                 status = "ACTIVE";
2605         else if (tipc_link_is_up(l))
2606                 status = "STANDBY";
2607         else
2608                 status = "DEFUNCT";
2609
2610         ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
2611                             "  %s  MTU:%u  Priority:%u  Tolerance:%u ms"
2612                             "  Window:%u packets\n",
2613                             l->name, status, l->max_pkt, l->priority,
2614                             l->tolerance, l->queue_limit[0]);
2615
2616         ret += tipc_snprintf(buf + ret, buf_size - ret,
2617                              "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2618                              l->next_in_no - s->recv_info, s->recv_fragments,
2619                              s->recv_fragmented, s->recv_bundles,
2620                              s->recv_bundled);
2621
2622         ret += tipc_snprintf(buf + ret, buf_size - ret,
2623                              "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2624                              l->next_out_no - s->sent_info, s->sent_fragments,
2625                              s->sent_fragmented, s->sent_bundles,
2626                              s->sent_bundled);
2627
2628         profile_total = s->msg_length_counts;
2629         if (!profile_total)
2630                 profile_total = 1;
2631
2632         ret += tipc_snprintf(buf + ret, buf_size - ret,
2633                              "  TX profile sample:%u packets  average:%u octets\n"
2634                              "  0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
2635                              "-16384:%u%% -32768:%u%% -66000:%u%%\n",
2636                              s->msg_length_counts,
2637                              s->msg_lengths_total / profile_total,
2638                              percent(s->msg_length_profile[0], profile_total),
2639                              percent(s->msg_length_profile[1], profile_total),
2640                              percent(s->msg_length_profile[2], profile_total),
2641                              percent(s->msg_length_profile[3], profile_total),
2642                              percent(s->msg_length_profile[4], profile_total),
2643                              percent(s->msg_length_profile[5], profile_total),
2644                              percent(s->msg_length_profile[6], profile_total));
2645
2646         ret += tipc_snprintf(buf + ret, buf_size - ret,
2647                              "  RX states:%u probes:%u naks:%u defs:%u"
2648                              " dups:%u\n", s->recv_states, s->recv_probes,
2649                              s->recv_nacks, s->deferred_recv, s->duplicates);
2650
2651         ret += tipc_snprintf(buf + ret, buf_size - ret,
2652                              "  TX states:%u probes:%u naks:%u acks:%u"
2653                              " dups:%u\n", s->sent_states, s->sent_probes,
2654                              s->sent_nacks, s->sent_acks, s->retransmitted);
2655
2656         ret += tipc_snprintf(buf + ret, buf_size - ret,
2657                              "  Congestion link:%u  Send queue"
2658                              " max:%u avg:%u\n", s->link_congs,
2659                              s->max_queue_sz, s->queue_sz_counts ?
2660                              (s->accu_queue_sz / s->queue_sz_counts) : 0);
2661
2662         tipc_node_unlock(node);
2663         read_unlock_bh(&tipc_net_lock);
2664         return ret;
2665 }
2666
2667 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
2668 {
2669         struct sk_buff *buf;
2670         struct tlv_desc *rep_tlv;
2671         int str_len;
2672         int pb_len;
2673         char *pb;
2674
2675         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2676                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2677
2678         buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
2679         if (!buf)
2680                 return NULL;
2681
2682         rep_tlv = (struct tlv_desc *)buf->data;
2683         pb = TLV_DATA(rep_tlv);
2684         pb_len = ULTRA_STRING_MAX_LEN;
2685         str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
2686                                   pb, pb_len);
2687         if (!str_len) {
2688                 kfree_skb(buf);
2689                 return tipc_cfg_reply_error_string("link not found");
2690         }
2691         str_len += 1;   /* for "\0" */
2692         skb_put(buf, TLV_SPACE(str_len));
2693         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
2694
2695         return buf;
2696 }
2697
2698 /**
2699  * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
2700  * @dest: network address of destination node
2701  * @selector: used to select from set of active links
2702  *
2703  * If no active link can be found, uses default maximum packet size.
2704  */
2705 u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
2706 {
2707         struct tipc_node *n_ptr;
2708         struct tipc_link *l_ptr;
2709         u32 res = MAX_PKT_DEFAULT;
2710
2711         if (dest == tipc_own_addr)
2712                 return MAX_MSG_SIZE;
2713
2714         read_lock_bh(&tipc_net_lock);
2715         n_ptr = tipc_node_find(dest);
2716         if (n_ptr) {
2717                 tipc_node_lock(n_ptr);
2718                 l_ptr = n_ptr->active_links[selector & 1];
2719                 if (l_ptr)
2720                         res = l_ptr->max_pkt;
2721                 tipc_node_unlock(n_ptr);
2722         }
2723         read_unlock_bh(&tipc_net_lock);
2724         return res;
2725 }
2726
2727 static void link_print(struct tipc_link *l_ptr, const char *str)
2728 {
2729         pr_info("%s Link %x<%s>:", str, l_ptr->addr, l_ptr->b_ptr->name);
2730
2731         if (link_working_unknown(l_ptr))
2732                 pr_cont(":WU\n");
2733         else if (link_reset_reset(l_ptr))
2734                 pr_cont(":RR\n");
2735         else if (link_reset_unknown(l_ptr))
2736                 pr_cont(":RU\n");
2737         else if (link_working_working(l_ptr))
2738                 pr_cont(":WW\n");
2739         else
2740                 pr_cont("\n");
2741 }