net/tipc/link.c

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