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         u32 max_pkt;
 105
 106         max_pkt = (l_ptr->b_ptr->mtu & ~3);
 107         if (max_pkt > MAX_MSG_SIZE)
 108                 max_pkt = MAX_MSG_SIZE;
 109
 110         l_ptr->max_pkt_target = max_pkt;
 111         if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
 112                 l_ptr->max_pkt = l_ptr->max_pkt_target;
 113         else
 114                 l_ptr->max_pkt = MAX_PKT_DEFAULT;
 115
 116         l_ptr->max_pkt_probes = 0;
 117 }
 118
 119 static u32 link_next_sent(struct tipc_link *l_ptr)
 120 {
 121         if (l_ptr->next_out)
 122                 return buf_seqno(l_ptr->next_out);
 123         return mod(l_ptr->next_out_no);
 124 }
 125
 126 static u32 link_last_sent(struct tipc_link *l_ptr)
 127 {
 128         return mod(link_next_sent(l_ptr) - 1);
 129 }
 130
 131 /*
 132  *  Simple non-static link routines (i.e. referenced outside this file)
 133  */
 134 int tipc_link_is_up(struct tipc_link *l_ptr)
 135 {
 136         if (!l_ptr)
 137                 return 0;
 138         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 139 }
 140
 141 int tipc_link_is_active(struct tipc_link *l_ptr)
 142 {
 143         return  (l_ptr->owner->active_links[0] == l_ptr) ||
 144                 (l_ptr->owner->active_links[1] == l_ptr);
 145 }
 146
 147 /**
 148  * link_timeout - handle expiration of link timer
 149  * @l_ptr: pointer to link
 150  */
 151 static void link_timeout(struct tipc_link *l_ptr)
 152 {
 153         tipc_node_lock(l_ptr->owner);
 154
 155         /* update counters used in statistical profiling of send traffic */
 156         l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
 157         l_ptr->stats.queue_sz_counts++;
 158
 159         if (l_ptr->first_out) {
 160                 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
 161                 u32 length = msg_size(msg);
 162
 163                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 164                     (msg_type(msg) == FIRST_FRAGMENT)) {
 165                         length = msg_size(msg_get_wrapped(msg));
 166                 }
 167                 if (length) {
 168                         l_ptr->stats.msg_lengths_total += length;
 169                         l_ptr->stats.msg_length_counts++;
 170                         if (length <= 64)
 171                                 l_ptr->stats.msg_length_profile[0]++;
 172                         else if (length <= 256)
 173                                 l_ptr->stats.msg_length_profile[1]++;
 174                         else if (length <= 1024)
 175                                 l_ptr->stats.msg_length_profile[2]++;
 176                         else if (length <= 4096)
 177                                 l_ptr->stats.msg_length_profile[3]++;
 178                         else if (length <= 16384)
 179                                 l_ptr->stats.msg_length_profile[4]++;
 180                         else if (length <= 32768)
 181                                 l_ptr->stats.msg_length_profile[5]++;
 182                         else
 183                                 l_ptr->stats.msg_length_profile[6]++;
 184                 }
 185         }
 186
 187         /* do all other link processing performed on a periodic basis */
 188
 189         link_state_event(l_ptr, TIMEOUT_EVT);
 190
 191         if (l_ptr->next_out)
 192                 tipc_link_push_queue(l_ptr);
 193
 194         tipc_node_unlock(l_ptr->owner);
 195 }
 196
 197 static void link_set_timer(struct tipc_link *l_ptr, u32 time)
 198 {
 199         k_start_timer(&l_ptr->timer, time);
 200 }
 201
 202 /**
 203  * tipc_link_create - create a new link
 204  * @n_ptr: pointer to associated node
 205  * @b_ptr: pointer to associated bearer
 206  * @media_addr: media address to use when sending messages over link
 207  *
 208  * Returns pointer to link.
 209  */
 210 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 211                                    struct tipc_bearer *b_ptr,
 212                                    const struct tipc_media_addr *media_addr)
 213 {
 214         struct tipc_link *l_ptr;
 215         struct tipc_msg *msg;
 216         char *if_name;
 217         char addr_string[16];
 218         u32 peer = n_ptr->addr;
 219
 220         if (n_ptr->link_cnt >= 2) {
 221                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 222                 pr_err("Attempt to establish third link to %s\n", addr_string);
 223                 return NULL;
 224         }
 225
 226         if (n_ptr->links[b_ptr->identity]) {
 227                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 228                 pr_err("Attempt to establish second link on <%s> to %s\n",
 229                        b_ptr->name, addr_string);
 230                 return NULL;
 231         }
 232
 233         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 234         if (!l_ptr) {
 235                 pr_warn("Link creation failed, no memory\n");
 236                 return NULL;
 237         }
 238
 239         l_ptr->addr = peer;
 240         if_name = strchr(b_ptr->name, ':') + 1;
 241         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 242                 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
 243                 tipc_node(tipc_own_addr),
 244                 if_name,
 245                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 246                 /* note: peer i/f name is updated by reset/activate message */
 247         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 248         l_ptr->owner = n_ptr;
 249         l_ptr->checkpoint = 1;
 250         l_ptr->peer_session = INVALID_SESSION;
 251         l_ptr->b_ptr = b_ptr;
 252         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 253         l_ptr->state = RESET_UNKNOWN;
 254
 255         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 256         msg = l_ptr->pmsg;
 257         tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
 258         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 259         msg_set_session(msg, (tipc_random & 0xffff));
 260         msg_set_bearer_id(msg, b_ptr->identity);
 261         strcpy((char *)msg_data(msg), if_name);
 262
 263         l_ptr->priority = b_ptr->priority;
 264         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 265
 266         link_init_max_pkt(l_ptr);
 267
 268         l_ptr->next_out_no = 1;
 269         INIT_LIST_HEAD(&l_ptr->waiting_ports);
 270
 271         link_reset_statistics(l_ptr);
 272
 273         tipc_node_attach_link(n_ptr, l_ptr);
 274
 275         k_init_timer(&l_ptr->timer, (Handler)link_timeout,
 276                      (unsigned long)l_ptr);
 277
 278         link_state_event(l_ptr, STARTING_EVT);
 279
 280         return l_ptr;
 281 }
 282
 283
 284 void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down)
 285 {
 286         struct tipc_link *l_ptr;
 287         struct tipc_node *n_ptr;
 288
 289         list_for_each_entry(n_ptr, &tipc_node_list, list) {
 290                 spin_lock_bh(&n_ptr->lock);
 291                 l_ptr = n_ptr->links[bearer_id];
 292                 if (l_ptr) {
 293                         tipc_link_reset(l_ptr);
 294                         if (shutting_down || !tipc_node_is_up(n_ptr)) {
 295                                 tipc_node_detach_link(l_ptr->owner, l_ptr);
 296                                 tipc_link_reset_fragments(l_ptr);
 297                                 spin_unlock_bh(&n_ptr->lock);
 298
 299                                 /* Nobody else can access this link now: */
 300                                 del_timer_sync(&l_ptr->timer);
 301                                 kfree(l_ptr);
 302                         } else {
 303                                 /* Detach/delete when failover is finished: */
 304                                 l_ptr->flags |= LINK_STOPPED;
 305                                 spin_unlock_bh(&n_ptr->lock);
 306                                 del_timer_sync(&l_ptr->timer);
 307                         }
 308                         continue;
 309                 }
 310                 spin_unlock_bh(&n_ptr->lock);
 311         }
 312 }
 313
 314 /**
 315  * link_schedule_port - schedule port for deferred sending
 316  * @l_ptr: pointer to link
 317  * @origport: reference to sending port
 318  * @sz: amount of data to be sent
 319  *
 320  * Schedules port for renewed sending of messages after link congestion
 321  * has abated.
 322  */
 323 static int link_schedule_port(struct tipc_link *l_ptr, u32 origport, u32 sz)
 324 {
 325         struct tipc_port *p_ptr;
 326
 327         spin_lock_bh(&tipc_port_list_lock);
 328         p_ptr = tipc_port_lock(origport);
 329         if (p_ptr) {
 330                 if (!list_empty(&p_ptr->wait_list))
 331                         goto exit;
 332                 p_ptr->congested = 1;
 333                 p_ptr->waiting_pkts = 1 + ((sz - 1) / l_ptr->max_pkt);
 334                 list_add_tail(&p_ptr->wait_list, &l_ptr->waiting_ports);
 335                 l_ptr->stats.link_congs++;
 336 exit:
 337                 tipc_port_unlock(p_ptr);
 338         }
 339         spin_unlock_bh(&tipc_port_list_lock);
 340         return -ELINKCONG;
 341 }
 342
 343 void tipc_link_wakeup_ports(struct tipc_link *l_ptr, int all)
 344 {
 345         struct tipc_port *p_ptr;
 346         struct tipc_port *temp_p_ptr;
 347         int win = l_ptr->queue_limit[0] - l_ptr->out_queue_size;
 348
 349         if (all)
 350                 win = 100000;
 351         if (win <= 0)
 352                 return;
 353         if (!spin_trylock_bh(&tipc_port_list_lock))
 354                 return;
 355         if (link_congested(l_ptr))
 356                 goto exit;
 357         list_for_each_entry_safe(p_ptr, temp_p_ptr, &l_ptr->waiting_ports,
 358                                  wait_list) {
 359                 if (win <= 0)
 360                         break;
 361                 list_del_init(&p_ptr->wait_list);
 362                 spin_lock_bh(p_ptr->lock);
 363                 p_ptr->congested = 0;
 364                 tipc_port_wakeup(p_ptr);
 365                 win -= p_ptr->waiting_pkts;
 366                 spin_unlock_bh(p_ptr->lock);
 367         }
 368
 369 exit:
 370         spin_unlock_bh(&tipc_port_list_lock);
 371 }
 372
 373 /**
 374  * link_release_outqueue - purge link's outbound message queue
 375  * @l_ptr: pointer to link
 376  */
 377 static void link_release_outqueue(struct tipc_link *l_ptr)
 378 {
 379         kfree_skb_list(l_ptr->first_out);
 380         l_ptr->first_out = NULL;
 381         l_ptr->out_queue_size = 0;
 382 }
 383
 384 /**
 385  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 386  * @l_ptr: pointer to link
 387  */
 388 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 389 {
 390         kfree_skb(l_ptr->reasm_head);
 391         l_ptr->reasm_head = NULL;
 392         l_ptr->reasm_tail = NULL;
 393 }
 394
 395 /**
 396  * tipc_link_purge_queues - purge all pkt queues associated with link
 397  * @l_ptr: pointer to link
 398  */
 399 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 400 {
 401         kfree_skb_list(l_ptr->oldest_deferred_in);
 402         kfree_skb_list(l_ptr->first_out);
 403         tipc_link_reset_fragments(l_ptr);
 404         kfree_skb(l_ptr->proto_msg_queue);
 405         l_ptr->proto_msg_queue = NULL;
 406 }
 407
 408 void tipc_link_reset(struct tipc_link *l_ptr)
 409 {
 410         u32 prev_state = l_ptr->state;
 411         u32 checkpoint = l_ptr->next_in_no;
 412         int was_active_link = tipc_link_is_active(l_ptr);
 413
 414         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 415
 416         /* Link is down, accept any session */
 417         l_ptr->peer_session = INVALID_SESSION;
 418
 419         /* Prepare for max packet size negotiation */
 420         link_init_max_pkt(l_ptr);
 421
 422         l_ptr->state = RESET_UNKNOWN;
 423
 424         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 425                 return;
 426
 427         tipc_node_link_down(l_ptr->owner, l_ptr);
 428         tipc_bearer_remove_dest(l_ptr->b_ptr, l_ptr->addr);
 429
 430         if (was_active_link && tipc_node_active_links(l_ptr->owner)) {
 431                 l_ptr->reset_checkpoint = checkpoint;
 432                 l_ptr->exp_msg_count = START_CHANGEOVER;
 433         }
 434
 435         /* Clean up all queues: */
 436         link_release_outqueue(l_ptr);
 437         kfree_skb(l_ptr->proto_msg_queue);
 438         l_ptr->proto_msg_queue = NULL;
 439         kfree_skb_list(l_ptr->oldest_deferred_in);
 440         if (!list_empty(&l_ptr->waiting_ports))
 441                 tipc_link_wakeup_ports(l_ptr, 1);
 442
 443         l_ptr->retransm_queue_head = 0;
 444         l_ptr->retransm_queue_size = 0;
 445         l_ptr->last_out = NULL;
 446         l_ptr->first_out = NULL;
 447         l_ptr->next_out = NULL;
 448         l_ptr->unacked_window = 0;
 449         l_ptr->checkpoint = 1;
 450         l_ptr->next_out_no = 1;
 451         l_ptr->deferred_inqueue_sz = 0;
 452         l_ptr->oldest_deferred_in = NULL;
 453         l_ptr->newest_deferred_in = NULL;
 454         l_ptr->fsm_msg_cnt = 0;
 455         l_ptr->stale_count = 0;
 456         link_reset_statistics(l_ptr);
 457 }
 458
 459 void tipc_link_reset_list(unsigned int bearer_id)
 460 {
 461         struct tipc_link *l_ptr;
 462         struct tipc_node *n_ptr;
 463
 464         list_for_each_entry(n_ptr, &tipc_node_list, list) {
 465                 spin_lock_bh(&n_ptr->lock);
 466                 l_ptr = n_ptr->links[bearer_id];
 467                 if (l_ptr)
 468                         tipc_link_reset(l_ptr);
 469                 spin_unlock_bh(&n_ptr->lock);
 470         }
 471 }
 472
 473 static void link_activate(struct tipc_link *l_ptr)
 474 {
 475         l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
 476         tipc_node_link_up(l_ptr->owner, l_ptr);
 477         tipc_bearer_add_dest(l_ptr->b_ptr, l_ptr->addr);
 478 }
 479
 480 /**
 481  * link_state_event - link finite state machine
 482  * @l_ptr: pointer to link
 483  * @event: state machine event to process
 484  */
 485 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 486 {
 487         struct tipc_link *other;
 488         u32 cont_intv = l_ptr->continuity_interval;
 489
 490         if (l_ptr->flags & LINK_STOPPED)
 491                 return;
 492
 493         if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 494                 return;         /* Not yet. */
 495
 496         /* Check whether changeover is going on */
 497         if (l_ptr->exp_msg_count) {
 498                 if (event == TIMEOUT_EVT)
 499                         link_set_timer(l_ptr, cont_intv);
 500                 return;
 501         }
 502
 503         switch (l_ptr->state) {
 504         case WORKING_WORKING:
 505                 switch (event) {
 506                 case TRAFFIC_MSG_EVT:
 507                 case ACTIVATE_MSG:
 508                         break;
 509                 case TIMEOUT_EVT:
 510                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 511                                 l_ptr->checkpoint = l_ptr->next_in_no;
 512                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 513                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 514                                                              0, 0, 0, 0, 0);
 515                                         l_ptr->fsm_msg_cnt++;
 516                                 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
 517                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 518                                                              1, 0, 0, 0, 0);
 519                                         l_ptr->fsm_msg_cnt++;
 520                                 }
 521                                 link_set_timer(l_ptr, cont_intv);
 522                                 break;
 523                         }
 524                         l_ptr->state = WORKING_UNKNOWN;
 525                         l_ptr->fsm_msg_cnt = 0;
 526                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 527                         l_ptr->fsm_msg_cnt++;
 528                         link_set_timer(l_ptr, cont_intv / 4);
 529                         break;
 530                 case RESET_MSG:
 531                         pr_info("%s<%s>, requested by peer\n", link_rst_msg,
 532                                 l_ptr->name);
 533                         tipc_link_reset(l_ptr);
 534                         l_ptr->state = RESET_RESET;
 535                         l_ptr->fsm_msg_cnt = 0;
 536                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 537                                              0, 0, 0, 0, 0);
 538                         l_ptr->fsm_msg_cnt++;
 539                         link_set_timer(l_ptr, cont_intv);
 540                         break;
 541                 default:
 542                         pr_err("%s%u in WW state\n", link_unk_evt, event);
 543                 }
 544                 break;
 545         case WORKING_UNKNOWN:
 546                 switch (event) {
 547                 case TRAFFIC_MSG_EVT:
 548                 case ACTIVATE_MSG:
 549                         l_ptr->state = WORKING_WORKING;
 550                         l_ptr->fsm_msg_cnt = 0;
 551                         link_set_timer(l_ptr, cont_intv);
 552                         break;
 553                 case RESET_MSG:
 554                         pr_info("%s<%s>, requested by peer while probing\n",
 555                                 link_rst_msg, l_ptr->name);
 556                         tipc_link_reset(l_ptr);
 557                         l_ptr->state = RESET_RESET;
 558                         l_ptr->fsm_msg_cnt = 0;
 559                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 560                                              0, 0, 0, 0, 0);
 561                         l_ptr->fsm_msg_cnt++;
 562                         link_set_timer(l_ptr, cont_intv);
 563                         break;
 564                 case TIMEOUT_EVT:
 565                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 566                                 l_ptr->state = WORKING_WORKING;
 567                                 l_ptr->fsm_msg_cnt = 0;
 568                                 l_ptr->checkpoint = l_ptr->next_in_no;
 569                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 570                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 571                                                              0, 0, 0, 0, 0);
 572                                         l_ptr->fsm_msg_cnt++;
 573                                 }
 574                                 link_set_timer(l_ptr, cont_intv);
 575                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 576                                 tipc_link_proto_xmit(l_ptr, STATE_MSG,
 577                                                      1, 0, 0, 0, 0);
 578                                 l_ptr->fsm_msg_cnt++;
 579                                 link_set_timer(l_ptr, cont_intv / 4);
 580                         } else {        /* Link has failed */
 581                                 pr_warn("%s<%s>, peer not responding\n",
 582                                         link_rst_msg, l_ptr->name);
 583                                 tipc_link_reset(l_ptr);
 584                                 l_ptr->state = RESET_UNKNOWN;
 585                                 l_ptr->fsm_msg_cnt = 0;
 586                                 tipc_link_proto_xmit(l_ptr, RESET_MSG,
 587                                                      0, 0, 0, 0, 0);
 588                                 l_ptr->fsm_msg_cnt++;
 589                                 link_set_timer(l_ptr, cont_intv);
 590                         }
 591                         break;
 592                 default:
 593                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 594                 }
 595                 break;
 596         case RESET_UNKNOWN:
 597                 switch (event) {
 598                 case TRAFFIC_MSG_EVT:
 599                         break;
 600                 case ACTIVATE_MSG:
 601                         other = l_ptr->owner->active_links[0];
 602                         if (other && link_working_unknown(other))
 603                                 break;
 604                         l_ptr->state = WORKING_WORKING;
 605                         l_ptr->fsm_msg_cnt = 0;
 606                         link_activate(l_ptr);
 607                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 608                         l_ptr->fsm_msg_cnt++;
 609                         if (l_ptr->owner->working_links == 1)
 610                                 tipc_link_sync_xmit(l_ptr);
 611                         link_set_timer(l_ptr, cont_intv);
 612                         break;
 613                 case RESET_MSG:
 614                         l_ptr->state = RESET_RESET;
 615                         l_ptr->fsm_msg_cnt = 0;
 616                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 617                                              1, 0, 0, 0, 0);
 618                         l_ptr->fsm_msg_cnt++;
 619                         link_set_timer(l_ptr, cont_intv);
 620                         break;
 621                 case STARTING_EVT:
 622                         l_ptr->flags |= LINK_STARTED;
 623                         /* fall through */
 624                 case TIMEOUT_EVT:
 625                         tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
 626                         l_ptr->fsm_msg_cnt++;
 627                         link_set_timer(l_ptr, cont_intv);
 628                         break;
 629                 default:
 630                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 631                 }
 632                 break;
 633         case RESET_RESET:
 634                 switch (event) {
 635                 case TRAFFIC_MSG_EVT:
 636                 case ACTIVATE_MSG:
 637                         other = l_ptr->owner->active_links[0];
 638                         if (other && link_working_unknown(other))
 639                                 break;
 640                         l_ptr->state = WORKING_WORKING;
 641                         l_ptr->fsm_msg_cnt = 0;
 642                         link_activate(l_ptr);
 643                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 644                         l_ptr->fsm_msg_cnt++;
 645                         if (l_ptr->owner->working_links == 1)
 646                                 tipc_link_sync_xmit(l_ptr);
 647                         link_set_timer(l_ptr, cont_intv);
 648                         break;
 649                 case RESET_MSG:
 650                         break;
 651                 case TIMEOUT_EVT:
 652                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 653                                              0, 0, 0, 0, 0);
 654                         l_ptr->fsm_msg_cnt++;
 655                         link_set_timer(l_ptr, cont_intv);
 656                         break;
 657                 default:
 658                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 659                 }
 660                 break;
 661         default:
 662                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 663         }
 664 }
 665
 666 /*
 667  * link_bundle_buf(): Append contents of a buffer to
 668  * the tail of an existing one.
 669  */
 670 static int link_bundle_buf(struct tipc_link *l_ptr, struct sk_buff *bundler,
 671                            struct sk_buff *buf)
 672 {
 673         struct tipc_msg *bundler_msg = buf_msg(bundler);
 674         struct tipc_msg *msg = buf_msg(buf);
 675         u32 size = msg_size(msg);
 676         u32 bundle_size = msg_size(bundler_msg);
 677         u32 to_pos = align(bundle_size);
 678         u32 pad = to_pos - bundle_size;
 679
 680         if (msg_user(bundler_msg) != MSG_BUNDLER)
 681                 return 0;
 682         if (msg_type(bundler_msg) != OPEN_MSG)
 683                 return 0;
 684         if (skb_tailroom(bundler) < (pad + size))
 685                 return 0;
 686         if (l_ptr->max_pkt < (to_pos + size))
 687                 return 0;
 688
 689         skb_put(bundler, pad + size);
 690         skb_copy_to_linear_data_offset(bundler, to_pos, buf->data, size);
 691         msg_set_size(bundler_msg, to_pos + size);
 692         msg_set_msgcnt(bundler_msg, msg_msgcnt(bundler_msg) + 1);
 693         kfree_skb(buf);
 694         l_ptr->stats.sent_bundled++;
 695         return 1;
 696 }
 697
 698 static void link_add_to_outqueue(struct tipc_link *l_ptr,
 699                                  struct sk_buff *buf,
 700                                  struct tipc_msg *msg)
 701 {
 702         u32 ack = mod(l_ptr->next_in_no - 1);
 703         u32 seqno = mod(l_ptr->next_out_no++);
 704
 705         msg_set_word(msg, 2, ((ack << 16) | seqno));
 706         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 707         buf->next = NULL;
 708         if (l_ptr->first_out) {
 709                 l_ptr->last_out->next = buf;
 710                 l_ptr->last_out = buf;
 711         } else
 712                 l_ptr->first_out = l_ptr->last_out = buf;
 713
 714         l_ptr->out_queue_size++;
 715         if (l_ptr->out_queue_size > l_ptr->stats.max_queue_sz)
 716                 l_ptr->stats.max_queue_sz = l_ptr->out_queue_size;
 717 }
 718
 719 static void link_add_chain_to_outqueue(struct tipc_link *l_ptr,
 720                                        struct sk_buff *buf_chain,
 721                                        u32 long_msgno)
 722 {
 723         struct sk_buff *buf;
 724         struct tipc_msg *msg;
 725
 726         if (!l_ptr->next_out)
 727                 l_ptr->next_out = buf_chain;
 728         while (buf_chain) {
 729                 buf = buf_chain;
 730                 buf_chain = buf_chain->next;
 731
 732                 msg = buf_msg(buf);
 733                 msg_set_long_msgno(msg, long_msgno);
 734                 link_add_to_outqueue(l_ptr, buf, msg);
 735         }
 736 }
 737
 738 /*
 739  * tipc_link_xmit() is the 'full path' for messages, called from
 740  * inside TIPC when the 'fast path' in tipc_send_xmit
 741  * has failed, and from link_send()
 742  */
 743 int __tipc_link_xmit(struct tipc_link *l_ptr, struct sk_buff *buf)
 744 {
 745         struct tipc_msg *msg = buf_msg(buf);
 746         u32 size = msg_size(msg);
 747         u32 dsz = msg_data_sz(msg);
 748         u32 queue_size = l_ptr->out_queue_size;
 749         u32 imp = tipc_msg_tot_importance(msg);
 750         u32 queue_limit = l_ptr->queue_limit[imp];
 751         u32 max_packet = l_ptr->max_pkt;
 752
 753         /* Match msg importance against queue limits: */
 754         if (unlikely(queue_size >= queue_limit)) {
 755                 if (imp <= TIPC_CRITICAL_IMPORTANCE) {
 756                         link_schedule_port(l_ptr, msg_origport(msg), size);
 757                         kfree_skb(buf);
 758                         return -ELINKCONG;
 759                 }
 760                 kfree_skb(buf);
 761                 if (imp > CONN_MANAGER) {
 762                         pr_warn("%s<%s>, send queue full", link_rst_msg,
 763                                 l_ptr->name);
 764                         tipc_link_reset(l_ptr);
 765                 }
 766                 return dsz;
 767         }
 768
 769         /* Fragmentation needed ? */
 770         if (size > max_packet)
 771                 return tipc_link_frag_xmit(l_ptr, buf);
 772
 773         /* Packet can be queued or sent. */
 774         if (likely(!link_congested(l_ptr))) {
 775                 link_add_to_outqueue(l_ptr, buf, msg);
 776
 777                 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
 778                 l_ptr->unacked_window = 0;
 779                 return dsz;
 780         }
 781         /* Congestion: can message be bundled ? */
 782         if ((msg_user(msg) != CHANGEOVER_PROTOCOL) &&
 783             (msg_user(msg) != MSG_FRAGMENTER)) {
 784
 785                 /* Try adding message to an existing bundle */
 786                 if (l_ptr->next_out &&
 787                     link_bundle_buf(l_ptr, l_ptr->last_out, buf))
 788                         return dsz;
 789
 790                 /* Try creating a new bundle */
 791                 if (size <= max_packet * 2 / 3) {
 792                         struct sk_buff *bundler = tipc_buf_acquire(max_packet);
 793                         struct tipc_msg bundler_hdr;
 794
 795                         if (bundler) {
 796                                 tipc_msg_init(&bundler_hdr, MSG_BUNDLER, OPEN_MSG,
 797                                          INT_H_SIZE, l_ptr->addr);
 798                                 skb_copy_to_linear_data(bundler, &bundler_hdr,
 799                                                         INT_H_SIZE);
 800                                 skb_trim(bundler, INT_H_SIZE);
 801                                 link_bundle_buf(l_ptr, bundler, buf);
 802                                 buf = bundler;
 803                                 msg = buf_msg(buf);
 804                                 l_ptr->stats.sent_bundles++;
 805                         }
 806                 }
 807         }
 808         if (!l_ptr->next_out)
 809                 l_ptr->next_out = buf;
 810         link_add_to_outqueue(l_ptr, buf, msg);
 811         return dsz;
 812 }
 813
 814 /*
 815  * tipc_link_xmit(): same as __tipc_link_xmit(), but the link to use
 816  * has not been selected yet, and the the owner node is not locked
 817  * Called by TIPC internal users, e.g. the name distributor
 818  */
 819 int tipc_link_xmit(struct sk_buff *buf, u32 dest, u32 selector)
 820 {
 821         struct tipc_link *l_ptr;
 822         struct tipc_node *n_ptr;
 823         int res = -ELINKCONG;
 824
 825         read_lock_bh(&tipc_net_lock);
 826         n_ptr = tipc_node_find(dest);
 827         if (n_ptr) {
 828                 tipc_node_lock(n_ptr);
 829                 l_ptr = n_ptr->active_links[selector & 1];
 830                 if (l_ptr)
 831                         res = __tipc_link_xmit(l_ptr, buf);
 832                 else
 833                         kfree_skb(buf);
 834                 tipc_node_unlock(n_ptr);
 835         } else {
 836                 kfree_skb(buf);
 837         }
 838         read_unlock_bh(&tipc_net_lock);
 839         return res;
 840 }
 841
 842 /*
 843  * tipc_link_sync_xmit - synchronize broadcast link endpoints.
 844  *
 845  * Give a newly added peer node the sequence number where it should
 846  * start receiving and acking broadcast packets.
 847  *
 848  * Called with node locked
 849  */
 850 static void tipc_link_sync_xmit(struct tipc_link *l)
 851 {
 852         struct sk_buff *buf;
 853         struct tipc_msg *msg;
 854
 855         buf = tipc_buf_acquire(INT_H_SIZE);
 856         if (!buf)
 857                 return;
 858
 859         msg = buf_msg(buf);
 860         tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE, l->addr);
 861         msg_set_last_bcast(msg, l->owner->bclink.acked);
 862         link_add_chain_to_outqueue(l, buf, 0);
 863         tipc_link_push_queue(l);
 864 }
 865
 866 /*
 867  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 868  * Receive the sequence number where we should start receiving and
 869  * acking broadcast packets from a newly added peer node, and open
 870  * up for reception of such packets.
 871  *
 872  * Called with node locked
 873  */
 874 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 875 {
 876         struct tipc_msg *msg = buf_msg(buf);
 877
 878         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 879         n->bclink.recv_permitted = true;
 880         kfree_skb(buf);
 881 }
 882
 883 /*
 884  * tipc_link_names_xmit - send name table entries to new neighbor
 885  *
 886  * Send routine for bulk delivery of name table messages when contact
 887  * with a new neighbor occurs. No link congestion checking is performed
 888  * because name table messages *must* be delivered. The messages must be
 889  * small enough not to require fragmentation.
 890  * Called without any locks held.
 891  */
 892 void tipc_link_names_xmit(struct list_head *message_list, u32 dest)
 893 {
 894         struct tipc_node *n_ptr;
 895         struct tipc_link *l_ptr;
 896         struct sk_buff *buf;
 897         struct sk_buff *temp_buf;
 898
 899         if (list_empty(message_list))
 900                 return;
 901
 902         read_lock_bh(&tipc_net_lock);
 903         n_ptr = tipc_node_find(dest);
 904         if (n_ptr) {
 905                 tipc_node_lock(n_ptr);
 906                 l_ptr = n_ptr->active_links[0];
 907                 if (l_ptr) {
 908                         /* convert circular list to linear list */
 909                         ((struct sk_buff *)message_list->prev)->next = NULL;
 910                         link_add_chain_to_outqueue(l_ptr,
 911                                 (struct sk_buff *)message_list->next, 0);
 912                         tipc_link_push_queue(l_ptr);
 913                         INIT_LIST_HEAD(message_list);
 914                 }
 915                 tipc_node_unlock(n_ptr);
 916         }
 917         read_unlock_bh(&tipc_net_lock);
 918
 919         /* discard the messages if they couldn't be sent */
 920         list_for_each_safe(buf, temp_buf, ((struct sk_buff *)message_list)) {
 921                 list_del((struct list_head *)buf);
 922                 kfree_skb(buf);
 923         }
 924 }
 925
 926 /*
 927  * tipc_link_xmit_fast: Entry for data messages where the
 928  * destination link is known and the header is complete,
 929  * inclusive total message length. Very time critical.
 930  * Link is locked. Returns user data length.
 931  */
 932 static int tipc_link_xmit_fast(struct tipc_link *l_ptr, struct sk_buff *buf,
 933                                u32 *used_max_pkt)
 934 {
 935         struct tipc_msg *msg = buf_msg(buf);
 936         int res = msg_data_sz(msg);
 937
 938         if (likely(!link_congested(l_ptr))) {
 939                 if (likely(msg_size(msg) <= l_ptr->max_pkt)) {
 940                         link_add_to_outqueue(l_ptr, buf, msg);
 941                         tipc_bearer_send(l_ptr->b_ptr, buf,
 942                                          &l_ptr->media_addr);
 943                         l_ptr->unacked_window = 0;
 944                         return res;
 945                 }
 946                 else
 947                         *used_max_pkt = l_ptr->max_pkt;
 948         }
 949         return __tipc_link_xmit(l_ptr, buf);  /* All other cases */
 950 }
 951
 952 /*
 953  * tipc_link_iovec_xmit_fast: Entry for messages where the
 954  * destination processor is known and the header is complete,
 955  * except for total message length.
 956  * Returns user data length or errno.
 957  */
 958 int tipc_link_iovec_xmit_fast(struct tipc_port *sender,
 959                               struct iovec const *msg_sect,
 960                               unsigned int len, u32 destaddr)
 961 {
 962         struct tipc_msg *hdr = &sender->phdr;
 963         struct tipc_link *l_ptr;
 964         struct sk_buff *buf;
 965         struct tipc_node *node;
 966         int res;
 967         u32 selector = msg_origport(hdr) & 1;
 968
 969 again:
 970         /*
 971          * Try building message using port's max_pkt hint.
 972          * (Must not hold any locks while building message.)
 973          */
 974         res = tipc_msg_build(hdr, msg_sect, len, sender->max_pkt, &buf);
 975         /* Exit if build request was invalid */
 976         if (unlikely(res < 0))
 977                 return res;
 978
 979         read_lock_bh(&tipc_net_lock);
 980         node = tipc_node_find(destaddr);
 981         if (likely(node)) {
 982                 tipc_node_lock(node);
 983                 l_ptr = node->active_links[selector];
 984                 if (likely(l_ptr)) {
 985                         if (likely(buf)) {
 986                                 res = tipc_link_xmit_fast(l_ptr, buf,
 987                                                           &sender->max_pkt);
 988 exit:
 989                                 tipc_node_unlock(node);
 990                                 read_unlock_bh(&tipc_net_lock);
 991                                 return res;
 992                         }
 993
 994                         /* Exit if link (or bearer) is congested */
 995                         if (link_congested(l_ptr)) {
 996                                 res = link_schedule_port(l_ptr,
 997                                                          sender->ref, res);
 998                                 goto exit;
 999                         }
1000
1001                         /*
1002                          * Message size exceeds max_pkt hint; update hint,
1003                          * then re-try fast path or fragment the message
1004                          */
1005                         sender->max_pkt = l_ptr->max_pkt;
1006                         tipc_node_unlock(node);
1007                         read_unlock_bh(&tipc_net_lock);
1008
1009
1010                         if ((msg_hdr_sz(hdr) + res) <= sender->max_pkt)
1011                                 goto again;
1012
1013                         return tipc_link_iovec_long_xmit(sender, msg_sect,
1014                                                          len, destaddr);
1015                 }
1016                 tipc_node_unlock(node);
1017         }
1018         read_unlock_bh(&tipc_net_lock);
1019
1020         /* Couldn't find a link to the destination node */
1021         kfree_skb(buf);
1022         tipc_port_iovec_reject(sender, hdr, msg_sect, len, TIPC_ERR_NO_NODE);
1023         return -ENETUNREACH;
1024 }
1025
1026 /*
1027  * tipc_link_iovec_long_xmit(): Entry for long messages where the
1028  * destination node is known and the header is complete,
1029  * inclusive total message length.
1030  * Link and bearer congestion status have been checked to be ok,
1031  * and are ignored if they change.
1032  *
1033  * Note that fragments do not use the full link MTU so that they won't have
1034  * to undergo refragmentation if link changeover causes them to be sent
1035  * over another link with an additional tunnel header added as prefix.
1036  * (Refragmentation will still occur if the other link has a smaller MTU.)
1037  *
1038  * Returns user data length or errno.
1039  */
1040 static int tipc_link_iovec_long_xmit(struct tipc_port *sender,
1041                                      struct iovec const *msg_sect,
1042                                      unsigned int len, u32 destaddr)
1043 {
1044         struct tipc_link *l_ptr;
1045         struct tipc_node *node;
1046         struct tipc_msg *hdr = &sender->phdr;
1047         u32 dsz = len;
1048         u32 max_pkt, fragm_sz, rest;
1049         struct tipc_msg fragm_hdr;
1050         struct sk_buff *buf, *buf_chain, *prev;
1051         u32 fragm_crs, fragm_rest, hsz, sect_rest;
1052         const unchar __user *sect_crs;
1053         int curr_sect;
1054         u32 fragm_no;
1055         int res = 0;
1056
1057 again:
1058         fragm_no = 1;
1059         max_pkt = sender->max_pkt - INT_H_SIZE;
1060                 /* leave room for tunnel header in case of link changeover */
1061         fragm_sz = max_pkt - INT_H_SIZE;
1062                 /* leave room for fragmentation header in each fragment */
1063         rest = dsz;
1064         fragm_crs = 0;
1065         fragm_rest = 0;
1066         sect_rest = 0;
1067         sect_crs = NULL;
1068         curr_sect = -1;
1069
1070         /* Prepare reusable fragment header */
1071         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
1072                  INT_H_SIZE, msg_destnode(hdr));
1073         msg_set_size(&fragm_hdr, max_pkt);
1074         msg_set_fragm_no(&fragm_hdr, 1);
1075
1076         /* Prepare header of first fragment */
1077         buf_chain = buf = tipc_buf_acquire(max_pkt);
1078         if (!buf)
1079                 return -ENOMEM;
1080         buf->next = NULL;
1081         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1082         hsz = msg_hdr_sz(hdr);
1083         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, hdr, hsz);
1084
1085         /* Chop up message */
1086         fragm_crs = INT_H_SIZE + hsz;
1087         fragm_rest = fragm_sz - hsz;
1088
1089         do {            /* For all sections */
1090                 u32 sz;
1091
1092                 if (!sect_rest) {
1093                         sect_rest = msg_sect[++curr_sect].iov_len;
1094                         sect_crs = msg_sect[curr_sect].iov_base;
1095                 }
1096
1097                 if (sect_rest < fragm_rest)
1098                         sz = sect_rest;
1099                 else
1100                         sz = fragm_rest;
1101
1102                 if (copy_from_user(buf->data + fragm_crs, sect_crs, sz)) {
1103                         res = -EFAULT;
1104 error:
1105                         kfree_skb_list(buf_chain);
1106                         return res;
1107                 }
1108                 sect_crs += sz;
1109                 sect_rest -= sz;
1110                 fragm_crs += sz;
1111                 fragm_rest -= sz;
1112                 rest -= sz;
1113
1114                 if (!fragm_rest && rest) {
1115
1116                         /* Initiate new fragment: */
1117                         if (rest <= fragm_sz) {
1118                                 fragm_sz = rest;
1119                                 msg_set_type(&fragm_hdr, LAST_FRAGMENT);
1120                         } else {
1121                                 msg_set_type(&fragm_hdr, FRAGMENT);
1122                         }
1123                         msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
1124                         msg_set_fragm_no(&fragm_hdr, ++fragm_no);
1125                         prev = buf;
1126                         buf = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
1127                         if (!buf) {
1128                                 res = -ENOMEM;
1129                                 goto error;
1130                         }
1131
1132                         buf->next = NULL;
1133                         prev->next = buf;
1134                         skb_copy_to_linear_data(buf, &fragm_hdr, INT_H_SIZE);
1135                         fragm_crs = INT_H_SIZE;
1136                         fragm_rest = fragm_sz;
1137                 }
1138         } while (rest > 0);
1139
1140         /*
1141          * Now we have a buffer chain. Select a link and check
1142          * that packet size is still OK
1143          */
1144         node = tipc_node_find(destaddr);
1145         if (likely(node)) {
1146                 tipc_node_lock(node);
1147                 l_ptr = node->active_links[sender->ref & 1];
1148                 if (!l_ptr) {
1149                         tipc_node_unlock(node);
1150                         goto reject;
1151                 }
1152                 if (l_ptr->max_pkt < max_pkt) {
1153                         sender->max_pkt = l_ptr->max_pkt;
1154                         tipc_node_unlock(node);
1155                         kfree_skb_list(buf_chain);
1156                         goto again;
1157                 }
1158         } else {
1159 reject:
1160                 kfree_skb_list(buf_chain);
1161                 tipc_port_iovec_reject(sender, hdr, msg_sect, len,
1162                                        TIPC_ERR_NO_NODE);
1163                 return -ENETUNREACH;
1164         }
1165
1166         /* Append chain of fragments to send queue & send them */
1167         l_ptr->long_msg_seq_no++;
1168         link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
1169         l_ptr->stats.sent_fragments += fragm_no;
1170         l_ptr->stats.sent_fragmented++;
1171         tipc_link_push_queue(l_ptr);
1172         tipc_node_unlock(node);
1173         return dsz;
1174 }
1175
1176 /*
1177  * tipc_link_push_packet: Push one unsent packet to the media
1178  */
1179 static u32 tipc_link_push_packet(struct tipc_link *l_ptr)
1180 {
1181         struct sk_buff *buf = l_ptr->first_out;
1182         u32 r_q_size = l_ptr->retransm_queue_size;
1183         u32 r_q_head = l_ptr->retransm_queue_head;
1184
1185         /* Step to position where retransmission failed, if any,    */
1186         /* consider that buffers may have been released in meantime */
1187         if (r_q_size && buf) {
1188                 u32 last = lesser(mod(r_q_head + r_q_size),
1189                                   link_last_sent(l_ptr));
1190                 u32 first = buf_seqno(buf);
1191
1192                 while (buf && less(first, r_q_head)) {
1193                         first = mod(first + 1);
1194                         buf = buf->next;
1195                 }
1196                 l_ptr->retransm_queue_head = r_q_head = first;
1197                 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
1198         }
1199
1200         /* Continue retransmission now, if there is anything: */
1201         if (r_q_size && buf) {
1202                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1203                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1204                 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1205                 l_ptr->retransm_queue_head = mod(++r_q_head);
1206                 l_ptr->retransm_queue_size = --r_q_size;
1207                 l_ptr->stats.retransmitted++;
1208                 return 0;
1209         }
1210
1211         /* Send deferred protocol message, if any: */
1212         buf = l_ptr->proto_msg_queue;
1213         if (buf) {
1214                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
1215                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
1216                 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1217                 l_ptr->unacked_window = 0;
1218                 kfree_skb(buf);
1219                 l_ptr->proto_msg_queue = NULL;
1220                 return 0;
1221         }
1222
1223         /* Send one deferred data message, if send window not full: */
1224         buf = l_ptr->next_out;
1225         if (buf) {
1226                 struct tipc_msg *msg = buf_msg(buf);
1227                 u32 next = msg_seqno(msg);
1228                 u32 first = buf_seqno(l_ptr->first_out);
1229
1230                 if (mod(next - first) < l_ptr->queue_limit[0]) {
1231                         msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1232                         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1233                         tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1234                         if (msg_user(msg) == MSG_BUNDLER)
1235                                 msg_set_type(msg, CLOSED_MSG);
1236                         l_ptr->next_out = buf->next;
1237                         return 0;
1238                 }
1239         }
1240         return 1;
1241 }
1242
1243 /*
1244  * push_queue(): push out the unsent messages of a link where
1245  *               congestion has abated. Node is locked
1246  */
1247 void tipc_link_push_queue(struct tipc_link *l_ptr)
1248 {
1249         u32 res;
1250
1251         do {
1252                 res = tipc_link_push_packet(l_ptr);
1253         } while (!res);
1254 }
1255
1256 static void link_reset_all(unsigned long addr)
1257 {
1258         struct tipc_node *n_ptr;
1259         char addr_string[16];
1260         u32 i;
1261
1262         read_lock_bh(&tipc_net_lock);
1263         n_ptr = tipc_node_find((u32)addr);
1264         if (!n_ptr) {
1265                 read_unlock_bh(&tipc_net_lock);
1266                 return; /* node no longer exists */
1267         }
1268
1269         tipc_node_lock(n_ptr);
1270
1271         pr_warn("Resetting all links to %s\n",
1272                 tipc_addr_string_fill(addr_string, n_ptr->addr));
1273
1274         for (i = 0; i < MAX_BEARERS; i++) {
1275                 if (n_ptr->links[i]) {
1276                         link_print(n_ptr->links[i], "Resetting link\n");
1277                         tipc_link_reset(n_ptr->links[i]);
1278                 }
1279         }
1280
1281         tipc_node_unlock(n_ptr);
1282         read_unlock_bh(&tipc_net_lock);
1283 }
1284
1285 static void link_retransmit_failure(struct tipc_link *l_ptr,
1286                                     struct sk_buff *buf)
1287 {
1288         struct tipc_msg *msg = buf_msg(buf);
1289
1290         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
1291
1292         if (l_ptr->addr) {
1293                 /* Handle failure on standard link */
1294                 link_print(l_ptr, "Resetting link\n");
1295                 tipc_link_reset(l_ptr);
1296
1297         } else {
1298                 /* Handle failure on broadcast link */
1299                 struct tipc_node *n_ptr;
1300                 char addr_string[16];
1301
1302                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
1303                 pr_cont("Outstanding acks: %lu\n",
1304                         (unsigned long) TIPC_SKB_CB(buf)->handle);
1305
1306                 n_ptr = tipc_bclink_retransmit_to();
1307                 tipc_node_lock(n_ptr);
1308
1309                 tipc_addr_string_fill(addr_string, n_ptr->addr);
1310                 pr_info("Broadcast link info for %s\n", addr_string);
1311                 pr_info("Reception permitted: %d,  Acked: %u\n",
1312                         n_ptr->bclink.recv_permitted,
1313                         n_ptr->bclink.acked);
1314                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
1315                         n_ptr->bclink.last_in,
1316                         n_ptr->bclink.oos_state,
1317                         n_ptr->bclink.last_sent);
1318
1319                 tipc_k_signal((Handler)link_reset_all, (unsigned long)n_ptr->addr);
1320
1321                 tipc_node_unlock(n_ptr);
1322
1323                 l_ptr->stale_count = 0;
1324         }
1325 }
1326
1327 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *buf,
1328                           u32 retransmits)
1329 {
1330         struct tipc_msg *msg;
1331
1332         if (!buf)
1333                 return;
1334
1335         msg = buf_msg(buf);
1336
1337         /* Detect repeated retransmit failures */
1338         if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1339                 if (++l_ptr->stale_count > 100) {
1340                         link_retransmit_failure(l_ptr, buf);
1341                         return;
1342                 }
1343         } else {
1344                 l_ptr->last_retransmitted = msg_seqno(msg);
1345                 l_ptr->stale_count = 1;
1346         }
1347
1348         while (retransmits && (buf != l_ptr->next_out) && buf) {
1349                 msg = buf_msg(buf);
1350                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1351                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1352                 tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1353                 buf = buf->next;
1354                 retransmits--;
1355                 l_ptr->stats.retransmitted++;
1356         }
1357
1358         l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1359 }
1360
1361 /**
1362  * link_insert_deferred_queue - insert deferred messages back into receive chain
1363  */
1364 static struct sk_buff *link_insert_deferred_queue(struct tipc_link *l_ptr,
1365                                                   struct sk_buff *buf)
1366 {
1367         u32 seq_no;
1368
1369         if (l_ptr->oldest_deferred_in == NULL)
1370                 return buf;
1371
1372         seq_no = buf_seqno(l_ptr->oldest_deferred_in);
1373         if (seq_no == mod(l_ptr->next_in_no)) {
1374                 l_ptr->newest_deferred_in->next = buf;
1375                 buf = l_ptr->oldest_deferred_in;
1376                 l_ptr->oldest_deferred_in = NULL;
1377                 l_ptr->deferred_inqueue_sz = 0;
1378         }
1379         return buf;
1380 }
1381
1382 /**
1383  * link_recv_buf_validate - validate basic format of received message
1384  *
1385  * This routine ensures a TIPC message has an acceptable header, and at least
1386  * as much data as the header indicates it should.  The routine also ensures
1387  * that the entire message header is stored in the main fragment of the message
1388  * buffer, to simplify future access to message header fields.
1389  *
1390  * Note: Having extra info present in the message header or data areas is OK.
1391  * TIPC will ignore the excess, under the assumption that it is optional info
1392  * introduced by a later release of the protocol.
1393  */
1394 static int link_recv_buf_validate(struct sk_buff *buf)
1395 {
1396         static u32 min_data_hdr_size[8] = {
1397                 SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
1398                 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1399                 };
1400
1401         struct tipc_msg *msg;
1402         u32 tipc_hdr[2];
1403         u32 size;
1404         u32 hdr_size;
1405         u32 min_hdr_size;
1406
1407         /* If this packet comes from the defer queue, the skb has already
1408          * been validated
1409          */
1410         if (unlikely(TIPC_SKB_CB(buf)->deferred))
1411                 return 1;
1412
1413         if (unlikely(buf->len < MIN_H_SIZE))
1414                 return 0;
1415
1416         msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1417         if (msg == NULL)
1418                 return 0;
1419
1420         if (unlikely(msg_version(msg) != TIPC_VERSION))
1421                 return 0;
1422
1423         size = msg_size(msg);
1424         hdr_size = msg_hdr_sz(msg);
1425         min_hdr_size = msg_isdata(msg) ?
1426                 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1427
1428         if (unlikely((hdr_size < min_hdr_size) ||
1429                      (size < hdr_size) ||
1430                      (buf->len < size) ||
1431                      (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1432                 return 0;
1433
1434         return pskb_may_pull(buf, hdr_size);
1435 }
1436
1437 /**
1438  * tipc_rcv - process TIPC packets/messages arriving from off-node
1439  * @head: pointer to message buffer chain
1440  * @tb_ptr: pointer to bearer message arrived on
1441  *
1442  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1443  * structure (i.e. cannot be NULL), but bearer can be inactive.
1444  */
1445 void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
1446 {
1447         read_lock_bh(&tipc_net_lock);
1448         while (head) {
1449                 struct tipc_node *n_ptr;
1450                 struct tipc_link *l_ptr;
1451                 struct sk_buff *crs;
1452                 struct sk_buff *buf = head;
1453                 struct tipc_msg *msg;
1454                 u32 seq_no;
1455                 u32 ackd;
1456                 u32 released = 0;
1457
1458                 head = head->next;
1459                 buf->next = NULL;
1460
1461                 /* Ensure bearer is still enabled */
1462                 if (unlikely(!b_ptr->active))
1463                         goto discard;
1464
1465                 /* Ensure message is well-formed */
1466                 if (unlikely(!link_recv_buf_validate(buf)))
1467                         goto discard;
1468
1469                 /* Ensure message data is a single contiguous unit */
1470                 if (unlikely(skb_linearize(buf)))
1471                         goto discard;
1472
1473                 /* Handle arrival of a non-unicast link message */
1474                 msg = buf_msg(buf);
1475
1476                 if (unlikely(msg_non_seq(msg))) {
1477                         if (msg_user(msg) ==  LINK_CONFIG)
1478                                 tipc_disc_rcv(buf, b_ptr);
1479                         else
1480                                 tipc_bclink_rcv(buf);
1481                         continue;
1482                 }
1483
1484                 /* Discard unicast link messages destined for another node */
1485                 if (unlikely(!msg_short(msg) &&
1486                              (msg_destnode(msg) != tipc_own_addr)))
1487                         goto discard;
1488
1489                 /* Locate neighboring node that sent message */
1490                 n_ptr = tipc_node_find(msg_prevnode(msg));
1491                 if (unlikely(!n_ptr))
1492                         goto discard;
1493                 tipc_node_lock(n_ptr);
1494
1495                 /* Locate unicast link endpoint that should handle message */
1496                 l_ptr = n_ptr->links[b_ptr->identity];
1497                 if (unlikely(!l_ptr))
1498                         goto unlock_discard;
1499
1500                 /* Verify that communication with node is currently allowed */
1501                 if ((n_ptr->block_setup & WAIT_PEER_DOWN) &&
1502                         msg_user(msg) == LINK_PROTOCOL &&
1503                         (msg_type(msg) == RESET_MSG ||
1504                          msg_type(msg) == ACTIVATE_MSG) &&
1505                         !msg_redundant_link(msg))
1506                         n_ptr->block_setup &= ~WAIT_PEER_DOWN;
1507
1508                 if (n_ptr->block_setup)
1509                         goto unlock_discard;
1510
1511                 /* Validate message sequence number info */
1512                 seq_no = msg_seqno(msg);
1513                 ackd = msg_ack(msg);
1514
1515                 /* Release acked messages */
1516                 if (n_ptr->bclink.recv_permitted)
1517                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1518
1519                 crs = l_ptr->first_out;
1520                 while ((crs != l_ptr->next_out) &&
1521                        less_eq(buf_seqno(crs), ackd)) {
1522                         struct sk_buff *next = crs->next;
1523                         kfree_skb(crs);
1524                         crs = next;
1525                         released++;
1526                 }
1527                 if (released) {
1528                         l_ptr->first_out = crs;
1529                         l_ptr->out_queue_size -= released;
1530                 }
1531
1532                 /* Try sending any messages link endpoint has pending */
1533                 if (unlikely(l_ptr->next_out))
1534                         tipc_link_push_queue(l_ptr);
1535
1536                 if (unlikely(!list_empty(&l_ptr->waiting_ports)))
1537                         tipc_link_wakeup_ports(l_ptr, 0);
1538
1539                 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1540                         l_ptr->stats.sent_acks++;
1541                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1542                 }
1543
1544                 /* Process the incoming packet */
1545                 if (unlikely(!link_working_working(l_ptr))) {
1546                         if (msg_user(msg) == LINK_PROTOCOL) {
1547                                 tipc_link_proto_rcv(l_ptr, buf);
1548                                 head = link_insert_deferred_queue(l_ptr, head);
1549                                 tipc_node_unlock(n_ptr);
1550                                 continue;
1551                         }
1552
1553                         /* Traffic message. Conditionally activate link */
1554                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1555
1556                         if (link_working_working(l_ptr)) {
1557                                 /* Re-insert buffer in front of queue */
1558                                 buf->next = head;
1559                                 head = buf;
1560                                 tipc_node_unlock(n_ptr);
1561                                 continue;
1562                         }
1563                         goto unlock_discard;
1564                 }
1565
1566                 /* Link is now in state WORKING_WORKING */
1567                 if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
1568                         link_handle_out_of_seq_msg(l_ptr, buf);
1569                         head = link_insert_deferred_queue(l_ptr, head);
1570                         tipc_node_unlock(n_ptr);
1571                         continue;
1572                 }
1573                 l_ptr->next_in_no++;
1574                 if (unlikely(l_ptr->oldest_deferred_in))
1575                         head = link_insert_deferred_queue(l_ptr, head);
1576
1577                 /* Deliver packet/message to correct user: */
1578                 if (unlikely(msg_user(msg) ==  CHANGEOVER_PROTOCOL)) {
1579                         if (!tipc_link_tunnel_rcv(n_ptr, &buf)) {
1580                                 tipc_node_unlock(n_ptr);
1581                                 continue;
1582                         }
1583                         msg = buf_msg(buf);
1584                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
1585                         int rc;
1586
1587                         l_ptr->stats.recv_fragments++;
1588                         rc = tipc_link_frag_rcv(&l_ptr->reasm_head,
1589                                                 &l_ptr->reasm_tail,
1590                                                 &buf);
1591                         if (rc == LINK_REASM_COMPLETE) {
1592                                 l_ptr->stats.recv_fragmented++;
1593                                 msg = buf_msg(buf);
1594                         } else {
1595                                 if (rc == LINK_REASM_ERROR)
1596                                         tipc_link_reset(l_ptr);
1597                                 tipc_node_unlock(n_ptr);
1598                                 continue;
1599                         }
1600                 }
1601
1602                 switch (msg_user(msg)) {
1603                 case TIPC_LOW_IMPORTANCE:
1604                 case TIPC_MEDIUM_IMPORTANCE:
1605                 case TIPC_HIGH_IMPORTANCE:
1606                 case TIPC_CRITICAL_IMPORTANCE:
1607                         tipc_node_unlock(n_ptr);
1608                         tipc_port_rcv(buf);
1609                         continue;
1610                 case MSG_BUNDLER:
1611                         l_ptr->stats.recv_bundles++;
1612                         l_ptr->stats.recv_bundled += msg_msgcnt(msg);
1613                         tipc_node_unlock(n_ptr);
1614                         tipc_link_bundle_rcv(buf);
1615                         continue;
1616                 case NAME_DISTRIBUTOR:
1617                         n_ptr->bclink.recv_permitted = true;
1618                         tipc_node_unlock(n_ptr);
1619                         tipc_named_rcv(buf);
1620                         continue;
1621                 case CONN_MANAGER:
1622                         tipc_node_unlock(n_ptr);
1623                         tipc_port_proto_rcv(buf);
1624                         continue;
1625                 case BCAST_PROTOCOL:
1626                         tipc_link_sync_rcv(n_ptr, buf);
1627                         break;
1628                 default:
1629                         kfree_skb(buf);
1630                         break;
1631                 }
1632                 tipc_node_unlock(n_ptr);
1633                 continue;
1634 unlock_discard:
1635                 tipc_node_unlock(n_ptr);
1636 discard:
1637                 kfree_skb(buf);
1638         }
1639         read_unlock_bh(&tipc_net_lock);
1640 }
1641
1642 /**
1643  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1644  *
1645  * Returns increase in queue length (i.e. 0 or 1)
1646  */
1647 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
1648                         struct sk_buff *buf)
1649 {
1650         struct sk_buff *queue_buf;
1651         struct sk_buff **prev;
1652         u32 seq_no = buf_seqno(buf);
1653
1654         buf->next = NULL;
1655
1656         /* Empty queue ? */
1657         if (*head == NULL) {
1658                 *head = *tail = buf;
1659                 return 1;
1660         }
1661
1662         /* Last ? */
1663         if (less(buf_seqno(*tail), seq_no)) {
1664                 (*tail)->next = buf;
1665                 *tail = buf;
1666                 return 1;
1667         }
1668
1669         /* Locate insertion point in queue, then insert; discard if duplicate */
1670         prev = head;
1671         queue_buf = *head;
1672         for (;;) {
1673                 u32 curr_seqno = buf_seqno(queue_buf);
1674
1675                 if (seq_no == curr_seqno) {
1676                         kfree_skb(buf);
1677                         return 0;
1678                 }
1679
1680                 if (less(seq_no, curr_seqno))
1681                         break;
1682
1683                 prev = &queue_buf->next;
1684                 queue_buf = queue_buf->next;
1685         }
1686
1687         buf->next = queue_buf;
1688         *prev = buf;
1689         return 1;
1690 }
1691
1692 /*
1693  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1694  */
1695 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1696                                        struct sk_buff *buf)
1697 {
1698         u32 seq_no = buf_seqno(buf);
1699
1700         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1701                 tipc_link_proto_rcv(l_ptr, buf);
1702                 return;
1703         }
1704
1705         /* Record OOS packet arrival (force mismatch on next timeout) */
1706         l_ptr->checkpoint--;
1707
1708         /*
1709          * Discard packet if a duplicate; otherwise add it to deferred queue
1710          * and notify peer of gap as per protocol specification
1711          */
1712         if (less(seq_no, mod(l_ptr->next_in_no))) {
1713                 l_ptr->stats.duplicates++;
1714                 kfree_skb(buf);
1715                 return;
1716         }
1717
1718         if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
1719                                 &l_ptr->newest_deferred_in, buf)) {
1720                 l_ptr->deferred_inqueue_sz++;
1721                 l_ptr->stats.deferred_recv++;
1722                 TIPC_SKB_CB(buf)->deferred = true;
1723                 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
1724                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1725         } else
1726                 l_ptr->stats.duplicates++;
1727 }
1728
1729 /*
1730  * Send protocol message to the other endpoint.
1731  */
1732 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1733                           u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
1734 {
1735         struct sk_buff *buf = NULL;
1736         struct tipc_msg *msg = l_ptr->pmsg;
1737         u32 msg_size = sizeof(l_ptr->proto_msg);
1738         int r_flag;
1739
1740         /* Discard any previous message that was deferred due to congestion */
1741         if (l_ptr->proto_msg_queue) {
1742                 kfree_skb(l_ptr->proto_msg_queue);
1743                 l_ptr->proto_msg_queue = NULL;
1744         }
1745
1746         /* Don't send protocol message during link changeover */
1747         if (l_ptr->exp_msg_count)
1748                 return;
1749
1750         /* Abort non-RESET send if communication with node is prohibited */
1751         if ((l_ptr->owner->block_setup) && (msg_typ != RESET_MSG))
1752                 return;
1753
1754         /* Create protocol message with "out-of-sequence" sequence number */
1755         msg_set_type(msg, msg_typ);
1756         msg_set_net_plane(msg, l_ptr->b_ptr->net_plane);
1757         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1758         msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
1759
1760         if (msg_typ == STATE_MSG) {
1761                 u32 next_sent = mod(l_ptr->next_out_no);
1762
1763                 if (!tipc_link_is_up(l_ptr))
1764                         return;
1765                 if (l_ptr->next_out)
1766                         next_sent = buf_seqno(l_ptr->next_out);
1767                 msg_set_next_sent(msg, next_sent);
1768                 if (l_ptr->oldest_deferred_in) {
1769                         u32 rec = buf_seqno(l_ptr->oldest_deferred_in);
1770                         gap = mod(rec - mod(l_ptr->next_in_no));
1771                 }
1772                 msg_set_seq_gap(msg, gap);
1773                 if (gap)
1774                         l_ptr->stats.sent_nacks++;
1775                 msg_set_link_tolerance(msg, tolerance);
1776                 msg_set_linkprio(msg, priority);
1777                 msg_set_max_pkt(msg, ack_mtu);
1778                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1779                 msg_set_probe(msg, probe_msg != 0);
1780                 if (probe_msg) {
1781                         u32 mtu = l_ptr->max_pkt;
1782
1783                         if ((mtu < l_ptr->max_pkt_target) &&
1784                             link_working_working(l_ptr) &&
1785                             l_ptr->fsm_msg_cnt) {
1786                                 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1787                                 if (l_ptr->max_pkt_probes == 10) {
1788                                         l_ptr->max_pkt_target = (msg_size - 4);
1789                                         l_ptr->max_pkt_probes = 0;
1790                                         msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1791                                 }
1792                                 l_ptr->max_pkt_probes++;
1793                         }
1794
1795                         l_ptr->stats.sent_probes++;
1796                 }
1797                 l_ptr->stats.sent_states++;
1798         } else {                /* RESET_MSG or ACTIVATE_MSG */
1799                 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
1800                 msg_set_seq_gap(msg, 0);
1801                 msg_set_next_sent(msg, 1);
1802                 msg_set_probe(msg, 0);
1803                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1804                 msg_set_linkprio(msg, l_ptr->priority);
1805                 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
1806         }
1807
1808         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1809         msg_set_redundant_link(msg, r_flag);
1810         msg_set_linkprio(msg, l_ptr->priority);
1811         msg_set_size(msg, msg_size);
1812
1813         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1814
1815         buf = tipc_buf_acquire(msg_size);
1816         if (!buf)
1817                 return;
1818
1819         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1820         buf->priority = TC_PRIO_CONTROL;
1821
1822         tipc_bearer_send(l_ptr->b_ptr, buf, &l_ptr->media_addr);
1823         l_ptr->unacked_window = 0;
1824         kfree_skb(buf);
1825 }
1826
1827 /*
1828  * Receive protocol message :
1829  * Note that network plane id propagates through the network, and may
1830  * change at any time. The node with lowest address rules
1831  */
1832 static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf)
1833 {
1834         u32 rec_gap = 0;
1835         u32 max_pkt_info;
1836         u32 max_pkt_ack;
1837         u32 msg_tol;
1838         struct tipc_msg *msg = buf_msg(buf);
1839
1840         /* Discard protocol message during link changeover */
1841         if (l_ptr->exp_msg_count)
1842                 goto exit;
1843
1844         /* record unnumbered packet arrival (force mismatch on next timeout) */
1845         l_ptr->checkpoint--;
1846
1847         if (l_ptr->b_ptr->net_plane != msg_net_plane(msg))
1848                 if (tipc_own_addr > msg_prevnode(msg))
1849                         l_ptr->b_ptr->net_plane = msg_net_plane(msg);
1850
1851         switch (msg_type(msg)) {
1852
1853         case RESET_MSG:
1854                 if (!link_working_unknown(l_ptr) &&
1855                     (l_ptr->peer_session != INVALID_SESSION)) {
1856                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1857                                 break; /* duplicate or old reset: ignore */
1858                 }
1859
1860                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1861                                 link_working_unknown(l_ptr))) {
1862                         /*
1863                          * peer has lost contact -- don't allow peer's links
1864                          * to reactivate before we recognize loss & clean up
1865                          */
1866                         l_ptr->owner->block_setup = WAIT_NODE_DOWN;
1867                 }
1868
1869                 link_state_event(l_ptr, RESET_MSG);
1870
1871                 /* fall thru' */
1872         case ACTIVATE_MSG:
1873                 /* Update link settings according other endpoint's values */
1874                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1875
1876                 msg_tol = msg_link_tolerance(msg);
1877                 if (msg_tol > l_ptr->tolerance)
1878                         link_set_supervision_props(l_ptr, msg_tol);
1879
1880                 if (msg_linkprio(msg) > l_ptr->priority)
1881                         l_ptr->priority = msg_linkprio(msg);
1882
1883                 max_pkt_info = msg_max_pkt(msg);
1884                 if (max_pkt_info) {
1885                         if (max_pkt_info < l_ptr->max_pkt_target)
1886                                 l_ptr->max_pkt_target = max_pkt_info;
1887                         if (l_ptr->max_pkt > l_ptr->max_pkt_target)
1888                                 l_ptr->max_pkt = l_ptr->max_pkt_target;
1889                 } else {
1890                         l_ptr->max_pkt = l_ptr->max_pkt_target;
1891                 }
1892
1893                 /* Synchronize broadcast link info, if not done previously */
1894                 if (!tipc_node_is_up(l_ptr->owner)) {
1895                         l_ptr->owner->bclink.last_sent =
1896                                 l_ptr->owner->bclink.last_in =
1897                                 msg_last_bcast(msg);
1898                         l_ptr->owner->bclink.oos_state = 0;
1899                 }
1900
1901                 l_ptr->peer_session = msg_session(msg);
1902                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1903
1904                 if (msg_type(msg) == ACTIVATE_MSG)
1905                         link_state_event(l_ptr, ACTIVATE_MSG);
1906                 break;
1907         case STATE_MSG:
1908
1909                 msg_tol = msg_link_tolerance(msg);
1910                 if (msg_tol)
1911                         link_set_supervision_props(l_ptr, msg_tol);
1912
1913                 if (msg_linkprio(msg) &&
1914                     (msg_linkprio(msg) != l_ptr->priority)) {
1915                         pr_warn("%s<%s>, priority change %u->%u\n",
1916                                 link_rst_msg, l_ptr->name, l_ptr->priority,
1917                                 msg_linkprio(msg));
1918                         l_ptr->priority = msg_linkprio(msg);
1919                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1920                         break;
1921                 }
1922                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1923                 l_ptr->stats.recv_states++;
1924                 if (link_reset_unknown(l_ptr))
1925                         break;
1926
1927                 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
1928                         rec_gap = mod(msg_next_sent(msg) -
1929                                       mod(l_ptr->next_in_no));
1930                 }
1931
1932                 max_pkt_ack = msg_max_pkt(msg);
1933                 if (max_pkt_ack > l_ptr->max_pkt) {
1934                         l_ptr->max_pkt = max_pkt_ack;
1935                         l_ptr->max_pkt_probes = 0;
1936                 }
1937
1938                 max_pkt_ack = 0;
1939                 if (msg_probe(msg)) {
1940                         l_ptr->stats.recv_probes++;
1941                         if (msg_size(msg) > sizeof(l_ptr->proto_msg))
1942                                 max_pkt_ack = msg_size(msg);
1943                 }
1944
1945                 /* Protocol message before retransmits, reduce loss risk */
1946                 if (l_ptr->owner->bclink.recv_permitted)
1947                         tipc_bclink_update_link_state(l_ptr->owner,
1948                                                       msg_last_bcast(msg));
1949
1950                 if (rec_gap || (msg_probe(msg))) {
1951                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, rec_gap, 0,
1952                                              0, max_pkt_ack);
1953                 }
1954                 if (msg_seq_gap(msg)) {
1955                         l_ptr->stats.recv_nacks++;
1956                         tipc_link_retransmit(l_ptr, l_ptr->first_out,
1957                                              msg_seq_gap(msg));
1958                 }
1959                 break;
1960         }
1961 exit:
1962         kfree_skb(buf);
1963 }
1964
1965
1966 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1967  * a different bearer. Owner node is locked.
1968  */
1969 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1970                                   struct tipc_msg *tunnel_hdr,
1971                                   struct tipc_msg *msg,
1972                                   u32 selector)
1973 {
1974         struct tipc_link *tunnel;
1975         struct sk_buff *buf;
1976         u32 length = msg_size(msg);
1977
1978         tunnel = l_ptr->owner->active_links[selector & 1];
1979         if (!tipc_link_is_up(tunnel)) {
1980                 pr_warn("%stunnel link no longer available\n", link_co_err);
1981                 return;
1982         }
1983         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1984         buf = tipc_buf_acquire(length + INT_H_SIZE);
1985         if (!buf) {
1986                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1987                 return;
1988         }
1989         skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
1990         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
1991         __tipc_link_xmit(tunnel, buf);
1992 }
1993
1994
1995 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1996  * link is still active. We can do failover. Tunnel the failing link's
1997  * whole send queue via the remaining link. This way, we don't lose
1998  * any packets, and sequence order is preserved for subsequent traffic
1999  * sent over the remaining link. Owner node is locked.
2000  */
2001 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
2002 {
2003         u32 msgcount = l_ptr->out_queue_size;
2004         struct sk_buff *crs = l_ptr->first_out;
2005         struct tipc_link *tunnel = l_ptr->owner->active_links[0];
2006         struct tipc_msg tunnel_hdr;
2007         int split_bundles;
2008
2009         if (!tunnel)
2010                 return;
2011
2012         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2013                  ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
2014         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2015         msg_set_msgcnt(&tunnel_hdr, msgcount);
2016
2017         if (!l_ptr->first_out) {
2018                 struct sk_buff *buf;
2019
2020                 buf = tipc_buf_acquire(INT_H_SIZE);
2021                 if (buf) {
2022                         skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
2023                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
2024                         __tipc_link_xmit(tunnel, buf);
2025                 } else {
2026                         pr_warn("%sunable to send changeover msg\n",
2027                                 link_co_err);
2028                 }
2029                 return;
2030         }
2031
2032         split_bundles = (l_ptr->owner->active_links[0] !=
2033                          l_ptr->owner->active_links[1]);
2034
2035         while (crs) {
2036                 struct tipc_msg *msg = buf_msg(crs);
2037
2038                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
2039                         struct tipc_msg *m = msg_get_wrapped(msg);
2040                         unchar *pos = (unchar *)m;
2041
2042                         msgcount = msg_msgcnt(msg);
2043                         while (msgcount--) {
2044                                 msg_set_seqno(m, msg_seqno(msg));
2045                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
2046                                                       msg_link_selector(m));
2047                                 pos += align(msg_size(m));
2048                                 m = (struct tipc_msg *)pos;
2049                         }
2050                 } else {
2051                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
2052                                               msg_link_selector(msg));
2053                 }
2054                 crs = crs->next;
2055         }
2056 }
2057
2058 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
2059  * duplicate of the first link's send queue via the new link. This way, we
2060  * are guaranteed that currently queued packets from a socket are delivered
2061  * before future traffic from the same socket, even if this is using the
2062  * new link. The last arriving copy of each duplicate packet is dropped at
2063  * the receiving end by the regular protocol check, so packet cardinality
2064  * and sequence order is preserved per sender/receiver socket pair.
2065  * Owner node is locked.
2066  */
2067 void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr,
2068                               struct tipc_link *tunnel)
2069 {
2070         struct sk_buff *iter;
2071         struct tipc_msg tunnel_hdr;
2072
2073         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
2074                  DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
2075         msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
2076         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
2077         iter = l_ptr->first_out;
2078         while (iter) {
2079                 struct sk_buff *outbuf;
2080                 struct tipc_msg *msg = buf_msg(iter);
2081                 u32 length = msg_size(msg);
2082
2083                 if (msg_user(msg) == MSG_BUNDLER)
2084                         msg_set_type(msg, CLOSED_MSG);
2085                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));   /* Update */
2086                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
2087                 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
2088                 outbuf = tipc_buf_acquire(length + INT_H_SIZE);
2089                 if (outbuf == NULL) {
2090                         pr_warn("%sunable to send duplicate msg\n",
2091                                 link_co_err);
2092                         return;
2093                 }
2094                 skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
2095                 skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
2096                                                length);
2097                 __tipc_link_xmit(tunnel, outbuf);
2098                 if (!tipc_link_is_up(l_ptr))
2099                         return;
2100                 iter = iter->next;
2101         }
2102 }
2103
2104 /**
2105  * buf_extract - extracts embedded TIPC message from another message
2106  * @skb: encapsulating message buffer
2107  * @from_pos: offset to extract from
2108  *
2109  * Returns a new message buffer containing an embedded message.  The
2110  * encapsulating message itself is left unchanged.
2111  */
2112 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
2113 {
2114         struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
2115         u32 size = msg_size(msg);
2116         struct sk_buff *eb;
2117
2118         eb = tipc_buf_acquire(size);
2119         if (eb)
2120                 skb_copy_to_linear_data(eb, msg, size);
2121         return eb;
2122 }
2123
2124
2125
2126 /* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet.
2127  * Owner node is locked.
2128  */
2129 static void tipc_link_dup_rcv(struct tipc_link *l_ptr,
2130                               struct sk_buff *t_buf)
2131 {
2132         struct sk_buff *buf;
2133
2134         if (!tipc_link_is_up(l_ptr))
2135                 return;
2136
2137         buf = buf_extract(t_buf, INT_H_SIZE);
2138         if (buf == NULL) {
2139                 pr_warn("%sfailed to extract inner dup pkt\n", link_co_err);
2140                 return;
2141         }
2142
2143         /* Add buffer to deferred queue, if applicable: */
2144         link_handle_out_of_seq_msg(l_ptr, buf);
2145 }
2146
2147 /*  tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet
2148  *  Owner node is locked.
2149  */
2150 static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
2151                                               struct sk_buff *t_buf)
2152 {
2153         struct tipc_msg *t_msg = buf_msg(t_buf);
2154         struct sk_buff *buf = NULL;
2155         struct tipc_msg *msg;
2156
2157         if (tipc_link_is_up(l_ptr))
2158                 tipc_link_reset(l_ptr);
2159
2160         /* First failover packet? */
2161         if (l_ptr->exp_msg_count == START_CHANGEOVER)
2162                 l_ptr->exp_msg_count = msg_msgcnt(t_msg);
2163
2164         /* Should there be an inner packet? */
2165         if (l_ptr->exp_msg_count) {
2166                 l_ptr->exp_msg_count--;
2167                 buf = buf_extract(t_buf, INT_H_SIZE);
2168                 if (buf == NULL) {
2169                         pr_warn("%sno inner failover pkt\n", link_co_err);
2170                         goto exit;
2171                 }
2172                 msg = buf_msg(buf);
2173
2174                 if (less(msg_seqno(msg), l_ptr->reset_checkpoint)) {
2175                         kfree_skb(buf);
2176                         buf = NULL;
2177                         goto exit;
2178                 }
2179                 if (msg_user(msg) == MSG_FRAGMENTER) {
2180                         l_ptr->stats.recv_fragments++;
2181                         tipc_link_frag_rcv(&l_ptr->reasm_head,
2182                                            &l_ptr->reasm_tail,
2183                                            &buf);
2184                 }
2185         }
2186 exit:
2187         if ((l_ptr->exp_msg_count == 0) && (l_ptr->flags & LINK_STOPPED)) {
2188                 tipc_node_detach_link(l_ptr->owner, l_ptr);
2189                 kfree(l_ptr);
2190         }
2191         return buf;
2192 }
2193
2194 /*  tipc_link_tunnel_rcv(): Receive a tunnelled packet, sent
2195  *  via other link as result of a failover (ORIGINAL_MSG) or
2196  *  a new active link (DUPLICATE_MSG). Failover packets are
2197  *  returned to the active link for delivery upwards.
2198  *  Owner node is locked.
2199  */
2200 static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr,
2201                                 struct sk_buff **buf)
2202 {
2203         struct sk_buff *t_buf = *buf;
2204         struct tipc_link *l_ptr;
2205         struct tipc_msg *t_msg = buf_msg(t_buf);
2206         u32 bearer_id = msg_bearer_id(t_msg);
2207
2208         *buf = NULL;
2209
2210         if (bearer_id >= MAX_BEARERS)
2211                 goto exit;
2212
2213         l_ptr = n_ptr->links[bearer_id];
2214         if (!l_ptr)
2215                 goto exit;
2216
2217         if (msg_type(t_msg) == DUPLICATE_MSG)
2218                 tipc_link_dup_rcv(l_ptr, t_buf);
2219         else if (msg_type(t_msg) == ORIGINAL_MSG)
2220                 *buf = tipc_link_failover_rcv(l_ptr, t_buf);
2221         else
2222                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
2223 exit:
2224         kfree_skb(t_buf);
2225         return *buf != NULL;
2226 }
2227
2228 /*
2229  *  Bundler functionality:
2230  */
2231 void tipc_link_bundle_rcv(struct sk_buff *buf)
2232 {
2233         u32 msgcount = msg_msgcnt(buf_msg(buf));
2234         u32 pos = INT_H_SIZE;
2235         struct sk_buff *obuf;
2236
2237         while (msgcount--) {
2238                 obuf = buf_extract(buf, pos);
2239                 if (obuf == NULL) {
2240                         pr_warn("Link unable to unbundle message(s)\n");
2241                         break;
2242                 }
2243                 pos += align(msg_size(buf_msg(obuf)));
2244                 tipc_net_route_msg(obuf);
2245         }
2246         kfree_skb(buf);
2247 }
2248
2249 /*
2250  *  Fragmentation/defragmentation:
2251  */
2252
2253 /*
2254  * tipc_link_frag_xmit: Entry for buffers needing fragmentation.
2255  * The buffer is complete, inclusive total message length.
2256  * Returns user data length.
2257  */
2258 static int tipc_link_frag_xmit(struct tipc_link *l_ptr, struct sk_buff *buf)
2259 {
2260         struct sk_buff *buf_chain = NULL;
2261         struct sk_buff *buf_chain_tail = (struct sk_buff *)&buf_chain;
2262         struct tipc_msg *inmsg = buf_msg(buf);
2263         struct tipc_msg fragm_hdr;
2264         u32 insize = msg_size(inmsg);
2265         u32 dsz = msg_data_sz(inmsg);
2266         unchar *crs = buf->data;
2267         u32 rest = insize;
2268         u32 pack_sz = l_ptr->max_pkt;
2269         u32 fragm_sz = pack_sz - INT_H_SIZE;
2270         u32 fragm_no = 0;
2271         u32 destaddr;
2272
2273         if (msg_short(inmsg))
2274                 destaddr = l_ptr->addr;
2275         else
2276                 destaddr = msg_destnode(inmsg);
2277
2278         /* Prepare reusable fragment header: */
2279         tipc_msg_init(&fragm_hdr, MSG_FRAGMENTER, FIRST_FRAGMENT,
2280                  INT_H_SIZE, destaddr);
2281
2282         /* Chop up message: */
2283         while (rest > 0) {
2284                 struct sk_buff *fragm;
2285
2286                 if (rest <= fragm_sz) {
2287                         fragm_sz = rest;
2288                         msg_set_type(&fragm_hdr, LAST_FRAGMENT);
2289                 }
2290                 fragm = tipc_buf_acquire(fragm_sz + INT_H_SIZE);
2291                 if (fragm == NULL) {
2292                         kfree_skb(buf);
2293                         kfree_skb_list(buf_chain);
2294                         return -ENOMEM;
2295                 }
2296                 msg_set_size(&fragm_hdr, fragm_sz + INT_H_SIZE);
2297                 fragm_no++;
2298                 msg_set_fragm_no(&fragm_hdr, fragm_no);
2299                 skb_copy_to_linear_data(fragm, &fragm_hdr, INT_H_SIZE);
2300                 skb_copy_to_linear_data_offset(fragm, INT_H_SIZE, crs,
2301                                                fragm_sz);
2302                 buf_chain_tail->next = fragm;
2303                 buf_chain_tail = fragm;
2304
2305                 rest -= fragm_sz;
2306                 crs += fragm_sz;
2307                 msg_set_type(&fragm_hdr, FRAGMENT);
2308         }
2309         kfree_skb(buf);
2310
2311         /* Append chain of fragments to send queue & send them */
2312         l_ptr->long_msg_seq_no++;
2313         link_add_chain_to_outqueue(l_ptr, buf_chain, l_ptr->long_msg_seq_no);
2314         l_ptr->stats.sent_fragments += fragm_no;
2315         l_ptr->stats.sent_fragmented++;
2316         tipc_link_push_queue(l_ptr);
2317
2318         return dsz;
2319 }
2320
2321 /* tipc_link_frag_rcv(): Called with node lock on. Returns
2322  * the reassembled buffer if message is complete.
2323  */
2324 int tipc_link_frag_rcv(struct sk_buff **head, struct sk_buff **tail,
2325                        struct sk_buff **fbuf)
2326 {
2327         struct sk_buff *frag = *fbuf;
2328         struct tipc_msg *msg = buf_msg(frag);
2329         u32 fragid = msg_type(msg);
2330         bool headstolen;
2331         int delta;
2332
2333         skb_pull(frag, msg_hdr_sz(msg));
2334         if (fragid == FIRST_FRAGMENT) {
2335                 if (*head || skb_unclone(frag, GFP_ATOMIC))
2336                         goto out_free;
2337                 *head = frag;
2338                 skb_frag_list_init(*head);
2339                 *fbuf = NULL;
2340                 return 0;
2341         } else if (*head &&
2342                    skb_try_coalesce(*head, frag, &headstolen, &delta)) {
2343                 kfree_skb_partial(frag, headstolen);
2344         } else {
2345                 if (!*head)
2346                         goto out_free;
2347                 if (!skb_has_frag_list(*head))
2348                         skb_shinfo(*head)->frag_list = frag;
2349                 else
2350                         (*tail)->next = frag;
2351                 *tail = frag;
2352                 (*head)->truesize += frag->truesize;
2353         }
2354         if (fragid == LAST_FRAGMENT) {
2355                 *fbuf = *head;
2356                 *tail = *head = NULL;
2357                 return LINK_REASM_COMPLETE;
2358         }
2359         *fbuf = NULL;
2360         return 0;
2361 out_free:
2362         pr_warn_ratelimited("Link unable to reassemble fragmented message\n");
2363         kfree_skb(*fbuf);
2364         *fbuf = NULL;
2365         return LINK_REASM_ERROR;
2366 }
2367
2368 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
2369 {
2370         if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
2371                 return;
2372
2373         l_ptr->tolerance = tolerance;
2374         l_ptr->continuity_interval =
2375                 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
2376         l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
2377 }
2378
2379 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
2380 {
2381         /* Data messages from this node, inclusive FIRST_FRAGM */
2382         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
2383         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
2384         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
2385         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
2386         /* Transiting data messages,inclusive FIRST_FRAGM */
2387         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
2388         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
2389         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
2390         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
2391         l_ptr->queue_limit[CONN_MANAGER] = 1200;
2392         l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
2393         l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
2394         /* FRAGMENT and LAST_FRAGMENT packets */
2395         l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
2396 }
2397
2398 /* tipc_link_find_owner - locate owner node of link by link's name
2399  * @name: pointer to link name string
2400  * @bearer_id: pointer to index in 'node->links' array where the link was found.
2401  * Caller must hold 'tipc_net_lock' to ensure node and bearer are not deleted;
2402  * this also prevents link deletion.
2403  *
2404  * Returns pointer to node owning the link, or 0 if no matching link is found.
2405  */
2406 static struct tipc_node *tipc_link_find_owner(const char *link_name,
2407                                               unsigned int *bearer_id)
2408 {
2409         struct tipc_link *l_ptr;
2410         struct tipc_node *n_ptr;
2411         struct tipc_node *tmp_n_ptr;
2412         struct tipc_node *found_node = 0;
2413
2414         int i;
2415
2416         *bearer_id = 0;
2417         list_for_each_entry_safe(n_ptr, tmp_n_ptr, &tipc_node_list, list) {
2418                 tipc_node_lock(n_ptr);
2419                 for (i = 0; i < MAX_BEARERS; i++) {
2420                         l_ptr = n_ptr->links[i];
2421                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
2422                                 *bearer_id = i;
2423                                 found_node = n_ptr;
2424                                 break;
2425                         }
2426                 }
2427                 tipc_node_unlock(n_ptr);
2428                 if (found_node)
2429                         break;
2430         }
2431         return found_node;
2432 }
2433
2434 /**
2435  * link_value_is_valid -- validate proposed link tolerance/priority/window
2436  *
2437  * @cmd: value type (TIPC_CMD_SET_LINK_*)
2438  * @new_value: the new value
2439  *
2440  * Returns 1 if value is within range, 0 if not.
2441  */
2442 static int link_value_is_valid(u16 cmd, u32 new_value)
2443 {
2444         switch (cmd) {
2445         case TIPC_CMD_SET_LINK_TOL:
2446                 return (new_value >= TIPC_MIN_LINK_TOL) &&
2447                         (new_value <= TIPC_MAX_LINK_TOL);
2448         case TIPC_CMD_SET_LINK_PRI:
2449                 return (new_value <= TIPC_MAX_LINK_PRI);
2450         case TIPC_CMD_SET_LINK_WINDOW:
2451                 return (new_value >= TIPC_MIN_LINK_WIN) &&
2452                         (new_value <= TIPC_MAX_LINK_WIN);
2453         }
2454         return 0;
2455 }
2456
2457 /**
2458  * link_cmd_set_value - change priority/tolerance/window for link/bearer/media
2459  * @name: ptr to link, bearer, or media name
2460  * @new_value: new value of link, bearer, or media setting
2461  * @cmd: which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*)
2462  *
2463  * Caller must hold 'tipc_net_lock' to ensure link/bearer/media is not deleted.
2464  *
2465  * Returns 0 if value updated and negative value on error.
2466  */
2467 static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
2468 {
2469         struct tipc_node *node;
2470         struct tipc_link *l_ptr;
2471         struct tipc_bearer *b_ptr;
2472         struct tipc_media *m_ptr;
2473         int bearer_id;
2474         int res = 0;
2475
2476         node = tipc_link_find_owner(name, &bearer_id);
2477         if (node) {
2478                 tipc_node_lock(node);
2479                 l_ptr = node->links[bearer_id];
2480
2481                 if (l_ptr) {
2482                         switch (cmd) {
2483                         case TIPC_CMD_SET_LINK_TOL:
2484                                 link_set_supervision_props(l_ptr, new_value);
2485                                 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2486                                                      new_value, 0, 0);
2487                                 break;
2488                         case TIPC_CMD_SET_LINK_PRI:
2489                                 l_ptr->priority = new_value;
2490                                 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2491                                                      0, new_value, 0);
2492                                 break;
2493                         case TIPC_CMD_SET_LINK_WINDOW:
2494                                 tipc_link_set_queue_limits(l_ptr, new_value);
2495                                 break;
2496                         default:
2497                                 res = -EINVAL;
2498                                 break;
2499                         }
2500                 }
2501                 tipc_node_unlock(node);
2502                 return res;
2503         }
2504
2505         b_ptr = tipc_bearer_find(name);
2506         if (b_ptr) {
2507                 switch (cmd) {
2508                 case TIPC_CMD_SET_LINK_TOL:
2509                         b_ptr->tolerance = new_value;
2510                         break;
2511                 case TIPC_CMD_SET_LINK_PRI:
2512                         b_ptr->priority = new_value;
2513                         break;
2514                 case TIPC_CMD_SET_LINK_WINDOW:
2515                         b_ptr->window = new_value;
2516                         break;
2517                 default:
2518                         res = -EINVAL;
2519                         break;
2520                 }
2521                 return res;
2522         }
2523
2524         m_ptr = tipc_media_find(name);
2525         if (!m_ptr)
2526                 return -ENODEV;
2527         switch (cmd) {
2528         case TIPC_CMD_SET_LINK_TOL:
2529                 m_ptr->tolerance = new_value;
2530                 break;
2531         case TIPC_CMD_SET_LINK_PRI:
2532                 m_ptr->priority = new_value;
2533                 break;
2534         case TIPC_CMD_SET_LINK_WINDOW:
2535                 m_ptr->window = new_value;
2536                 break;
2537         default:
2538                 res = -EINVAL;
2539                 break;
2540         }
2541         return res;
2542 }
2543
2544 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2545                                      u16 cmd)
2546 {
2547         struct tipc_link_config *args;
2548         u32 new_value;
2549         int res;
2550
2551         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2552                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2553
2554         args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2555         new_value = ntohl(args->value);
2556
2557         if (!link_value_is_valid(cmd, new_value))
2558                 return tipc_cfg_reply_error_string(
2559                         "cannot change, value invalid");
2560
2561         if (!strcmp(args->name, tipc_bclink_name)) {
2562                 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2563                     (tipc_bclink_set_queue_limits(new_value) == 0))
2564                         return tipc_cfg_reply_none();
2565                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2566                                                    " (cannot change setting on broadcast link)");
2567         }
2568
2569         read_lock_bh(&tipc_net_lock);
2570         res = link_cmd_set_value(args->name, new_value, cmd);
2571         read_unlock_bh(&tipc_net_lock);
2572         if (res)
2573                 return tipc_cfg_reply_error_string("cannot change link setting");
2574
2575         return tipc_cfg_reply_none();
2576 }
2577
2578 /**
2579  * link_reset_statistics - reset link statistics
2580  * @l_ptr: pointer to link
2581  */
2582 static void link_reset_statistics(struct tipc_link *l_ptr)
2583 {
2584         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2585         l_ptr->stats.sent_info = l_ptr->next_out_no;
2586         l_ptr->stats.recv_info = l_ptr->next_in_no;
2587 }
2588
2589 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2590 {
2591         char *link_name;
2592         struct tipc_link *l_ptr;
2593         struct tipc_node *node;
2594         unsigned int bearer_id;
2595
2596         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2597                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2598
2599         link_name = (char *)TLV_DATA(req_tlv_area);
2600         if (!strcmp(link_name, tipc_bclink_name)) {
2601                 if (tipc_bclink_reset_stats())
2602                         return tipc_cfg_reply_error_string("link not found");
2603                 return tipc_cfg_reply_none();
2604         }
2605         read_lock_bh(&tipc_net_lock);
2606         node = tipc_link_find_owner(link_name, &bearer_id);
2607         if (!node) {
2608                 read_unlock_bh(&tipc_net_lock);
2609                 return tipc_cfg_reply_error_string("link not found");
2610         }
2611         tipc_node_lock(node);
2612         l_ptr = node->links[bearer_id];
2613         if (!l_ptr) {
2614                 tipc_node_unlock(node);
2615                 read_unlock_bh(&tipc_net_lock);
2616                 return tipc_cfg_reply_error_string("link not found");
2617         }
2618         link_reset_statistics(l_ptr);
2619         tipc_node_unlock(node);
2620         read_unlock_bh(&tipc_net_lock);
2621         return tipc_cfg_reply_none();
2622 }
2623
2624 /**
2625  * percent - convert count to a percentage of total (rounding up or down)
2626  */
2627 static u32 percent(u32 count, u32 total)
2628 {
2629         return (count * 100 + (total / 2)) / total;
2630 }
2631
2632 /**
2633  * tipc_link_stats - print link statistics
2634  * @name: link name
2635  * @buf: print buffer area
2636  * @buf_size: size of print buffer area
2637  *
2638  * Returns length of print buffer data string (or 0 if error)
2639  */
2640 static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
2641 {
2642         struct tipc_link *l;
2643         struct tipc_stats *s;
2644         struct tipc_node *node;
2645         char *status;
2646         u32 profile_total = 0;
2647         unsigned int bearer_id;
2648         int ret;
2649
2650         if (!strcmp(name, tipc_bclink_name))
2651                 return tipc_bclink_stats(buf, buf_size);
2652
2653         read_lock_bh(&tipc_net_lock);
2654         node = tipc_link_find_owner(name, &bearer_id);
2655         if (!node) {
2656                 read_unlock_bh(&tipc_net_lock);
2657                 return 0;
2658         }
2659         tipc_node_lock(node);
2660
2661         l = node->links[bearer_id];
2662         if (!l) {
2663                 tipc_node_unlock(node);
2664                 read_unlock_bh(&tipc_net_lock);
2665                 return 0;
2666         }
2667
2668         s = &l->stats;
2669
2670         if (tipc_link_is_active(l))
2671                 status = "ACTIVE";
2672         else if (tipc_link_is_up(l))
2673                 status = "STANDBY";
2674         else
2675                 status = "DEFUNCT";
2676
2677         ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
2678                             "  %s  MTU:%u  Priority:%u  Tolerance:%u ms"
2679                             "  Window:%u packets\n",
2680                             l->name, status, l->max_pkt, l->priority,
2681                             l->tolerance, l->queue_limit[0]);
2682
2683         ret += tipc_snprintf(buf + ret, buf_size - ret,
2684                              "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2685                              l->next_in_no - s->recv_info, s->recv_fragments,
2686                              s->recv_fragmented, s->recv_bundles,
2687                              s->recv_bundled);
2688
2689         ret += tipc_snprintf(buf + ret, buf_size - ret,
2690                              "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2691                              l->next_out_no - s->sent_info, s->sent_fragments,
2692                              s->sent_fragmented, s->sent_bundles,
2693                              s->sent_bundled);
2694
2695         profile_total = s->msg_length_counts;
2696         if (!profile_total)
2697                 profile_total = 1;
2698
2699         ret += tipc_snprintf(buf + ret, buf_size - ret,
2700                              "  TX profile sample:%u packets  average:%u octets\n"
2701                              "  0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
2702                              "-16384:%u%% -32768:%u%% -66000:%u%%\n",
2703                              s->msg_length_counts,
2704                              s->msg_lengths_total / profile_total,
2705                              percent(s->msg_length_profile[0], profile_total),
2706                              percent(s->msg_length_profile[1], profile_total),
2707                              percent(s->msg_length_profile[2], profile_total),
2708                              percent(s->msg_length_profile[3], profile_total),
2709                              percent(s->msg_length_profile[4], profile_total),
2710                              percent(s->msg_length_profile[5], profile_total),
2711                              percent(s->msg_length_profile[6], profile_total));
2712
2713         ret += tipc_snprintf(buf + ret, buf_size - ret,
2714                              "  RX states:%u probes:%u naks:%u defs:%u"
2715                              " dups:%u\n", s->recv_states, s->recv_probes,
2716                              s->recv_nacks, s->deferred_recv, s->duplicates);
2717
2718         ret += tipc_snprintf(buf + ret, buf_size - ret,
2719                              "  TX states:%u probes:%u naks:%u acks:%u"
2720                              " dups:%u\n", s->sent_states, s->sent_probes,
2721                              s->sent_nacks, s->sent_acks, s->retransmitted);
2722
2723         ret += tipc_snprintf(buf + ret, buf_size - ret,
2724                              "  Congestion link:%u  Send queue"
2725                              " max:%u avg:%u\n", s->link_congs,
2726                              s->max_queue_sz, s->queue_sz_counts ?
2727                              (s->accu_queue_sz / s->queue_sz_counts) : 0);
2728
2729         tipc_node_unlock(node);
2730         read_unlock_bh(&tipc_net_lock);
2731         return ret;
2732 }
2733
2734 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
2735 {
2736         struct sk_buff *buf;
2737         struct tlv_desc *rep_tlv;
2738         int str_len;
2739         int pb_len;
2740         char *pb;
2741
2742         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2743                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2744
2745         buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
2746         if (!buf)
2747                 return NULL;
2748
2749         rep_tlv = (struct tlv_desc *)buf->data;
2750         pb = TLV_DATA(rep_tlv);
2751         pb_len = ULTRA_STRING_MAX_LEN;
2752         str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
2753                                   pb, pb_len);
2754         if (!str_len) {
2755                 kfree_skb(buf);
2756                 return tipc_cfg_reply_error_string("link not found");
2757         }
2758         str_len += 1;   /* for "\0" */
2759         skb_put(buf, TLV_SPACE(str_len));
2760         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
2761
2762         return buf;
2763 }
2764
2765 /**
2766  * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
2767  * @dest: network address of destination node
2768  * @selector: used to select from set of active links
2769  *
2770  * If no active link can be found, uses default maximum packet size.
2771  */
2772 u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
2773 {
2774         struct tipc_node *n_ptr;
2775         struct tipc_link *l_ptr;
2776         u32 res = MAX_PKT_DEFAULT;
2777
2778         if (dest == tipc_own_addr)
2779                 return MAX_MSG_SIZE;
2780
2781         read_lock_bh(&tipc_net_lock);
2782         n_ptr = tipc_node_find(dest);
2783         if (n_ptr) {
2784                 tipc_node_lock(n_ptr);
2785                 l_ptr = n_ptr->active_links[selector & 1];
2786                 if (l_ptr)
2787                         res = l_ptr->max_pkt;
2788                 tipc_node_unlock(n_ptr);
2789         }
2790         read_unlock_bh(&tipc_net_lock);
2791         return res;
2792 }
2793
2794 static void link_print(struct tipc_link *l_ptr, const char *str)
2795 {
2796         pr_info("%s Link %x<%s>:", str, l_ptr->addr, l_ptr->b_ptr->name);
2797
2798         if (link_working_unknown(l_ptr))
2799                 pr_cont(":WU\n");
2800         else if (link_reset_reset(l_ptr))
2801                 pr_cont(":RR\n");
2802         else if (link_reset_unknown(l_ptr))
2803                 pr_cont(":RU\n");
2804         else if (link_working_working(l_ptr))
2805                 pr_cont(":WW\n");
2806         else
2807                 pr_cont("\n");
2808 }