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