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