net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, 2012-2015, 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 "subscr.h"
  39 #include "link.h"
  40 #include "bcast.h"
  41 #include "socket.h"
  42 #include "name_distr.h"
  43 #include "discover.h"
  44 #include "netlink.h"
  45
  46 #include <linux/pkt_sched.h>
  47
  48 /*
  49  * Error message prefixes
  50  */
  51 static const char *link_co_err = "Link tunneling error, ";
  52 static const char *link_rst_msg = "Resetting link ";
  53 static const char tipc_bclink_name[] = "broadcast-link";
  54
  55 static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
  56         [TIPC_NLA_LINK_UNSPEC]          = { .type = NLA_UNSPEC },
  57         [TIPC_NLA_LINK_NAME] = {
  58                 .type = NLA_STRING,
  59                 .len = TIPC_MAX_LINK_NAME
  60         },
  61         [TIPC_NLA_LINK_MTU]             = { .type = NLA_U32 },
  62         [TIPC_NLA_LINK_BROADCAST]       = { .type = NLA_FLAG },
  63         [TIPC_NLA_LINK_UP]              = { .type = NLA_FLAG },
  64         [TIPC_NLA_LINK_ACTIVE]          = { .type = NLA_FLAG },
  65         [TIPC_NLA_LINK_PROP]            = { .type = NLA_NESTED },
  66         [TIPC_NLA_LINK_STATS]           = { .type = NLA_NESTED },
  67         [TIPC_NLA_LINK_RX]              = { .type = NLA_U32 },
  68         [TIPC_NLA_LINK_TX]              = { .type = NLA_U32 }
  69 };
  70
  71 /* Properties valid for media, bearar and link */
  72 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
  73         [TIPC_NLA_PROP_UNSPEC]          = { .type = NLA_UNSPEC },
  74         [TIPC_NLA_PROP_PRIO]            = { .type = NLA_U32 },
  75         [TIPC_NLA_PROP_TOL]             = { .type = NLA_U32 },
  76         [TIPC_NLA_PROP_WIN]             = { .type = NLA_U32 }
  77 };
  78
  79 /*
  80  * Interval between NACKs when packets arrive out of order
  81  */
  82 #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
  83 /*
  84  * Out-of-range value for link session numbers
  85  */
  86 #define WILDCARD_SESSION 0x10000
  87
  88 /* Link FSM states:
  89  */
  90 enum {
  91         LINK_ESTABLISHED     = 0xe,
  92         LINK_ESTABLISHING    = 0xe  << 4,
  93         LINK_RESET           = 0x1  << 8,
  94         LINK_RESETTING       = 0x2  << 12,
  95         LINK_PEER_RESET      = 0xd  << 16,
  96         LINK_FAILINGOVER     = 0xf  << 20,
  97         LINK_SYNCHING        = 0xc  << 24
  98 };
  99
 100 /* Link FSM state checking routines
 101  */
 102 static int link_is_up(struct tipc_link *l)
 103 {
 104         return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
 105 }
 106
 107 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 108                                struct sk_buff_head *xmitq);
 109 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 110                                       u16 rcvgap, int tolerance, int priority,
 111                                       struct sk_buff_head *xmitq);
 112 static void link_reset_statistics(struct tipc_link *l_ptr);
 113 static void link_print(struct tipc_link *l_ptr, const char *str);
 114 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 115
 116 /*
 117  *  Simple non-static link routines (i.e. referenced outside this file)
 118  */
 119 bool tipc_link_is_up(struct tipc_link *l)
 120 {
 121         return link_is_up(l);
 122 }
 123
 124 bool tipc_link_peer_is_down(struct tipc_link *l)
 125 {
 126         return l->state == LINK_PEER_RESET;
 127 }
 128
 129 bool tipc_link_is_reset(struct tipc_link *l)
 130 {
 131         return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
 132 }
 133
 134 bool tipc_link_is_establishing(struct tipc_link *l)
 135 {
 136         return l->state == LINK_ESTABLISHING;
 137 }
 138
 139 bool tipc_link_is_synching(struct tipc_link *l)
 140 {
 141         return l->state == LINK_SYNCHING;
 142 }
 143
 144 bool tipc_link_is_failingover(struct tipc_link *l)
 145 {
 146         return l->state == LINK_FAILINGOVER;
 147 }
 148
 149 bool tipc_link_is_blocked(struct tipc_link *l)
 150 {
 151         return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
 152 }
 153
 154 int tipc_link_is_active(struct tipc_link *l)
 155 {
 156         struct tipc_node *n = l->owner;
 157
 158         return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
 159 }
 160
 161 void tipc_link_add_bc_peer(struct tipc_link *l)
 162 {
 163         l->ackers++;
 164 }
 165
 166 void tipc_link_remove_bc_peer(struct tipc_link *l)
 167 {
 168         l->ackers--;
 169 }
 170
 171 int tipc_link_bc_peers(struct tipc_link *l)
 172 {
 173         return l->ackers;
 174 }
 175
 176 static u32 link_own_addr(struct tipc_link *l)
 177 {
 178         return msg_prevnode(l->pmsg);
 179 }
 180
 181 /**
 182  * tipc_link_create - create a new link
 183  * @n: pointer to associated node
 184  * @if_name: associated interface name
 185  * @bearer_id: id (index) of associated bearer
 186  * @tolerance: link tolerance to be used by link
 187  * @net_plane: network plane (A,B,c..) this link belongs to
 188  * @mtu: mtu to be advertised by link
 189  * @priority: priority to be used by link
 190  * @window: send window to be used by link
 191  * @session: session to be used by link
 192  * @ownnode: identity of own node
 193  * @peer: node id of peer node
 194  * @maddr: media address to be used
 195  * @inputq: queue to put messages ready for delivery
 196  * @namedq: queue to put binding table update messages ready for delivery
 197  * @link: return value, pointer to put the created link
 198  *
 199  * Returns true if link was created, otherwise false
 200  */
 201 bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
 202                       int tolerance, char net_plane, u32 mtu, int priority,
 203                       int window, u32 session, u32 ownnode, u32 peer,
 204                       struct tipc_media_addr *maddr,
 205                       struct sk_buff_head *inputq, struct sk_buff_head *namedq,
 206                       struct tipc_link **link)
 207 {
 208         struct tipc_link *l;
 209         struct tipc_msg *hdr;
 210
 211         l = kzalloc(sizeof(*l), GFP_ATOMIC);
 212         if (!l)
 213                 return false;
 214         *link = l;
 215         l->pmsg = (struct tipc_msg *)&l->proto_msg;
 216         hdr = l->pmsg;
 217         tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
 218         msg_set_size(hdr, sizeof(l->proto_msg));
 219         msg_set_session(hdr, session);
 220         msg_set_bearer_id(hdr, l->bearer_id);
 221
 222         /* Note: peer i/f name is completed by reset/activate message */
 223         sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 224                 tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
 225                 if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 226         strcpy((char *)msg_data(hdr), if_name);
 227
 228         l->addr = peer;
 229         l->media_addr = maddr;
 230         l->owner = n;
 231         l->peer_session = WILDCARD_SESSION;
 232         l->bearer_id = bearer_id;
 233         l->tolerance = tolerance;
 234         l->net_plane = net_plane;
 235         l->advertised_mtu = mtu;
 236         l->mtu = mtu;
 237         l->priority = priority;
 238         tipc_link_set_queue_limits(l, window);
 239         l->ackers = 1;
 240         l->inputq = inputq;
 241         l->namedq = namedq;
 242         l->state = LINK_RESETTING;
 243         __skb_queue_head_init(&l->transmq);
 244         __skb_queue_head_init(&l->backlogq);
 245         __skb_queue_head_init(&l->deferdq);
 246         skb_queue_head_init(&l->wakeupq);
 247         skb_queue_head_init(l->inputq);
 248         return true;
 249 }
 250
 251 /**
 252  * tipc_link_bc_create - create new link to be used for broadcast
 253  * @n: pointer to associated node
 254  * @mtu: mtu to be used
 255  * @window: send window to be used
 256  * @inputq: queue to put messages ready for delivery
 257  * @namedq: queue to put binding table update messages ready for delivery
 258  * @link: return value, pointer to put the created link
 259  *
 260  * Returns true if link was created, otherwise false
 261  */
 262 bool tipc_link_bc_create(struct tipc_node *n, int mtu, int window,
 263                          struct sk_buff_head *inputq,
 264                          struct sk_buff_head *namedq,
 265                          struct tipc_link **link)
 266 {
 267         struct tipc_link *l;
 268
 269         if (!tipc_link_create(n, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
 270                               0, 0, 0, NULL, inputq, namedq, link))
 271                 return false;
 272
 273         l = *link;
 274         strcpy(l->name, tipc_bclink_name);
 275         tipc_link_reset(l);
 276         l->ackers = 0;
 277         return true;
 278 }
 279
 280 /* tipc_link_build_bcast_sync_msg() - synchronize broadcast link endpoints.
 281  *
 282  * Give a newly added peer node the sequence number where it should
 283  * start receiving and acking broadcast packets.
 284  */
 285 void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
 286                                     struct sk_buff_head *xmitq)
 287 {
 288         struct sk_buff *skb;
 289         struct sk_buff_head list;
 290         u16 last_sent;
 291
 292         skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
 293                               0, l->addr, link_own_addr(l), 0, 0, 0);
 294         if (!skb)
 295                 return;
 296         last_sent = tipc_bclink_get_last_sent(l->owner->net);
 297         msg_set_last_bcast(buf_msg(skb), last_sent);
 298         __skb_queue_head_init(&list);
 299         __skb_queue_tail(&list, skb);
 300         tipc_link_xmit(l, &list, xmitq);
 301 }
 302
 303 /**
 304  * tipc_link_fsm_evt - link finite state machine
 305  * @l: pointer to link
 306  * @evt: state machine event to be processed
 307  */
 308 int tipc_link_fsm_evt(struct tipc_link *l, int evt)
 309 {
 310         int rc = 0;
 311
 312         switch (l->state) {
 313         case LINK_RESETTING:
 314                 switch (evt) {
 315                 case LINK_PEER_RESET_EVT:
 316                         l->state = LINK_PEER_RESET;
 317                         break;
 318                 case LINK_RESET_EVT:
 319                         l->state = LINK_RESET;
 320                         break;
 321                 case LINK_FAILURE_EVT:
 322                 case LINK_FAILOVER_BEGIN_EVT:
 323                 case LINK_ESTABLISH_EVT:
 324                 case LINK_FAILOVER_END_EVT:
 325                 case LINK_SYNCH_BEGIN_EVT:
 326                 case LINK_SYNCH_END_EVT:
 327                 default:
 328                         goto illegal_evt;
 329                 }
 330                 break;
 331         case LINK_RESET:
 332                 switch (evt) {
 333                 case LINK_PEER_RESET_EVT:
 334                         l->state = LINK_ESTABLISHING;
 335                         break;
 336                 case LINK_FAILOVER_BEGIN_EVT:
 337                         l->state = LINK_FAILINGOVER;
 338                 case LINK_FAILURE_EVT:
 339                 case LINK_RESET_EVT:
 340                 case LINK_ESTABLISH_EVT:
 341                 case LINK_FAILOVER_END_EVT:
 342                         break;
 343                 case LINK_SYNCH_BEGIN_EVT:
 344                 case LINK_SYNCH_END_EVT:
 345                 default:
 346                         goto illegal_evt;
 347                 }
 348                 break;
 349         case LINK_PEER_RESET:
 350                 switch (evt) {
 351                 case LINK_RESET_EVT:
 352                         l->state = LINK_ESTABLISHING;
 353                         break;
 354                 case LINK_PEER_RESET_EVT:
 355                 case LINK_ESTABLISH_EVT:
 356                 case LINK_FAILURE_EVT:
 357                         break;
 358                 case LINK_SYNCH_BEGIN_EVT:
 359                 case LINK_SYNCH_END_EVT:
 360                 case LINK_FAILOVER_BEGIN_EVT:
 361                 case LINK_FAILOVER_END_EVT:
 362                 default:
 363                         goto illegal_evt;
 364                 }
 365                 break;
 366         case LINK_FAILINGOVER:
 367                 switch (evt) {
 368                 case LINK_FAILOVER_END_EVT:
 369                         l->state = LINK_RESET;
 370                         break;
 371                 case LINK_PEER_RESET_EVT:
 372                 case LINK_RESET_EVT:
 373                 case LINK_ESTABLISH_EVT:
 374                 case LINK_FAILURE_EVT:
 375                         break;
 376                 case LINK_FAILOVER_BEGIN_EVT:
 377                 case LINK_SYNCH_BEGIN_EVT:
 378                 case LINK_SYNCH_END_EVT:
 379                 default:
 380                         goto illegal_evt;
 381                 }
 382                 break;
 383         case LINK_ESTABLISHING:
 384                 switch (evt) {
 385                 case LINK_ESTABLISH_EVT:
 386                         l->state = LINK_ESTABLISHED;
 387                         break;
 388                 case LINK_FAILOVER_BEGIN_EVT:
 389                         l->state = LINK_FAILINGOVER;
 390                         break;
 391                 case LINK_RESET_EVT:
 392                         l->state = LINK_RESET;
 393                         break;
 394                 case LINK_FAILURE_EVT:
 395                 case LINK_PEER_RESET_EVT:
 396                 case LINK_SYNCH_BEGIN_EVT:
 397                 case LINK_FAILOVER_END_EVT:
 398                         break;
 399                 case LINK_SYNCH_END_EVT:
 400                 default:
 401                         goto illegal_evt;
 402                 }
 403                 break;
 404         case LINK_ESTABLISHED:
 405                 switch (evt) {
 406                 case LINK_PEER_RESET_EVT:
 407                         l->state = LINK_PEER_RESET;
 408                         rc |= TIPC_LINK_DOWN_EVT;
 409                         break;
 410                 case LINK_FAILURE_EVT:
 411                         l->state = LINK_RESETTING;
 412                         rc |= TIPC_LINK_DOWN_EVT;
 413                         break;
 414                 case LINK_RESET_EVT:
 415                         l->state = LINK_RESET;
 416                         break;
 417                 case LINK_ESTABLISH_EVT:
 418                 case LINK_SYNCH_END_EVT:
 419                         break;
 420                 case LINK_SYNCH_BEGIN_EVT:
 421                         l->state = LINK_SYNCHING;
 422                         break;
 423                 case LINK_FAILOVER_BEGIN_EVT:
 424                 case LINK_FAILOVER_END_EVT:
 425                 default:
 426                         goto illegal_evt;
 427                 }
 428                 break;
 429         case LINK_SYNCHING:
 430                 switch (evt) {
 431                 case LINK_PEER_RESET_EVT:
 432                         l->state = LINK_PEER_RESET;
 433                         rc |= TIPC_LINK_DOWN_EVT;
 434                         break;
 435                 case LINK_FAILURE_EVT:
 436                         l->state = LINK_RESETTING;
 437                         rc |= TIPC_LINK_DOWN_EVT;
 438                         break;
 439                 case LINK_RESET_EVT:
 440                         l->state = LINK_RESET;
 441                         break;
 442                 case LINK_ESTABLISH_EVT:
 443                 case LINK_SYNCH_BEGIN_EVT:
 444                         break;
 445                 case LINK_SYNCH_END_EVT:
 446                         l->state = LINK_ESTABLISHED;
 447                         break;
 448                 case LINK_FAILOVER_BEGIN_EVT:
 449                 case LINK_FAILOVER_END_EVT:
 450                 default:
 451                         goto illegal_evt;
 452                 }
 453                 break;
 454         default:
 455                 pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
 456         }
 457         return rc;
 458 illegal_evt:
 459         pr_err("Illegal FSM event %x in state %x on link %s\n",
 460                evt, l->state, l->name);
 461         return rc;
 462 }
 463
 464 /* link_profile_stats - update statistical profiling of traffic
 465  */
 466 static void link_profile_stats(struct tipc_link *l)
 467 {
 468         struct sk_buff *skb;
 469         struct tipc_msg *msg;
 470         int length;
 471
 472         /* Update counters used in statistical profiling of send traffic */
 473         l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 474         l->stats.queue_sz_counts++;
 475
 476         skb = skb_peek(&l->transmq);
 477         if (!skb)
 478                 return;
 479         msg = buf_msg(skb);
 480         length = msg_size(msg);
 481
 482         if (msg_user(msg) == MSG_FRAGMENTER) {
 483                 if (msg_type(msg) != FIRST_FRAGMENT)
 484                         return;
 485                 length = msg_size(msg_get_wrapped(msg));
 486         }
 487         l->stats.msg_lengths_total += length;
 488         l->stats.msg_length_counts++;
 489         if (length <= 64)
 490                 l->stats.msg_length_profile[0]++;
 491         else if (length <= 256)
 492                 l->stats.msg_length_profile[1]++;
 493         else if (length <= 1024)
 494                 l->stats.msg_length_profile[2]++;
 495         else if (length <= 4096)
 496                 l->stats.msg_length_profile[3]++;
 497         else if (length <= 16384)
 498                 l->stats.msg_length_profile[4]++;
 499         else if (length <= 32768)
 500                 l->stats.msg_length_profile[5]++;
 501         else
 502                 l->stats.msg_length_profile[6]++;
 503 }
 504
 505 /* tipc_link_timeout - perform periodic task as instructed from node timeout
 506  */
 507 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 508 {
 509         int rc = 0;
 510         int mtyp = STATE_MSG;
 511         bool xmit = false;
 512         bool prb = false;
 513
 514         link_profile_stats(l);
 515
 516         switch (l->state) {
 517         case LINK_ESTABLISHED:
 518         case LINK_SYNCHING:
 519                 if (!l->silent_intv_cnt) {
 520                         if (tipc_bclink_acks_missing(l->owner))
 521                                 xmit = true;
 522                 } else if (l->silent_intv_cnt <= l->abort_limit) {
 523                         xmit = true;
 524                         prb = true;
 525                 } else {
 526                         rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 527                 }
 528                 l->silent_intv_cnt++;
 529                 break;
 530         case LINK_RESET:
 531                 xmit = true;
 532                 mtyp = RESET_MSG;
 533                 break;
 534         case LINK_ESTABLISHING:
 535                 xmit = true;
 536                 mtyp = ACTIVATE_MSG;
 537                 break;
 538         case LINK_PEER_RESET:
 539         case LINK_RESETTING:
 540         case LINK_FAILINGOVER:
 541                 break;
 542         default:
 543                 break;
 544         }
 545
 546         if (xmit)
 547                 tipc_link_build_proto_msg(l, mtyp, prb, 0, 0, 0, xmitq);
 548
 549         return rc;
 550 }
 551
 552 /**
 553  * link_schedule_user - schedule a message sender for wakeup after congestion
 554  * @link: congested link
 555  * @list: message that was attempted sent
 556  * Create pseudo msg to send back to user when congestion abates
 557  * Does not consume buffer list
 558  */
 559 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 560 {
 561         struct tipc_msg *msg = buf_msg(skb_peek(list));
 562         int imp = msg_importance(msg);
 563         u32 oport = msg_origport(msg);
 564         u32 addr = link_own_addr(link);
 565         struct sk_buff *skb;
 566
 567         /* This really cannot happen...  */
 568         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 569                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 570                 return -ENOBUFS;
 571         }
 572         /* Non-blocking sender: */
 573         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 574                 return -ELINKCONG;
 575
 576         /* Create and schedule wakeup pseudo message */
 577         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 578                               addr, addr, oport, 0, 0);
 579         if (!skb)
 580                 return -ENOBUFS;
 581         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 582         TIPC_SKB_CB(skb)->chain_imp = imp;
 583         skb_queue_tail(&link->wakeupq, skb);
 584         link->stats.link_congs++;
 585         return -ELINKCONG;
 586 }
 587
 588 /**
 589  * link_prepare_wakeup - prepare users for wakeup after congestion
 590  * @link: congested link
 591  * Move a number of waiting users, as permitted by available space in
 592  * the send queue, from link wait queue to node wait queue for wakeup
 593  */
 594 void link_prepare_wakeup(struct tipc_link *l)
 595 {
 596         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 597         int imp, lim;
 598         struct sk_buff *skb, *tmp;
 599
 600         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 601                 imp = TIPC_SKB_CB(skb)->chain_imp;
 602                 lim = l->window + l->backlog[imp].limit;
 603                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 604                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 605                         break;
 606                 skb_unlink(skb, &l->wakeupq);
 607                 skb_queue_tail(l->inputq, skb);
 608         }
 609 }
 610
 611 /**
 612  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 613  * @l_ptr: pointer to link
 614  */
 615 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 616 {
 617         kfree_skb(l_ptr->reasm_buf);
 618         l_ptr->reasm_buf = NULL;
 619 }
 620
 621 void tipc_link_purge_backlog(struct tipc_link *l)
 622 {
 623         __skb_queue_purge(&l->backlogq);
 624         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 625         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 626         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 627         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 628         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 629 }
 630
 631 /**
 632  * tipc_link_purge_queues - purge all pkt queues associated with link
 633  * @l_ptr: pointer to link
 634  */
 635 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 636 {
 637         __skb_queue_purge(&l_ptr->deferdq);
 638         __skb_queue_purge(&l_ptr->transmq);
 639         tipc_link_purge_backlog(l_ptr);
 640         tipc_link_reset_fragments(l_ptr);
 641 }
 642
 643 void tipc_link_reset(struct tipc_link *l)
 644 {
 645         /* Link is down, accept any session */
 646         l->peer_session = WILDCARD_SESSION;
 647
 648         /* If peer is up, it only accepts an incremented session number */
 649         msg_set_session(l->pmsg, msg_session(l->pmsg) + 1);
 650
 651         /* Prepare for renewed mtu size negotiation */
 652         l->mtu = l->advertised_mtu;
 653
 654         /* Clean up all queues: */
 655         __skb_queue_purge(&l->transmq);
 656         __skb_queue_purge(&l->deferdq);
 657         skb_queue_splice_init(&l->wakeupq, l->inputq);
 658
 659         tipc_link_purge_backlog(l);
 660         kfree_skb(l->reasm_buf);
 661         kfree_skb(l->failover_reasm_skb);
 662         l->reasm_buf = NULL;
 663         l->failover_reasm_skb = NULL;
 664         l->rcv_unacked = 0;
 665         l->snd_nxt = 1;
 666         l->rcv_nxt = 1;
 667         l->acked = 0;
 668         l->silent_intv_cnt = 0;
 669         l->stats.recv_info = 0;
 670         l->stale_count = 0;
 671         link_reset_statistics(l);
 672 }
 673
 674 /**
 675  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 676  * @link: link to use
 677  * @list: chain of buffers containing message
 678  *
 679  * Consumes the buffer chain, except when returning an error code,
 680  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 681  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 682  */
 683 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 684                      struct sk_buff_head *list)
 685 {
 686         struct tipc_msg *msg = buf_msg(skb_peek(list));
 687         unsigned int maxwin = link->window;
 688         unsigned int i, imp = msg_importance(msg);
 689         uint mtu = link->mtu;
 690         u16 ack = mod(link->rcv_nxt - 1);
 691         u16 seqno = link->snd_nxt;
 692         u16 bc_last_in = link->owner->bclink.last_in;
 693         struct tipc_media_addr *addr = link->media_addr;
 694         struct sk_buff_head *transmq = &link->transmq;
 695         struct sk_buff_head *backlogq = &link->backlogq;
 696         struct sk_buff *skb, *bskb;
 697
 698         /* Match msg importance against this and all higher backlog limits: */
 699         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 700                 if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
 701                         return link_schedule_user(link, list);
 702         }
 703         if (unlikely(msg_size(msg) > mtu))
 704                 return -EMSGSIZE;
 705
 706         /* Prepare each packet for sending, and add to relevant queue: */
 707         while (skb_queue_len(list)) {
 708                 skb = skb_peek(list);
 709                 msg = buf_msg(skb);
 710                 msg_set_seqno(msg, seqno);
 711                 msg_set_ack(msg, ack);
 712                 msg_set_bcast_ack(msg, bc_last_in);
 713
 714                 if (likely(skb_queue_len(transmq) < maxwin)) {
 715                         __skb_dequeue(list);
 716                         __skb_queue_tail(transmq, skb);
 717                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 718                         link->rcv_unacked = 0;
 719                         seqno++;
 720                         continue;
 721                 }
 722                 if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
 723                         kfree_skb(__skb_dequeue(list));
 724                         link->stats.sent_bundled++;
 725                         continue;
 726                 }
 727                 if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
 728                         kfree_skb(__skb_dequeue(list));
 729                         __skb_queue_tail(backlogq, bskb);
 730                         link->backlog[msg_importance(buf_msg(bskb))].len++;
 731                         link->stats.sent_bundled++;
 732                         link->stats.sent_bundles++;
 733                         continue;
 734                 }
 735                 link->backlog[imp].len += skb_queue_len(list);
 736                 skb_queue_splice_tail_init(list, backlogq);
 737         }
 738         link->snd_nxt = seqno;
 739         return 0;
 740 }
 741
 742 /**
 743  * tipc_link_xmit(): enqueue buffer list according to queue situation
 744  * @link: link to use
 745  * @list: chain of buffers containing message
 746  * @xmitq: returned list of packets to be sent by caller
 747  *
 748  * Consumes the buffer chain, except when returning -ELINKCONG,
 749  * since the caller then may want to make more send attempts.
 750  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 751  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 752  */
 753 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 754                    struct sk_buff_head *xmitq)
 755 {
 756         struct tipc_msg *hdr = buf_msg(skb_peek(list));
 757         unsigned int maxwin = l->window;
 758         unsigned int i, imp = msg_importance(hdr);
 759         unsigned int mtu = l->mtu;
 760         u16 ack = l->rcv_nxt - 1;
 761         u16 seqno = l->snd_nxt;
 762         u16 bc_last_in = l->owner->bclink.last_in;
 763         struct sk_buff_head *transmq = &l->transmq;
 764         struct sk_buff_head *backlogq = &l->backlogq;
 765         struct sk_buff *skb, *_skb, *bskb;
 766
 767         /* Match msg importance against this and all higher backlog limits: */
 768         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 769                 if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
 770                         return link_schedule_user(l, list);
 771         }
 772         if (unlikely(msg_size(hdr) > mtu))
 773                 return -EMSGSIZE;
 774
 775         /* Prepare each packet for sending, and add to relevant queue: */
 776         while (skb_queue_len(list)) {
 777                 skb = skb_peek(list);
 778                 hdr = buf_msg(skb);
 779                 msg_set_seqno(hdr, seqno);
 780                 msg_set_ack(hdr, ack);
 781                 msg_set_bcast_ack(hdr, bc_last_in);
 782
 783                 if (likely(skb_queue_len(transmq) < maxwin)) {
 784                         _skb = skb_clone(skb, GFP_ATOMIC);
 785                         if (!_skb)
 786                                 return -ENOBUFS;
 787                         __skb_dequeue(list);
 788                         __skb_queue_tail(transmq, skb);
 789                         __skb_queue_tail(xmitq, _skb);
 790                         TIPC_SKB_CB(skb)->ackers = l->ackers;
 791                         l->rcv_unacked = 0;
 792                         seqno++;
 793                         continue;
 794                 }
 795                 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
 796                         kfree_skb(__skb_dequeue(list));
 797                         l->stats.sent_bundled++;
 798                         continue;
 799                 }
 800                 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
 801                         kfree_skb(__skb_dequeue(list));
 802                         __skb_queue_tail(backlogq, bskb);
 803                         l->backlog[msg_importance(buf_msg(bskb))].len++;
 804                         l->stats.sent_bundled++;
 805                         l->stats.sent_bundles++;
 806                         continue;
 807                 }
 808                 l->backlog[imp].len += skb_queue_len(list);
 809                 skb_queue_splice_tail_init(list, backlogq);
 810         }
 811         l->snd_nxt = seqno;
 812         return 0;
 813 }
 814
 815 /*
 816  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 817  * Receive the sequence number where we should start receiving and
 818  * acking broadcast packets from a newly added peer node, and open
 819  * up for reception of such packets.
 820  *
 821  * Called with node locked
 822  */
 823 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 824 {
 825         struct tipc_msg *msg = buf_msg(buf);
 826
 827         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 828         n->bclink.recv_permitted = true;
 829         kfree_skb(buf);
 830 }
 831
 832 /*
 833  * tipc_link_push_packets - push unsent packets to bearer
 834  *
 835  * Push out the unsent messages of a link where congestion
 836  * has abated. Node is locked.
 837  *
 838  * Called with node locked
 839  */
 840 void tipc_link_push_packets(struct tipc_link *link)
 841 {
 842         struct sk_buff *skb;
 843         struct tipc_msg *msg;
 844         u16 seqno = link->snd_nxt;
 845         u16 ack = mod(link->rcv_nxt - 1);
 846
 847         while (skb_queue_len(&link->transmq) < link->window) {
 848                 skb = __skb_dequeue(&link->backlogq);
 849                 if (!skb)
 850                         break;
 851                 TIPC_SKB_CB(skb)->ackers = link->ackers;
 852                 msg = buf_msg(skb);
 853                 link->backlog[msg_importance(msg)].len--;
 854                 msg_set_ack(msg, ack);
 855                 msg_set_seqno(msg, seqno);
 856                 seqno = mod(seqno + 1);
 857                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 858                 link->rcv_unacked = 0;
 859                 __skb_queue_tail(&link->transmq, skb);
 860                 tipc_bearer_send(link->owner->net, link->bearer_id,
 861                                  skb, link->media_addr);
 862         }
 863         link->snd_nxt = seqno;
 864 }
 865
 866 void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
 867 {
 868         struct sk_buff *skb, *_skb;
 869         struct tipc_msg *hdr;
 870         u16 seqno = l->snd_nxt;
 871         u16 ack = l->rcv_nxt - 1;
 872
 873         while (skb_queue_len(&l->transmq) < l->window) {
 874                 skb = skb_peek(&l->backlogq);
 875                 if (!skb)
 876                         break;
 877                 _skb = skb_clone(skb, GFP_ATOMIC);
 878                 if (!_skb)
 879                         break;
 880                 __skb_dequeue(&l->backlogq);
 881                 hdr = buf_msg(skb);
 882                 l->backlog[msg_importance(hdr)].len--;
 883                 __skb_queue_tail(&l->transmq, skb);
 884                 __skb_queue_tail(xmitq, _skb);
 885                 TIPC_SKB_CB(skb)->ackers = l->ackers;
 886                 msg_set_ack(hdr, ack);
 887                 msg_set_seqno(hdr, seqno);
 888                 msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
 889                 l->rcv_unacked = 0;
 890                 seqno++;
 891         }
 892         l->snd_nxt = seqno;
 893 }
 894
 895 static void link_retransmit_failure(struct tipc_link *l_ptr,
 896                                     struct sk_buff *buf)
 897 {
 898         struct tipc_msg *msg = buf_msg(buf);
 899         struct net *net = l_ptr->owner->net;
 900
 901         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 902
 903         if (l_ptr->addr) {
 904                 /* Handle failure on standard link */
 905                 link_print(l_ptr, "Resetting link ");
 906                 pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
 907                         msg_user(msg), msg_type(msg), msg_size(msg),
 908                         msg_errcode(msg));
 909                 pr_info("sqno %u, prev: %x, src: %x\n",
 910                         msg_seqno(msg), msg_prevnode(msg), msg_orignode(msg));
 911         } else {
 912                 /* Handle failure on broadcast link */
 913                 struct tipc_node *n_ptr;
 914                 char addr_string[16];
 915
 916                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 917                 pr_cont("Outstanding acks: %u\n", TIPC_SKB_CB(buf)->ackers);
 918
 919                 n_ptr = tipc_bclink_retransmit_to(net);
 920
 921                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 922                 pr_info("Broadcast link info for %s\n", addr_string);
 923                 pr_info("Reception permitted: %d,  Acked: %u\n",
 924                         n_ptr->bclink.recv_permitted,
 925                         n_ptr->bclink.acked);
 926                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 927                         n_ptr->bclink.last_in,
 928                         n_ptr->bclink.oos_state,
 929                         n_ptr->bclink.last_sent);
 930
 931                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 932                 l_ptr->stale_count = 0;
 933         }
 934 }
 935
 936 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 937                           u32 retransmits)
 938 {
 939         struct tipc_msg *msg;
 940
 941         if (!skb)
 942                 return;
 943
 944         msg = buf_msg(skb);
 945
 946         /* Detect repeated retransmit failures */
 947         if (l_ptr->last_retransm == msg_seqno(msg)) {
 948                 if (++l_ptr->stale_count > 100) {
 949                         link_retransmit_failure(l_ptr, skb);
 950                         return;
 951                 }
 952         } else {
 953                 l_ptr->last_retransm = msg_seqno(msg);
 954                 l_ptr->stale_count = 1;
 955         }
 956
 957         skb_queue_walk_from(&l_ptr->transmq, skb) {
 958                 if (!retransmits)
 959                         break;
 960                 msg = buf_msg(skb);
 961                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
 962                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 963                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 964                                  l_ptr->media_addr);
 965                 retransmits--;
 966                 l_ptr->stats.retransmitted++;
 967         }
 968 }
 969
 970 int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
 971                       struct sk_buff_head *xmitq)
 972 {
 973         struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
 974         struct tipc_msg *hdr;
 975         u16 ack = l->rcv_nxt - 1;
 976         u16 bc_ack = l->owner->bclink.last_in;
 977
 978         if (!skb)
 979                 return 0;
 980
 981         /* Detect repeated retransmit failures on same packet */
 982         if (likely(l->last_retransm != buf_seqno(skb))) {
 983                 l->last_retransm = buf_seqno(skb);
 984                 l->stale_count = 1;
 985         } else if (++l->stale_count > 100) {
 986                 link_retransmit_failure(l, skb);
 987                 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 988         }
 989
 990         /* Move forward to where retransmission should start */
 991         skb_queue_walk(&l->transmq, skb) {
 992                 if (!less(buf_seqno(skb), from))
 993                         break;
 994         }
 995
 996         skb_queue_walk_from(&l->transmq, skb) {
 997                 if (more(buf_seqno(skb), to))
 998                         break;
 999                 hdr = buf_msg(skb);
1000                 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
1001                 if (!_skb)
1002                         return 0;
1003                 hdr = buf_msg(_skb);
1004                 msg_set_ack(hdr, ack);
1005                 msg_set_bcast_ack(hdr, bc_ack);
1006                 _skb->priority = TC_PRIO_CONTROL;
1007                 __skb_queue_tail(xmitq, _skb);
1008                 l->stats.retransmitted++;
1009         }
1010         return 0;
1011 }
1012
1013 /* tipc_data_input - deliver data and name distr msgs to upper layer
1014  *
1015  * Consumes buffer if message is of right type
1016  * Node lock must be held
1017  */
1018 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb,
1019                             struct sk_buff_head *inputq)
1020 {
1021         struct tipc_node *node = link->owner;
1022
1023         switch (msg_user(buf_msg(skb))) {
1024         case TIPC_LOW_IMPORTANCE:
1025         case TIPC_MEDIUM_IMPORTANCE:
1026         case TIPC_HIGH_IMPORTANCE:
1027         case TIPC_CRITICAL_IMPORTANCE:
1028         case CONN_MANAGER:
1029                 skb_queue_tail(inputq, skb);
1030                 return true;
1031         case NAME_DISTRIBUTOR:
1032                 node->bclink.recv_permitted = true;
1033                 skb_queue_tail(link->namedq, skb);
1034                 return true;
1035         case MSG_BUNDLER:
1036         case TUNNEL_PROTOCOL:
1037         case MSG_FRAGMENTER:
1038         case BCAST_PROTOCOL:
1039                 return false;
1040         default:
1041                 pr_warn("Dropping received illegal msg type\n");
1042                 kfree_skb(skb);
1043                 return false;
1044         };
1045 }
1046
1047 /* tipc_link_input - process packet that has passed link protocol check
1048  *
1049  * Consumes buffer
1050  */
1051 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1052                            struct sk_buff_head *inputq)
1053 {
1054         struct tipc_node *node = l->owner;
1055         struct tipc_msg *hdr = buf_msg(skb);
1056         struct sk_buff **reasm_skb = &l->reasm_buf;
1057         struct sk_buff *iskb;
1058         struct sk_buff_head tmpq;
1059         int usr = msg_user(hdr);
1060         int rc = 0;
1061         int pos = 0;
1062         int ipos = 0;
1063
1064         if (unlikely(usr == TUNNEL_PROTOCOL)) {
1065                 if (msg_type(hdr) == SYNCH_MSG) {
1066                         __skb_queue_purge(&l->deferdq);
1067                         goto drop;
1068                 }
1069                 if (!tipc_msg_extract(skb, &iskb, &ipos))
1070                         return rc;
1071                 kfree_skb(skb);
1072                 skb = iskb;
1073                 hdr = buf_msg(skb);
1074                 if (less(msg_seqno(hdr), l->drop_point))
1075                         goto drop;
1076                 if (tipc_data_input(l, skb, inputq))
1077                         return rc;
1078                 usr = msg_user(hdr);
1079                 reasm_skb = &l->failover_reasm_skb;
1080         }
1081
1082         if (usr == MSG_BUNDLER) {
1083                 skb_queue_head_init(&tmpq);
1084                 l->stats.recv_bundles++;
1085                 l->stats.recv_bundled += msg_msgcnt(hdr);
1086                 while (tipc_msg_extract(skb, &iskb, &pos))
1087                         tipc_data_input(l, iskb, &tmpq);
1088                 tipc_skb_queue_splice_tail(&tmpq, inputq);
1089                 return 0;
1090         } else if (usr == MSG_FRAGMENTER) {
1091                 l->stats.recv_fragments++;
1092                 if (tipc_buf_append(reasm_skb, &skb)) {
1093                         l->stats.recv_fragmented++;
1094                         tipc_data_input(l, skb, inputq);
1095                 } else if (!*reasm_skb) {
1096                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1097                 }
1098                 return 0;
1099         } else if (usr == BCAST_PROTOCOL) {
1100                 tipc_link_sync_rcv(node, skb);
1101                 return 0;
1102         }
1103 drop:
1104         kfree_skb(skb);
1105         return 0;
1106 }
1107
1108 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1109 {
1110         bool released = false;
1111         struct sk_buff *skb, *tmp;
1112
1113         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1114                 if (more(buf_seqno(skb), acked))
1115                         break;
1116                 __skb_unlink(skb, &l->transmq);
1117                 kfree_skb(skb);
1118                 released = true;
1119         }
1120         return released;
1121 }
1122
1123 /* tipc_link_build_ack_msg: prepare link acknowledge message for transmission
1124  */
1125 void tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1126 {
1127         l->rcv_unacked = 0;
1128         l->stats.sent_acks++;
1129         tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1130 }
1131
1132 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1133  */
1134 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1135 {
1136         int mtyp = RESET_MSG;
1137
1138         if (l->state == LINK_ESTABLISHING)
1139                 mtyp = ACTIVATE_MSG;
1140
1141         tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
1142 }
1143
1144 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1145  */
1146 static void tipc_link_build_nack_msg(struct tipc_link *l,
1147                                      struct sk_buff_head *xmitq)
1148 {
1149         u32 def_cnt = ++l->stats.deferred_recv;
1150
1151         if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
1152                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1153 }
1154
1155 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1156  * @l: the link that should handle the message
1157  * @skb: TIPC packet
1158  * @xmitq: queue to place packets to be sent after this call
1159  */
1160 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1161                   struct sk_buff_head *xmitq)
1162 {
1163         struct sk_buff_head *defq = &l->deferdq;
1164         struct tipc_msg *hdr;
1165         u16 seqno, rcv_nxt, win_lim;
1166         int rc = 0;
1167
1168         do {
1169                 hdr = buf_msg(skb);
1170                 seqno = msg_seqno(hdr);
1171                 rcv_nxt = l->rcv_nxt;
1172                 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1173
1174                 /* Verify and update link state */
1175                 if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1176                         return tipc_link_proto_rcv(l, skb, xmitq);
1177
1178                 if (unlikely(!link_is_up(l))) {
1179                         if (l->state == LINK_ESTABLISHING)
1180                                 rc = TIPC_LINK_UP_EVT;
1181                         goto drop;
1182                 }
1183
1184                 /* Don't send probe at next timeout expiration */
1185                 l->silent_intv_cnt = 0;
1186
1187                 /* Drop if outside receive window */
1188                 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1189                         l->stats.duplicates++;
1190                         goto drop;
1191                 }
1192
1193                 /* Forward queues and wake up waiting users */
1194                 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1195                         tipc_link_advance_backlog(l, xmitq);
1196                         if (unlikely(!skb_queue_empty(&l->wakeupq)))
1197                                 link_prepare_wakeup(l);
1198                 }
1199
1200                 /* Defer delivery if sequence gap */
1201                 if (unlikely(seqno != rcv_nxt)) {
1202                         __tipc_skb_queue_sorted(defq, seqno, skb);
1203                         tipc_link_build_nack_msg(l, xmitq);
1204                         break;
1205                 }
1206
1207                 /* Deliver packet */
1208                 l->rcv_nxt++;
1209                 l->stats.recv_info++;
1210                 if (!tipc_data_input(l, skb, l->inputq))
1211                         rc = tipc_link_input(l, skb, l->inputq);
1212                 if (unlikely(rc))
1213                         break;
1214                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1215                         tipc_link_build_ack_msg(l, xmitq);
1216
1217         } while ((skb = __skb_dequeue(defq)));
1218
1219         return rc;
1220 drop:
1221         kfree_skb(skb);
1222         return rc;
1223 }
1224
1225 /**
1226  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1227  *
1228  * Returns increase in queue length (i.e. 0 or 1)
1229  */
1230 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1231 {
1232         struct sk_buff *skb1;
1233         u16 seq_no = buf_seqno(skb);
1234
1235         /* Empty queue ? */
1236         if (skb_queue_empty(list)) {
1237                 __skb_queue_tail(list, skb);
1238                 return 1;
1239         }
1240
1241         /* Last ? */
1242         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1243                 __skb_queue_tail(list, skb);
1244                 return 1;
1245         }
1246
1247         /* Locate insertion point in queue, then insert; discard if duplicate */
1248         skb_queue_walk(list, skb1) {
1249                 u16 curr_seqno = buf_seqno(skb1);
1250
1251                 if (seq_no == curr_seqno) {
1252                         kfree_skb(skb);
1253                         return 0;
1254                 }
1255
1256                 if (less(seq_no, curr_seqno))
1257                         break;
1258         }
1259
1260         __skb_queue_before(list, skb1, skb);
1261         return 1;
1262 }
1263
1264 /*
1265  * Send protocol message to the other endpoint.
1266  */
1267 void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg,
1268                           u32 gap, u32 tolerance, u32 priority)
1269 {
1270         struct sk_buff *skb = NULL;
1271         struct sk_buff_head xmitq;
1272
1273         __skb_queue_head_init(&xmitq);
1274         tipc_link_build_proto_msg(l, msg_typ, probe_msg, gap,
1275                                   tolerance, priority, &xmitq);
1276         skb = __skb_dequeue(&xmitq);
1277         if (!skb)
1278                 return;
1279         tipc_bearer_send(l->owner->net, l->bearer_id, skb, l->media_addr);
1280         l->rcv_unacked = 0;
1281         kfree_skb(skb);
1282 }
1283
1284 /* tipc_link_build_proto_msg: prepare link protocol message for transmission
1285  */
1286 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1287                                       u16 rcvgap, int tolerance, int priority,
1288                                       struct sk_buff_head *xmitq)
1289 {
1290         struct sk_buff *skb = NULL;
1291         struct tipc_msg *hdr = l->pmsg;
1292         u16 snd_nxt = l->snd_nxt;
1293         u16 rcv_nxt = l->rcv_nxt;
1294         u16 rcv_last = rcv_nxt - 1;
1295         int node_up = l->owner->bclink.recv_permitted;
1296
1297         /* Don't send protocol message during reset or link failover */
1298         if (tipc_link_is_blocked(l))
1299                 return;
1300
1301         msg_set_type(hdr, mtyp);
1302         msg_set_net_plane(hdr, l->net_plane);
1303         msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
1304         msg_set_last_bcast(hdr, tipc_bclink_get_last_sent(l->owner->net));
1305         msg_set_link_tolerance(hdr, tolerance);
1306         msg_set_linkprio(hdr, priority);
1307         msg_set_redundant_link(hdr, node_up);
1308         msg_set_seq_gap(hdr, 0);
1309
1310         /* Compatibility: created msg must not be in sequence with pkt flow */
1311         msg_set_seqno(hdr, snd_nxt + U16_MAX / 2);
1312
1313         if (mtyp == STATE_MSG) {
1314                 if (!tipc_link_is_up(l))
1315                         return;
1316                 msg_set_next_sent(hdr, snd_nxt);
1317
1318                 /* Override rcvgap if there are packets in deferred queue */
1319                 if (!skb_queue_empty(&l->deferdq))
1320                         rcvgap = buf_seqno(skb_peek(&l->deferdq)) - rcv_nxt;
1321                 if (rcvgap) {
1322                         msg_set_seq_gap(hdr, rcvgap);
1323                         l->stats.sent_nacks++;
1324                 }
1325                 msg_set_ack(hdr, rcv_last);
1326                 msg_set_probe(hdr, probe);
1327                 if (probe)
1328                         l->stats.sent_probes++;
1329                 l->stats.sent_states++;
1330         } else {
1331                 /* RESET_MSG or ACTIVATE_MSG */
1332                 msg_set_max_pkt(hdr, l->advertised_mtu);
1333                 msg_set_ack(hdr, l->rcv_nxt - 1);
1334                 msg_set_next_sent(hdr, 1);
1335         }
1336         skb = tipc_buf_acquire(msg_size(hdr));
1337         if (!skb)
1338                 return;
1339         skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
1340         skb->priority = TC_PRIO_CONTROL;
1341         __skb_queue_tail(xmitq, skb);
1342 }
1343
1344 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1345  * with contents of the link's transmit and backlog queues.
1346  */
1347 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1348                            int mtyp, struct sk_buff_head *xmitq)
1349 {
1350         struct sk_buff *skb, *tnlskb;
1351         struct tipc_msg *hdr, tnlhdr;
1352         struct sk_buff_head *queue = &l->transmq;
1353         struct sk_buff_head tmpxq, tnlq;
1354         u16 pktlen, pktcnt, seqno = l->snd_nxt;
1355
1356         if (!tnl)
1357                 return;
1358
1359         skb_queue_head_init(&tnlq);
1360         skb_queue_head_init(&tmpxq);
1361
1362         /* At least one packet required for safe algorithm => add dummy */
1363         skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1364                               BASIC_H_SIZE, 0, l->addr, link_own_addr(l),
1365                               0, 0, TIPC_ERR_NO_PORT);
1366         if (!skb) {
1367                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1368                 return;
1369         }
1370         skb_queue_tail(&tnlq, skb);
1371         tipc_link_xmit(l, &tnlq, &tmpxq);
1372         __skb_queue_purge(&tmpxq);
1373
1374         /* Initialize reusable tunnel packet header */
1375         tipc_msg_init(link_own_addr(l), &tnlhdr, TUNNEL_PROTOCOL,
1376                       mtyp, INT_H_SIZE, l->addr);
1377         pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
1378         msg_set_msgcnt(&tnlhdr, pktcnt);
1379         msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1380 tnl:
1381         /* Wrap each packet into a tunnel packet */
1382         skb_queue_walk(queue, skb) {
1383                 hdr = buf_msg(skb);
1384                 if (queue == &l->backlogq)
1385                         msg_set_seqno(hdr, seqno++);
1386                 pktlen = msg_size(hdr);
1387                 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1388                 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE);
1389                 if (!tnlskb) {
1390                         pr_warn("%sunable to send packet\n", link_co_err);
1391                         return;
1392                 }
1393                 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1394                 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1395                 __skb_queue_tail(&tnlq, tnlskb);
1396         }
1397         if (queue != &l->backlogq) {
1398                 queue = &l->backlogq;
1399                 goto tnl;
1400         }
1401
1402         tipc_link_xmit(tnl, &tnlq, xmitq);
1403
1404         if (mtyp == FAILOVER_MSG) {
1405                 tnl->drop_point = l->rcv_nxt;
1406                 tnl->failover_reasm_skb = l->reasm_buf;
1407                 l->reasm_buf = NULL;
1408         }
1409 }
1410
1411 /* tipc_link_proto_rcv(): receive link level protocol message :
1412  * Note that network plane id propagates through the network, and may
1413  * change at any time. The node with lowest numerical id determines
1414  * network plane
1415  */
1416 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1417                                struct sk_buff_head *xmitq)
1418 {
1419         struct tipc_msg *hdr = buf_msg(skb);
1420         u16 rcvgap = 0;
1421         u16 ack = msg_ack(hdr);
1422         u16 gap = msg_seq_gap(hdr);
1423         u16 peers_snd_nxt =  msg_next_sent(hdr);
1424         u16 peers_tol = msg_link_tolerance(hdr);
1425         u16 peers_prio = msg_linkprio(hdr);
1426         u16 rcv_nxt = l->rcv_nxt;
1427         int mtyp = msg_type(hdr);
1428         char *if_name;
1429         int rc = 0;
1430
1431         if (tipc_link_is_blocked(l))
1432                 goto exit;
1433
1434         if (link_own_addr(l) > msg_prevnode(hdr))
1435                 l->net_plane = msg_net_plane(hdr);
1436
1437         switch (mtyp) {
1438         case RESET_MSG:
1439
1440                 /* Ignore duplicate RESET with old session number */
1441                 if ((less_eq(msg_session(hdr), l->peer_session)) &&
1442                     (l->peer_session != WILDCARD_SESSION))
1443                         break;
1444                 /* fall thru' */
1445
1446         case ACTIVATE_MSG:
1447
1448                 /* Complete own link name with peer's interface name */
1449                 if_name =  strrchr(l->name, ':') + 1;
1450                 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1451                         break;
1452                 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1453                         break;
1454                 strncpy(if_name, msg_data(hdr), TIPC_MAX_IF_NAME);
1455
1456                 /* Update own tolerance if peer indicates a non-zero value */
1457                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1458                         l->tolerance = peers_tol;
1459
1460                 /* Update own priority if peer's priority is higher */
1461                 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1462                         l->priority = peers_prio;
1463
1464                 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
1465                 if ((mtyp == RESET_MSG) || !link_is_up(l))
1466                         rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
1467
1468                 /* ACTIVATE_MSG takes up link if it was already locally reset */
1469                 if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
1470                         rc = TIPC_LINK_UP_EVT;
1471
1472                 l->peer_session = msg_session(hdr);
1473                 l->peer_bearer_id = msg_bearer_id(hdr);
1474                 if (l->mtu > msg_max_pkt(hdr))
1475                         l->mtu = msg_max_pkt(hdr);
1476                 break;
1477
1478         case STATE_MSG:
1479
1480                 /* Update own tolerance if peer indicates a non-zero value */
1481                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1482                         l->tolerance = peers_tol;
1483
1484                 l->silent_intv_cnt = 0;
1485                 l->stats.recv_states++;
1486                 if (msg_probe(hdr))
1487                         l->stats.recv_probes++;
1488
1489                 if (!link_is_up(l)) {
1490                         if (l->state == LINK_ESTABLISHING)
1491                                 rc = TIPC_LINK_UP_EVT;
1492                         break;
1493                 }
1494
1495                 /* Send NACK if peer has sent pkts we haven't received yet */
1496                 if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
1497                         rcvgap = peers_snd_nxt - l->rcv_nxt;
1498                 if (rcvgap || (msg_probe(hdr)))
1499                         tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1500                                                   0, 0, xmitq);
1501                 tipc_link_release_pkts(l, ack);
1502
1503                 /* If NACK, retransmit will now start at right position */
1504                 if (gap) {
1505                         rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq);
1506                         l->stats.recv_nacks++;
1507                 }
1508
1509                 tipc_link_advance_backlog(l, xmitq);
1510                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1511                         link_prepare_wakeup(l);
1512         }
1513 exit:
1514         kfree_skb(skb);
1515         return rc;
1516 }
1517
1518 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1519 {
1520         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1521
1522         l->window = win;
1523         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1524         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1525         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1526         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1527         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1528 }
1529
1530 /* tipc_link_find_owner - locate owner node of link by link's name
1531  * @net: the applicable net namespace
1532  * @name: pointer to link name string
1533  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1534  *
1535  * Returns pointer to node owning the link, or 0 if no matching link is found.
1536  */
1537 static struct tipc_node *tipc_link_find_owner(struct net *net,
1538                                               const char *link_name,
1539                                               unsigned int *bearer_id)
1540 {
1541         struct tipc_net *tn = net_generic(net, tipc_net_id);
1542         struct tipc_link *l_ptr;
1543         struct tipc_node *n_ptr;
1544         struct tipc_node *found_node = NULL;
1545         int i;
1546
1547         *bearer_id = 0;
1548         rcu_read_lock();
1549         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1550                 tipc_node_lock(n_ptr);
1551                 for (i = 0; i < MAX_BEARERS; i++) {
1552                         l_ptr = n_ptr->links[i].link;
1553                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1554                                 *bearer_id = i;
1555                                 found_node = n_ptr;
1556                                 break;
1557                         }
1558                 }
1559                 tipc_node_unlock(n_ptr);
1560                 if (found_node)
1561                         break;
1562         }
1563         rcu_read_unlock();
1564
1565         return found_node;
1566 }
1567
1568 /**
1569  * link_reset_statistics - reset link statistics
1570  * @l_ptr: pointer to link
1571  */
1572 static void link_reset_statistics(struct tipc_link *l_ptr)
1573 {
1574         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1575         l_ptr->stats.sent_info = l_ptr->snd_nxt;
1576         l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1577 }
1578
1579 static void link_print(struct tipc_link *l, const char *str)
1580 {
1581         struct sk_buff *hskb = skb_peek(&l->transmq);
1582         u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
1583         u16 tail = l->snd_nxt - 1;
1584
1585         pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
1586         pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1587                 skb_queue_len(&l->transmq), head, tail,
1588                 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1589 }
1590
1591 /* Parse and validate nested (link) properties valid for media, bearer and link
1592  */
1593 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1594 {
1595         int err;
1596
1597         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1598                                tipc_nl_prop_policy);
1599         if (err)
1600                 return err;
1601
1602         if (props[TIPC_NLA_PROP_PRIO]) {
1603                 u32 prio;
1604
1605                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1606                 if (prio > TIPC_MAX_LINK_PRI)
1607                         return -EINVAL;
1608         }
1609
1610         if (props[TIPC_NLA_PROP_TOL]) {
1611                 u32 tol;
1612
1613                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1614                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1615                         return -EINVAL;
1616         }
1617
1618         if (props[TIPC_NLA_PROP_WIN]) {
1619                 u32 win;
1620
1621                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1622                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1623                         return -EINVAL;
1624         }
1625
1626         return 0;
1627 }
1628
1629 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1630 {
1631         int err;
1632         int res = 0;
1633         int bearer_id;
1634         char *name;
1635         struct tipc_link *link;
1636         struct tipc_node *node;
1637         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1638         struct net *net = sock_net(skb->sk);
1639
1640         if (!info->attrs[TIPC_NLA_LINK])
1641                 return -EINVAL;
1642
1643         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1644                                info->attrs[TIPC_NLA_LINK],
1645                                tipc_nl_link_policy);
1646         if (err)
1647                 return err;
1648
1649         if (!attrs[TIPC_NLA_LINK_NAME])
1650                 return -EINVAL;
1651
1652         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1653
1654         if (strcmp(name, tipc_bclink_name) == 0)
1655                 return tipc_nl_bc_link_set(net, attrs);
1656
1657         node = tipc_link_find_owner(net, name, &bearer_id);
1658         if (!node)
1659                 return -EINVAL;
1660
1661         tipc_node_lock(node);
1662
1663         link = node->links[bearer_id].link;
1664         if (!link) {
1665                 res = -EINVAL;
1666                 goto out;
1667         }
1668
1669         if (attrs[TIPC_NLA_LINK_PROP]) {
1670                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1671
1672                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1673                                               props);
1674                 if (err) {
1675                         res = err;
1676                         goto out;
1677                 }
1678
1679                 if (props[TIPC_NLA_PROP_TOL]) {
1680                         u32 tol;
1681
1682                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1683                         link->tolerance = tol;
1684                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1685                 }
1686                 if (props[TIPC_NLA_PROP_PRIO]) {
1687                         u32 prio;
1688
1689                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1690                         link->priority = prio;
1691                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1692                 }
1693                 if (props[TIPC_NLA_PROP_WIN]) {
1694                         u32 win;
1695
1696                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1697                         tipc_link_set_queue_limits(link, win);
1698                 }
1699         }
1700
1701 out:
1702         tipc_node_unlock(node);
1703
1704         return res;
1705 }
1706
1707 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1708 {
1709         int i;
1710         struct nlattr *stats;
1711
1712         struct nla_map {
1713                 u32 key;
1714                 u32 val;
1715         };
1716
1717         struct nla_map map[] = {
1718                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1719                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1720                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1721                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1722                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1723                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1724                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1725                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1726                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1727                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1728                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1729                         s->msg_length_counts : 1},
1730                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1731                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1732                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1733                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1734                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1735                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1736                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1737                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1738                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1739                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1740                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1741                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1742                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1743                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1744                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1745                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1746                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1747                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1748                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1749                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1750                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1751                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1752                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1753         };
1754
1755         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1756         if (!stats)
1757                 return -EMSGSIZE;
1758
1759         for (i = 0; i <  ARRAY_SIZE(map); i++)
1760                 if (nla_put_u32(skb, map[i].key, map[i].val))
1761                         goto msg_full;
1762
1763         nla_nest_end(skb, stats);
1764
1765         return 0;
1766 msg_full:
1767         nla_nest_cancel(skb, stats);
1768
1769         return -EMSGSIZE;
1770 }
1771
1772 /* Caller should hold appropriate locks to protect the link */
1773 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1774                               struct tipc_link *link, int nlflags)
1775 {
1776         int err;
1777         void *hdr;
1778         struct nlattr *attrs;
1779         struct nlattr *prop;
1780         struct tipc_net *tn = net_generic(net, tipc_net_id);
1781
1782         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1783                           nlflags, TIPC_NL_LINK_GET);
1784         if (!hdr)
1785                 return -EMSGSIZE;
1786
1787         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1788         if (!attrs)
1789                 goto msg_full;
1790
1791         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1792                 goto attr_msg_full;
1793         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1794                         tipc_cluster_mask(tn->own_addr)))
1795                 goto attr_msg_full;
1796         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1797                 goto attr_msg_full;
1798         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
1799                 goto attr_msg_full;
1800         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
1801                 goto attr_msg_full;
1802
1803         if (tipc_link_is_up(link))
1804                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1805                         goto attr_msg_full;
1806         if (tipc_link_is_active(link))
1807                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1808                         goto attr_msg_full;
1809
1810         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1811         if (!prop)
1812                 goto attr_msg_full;
1813         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1814                 goto prop_msg_full;
1815         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1816                 goto prop_msg_full;
1817         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1818                         link->window))
1819                 goto prop_msg_full;
1820         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1821                 goto prop_msg_full;
1822         nla_nest_end(msg->skb, prop);
1823
1824         err = __tipc_nl_add_stats(msg->skb, &link->stats);
1825         if (err)
1826                 goto attr_msg_full;
1827
1828         nla_nest_end(msg->skb, attrs);
1829         genlmsg_end(msg->skb, hdr);
1830
1831         return 0;
1832
1833 prop_msg_full:
1834         nla_nest_cancel(msg->skb, prop);
1835 attr_msg_full:
1836         nla_nest_cancel(msg->skb, attrs);
1837 msg_full:
1838         genlmsg_cancel(msg->skb, hdr);
1839
1840         return -EMSGSIZE;
1841 }
1842
1843 /* Caller should hold node lock  */
1844 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
1845                                     struct tipc_node *node, u32 *prev_link)
1846 {
1847         u32 i;
1848         int err;
1849
1850         for (i = *prev_link; i < MAX_BEARERS; i++) {
1851                 *prev_link = i;
1852
1853                 if (!node->links[i].link)
1854                         continue;
1855
1856                 err = __tipc_nl_add_link(net, msg,
1857                                          node->links[i].link, NLM_F_MULTI);
1858                 if (err)
1859                         return err;
1860         }
1861         *prev_link = 0;
1862
1863         return 0;
1864 }
1865
1866 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
1867 {
1868         struct net *net = sock_net(skb->sk);
1869         struct tipc_net *tn = net_generic(net, tipc_net_id);
1870         struct tipc_node *node;
1871         struct tipc_nl_msg msg;
1872         u32 prev_node = cb->args[0];
1873         u32 prev_link = cb->args[1];
1874         int done = cb->args[2];
1875         int err;
1876
1877         if (done)
1878                 return 0;
1879
1880         msg.skb = skb;
1881         msg.portid = NETLINK_CB(cb->skb).portid;
1882         msg.seq = cb->nlh->nlmsg_seq;
1883
1884         rcu_read_lock();
1885         if (prev_node) {
1886                 node = tipc_node_find(net, prev_node);
1887                 if (!node) {
1888                         /* We never set seq or call nl_dump_check_consistent()
1889                          * this means that setting prev_seq here will cause the
1890                          * consistence check to fail in the netlink callback
1891                          * handler. Resulting in the last NLMSG_DONE message
1892                          * having the NLM_F_DUMP_INTR flag set.
1893                          */
1894                         cb->prev_seq = 1;
1895                         goto out;
1896                 }
1897                 tipc_node_put(node);
1898
1899                 list_for_each_entry_continue_rcu(node, &tn->node_list,
1900                                                  list) {
1901                         tipc_node_lock(node);
1902                         err = __tipc_nl_add_node_links(net, &msg, node,
1903                                                        &prev_link);
1904                         tipc_node_unlock(node);
1905                         if (err)
1906                                 goto out;
1907
1908                         prev_node = node->addr;
1909                 }
1910         } else {
1911                 err = tipc_nl_add_bc_link(net, &msg);
1912                 if (err)
1913                         goto out;
1914
1915                 list_for_each_entry_rcu(node, &tn->node_list, list) {
1916                         tipc_node_lock(node);
1917                         err = __tipc_nl_add_node_links(net, &msg, node,
1918                                                        &prev_link);
1919                         tipc_node_unlock(node);
1920                         if (err)
1921                                 goto out;
1922
1923                         prev_node = node->addr;
1924                 }
1925         }
1926         done = 1;
1927 out:
1928         rcu_read_unlock();
1929
1930         cb->args[0] = prev_node;
1931         cb->args[1] = prev_link;
1932         cb->args[2] = done;
1933
1934         return skb->len;
1935 }
1936
1937 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
1938 {
1939         struct net *net = genl_info_net(info);
1940         struct tipc_nl_msg msg;
1941         char *name;
1942         int err;
1943
1944         msg.portid = info->snd_portid;
1945         msg.seq = info->snd_seq;
1946
1947         if (!info->attrs[TIPC_NLA_LINK_NAME])
1948                 return -EINVAL;
1949         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
1950
1951         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1952         if (!msg.skb)
1953                 return -ENOMEM;
1954
1955         if (strcmp(name, tipc_bclink_name) == 0) {
1956                 err = tipc_nl_add_bc_link(net, &msg);
1957                 if (err) {
1958                         nlmsg_free(msg.skb);
1959                         return err;
1960                 }
1961         } else {
1962                 int bearer_id;
1963                 struct tipc_node *node;
1964                 struct tipc_link *link;
1965
1966                 node = tipc_link_find_owner(net, name, &bearer_id);
1967                 if (!node)
1968                         return -EINVAL;
1969
1970                 tipc_node_lock(node);
1971                 link = node->links[bearer_id].link;
1972                 if (!link) {
1973                         tipc_node_unlock(node);
1974                         nlmsg_free(msg.skb);
1975                         return -EINVAL;
1976                 }
1977
1978                 err = __tipc_nl_add_link(net, &msg, link, 0);
1979                 tipc_node_unlock(node);
1980                 if (err) {
1981                         nlmsg_free(msg.skb);
1982                         return err;
1983                 }
1984         }
1985
1986         return genlmsg_reply(msg.skb, info);
1987 }
1988
1989 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
1990 {
1991         int err;
1992         char *link_name;
1993         unsigned int bearer_id;
1994         struct tipc_link *link;
1995         struct tipc_node *node;
1996         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1997         struct net *net = sock_net(skb->sk);
1998
1999         if (!info->attrs[TIPC_NLA_LINK])
2000                 return -EINVAL;
2001
2002         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2003                                info->attrs[TIPC_NLA_LINK],
2004                                tipc_nl_link_policy);
2005         if (err)
2006                 return err;
2007
2008         if (!attrs[TIPC_NLA_LINK_NAME])
2009                 return -EINVAL;
2010
2011         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2012
2013         if (strcmp(link_name, tipc_bclink_name) == 0) {
2014                 err = tipc_bclink_reset_stats(net);
2015                 if (err)
2016                         return err;
2017                 return 0;
2018         }
2019
2020         node = tipc_link_find_owner(net, link_name, &bearer_id);
2021         if (!node)
2022                 return -EINVAL;
2023
2024         tipc_node_lock(node);
2025
2026         link = node->links[bearer_id].link;
2027         if (!link) {
2028                 tipc_node_unlock(node);
2029                 return -EINVAL;
2030         }
2031
2032         link_reset_statistics(link);
2033
2034         tipc_node_unlock(node);
2035
2036         return 0;
2037 }