net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, 2012-2015, Ericsson AB
   5  * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "core.h"
  38 #include "subscr.h"
  39 #include "link.h"
  40 #include "bcast.h"
  41 #include "socket.h"
  42 #include "name_distr.h"
  43 #include "discover.h"
  44 #include "netlink.h"
  45
  46 #include <linux/pkt_sched.h>
  47
  48 /*
  49  * Error message prefixes
  50  */
  51 static const char *link_co_err = "Link tunneling error, ";
  52 static const char *link_rst_msg = "Resetting link ";
  53 static const char tipc_bclink_name[] = "broadcast-link";
  54
  55 static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
  56         [TIPC_NLA_LINK_UNSPEC]          = { .type = NLA_UNSPEC },
  57         [TIPC_NLA_LINK_NAME] = {
  58                 .type = NLA_STRING,
  59                 .len = TIPC_MAX_LINK_NAME
  60         },
  61         [TIPC_NLA_LINK_MTU]             = { .type = NLA_U32 },
  62         [TIPC_NLA_LINK_BROADCAST]       = { .type = NLA_FLAG },
  63         [TIPC_NLA_LINK_UP]              = { .type = NLA_FLAG },
  64         [TIPC_NLA_LINK_ACTIVE]          = { .type = NLA_FLAG },
  65         [TIPC_NLA_LINK_PROP]            = { .type = NLA_NESTED },
  66         [TIPC_NLA_LINK_STATS]           = { .type = NLA_NESTED },
  67         [TIPC_NLA_LINK_RX]              = { .type = NLA_U32 },
  68         [TIPC_NLA_LINK_TX]              = { .type = NLA_U32 }
  69 };
  70
  71 /* Properties valid for media, bearar and link */
  72 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
  73         [TIPC_NLA_PROP_UNSPEC]          = { .type = NLA_UNSPEC },
  74         [TIPC_NLA_PROP_PRIO]            = { .type = NLA_U32 },
  75         [TIPC_NLA_PROP_TOL]             = { .type = NLA_U32 },
  76         [TIPC_NLA_PROP_WIN]             = { .type = NLA_U32 }
  77 };
  78
  79 /*
  80  * Interval between NACKs when packets arrive out of order
  81  */
  82 #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
  83 /*
  84  * Out-of-range value for link session numbers
  85  */
  86 #define WILDCARD_SESSION 0x10000
  87
  88 /* Link FSM states:
  89  */
  90 enum {
  91         LINK_ESTABLISHED     = 0xe,
  92         LINK_ESTABLISHING    = 0xe  << 4,
  93         LINK_RESET           = 0x1  << 8,
  94         LINK_RESETTING       = 0x2  << 12,
  95         LINK_PEER_RESET      = 0xd  << 16,
  96         LINK_FAILINGOVER     = 0xf  << 20,
  97         LINK_SYNCHING        = 0xc  << 24
  98 };
  99
 100 /* Link FSM state checking routines
 101  */
 102 static int link_is_up(struct tipc_link *l)
 103 {
 104         return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
 105 }
 106
 107 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 108                                struct sk_buff_head *xmitq);
 109 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 110                                       u16 rcvgap, int tolerance, int priority,
 111                                       struct sk_buff_head *xmitq);
 112 static void link_reset_statistics(struct tipc_link *l_ptr);
 113 static void link_print(struct tipc_link *l_ptr, const char *str);
 114 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 115
 116 /*
 117  *  Simple non-static link routines (i.e. referenced outside this file)
 118  */
 119 bool tipc_link_is_up(struct tipc_link *l)
 120 {
 121         return link_is_up(l);
 122 }
 123
 124 bool tipc_link_peer_is_down(struct tipc_link *l)
 125 {
 126         return l->state == LINK_PEER_RESET;
 127 }
 128
 129 bool tipc_link_is_reset(struct tipc_link *l)
 130 {
 131         return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
 132 }
 133
 134 bool tipc_link_is_establishing(struct tipc_link *l)
 135 {
 136         return l->state == LINK_ESTABLISHING;
 137 }
 138
 139 bool tipc_link_is_synching(struct tipc_link *l)
 140 {
 141         return l->state == LINK_SYNCHING;
 142 }
 143
 144 bool tipc_link_is_failingover(struct tipc_link *l)
 145 {
 146         return l->state == LINK_FAILINGOVER;
 147 }
 148
 149 bool tipc_link_is_blocked(struct tipc_link *l)
 150 {
 151         return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
 152 }
 153
 154 int tipc_link_is_active(struct tipc_link *l)
 155 {
 156         struct tipc_node *n = l->owner;
 157
 158         return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
 159 }
 160
 161 void tipc_link_add_bc_peer(struct tipc_link *l)
 162 {
 163         l->ackers++;
 164 }
 165
 166 void tipc_link_remove_bc_peer(struct tipc_link *l)
 167 {
 168         l->ackers--;
 169 }
 170
 171 int tipc_link_bc_peers(struct tipc_link *l)
 172 {
 173         return l->ackers;
 174 }
 175
 176 static u32 link_own_addr(struct tipc_link *l)
 177 {
 178         return msg_prevnode(l->pmsg);
 179 }
 180
 181 /**
 182  * tipc_link_create - create a new link
 183  * @n: pointer to associated node
 184  * @if_name: associated interface name
 185  * @bearer_id: id (index) of associated bearer
 186  * @tolerance: link tolerance to be used by link
 187  * @net_plane: network plane (A,B,c..) this link belongs to
 188  * @mtu: mtu to be advertised by link
 189  * @priority: priority to be used by link
 190  * @window: send window to be used by link
 191  * @session: session to be used by link
 192  * @ownnode: identity of own node
 193  * @peer: node id of peer node
 194  * @peer_caps: bitmap describing peer node capabilities
 195  * @maddr: media address to be used
 196  * @inputq: queue to put messages ready for delivery
 197  * @namedq: queue to put binding table update messages ready for delivery
 198  * @link: return value, pointer to put the created link
 199  *
 200  * Returns true if link was created, otherwise false
 201  */
 202 bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
 203                       int tolerance, char net_plane, u32 mtu, int priority,
 204                       int window, u32 session, u32 ownnode, u32 peer,
 205                       u16 peer_caps, struct tipc_media_addr *maddr,
 206                       struct sk_buff_head *inputq, struct sk_buff_head *namedq,
 207                       struct tipc_link **link)
 208 {
 209         struct tipc_link *l;
 210         struct tipc_msg *hdr;
 211
 212         l = kzalloc(sizeof(*l), GFP_ATOMIC);
 213         if (!l)
 214                 return false;
 215         *link = l;
 216         l->pmsg = (struct tipc_msg *)&l->proto_msg;
 217         hdr = l->pmsg;
 218         tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
 219         msg_set_size(hdr, sizeof(l->proto_msg));
 220         msg_set_session(hdr, session);
 221         msg_set_bearer_id(hdr, l->bearer_id);
 222
 223         /* Note: peer i/f name is completed by reset/activate message */
 224         sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 225                 tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
 226                 if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 227         strcpy((char *)msg_data(hdr), if_name);
 228
 229         l->addr = peer;
 230         l->peer_caps = peer_caps;
 231         l->media_addr = maddr;
 232         l->owner = n;
 233         l->peer_session = WILDCARD_SESSION;
 234         l->bearer_id = bearer_id;
 235         l->tolerance = tolerance;
 236         l->net_plane = net_plane;
 237         l->advertised_mtu = mtu;
 238         l->mtu = mtu;
 239         l->priority = priority;
 240         tipc_link_set_queue_limits(l, window);
 241         l->ackers = 1;
 242         l->inputq = inputq;
 243         l->namedq = namedq;
 244         l->state = LINK_RESETTING;
 245         __skb_queue_head_init(&l->transmq);
 246         __skb_queue_head_init(&l->backlogq);
 247         __skb_queue_head_init(&l->deferdq);
 248         skb_queue_head_init(&l->wakeupq);
 249         skb_queue_head_init(l->inputq);
 250         return true;
 251 }
 252
 253 /**
 254  * tipc_link_bc_create - create new link to be used for broadcast
 255  * @n: pointer to associated node
 256  * @mtu: mtu to be used
 257  * @window: send window to be used
 258  * @inputq: queue to put messages ready for delivery
 259  * @namedq: queue to put binding table update messages ready for delivery
 260  * @link: return value, pointer to put the created link
 261  *
 262  * Returns true if link was created, otherwise false
 263  */
 264 bool tipc_link_bc_create(struct tipc_node *n, int mtu, int window,
 265                          u16 peer_caps,
 266                          struct sk_buff_head *inputq,
 267                          struct sk_buff_head *namedq,
 268                          struct tipc_link **link)
 269 {
 270         struct tipc_link *l;
 271
 272         if (!tipc_link_create(n, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
 273                               0, 0, 0, peer_caps, NULL, inputq, namedq, link))
 274                 return false;
 275
 276         l = *link;
 277         strcpy(l->name, tipc_bclink_name);
 278         tipc_link_reset(l);
 279         l->ackers = 0;
 280         return true;
 281 }
 282
 283 /* tipc_link_build_bcast_sync_msg() - synchronize broadcast link endpoints.
 284  *
 285  * Give a newly added peer node the sequence number where it should
 286  * start receiving and acking broadcast packets.
 287  */
 288 void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
 289                                     struct sk_buff_head *xmitq)
 290 {
 291         struct sk_buff *skb;
 292         struct sk_buff_head list;
 293         u16 last_sent;
 294
 295         skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
 296                               0, l->addr, link_own_addr(l), 0, 0, 0);
 297         if (!skb)
 298                 return;
 299         last_sent = tipc_bclink_get_last_sent(l->owner->net);
 300         msg_set_last_bcast(buf_msg(skb), last_sent);
 301         __skb_queue_head_init(&list);
 302         __skb_queue_tail(&list, skb);
 303         tipc_link_xmit(l, &list, xmitq);
 304 }
 305
 306 /**
 307  * tipc_link_fsm_evt - link finite state machine
 308  * @l: pointer to link
 309  * @evt: state machine event to be processed
 310  */
 311 int tipc_link_fsm_evt(struct tipc_link *l, int evt)
 312 {
 313         int rc = 0;
 314
 315         switch (l->state) {
 316         case LINK_RESETTING:
 317                 switch (evt) {
 318                 case LINK_PEER_RESET_EVT:
 319                         l->state = LINK_PEER_RESET;
 320                         break;
 321                 case LINK_RESET_EVT:
 322                         l->state = LINK_RESET;
 323                         break;
 324                 case LINK_FAILURE_EVT:
 325                 case LINK_FAILOVER_BEGIN_EVT:
 326                 case LINK_ESTABLISH_EVT:
 327                 case LINK_FAILOVER_END_EVT:
 328                 case LINK_SYNCH_BEGIN_EVT:
 329                 case LINK_SYNCH_END_EVT:
 330                 default:
 331                         goto illegal_evt;
 332                 }
 333                 break;
 334         case LINK_RESET:
 335                 switch (evt) {
 336                 case LINK_PEER_RESET_EVT:
 337                         l->state = LINK_ESTABLISHING;
 338                         break;
 339                 case LINK_FAILOVER_BEGIN_EVT:
 340                         l->state = LINK_FAILINGOVER;
 341                 case LINK_FAILURE_EVT:
 342                 case LINK_RESET_EVT:
 343                 case LINK_ESTABLISH_EVT:
 344                 case LINK_FAILOVER_END_EVT:
 345                         break;
 346                 case LINK_SYNCH_BEGIN_EVT:
 347                 case LINK_SYNCH_END_EVT:
 348                 default:
 349                         goto illegal_evt;
 350                 }
 351                 break;
 352         case LINK_PEER_RESET:
 353                 switch (evt) {
 354                 case LINK_RESET_EVT:
 355                         l->state = LINK_ESTABLISHING;
 356                         break;
 357                 case LINK_PEER_RESET_EVT:
 358                 case LINK_ESTABLISH_EVT:
 359                 case LINK_FAILURE_EVT:
 360                         break;
 361                 case LINK_SYNCH_BEGIN_EVT:
 362                 case LINK_SYNCH_END_EVT:
 363                 case LINK_FAILOVER_BEGIN_EVT:
 364                 case LINK_FAILOVER_END_EVT:
 365                 default:
 366                         goto illegal_evt;
 367                 }
 368                 break;
 369         case LINK_FAILINGOVER:
 370                 switch (evt) {
 371                 case LINK_FAILOVER_END_EVT:
 372                         l->state = LINK_RESET;
 373                         break;
 374                 case LINK_PEER_RESET_EVT:
 375                 case LINK_RESET_EVT:
 376                 case LINK_ESTABLISH_EVT:
 377                 case LINK_FAILURE_EVT:
 378                         break;
 379                 case LINK_FAILOVER_BEGIN_EVT:
 380                 case LINK_SYNCH_BEGIN_EVT:
 381                 case LINK_SYNCH_END_EVT:
 382                 default:
 383                         goto illegal_evt;
 384                 }
 385                 break;
 386         case LINK_ESTABLISHING:
 387                 switch (evt) {
 388                 case LINK_ESTABLISH_EVT:
 389                         l->state = LINK_ESTABLISHED;
 390                         break;
 391                 case LINK_FAILOVER_BEGIN_EVT:
 392                         l->state = LINK_FAILINGOVER;
 393                         break;
 394                 case LINK_RESET_EVT:
 395                         l->state = LINK_RESET;
 396                         break;
 397                 case LINK_FAILURE_EVT:
 398                 case LINK_PEER_RESET_EVT:
 399                 case LINK_SYNCH_BEGIN_EVT:
 400                 case LINK_FAILOVER_END_EVT:
 401                         break;
 402                 case LINK_SYNCH_END_EVT:
 403                 default:
 404                         goto illegal_evt;
 405                 }
 406                 break;
 407         case LINK_ESTABLISHED:
 408                 switch (evt) {
 409                 case LINK_PEER_RESET_EVT:
 410                         l->state = LINK_PEER_RESET;
 411                         rc |= TIPC_LINK_DOWN_EVT;
 412                         break;
 413                 case LINK_FAILURE_EVT:
 414                         l->state = LINK_RESETTING;
 415                         rc |= TIPC_LINK_DOWN_EVT;
 416                         break;
 417                 case LINK_RESET_EVT:
 418                         l->state = LINK_RESET;
 419                         break;
 420                 case LINK_ESTABLISH_EVT:
 421                 case LINK_SYNCH_END_EVT:
 422                         break;
 423                 case LINK_SYNCH_BEGIN_EVT:
 424                         l->state = LINK_SYNCHING;
 425                         break;
 426                 case LINK_FAILOVER_BEGIN_EVT:
 427                 case LINK_FAILOVER_END_EVT:
 428                 default:
 429                         goto illegal_evt;
 430                 }
 431                 break;
 432         case LINK_SYNCHING:
 433                 switch (evt) {
 434                 case LINK_PEER_RESET_EVT:
 435                         l->state = LINK_PEER_RESET;
 436                         rc |= TIPC_LINK_DOWN_EVT;
 437                         break;
 438                 case LINK_FAILURE_EVT:
 439                         l->state = LINK_RESETTING;
 440                         rc |= TIPC_LINK_DOWN_EVT;
 441                         break;
 442                 case LINK_RESET_EVT:
 443                         l->state = LINK_RESET;
 444                         break;
 445                 case LINK_ESTABLISH_EVT:
 446                 case LINK_SYNCH_BEGIN_EVT:
 447                         break;
 448                 case LINK_SYNCH_END_EVT:
 449                         l->state = LINK_ESTABLISHED;
 450                         break;
 451                 case LINK_FAILOVER_BEGIN_EVT:
 452                 case LINK_FAILOVER_END_EVT:
 453                 default:
 454                         goto illegal_evt;
 455                 }
 456                 break;
 457         default:
 458                 pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
 459         }
 460         return rc;
 461 illegal_evt:
 462         pr_err("Illegal FSM event %x in state %x on link %s\n",
 463                evt, l->state, l->name);
 464         return rc;
 465 }
 466
 467 /* link_profile_stats - update statistical profiling of traffic
 468  */
 469 static void link_profile_stats(struct tipc_link *l)
 470 {
 471         struct sk_buff *skb;
 472         struct tipc_msg *msg;
 473         int length;
 474
 475         /* Update counters used in statistical profiling of send traffic */
 476         l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 477         l->stats.queue_sz_counts++;
 478
 479         skb = skb_peek(&l->transmq);
 480         if (!skb)
 481                 return;
 482         msg = buf_msg(skb);
 483         length = msg_size(msg);
 484
 485         if (msg_user(msg) == MSG_FRAGMENTER) {
 486                 if (msg_type(msg) != FIRST_FRAGMENT)
 487                         return;
 488                 length = msg_size(msg_get_wrapped(msg));
 489         }
 490         l->stats.msg_lengths_total += length;
 491         l->stats.msg_length_counts++;
 492         if (length <= 64)
 493                 l->stats.msg_length_profile[0]++;
 494         else if (length <= 256)
 495                 l->stats.msg_length_profile[1]++;
 496         else if (length <= 1024)
 497                 l->stats.msg_length_profile[2]++;
 498         else if (length <= 4096)
 499                 l->stats.msg_length_profile[3]++;
 500         else if (length <= 16384)
 501                 l->stats.msg_length_profile[4]++;
 502         else if (length <= 32768)
 503                 l->stats.msg_length_profile[5]++;
 504         else
 505                 l->stats.msg_length_profile[6]++;
 506 }
 507
 508 /* tipc_link_timeout - perform periodic task as instructed from node timeout
 509  */
 510 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 511 {
 512         int rc = 0;
 513         int mtyp = STATE_MSG;
 514         bool xmit = false;
 515         bool prb = false;
 516
 517         link_profile_stats(l);
 518
 519         switch (l->state) {
 520         case LINK_ESTABLISHED:
 521         case LINK_SYNCHING:
 522                 if (!l->silent_intv_cnt) {
 523                         if (tipc_bclink_acks_missing(l->owner))
 524                                 xmit = true;
 525                 } else if (l->silent_intv_cnt <= l->abort_limit) {
 526                         xmit = true;
 527                         prb = true;
 528                 } else {
 529                         rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 530                 }
 531                 l->silent_intv_cnt++;
 532                 break;
 533         case LINK_RESET:
 534                 xmit = true;
 535                 mtyp = RESET_MSG;
 536                 break;
 537         case LINK_ESTABLISHING:
 538                 xmit = true;
 539                 mtyp = ACTIVATE_MSG;
 540                 break;
 541         case LINK_PEER_RESET:
 542         case LINK_RESETTING:
 543         case LINK_FAILINGOVER:
 544                 break;
 545         default:
 546                 break;
 547         }
 548
 549         if (xmit)
 550                 tipc_link_build_proto_msg(l, mtyp, prb, 0, 0, 0, xmitq);
 551
 552         return rc;
 553 }
 554
 555 /**
 556  * link_schedule_user - schedule a message sender for wakeup after congestion
 557  * @link: congested link
 558  * @list: message that was attempted sent
 559  * Create pseudo msg to send back to user when congestion abates
 560  * Does not consume buffer list
 561  */
 562 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 563 {
 564         struct tipc_msg *msg = buf_msg(skb_peek(list));
 565         int imp = msg_importance(msg);
 566         u32 oport = msg_origport(msg);
 567         u32 addr = link_own_addr(link);
 568         struct sk_buff *skb;
 569
 570         /* This really cannot happen...  */
 571         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 572                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 573                 return -ENOBUFS;
 574         }
 575         /* Non-blocking sender: */
 576         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 577                 return -ELINKCONG;
 578
 579         /* Create and schedule wakeup pseudo message */
 580         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 581                               addr, addr, oport, 0, 0);
 582         if (!skb)
 583                 return -ENOBUFS;
 584         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 585         TIPC_SKB_CB(skb)->chain_imp = imp;
 586         skb_queue_tail(&link->wakeupq, skb);
 587         link->stats.link_congs++;
 588         return -ELINKCONG;
 589 }
 590
 591 /**
 592  * link_prepare_wakeup - prepare users for wakeup after congestion
 593  * @link: congested link
 594  * Move a number of waiting users, as permitted by available space in
 595  * the send queue, from link wait queue to node wait queue for wakeup
 596  */
 597 void link_prepare_wakeup(struct tipc_link *l)
 598 {
 599         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 600         int imp, lim;
 601         struct sk_buff *skb, *tmp;
 602
 603         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 604                 imp = TIPC_SKB_CB(skb)->chain_imp;
 605                 lim = l->window + l->backlog[imp].limit;
 606                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 607                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 608                         break;
 609                 skb_unlink(skb, &l->wakeupq);
 610                 skb_queue_tail(l->inputq, skb);
 611         }
 612 }
 613
 614 /**
 615  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 616  * @l_ptr: pointer to link
 617  */
 618 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 619 {
 620         kfree_skb(l_ptr->reasm_buf);
 621         l_ptr->reasm_buf = NULL;
 622 }
 623
 624 void tipc_link_purge_backlog(struct tipc_link *l)
 625 {
 626         __skb_queue_purge(&l->backlogq);
 627         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 628         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 629         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 630         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 631         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 632 }
 633
 634 /**
 635  * tipc_link_purge_queues - purge all pkt queues associated with link
 636  * @l_ptr: pointer to link
 637  */
 638 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 639 {
 640         __skb_queue_purge(&l_ptr->deferdq);
 641         __skb_queue_purge(&l_ptr->transmq);
 642         tipc_link_purge_backlog(l_ptr);
 643         tipc_link_reset_fragments(l_ptr);
 644 }
 645
 646 void tipc_link_reset(struct tipc_link *l)
 647 {
 648         /* Link is down, accept any session */
 649         l->peer_session = WILDCARD_SESSION;
 650
 651         /* If peer is up, it only accepts an incremented session number */
 652         msg_set_session(l->pmsg, msg_session(l->pmsg) + 1);
 653
 654         /* Prepare for renewed mtu size negotiation */
 655         l->mtu = l->advertised_mtu;
 656
 657         /* Clean up all queues: */
 658         __skb_queue_purge(&l->transmq);
 659         __skb_queue_purge(&l->deferdq);
 660         skb_queue_splice_init(&l->wakeupq, l->inputq);
 661
 662         tipc_link_purge_backlog(l);
 663         kfree_skb(l->reasm_buf);
 664         kfree_skb(l->failover_reasm_skb);
 665         l->reasm_buf = NULL;
 666         l->failover_reasm_skb = NULL;
 667         l->rcv_unacked = 0;
 668         l->snd_nxt = 1;
 669         l->rcv_nxt = 1;
 670         l->acked = 0;
 671         l->silent_intv_cnt = 0;
 672         l->stats.recv_info = 0;
 673         l->stale_count = 0;
 674         link_reset_statistics(l);
 675 }
 676
 677 /**
 678  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 679  * @link: link to use
 680  * @list: chain of buffers containing message
 681  *
 682  * Consumes the buffer chain, except when returning an error code,
 683  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 684  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 685  */
 686 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 687                      struct sk_buff_head *list)
 688 {
 689         struct tipc_msg *msg = buf_msg(skb_peek(list));
 690         unsigned int maxwin = link->window;
 691         unsigned int i, imp = msg_importance(msg);
 692         uint mtu = link->mtu;
 693         u16 ack = mod(link->rcv_nxt - 1);
 694         u16 seqno = link->snd_nxt;
 695         u16 bc_last_in = link->owner->bclink.last_in;
 696         struct tipc_media_addr *addr = link->media_addr;
 697         struct sk_buff_head *transmq = &link->transmq;
 698         struct sk_buff_head *backlogq = &link->backlogq;
 699         struct sk_buff *skb, *bskb;
 700
 701         /* Match msg importance against this and all higher backlog limits: */
 702         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 703                 if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
 704                         return link_schedule_user(link, list);
 705         }
 706         if (unlikely(msg_size(msg) > mtu))
 707                 return -EMSGSIZE;
 708
 709         /* Prepare each packet for sending, and add to relevant queue: */
 710         while (skb_queue_len(list)) {
 711                 skb = skb_peek(list);
 712                 msg = buf_msg(skb);
 713                 msg_set_seqno(msg, seqno);
 714                 msg_set_ack(msg, ack);
 715                 msg_set_bcast_ack(msg, bc_last_in);
 716
 717                 if (likely(skb_queue_len(transmq) < maxwin)) {
 718                         __skb_dequeue(list);
 719                         __skb_queue_tail(transmq, skb);
 720                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 721                         link->rcv_unacked = 0;
 722                         seqno++;
 723                         continue;
 724                 }
 725                 if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
 726                         kfree_skb(__skb_dequeue(list));
 727                         link->stats.sent_bundled++;
 728                         continue;
 729                 }
 730                 if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
 731                         kfree_skb(__skb_dequeue(list));
 732                         __skb_queue_tail(backlogq, bskb);
 733                         link->backlog[msg_importance(buf_msg(bskb))].len++;
 734                         link->stats.sent_bundled++;
 735                         link->stats.sent_bundles++;
 736                         continue;
 737                 }
 738                 link->backlog[imp].len += skb_queue_len(list);
 739                 skb_queue_splice_tail_init(list, backlogq);
 740         }
 741         link->snd_nxt = seqno;
 742         return 0;
 743 }
 744
 745 /**
 746  * tipc_link_xmit(): enqueue buffer list according to queue situation
 747  * @link: link to use
 748  * @list: chain of buffers containing message
 749  * @xmitq: returned list of packets to be sent by caller
 750  *
 751  * Consumes the buffer chain, except when returning -ELINKCONG,
 752  * since the caller then may want to make more send attempts.
 753  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 754  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 755  */
 756 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 757                    struct sk_buff_head *xmitq)
 758 {
 759         struct tipc_msg *hdr = buf_msg(skb_peek(list));
 760         unsigned int maxwin = l->window;
 761         unsigned int i, imp = msg_importance(hdr);
 762         unsigned int mtu = l->mtu;
 763         u16 ack = l->rcv_nxt - 1;
 764         u16 seqno = l->snd_nxt;
 765         u16 bc_last_in = l->owner->bclink.last_in;
 766         struct sk_buff_head *transmq = &l->transmq;
 767         struct sk_buff_head *backlogq = &l->backlogq;
 768         struct sk_buff *skb, *_skb, *bskb;
 769
 770         /* Match msg importance against this and all higher backlog limits: */
 771         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 772                 if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
 773                         return link_schedule_user(l, list);
 774         }
 775         if (unlikely(msg_size(hdr) > mtu))
 776                 return -EMSGSIZE;
 777
 778         /* Prepare each packet for sending, and add to relevant queue: */
 779         while (skb_queue_len(list)) {
 780                 skb = skb_peek(list);
 781                 hdr = buf_msg(skb);
 782                 msg_set_seqno(hdr, seqno);
 783                 msg_set_ack(hdr, ack);
 784                 msg_set_bcast_ack(hdr, bc_last_in);
 785
 786                 if (likely(skb_queue_len(transmq) < maxwin)) {
 787                         _skb = skb_clone(skb, GFP_ATOMIC);
 788                         if (!_skb)
 789                                 return -ENOBUFS;
 790                         __skb_dequeue(list);
 791                         __skb_queue_tail(transmq, skb);
 792                         __skb_queue_tail(xmitq, _skb);
 793                         TIPC_SKB_CB(skb)->ackers = l->ackers;
 794                         l->rcv_unacked = 0;
 795                         seqno++;
 796                         continue;
 797                 }
 798                 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
 799                         kfree_skb(__skb_dequeue(list));
 800                         l->stats.sent_bundled++;
 801                         continue;
 802                 }
 803                 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
 804                         kfree_skb(__skb_dequeue(list));
 805                         __skb_queue_tail(backlogq, bskb);
 806                         l->backlog[msg_importance(buf_msg(bskb))].len++;
 807                         l->stats.sent_bundled++;
 808                         l->stats.sent_bundles++;
 809                         continue;
 810                 }
 811                 l->backlog[imp].len += skb_queue_len(list);
 812                 skb_queue_splice_tail_init(list, backlogq);
 813         }
 814         l->snd_nxt = seqno;
 815         return 0;
 816 }
 817
 818 /*
 819  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 820  * Receive the sequence number where we should start receiving and
 821  * acking broadcast packets from a newly added peer node, and open
 822  * up for reception of such packets.
 823  *
 824  * Called with node locked
 825  */
 826 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 827 {
 828         struct tipc_msg *msg = buf_msg(buf);
 829
 830         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 831         n->bclink.recv_permitted = true;
 832         kfree_skb(buf);
 833 }
 834
 835 /*
 836  * tipc_link_push_packets - push unsent packets to bearer
 837  *
 838  * Push out the unsent messages of a link where congestion
 839  * has abated. Node is locked.
 840  *
 841  * Called with node locked
 842  */
 843 void tipc_link_push_packets(struct tipc_link *link)
 844 {
 845         struct sk_buff *skb;
 846         struct tipc_msg *msg;
 847         u16 seqno = link->snd_nxt;
 848         u16 ack = mod(link->rcv_nxt - 1);
 849
 850         while (skb_queue_len(&link->transmq) < link->window) {
 851                 skb = __skb_dequeue(&link->backlogq);
 852                 if (!skb)
 853                         break;
 854                 TIPC_SKB_CB(skb)->ackers = link->ackers;
 855                 msg = buf_msg(skb);
 856                 link->backlog[msg_importance(msg)].len--;
 857                 msg_set_ack(msg, ack);
 858                 msg_set_seqno(msg, seqno);
 859                 seqno = mod(seqno + 1);
 860                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 861                 link->rcv_unacked = 0;
 862                 __skb_queue_tail(&link->transmq, skb);
 863                 tipc_bearer_send(link->owner->net, link->bearer_id,
 864                                  skb, link->media_addr);
 865         }
 866         link->snd_nxt = seqno;
 867 }
 868
 869 void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
 870 {
 871         struct sk_buff *skb, *_skb;
 872         struct tipc_msg *hdr;
 873         u16 seqno = l->snd_nxt;
 874         u16 ack = l->rcv_nxt - 1;
 875
 876         while (skb_queue_len(&l->transmq) < l->window) {
 877                 skb = skb_peek(&l->backlogq);
 878                 if (!skb)
 879                         break;
 880                 _skb = skb_clone(skb, GFP_ATOMIC);
 881                 if (!_skb)
 882                         break;
 883                 __skb_dequeue(&l->backlogq);
 884                 hdr = buf_msg(skb);
 885                 l->backlog[msg_importance(hdr)].len--;
 886                 __skb_queue_tail(&l->transmq, skb);
 887                 __skb_queue_tail(xmitq, _skb);
 888                 TIPC_SKB_CB(skb)->ackers = l->ackers;
 889                 msg_set_ack(hdr, ack);
 890                 msg_set_seqno(hdr, seqno);
 891                 msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
 892                 l->rcv_unacked = 0;
 893                 seqno++;
 894         }
 895         l->snd_nxt = seqno;
 896 }
 897
 898 static void link_retransmit_failure(struct tipc_link *l_ptr,
 899                                     struct sk_buff *buf)
 900 {
 901         struct tipc_msg *msg = buf_msg(buf);
 902         struct net *net = l_ptr->owner->net;
 903
 904         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 905
 906         if (l_ptr->addr) {
 907                 /* Handle failure on standard link */
 908                 link_print(l_ptr, "Resetting link ");
 909                 pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
 910                         msg_user(msg), msg_type(msg), msg_size(msg),
 911                         msg_errcode(msg));
 912                 pr_info("sqno %u, prev: %x, src: %x\n",
 913                         msg_seqno(msg), msg_prevnode(msg), msg_orignode(msg));
 914         } else {
 915                 /* Handle failure on broadcast link */
 916                 struct tipc_node *n_ptr;
 917                 char addr_string[16];
 918
 919                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 920                 pr_cont("Outstanding acks: %u\n", TIPC_SKB_CB(buf)->ackers);
 921
 922                 n_ptr = tipc_bclink_retransmit_to(net);
 923
 924                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 925                 pr_info("Broadcast link info for %s\n", addr_string);
 926                 pr_info("Reception permitted: %d,  Acked: %u\n",
 927                         n_ptr->bclink.recv_permitted,
 928                         n_ptr->bclink.acked);
 929                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 930                         n_ptr->bclink.last_in,
 931                         n_ptr->bclink.oos_state,
 932                         n_ptr->bclink.last_sent);
 933
 934                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 935                 l_ptr->stale_count = 0;
 936         }
 937 }
 938
 939 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 940                           u32 retransmits)
 941 {
 942         struct tipc_msg *msg;
 943
 944         if (!skb)
 945                 return;
 946
 947         msg = buf_msg(skb);
 948
 949         /* Detect repeated retransmit failures */
 950         if (l_ptr->last_retransm == msg_seqno(msg)) {
 951                 if (++l_ptr->stale_count > 100) {
 952                         link_retransmit_failure(l_ptr, skb);
 953                         return;
 954                 }
 955         } else {
 956                 l_ptr->last_retransm = msg_seqno(msg);
 957                 l_ptr->stale_count = 1;
 958         }
 959
 960         skb_queue_walk_from(&l_ptr->transmq, skb) {
 961                 if (!retransmits)
 962                         break;
 963                 msg = buf_msg(skb);
 964                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
 965                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 966                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 967                                  l_ptr->media_addr);
 968                 retransmits--;
 969                 l_ptr->stats.retransmitted++;
 970         }
 971 }
 972
 973 int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
 974                       struct sk_buff_head *xmitq)
 975 {
 976         struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
 977         struct tipc_msg *hdr;
 978         u16 ack = l->rcv_nxt - 1;
 979         u16 bc_ack = l->owner->bclink.last_in;
 980
 981         if (!skb)
 982                 return 0;
 983
 984         /* Detect repeated retransmit failures on same packet */
 985         if (likely(l->last_retransm != buf_seqno(skb))) {
 986                 l->last_retransm = buf_seqno(skb);
 987                 l->stale_count = 1;
 988         } else if (++l->stale_count > 100) {
 989                 link_retransmit_failure(l, skb);
 990                 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 991         }
 992
 993         /* Move forward to where retransmission should start */
 994         skb_queue_walk(&l->transmq, skb) {
 995                 if (!less(buf_seqno(skb), from))
 996                         break;
 997         }
 998
 999         skb_queue_walk_from(&l->transmq, skb) {
1000                 if (more(buf_seqno(skb), to))
1001                         break;
1002                 hdr = buf_msg(skb);
1003                 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
1004                 if (!_skb)
1005                         return 0;
1006                 hdr = buf_msg(_skb);
1007                 msg_set_ack(hdr, ack);
1008                 msg_set_bcast_ack(hdr, bc_ack);
1009                 _skb->priority = TC_PRIO_CONTROL;
1010                 __skb_queue_tail(xmitq, _skb);
1011                 l->stats.retransmitted++;
1012         }
1013         return 0;
1014 }
1015
1016 /* tipc_data_input - deliver data and name distr msgs to upper layer
1017  *
1018  * Consumes buffer if message is of right type
1019  * Node lock must be held
1020  */
1021 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb,
1022                             struct sk_buff_head *inputq)
1023 {
1024         struct tipc_node *node = link->owner;
1025
1026         switch (msg_user(buf_msg(skb))) {
1027         case TIPC_LOW_IMPORTANCE:
1028         case TIPC_MEDIUM_IMPORTANCE:
1029         case TIPC_HIGH_IMPORTANCE:
1030         case TIPC_CRITICAL_IMPORTANCE:
1031         case CONN_MANAGER:
1032                 skb_queue_tail(inputq, skb);
1033                 return true;
1034         case NAME_DISTRIBUTOR:
1035                 node->bclink.recv_permitted = true;
1036                 skb_queue_tail(link->namedq, skb);
1037                 return true;
1038         case MSG_BUNDLER:
1039         case TUNNEL_PROTOCOL:
1040         case MSG_FRAGMENTER:
1041         case BCAST_PROTOCOL:
1042                 return false;
1043         default:
1044                 pr_warn("Dropping received illegal msg type\n");
1045                 kfree_skb(skb);
1046                 return false;
1047         };
1048 }
1049
1050 /* tipc_link_input - process packet that has passed link protocol check
1051  *
1052  * Consumes buffer
1053  */
1054 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1055                            struct sk_buff_head *inputq)
1056 {
1057         struct tipc_node *node = l->owner;
1058         struct tipc_msg *hdr = buf_msg(skb);
1059         struct sk_buff **reasm_skb = &l->reasm_buf;
1060         struct sk_buff *iskb;
1061         struct sk_buff_head tmpq;
1062         int usr = msg_user(hdr);
1063         int rc = 0;
1064         int pos = 0;
1065         int ipos = 0;
1066
1067         if (unlikely(usr == TUNNEL_PROTOCOL)) {
1068                 if (msg_type(hdr) == SYNCH_MSG) {
1069                         __skb_queue_purge(&l->deferdq);
1070                         goto drop;
1071                 }
1072                 if (!tipc_msg_extract(skb, &iskb, &ipos))
1073                         return rc;
1074                 kfree_skb(skb);
1075                 skb = iskb;
1076                 hdr = buf_msg(skb);
1077                 if (less(msg_seqno(hdr), l->drop_point))
1078                         goto drop;
1079                 if (tipc_data_input(l, skb, inputq))
1080                         return rc;
1081                 usr = msg_user(hdr);
1082                 reasm_skb = &l->failover_reasm_skb;
1083         }
1084
1085         if (usr == MSG_BUNDLER) {
1086                 skb_queue_head_init(&tmpq);
1087                 l->stats.recv_bundles++;
1088                 l->stats.recv_bundled += msg_msgcnt(hdr);
1089                 while (tipc_msg_extract(skb, &iskb, &pos))
1090                         tipc_data_input(l, iskb, &tmpq);
1091                 tipc_skb_queue_splice_tail(&tmpq, inputq);
1092                 return 0;
1093         } else if (usr == MSG_FRAGMENTER) {
1094                 l->stats.recv_fragments++;
1095                 if (tipc_buf_append(reasm_skb, &skb)) {
1096                         l->stats.recv_fragmented++;
1097                         tipc_data_input(l, skb, inputq);
1098                 } else if (!*reasm_skb) {
1099                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1100                 }
1101                 return 0;
1102         } else if (usr == BCAST_PROTOCOL) {
1103                 tipc_link_sync_rcv(node, skb);
1104                 return 0;
1105         }
1106 drop:
1107         kfree_skb(skb);
1108         return 0;
1109 }
1110
1111 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1112 {
1113         bool released = false;
1114         struct sk_buff *skb, *tmp;
1115
1116         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1117                 if (more(buf_seqno(skb), acked))
1118                         break;
1119                 __skb_unlink(skb, &l->transmq);
1120                 kfree_skb(skb);
1121                 released = true;
1122         }
1123         return released;
1124 }
1125
1126 /* tipc_link_build_ack_msg: prepare link acknowledge message for transmission
1127  */
1128 void tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1129 {
1130         l->rcv_unacked = 0;
1131         l->stats.sent_acks++;
1132         tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1133 }
1134
1135 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1136  */
1137 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1138 {
1139         int mtyp = RESET_MSG;
1140
1141         if (l->state == LINK_ESTABLISHING)
1142                 mtyp = ACTIVATE_MSG;
1143
1144         tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
1145 }
1146
1147 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1148  */
1149 static void tipc_link_build_nack_msg(struct tipc_link *l,
1150                                      struct sk_buff_head *xmitq)
1151 {
1152         u32 def_cnt = ++l->stats.deferred_recv;
1153
1154         if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
1155                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1156 }
1157
1158 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1159  * @l: the link that should handle the message
1160  * @skb: TIPC packet
1161  * @xmitq: queue to place packets to be sent after this call
1162  */
1163 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1164                   struct sk_buff_head *xmitq)
1165 {
1166         struct sk_buff_head *defq = &l->deferdq;
1167         struct tipc_msg *hdr;
1168         u16 seqno, rcv_nxt, win_lim;
1169         int rc = 0;
1170
1171         do {
1172                 hdr = buf_msg(skb);
1173                 seqno = msg_seqno(hdr);
1174                 rcv_nxt = l->rcv_nxt;
1175                 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1176
1177                 /* Verify and update link state */
1178                 if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1179                         return tipc_link_proto_rcv(l, skb, xmitq);
1180
1181                 if (unlikely(!link_is_up(l))) {
1182                         if (l->state == LINK_ESTABLISHING)
1183                                 rc = TIPC_LINK_UP_EVT;
1184                         goto drop;
1185                 }
1186
1187                 /* Don't send probe at next timeout expiration */
1188                 l->silent_intv_cnt = 0;
1189
1190                 /* Drop if outside receive window */
1191                 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1192                         l->stats.duplicates++;
1193                         goto drop;
1194                 }
1195
1196                 /* Forward queues and wake up waiting users */
1197                 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1198                         tipc_link_advance_backlog(l, xmitq);
1199                         if (unlikely(!skb_queue_empty(&l->wakeupq)))
1200                                 link_prepare_wakeup(l);
1201                 }
1202
1203                 /* Defer delivery if sequence gap */
1204                 if (unlikely(seqno != rcv_nxt)) {
1205                         __tipc_skb_queue_sorted(defq, seqno, skb);
1206                         tipc_link_build_nack_msg(l, xmitq);
1207                         break;
1208                 }
1209
1210                 /* Deliver packet */
1211                 l->rcv_nxt++;
1212                 l->stats.recv_info++;
1213                 if (!tipc_data_input(l, skb, l->inputq))
1214                         rc = tipc_link_input(l, skb, l->inputq);
1215                 if (unlikely(rc))
1216                         break;
1217                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1218                         tipc_link_build_ack_msg(l, xmitq);
1219
1220         } while ((skb = __skb_dequeue(defq)));
1221
1222         return rc;
1223 drop:
1224         kfree_skb(skb);
1225         return rc;
1226 }
1227
1228 /**
1229  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1230  *
1231  * Returns increase in queue length (i.e. 0 or 1)
1232  */
1233 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1234 {
1235         struct sk_buff *skb1;
1236         u16 seq_no = buf_seqno(skb);
1237
1238         /* Empty queue ? */
1239         if (skb_queue_empty(list)) {
1240                 __skb_queue_tail(list, skb);
1241                 return 1;
1242         }
1243
1244         /* Last ? */
1245         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1246                 __skb_queue_tail(list, skb);
1247                 return 1;
1248         }
1249
1250         /* Locate insertion point in queue, then insert; discard if duplicate */
1251         skb_queue_walk(list, skb1) {
1252                 u16 curr_seqno = buf_seqno(skb1);
1253
1254                 if (seq_no == curr_seqno) {
1255                         kfree_skb(skb);
1256                         return 0;
1257                 }
1258
1259                 if (less(seq_no, curr_seqno))
1260                         break;
1261         }
1262
1263         __skb_queue_before(list, skb1, skb);
1264         return 1;
1265 }
1266
1267 /*
1268  * Send protocol message to the other endpoint.
1269  */
1270 void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg,
1271                           u32 gap, u32 tolerance, u32 priority)
1272 {
1273         struct sk_buff *skb = NULL;
1274         struct sk_buff_head xmitq;
1275
1276         __skb_queue_head_init(&xmitq);
1277         tipc_link_build_proto_msg(l, msg_typ, probe_msg, gap,
1278                                   tolerance, priority, &xmitq);
1279         skb = __skb_dequeue(&xmitq);
1280         if (!skb)
1281                 return;
1282         tipc_bearer_send(l->owner->net, l->bearer_id, skb, l->media_addr);
1283         l->rcv_unacked = 0;
1284         kfree_skb(skb);
1285 }
1286
1287 /* tipc_link_build_proto_msg: prepare link protocol message for transmission
1288  */
1289 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1290                                       u16 rcvgap, int tolerance, int priority,
1291                                       struct sk_buff_head *xmitq)
1292 {
1293         struct sk_buff *skb = NULL;
1294         struct tipc_msg *hdr = l->pmsg;
1295         u16 snd_nxt = l->snd_nxt;
1296         u16 rcv_nxt = l->rcv_nxt;
1297         u16 rcv_last = rcv_nxt - 1;
1298         int node_up = l->owner->bclink.recv_permitted;
1299
1300         /* Don't send protocol message during reset or link failover */
1301         if (tipc_link_is_blocked(l))
1302                 return;
1303
1304         msg_set_type(hdr, mtyp);
1305         msg_set_net_plane(hdr, l->net_plane);
1306         msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
1307         msg_set_last_bcast(hdr, tipc_bclink_get_last_sent(l->owner->net));
1308         msg_set_link_tolerance(hdr, tolerance);
1309         msg_set_linkprio(hdr, priority);
1310         msg_set_redundant_link(hdr, node_up);
1311         msg_set_seq_gap(hdr, 0);
1312
1313         /* Compatibility: created msg must not be in sequence with pkt flow */
1314         msg_set_seqno(hdr, snd_nxt + U16_MAX / 2);
1315
1316         if (mtyp == STATE_MSG) {
1317                 if (!tipc_link_is_up(l))
1318                         return;
1319                 msg_set_next_sent(hdr, snd_nxt);
1320
1321                 /* Override rcvgap if there are packets in deferred queue */
1322                 if (!skb_queue_empty(&l->deferdq))
1323                         rcvgap = buf_seqno(skb_peek(&l->deferdq)) - rcv_nxt;
1324                 if (rcvgap) {
1325                         msg_set_seq_gap(hdr, rcvgap);
1326                         l->stats.sent_nacks++;
1327                 }
1328                 msg_set_ack(hdr, rcv_last);
1329                 msg_set_probe(hdr, probe);
1330                 if (probe)
1331                         l->stats.sent_probes++;
1332                 l->stats.sent_states++;
1333         } else {
1334                 /* RESET_MSG or ACTIVATE_MSG */
1335                 msg_set_max_pkt(hdr, l->advertised_mtu);
1336                 msg_set_ack(hdr, l->rcv_nxt - 1);
1337                 msg_set_next_sent(hdr, 1);
1338         }
1339         skb = tipc_buf_acquire(msg_size(hdr));
1340         if (!skb)
1341                 return;
1342         skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
1343         skb->priority = TC_PRIO_CONTROL;
1344         __skb_queue_tail(xmitq, skb);
1345 }
1346
1347 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1348  * with contents of the link's transmit and backlog queues.
1349  */
1350 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1351                            int mtyp, struct sk_buff_head *xmitq)
1352 {
1353         struct sk_buff *skb, *tnlskb;
1354         struct tipc_msg *hdr, tnlhdr;
1355         struct sk_buff_head *queue = &l->transmq;
1356         struct sk_buff_head tmpxq, tnlq;
1357         u16 pktlen, pktcnt, seqno = l->snd_nxt;
1358
1359         if (!tnl)
1360                 return;
1361
1362         skb_queue_head_init(&tnlq);
1363         skb_queue_head_init(&tmpxq);
1364
1365         /* At least one packet required for safe algorithm => add dummy */
1366         skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1367                               BASIC_H_SIZE, 0, l->addr, link_own_addr(l),
1368                               0, 0, TIPC_ERR_NO_PORT);
1369         if (!skb) {
1370                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1371                 return;
1372         }
1373         skb_queue_tail(&tnlq, skb);
1374         tipc_link_xmit(l, &tnlq, &tmpxq);
1375         __skb_queue_purge(&tmpxq);
1376
1377         /* Initialize reusable tunnel packet header */
1378         tipc_msg_init(link_own_addr(l), &tnlhdr, TUNNEL_PROTOCOL,
1379                       mtyp, INT_H_SIZE, l->addr);
1380         pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
1381         msg_set_msgcnt(&tnlhdr, pktcnt);
1382         msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1383 tnl:
1384         /* Wrap each packet into a tunnel packet */
1385         skb_queue_walk(queue, skb) {
1386                 hdr = buf_msg(skb);
1387                 if (queue == &l->backlogq)
1388                         msg_set_seqno(hdr, seqno++);
1389                 pktlen = msg_size(hdr);
1390                 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1391                 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE);
1392                 if (!tnlskb) {
1393                         pr_warn("%sunable to send packet\n", link_co_err);
1394                         return;
1395                 }
1396                 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1397                 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1398                 __skb_queue_tail(&tnlq, tnlskb);
1399         }
1400         if (queue != &l->backlogq) {
1401                 queue = &l->backlogq;
1402                 goto tnl;
1403         }
1404
1405         tipc_link_xmit(tnl, &tnlq, xmitq);
1406
1407         if (mtyp == FAILOVER_MSG) {
1408                 tnl->drop_point = l->rcv_nxt;
1409                 tnl->failover_reasm_skb = l->reasm_buf;
1410                 l->reasm_buf = NULL;
1411         }
1412 }
1413
1414 /* tipc_link_proto_rcv(): receive link level protocol message :
1415  * Note that network plane id propagates through the network, and may
1416  * change at any time. The node with lowest numerical id determines
1417  * network plane
1418  */
1419 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1420                                struct sk_buff_head *xmitq)
1421 {
1422         struct tipc_msg *hdr = buf_msg(skb);
1423         u16 rcvgap = 0;
1424         u16 ack = msg_ack(hdr);
1425         u16 gap = msg_seq_gap(hdr);
1426         u16 peers_snd_nxt =  msg_next_sent(hdr);
1427         u16 peers_tol = msg_link_tolerance(hdr);
1428         u16 peers_prio = msg_linkprio(hdr);
1429         u16 rcv_nxt = l->rcv_nxt;
1430         int mtyp = msg_type(hdr);
1431         char *if_name;
1432         int rc = 0;
1433
1434         if (tipc_link_is_blocked(l))
1435                 goto exit;
1436
1437         if (link_own_addr(l) > msg_prevnode(hdr))
1438                 l->net_plane = msg_net_plane(hdr);
1439
1440         switch (mtyp) {
1441         case RESET_MSG:
1442
1443                 /* Ignore duplicate RESET with old session number */
1444                 if ((less_eq(msg_session(hdr), l->peer_session)) &&
1445                     (l->peer_session != WILDCARD_SESSION))
1446                         break;
1447                 /* fall thru' */
1448
1449         case ACTIVATE_MSG:
1450
1451                 /* Complete own link name with peer's interface name */
1452                 if_name =  strrchr(l->name, ':') + 1;
1453                 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1454                         break;
1455                 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1456                         break;
1457                 strncpy(if_name, msg_data(hdr), TIPC_MAX_IF_NAME);
1458
1459                 /* Update own tolerance if peer indicates a non-zero value */
1460                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1461                         l->tolerance = peers_tol;
1462
1463                 /* Update own priority if peer's priority is higher */
1464                 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1465                         l->priority = peers_prio;
1466
1467                 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
1468                 if ((mtyp == RESET_MSG) || !link_is_up(l))
1469                         rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
1470
1471                 /* ACTIVATE_MSG takes up link if it was already locally reset */
1472                 if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
1473                         rc = TIPC_LINK_UP_EVT;
1474
1475                 l->peer_session = msg_session(hdr);
1476                 l->peer_bearer_id = msg_bearer_id(hdr);
1477                 if (l->mtu > msg_max_pkt(hdr))
1478                         l->mtu = msg_max_pkt(hdr);
1479                 break;
1480
1481         case STATE_MSG:
1482
1483                 /* Update own tolerance if peer indicates a non-zero value */
1484                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1485                         l->tolerance = peers_tol;
1486
1487                 l->silent_intv_cnt = 0;
1488                 l->stats.recv_states++;
1489                 if (msg_probe(hdr))
1490                         l->stats.recv_probes++;
1491
1492                 if (!link_is_up(l)) {
1493                         if (l->state == LINK_ESTABLISHING)
1494                                 rc = TIPC_LINK_UP_EVT;
1495                         break;
1496                 }
1497
1498                 /* Send NACK if peer has sent pkts we haven't received yet */
1499                 if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
1500                         rcvgap = peers_snd_nxt - l->rcv_nxt;
1501                 if (rcvgap || (msg_probe(hdr)))
1502                         tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1503                                                   0, 0, xmitq);
1504                 tipc_link_release_pkts(l, ack);
1505
1506                 /* If NACK, retransmit will now start at right position */
1507                 if (gap) {
1508                         rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq);
1509                         l->stats.recv_nacks++;
1510                 }
1511
1512                 tipc_link_advance_backlog(l, xmitq);
1513                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1514                         link_prepare_wakeup(l);
1515         }
1516 exit:
1517         kfree_skb(skb);
1518         return rc;
1519 }
1520
1521 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1522 {
1523         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1524
1525         l->window = win;
1526         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1527         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1528         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1529         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1530         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1531 }
1532
1533 /* tipc_link_find_owner - locate owner node of link by link's name
1534  * @net: the applicable net namespace
1535  * @name: pointer to link name string
1536  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1537  *
1538  * Returns pointer to node owning the link, or 0 if no matching link is found.
1539  */
1540 static struct tipc_node *tipc_link_find_owner(struct net *net,
1541                                               const char *link_name,
1542                                               unsigned int *bearer_id)
1543 {
1544         struct tipc_net *tn = net_generic(net, tipc_net_id);
1545         struct tipc_link *l_ptr;
1546         struct tipc_node *n_ptr;
1547         struct tipc_node *found_node = NULL;
1548         int i;
1549
1550         *bearer_id = 0;
1551         rcu_read_lock();
1552         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1553                 tipc_node_lock(n_ptr);
1554                 for (i = 0; i < MAX_BEARERS; i++) {
1555                         l_ptr = n_ptr->links[i].link;
1556                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1557                                 *bearer_id = i;
1558                                 found_node = n_ptr;
1559                                 break;
1560                         }
1561                 }
1562                 tipc_node_unlock(n_ptr);
1563                 if (found_node)
1564                         break;
1565         }
1566         rcu_read_unlock();
1567
1568         return found_node;
1569 }
1570
1571 /**
1572  * link_reset_statistics - reset link statistics
1573  * @l_ptr: pointer to link
1574  */
1575 static void link_reset_statistics(struct tipc_link *l_ptr)
1576 {
1577         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1578         l_ptr->stats.sent_info = l_ptr->snd_nxt;
1579         l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1580 }
1581
1582 static void link_print(struct tipc_link *l, const char *str)
1583 {
1584         struct sk_buff *hskb = skb_peek(&l->transmq);
1585         u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
1586         u16 tail = l->snd_nxt - 1;
1587
1588         pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
1589         pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1590                 skb_queue_len(&l->transmq), head, tail,
1591                 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1592 }
1593
1594 /* Parse and validate nested (link) properties valid for media, bearer and link
1595  */
1596 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1597 {
1598         int err;
1599
1600         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1601                                tipc_nl_prop_policy);
1602         if (err)
1603                 return err;
1604
1605         if (props[TIPC_NLA_PROP_PRIO]) {
1606                 u32 prio;
1607
1608                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1609                 if (prio > TIPC_MAX_LINK_PRI)
1610                         return -EINVAL;
1611         }
1612
1613         if (props[TIPC_NLA_PROP_TOL]) {
1614                 u32 tol;
1615
1616                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1617                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1618                         return -EINVAL;
1619         }
1620
1621         if (props[TIPC_NLA_PROP_WIN]) {
1622                 u32 win;
1623
1624                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1625                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1626                         return -EINVAL;
1627         }
1628
1629         return 0;
1630 }
1631
1632 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1633 {
1634         int err;
1635         int res = 0;
1636         int bearer_id;
1637         char *name;
1638         struct tipc_link *link;
1639         struct tipc_node *node;
1640         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1641         struct net *net = sock_net(skb->sk);
1642
1643         if (!info->attrs[TIPC_NLA_LINK])
1644                 return -EINVAL;
1645
1646         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1647                                info->attrs[TIPC_NLA_LINK],
1648                                tipc_nl_link_policy);
1649         if (err)
1650                 return err;
1651
1652         if (!attrs[TIPC_NLA_LINK_NAME])
1653                 return -EINVAL;
1654
1655         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1656
1657         if (strcmp(name, tipc_bclink_name) == 0)
1658                 return tipc_nl_bc_link_set(net, attrs);
1659
1660         node = tipc_link_find_owner(net, name, &bearer_id);
1661         if (!node)
1662                 return -EINVAL;
1663
1664         tipc_node_lock(node);
1665
1666         link = node->links[bearer_id].link;
1667         if (!link) {
1668                 res = -EINVAL;
1669                 goto out;
1670         }
1671
1672         if (attrs[TIPC_NLA_LINK_PROP]) {
1673                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1674
1675                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1676                                               props);
1677                 if (err) {
1678                         res = err;
1679                         goto out;
1680                 }
1681
1682                 if (props[TIPC_NLA_PROP_TOL]) {
1683                         u32 tol;
1684
1685                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1686                         link->tolerance = tol;
1687                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1688                 }
1689                 if (props[TIPC_NLA_PROP_PRIO]) {
1690                         u32 prio;
1691
1692                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1693                         link->priority = prio;
1694                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1695                 }
1696                 if (props[TIPC_NLA_PROP_WIN]) {
1697                         u32 win;
1698
1699                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1700                         tipc_link_set_queue_limits(link, win);
1701                 }
1702         }
1703
1704 out:
1705         tipc_node_unlock(node);
1706
1707         return res;
1708 }
1709
1710 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1711 {
1712         int i;
1713         struct nlattr *stats;
1714
1715         struct nla_map {
1716                 u32 key;
1717                 u32 val;
1718         };
1719
1720         struct nla_map map[] = {
1721                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1722                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1723                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1724                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1725                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1726                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1727                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1728                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1729                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1730                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1731                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1732                         s->msg_length_counts : 1},
1733                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1734                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1735                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1736                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1737                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1738                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1739                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1740                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1741                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1742                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1743                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1744                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1745                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1746                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1747                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1748                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1749                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1750                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1751                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1752                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1753                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1754                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1755                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1756         };
1757
1758         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1759         if (!stats)
1760                 return -EMSGSIZE;
1761
1762         for (i = 0; i <  ARRAY_SIZE(map); i++)
1763                 if (nla_put_u32(skb, map[i].key, map[i].val))
1764                         goto msg_full;
1765
1766         nla_nest_end(skb, stats);
1767
1768         return 0;
1769 msg_full:
1770         nla_nest_cancel(skb, stats);
1771
1772         return -EMSGSIZE;
1773 }
1774
1775 /* Caller should hold appropriate locks to protect the link */
1776 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1777                               struct tipc_link *link, int nlflags)
1778 {
1779         int err;
1780         void *hdr;
1781         struct nlattr *attrs;
1782         struct nlattr *prop;
1783         struct tipc_net *tn = net_generic(net, tipc_net_id);
1784
1785         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1786                           nlflags, TIPC_NL_LINK_GET);
1787         if (!hdr)
1788                 return -EMSGSIZE;
1789
1790         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1791         if (!attrs)
1792                 goto msg_full;
1793
1794         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1795                 goto attr_msg_full;
1796         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1797                         tipc_cluster_mask(tn->own_addr)))
1798                 goto attr_msg_full;
1799         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1800                 goto attr_msg_full;
1801         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
1802                 goto attr_msg_full;
1803         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
1804                 goto attr_msg_full;
1805
1806         if (tipc_link_is_up(link))
1807                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1808                         goto attr_msg_full;
1809         if (tipc_link_is_active(link))
1810                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1811                         goto attr_msg_full;
1812
1813         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1814         if (!prop)
1815                 goto attr_msg_full;
1816         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1817                 goto prop_msg_full;
1818         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1819                 goto prop_msg_full;
1820         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1821                         link->window))
1822                 goto prop_msg_full;
1823         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1824                 goto prop_msg_full;
1825         nla_nest_end(msg->skb, prop);
1826
1827         err = __tipc_nl_add_stats(msg->skb, &link->stats);
1828         if (err)
1829                 goto attr_msg_full;
1830
1831         nla_nest_end(msg->skb, attrs);
1832         genlmsg_end(msg->skb, hdr);
1833
1834         return 0;
1835
1836 prop_msg_full:
1837         nla_nest_cancel(msg->skb, prop);
1838 attr_msg_full:
1839         nla_nest_cancel(msg->skb, attrs);
1840 msg_full:
1841         genlmsg_cancel(msg->skb, hdr);
1842
1843         return -EMSGSIZE;
1844 }
1845
1846 /* Caller should hold node lock  */
1847 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
1848                                     struct tipc_node *node, u32 *prev_link)
1849 {
1850         u32 i;
1851         int err;
1852
1853         for (i = *prev_link; i < MAX_BEARERS; i++) {
1854                 *prev_link = i;
1855
1856                 if (!node->links[i].link)
1857                         continue;
1858
1859                 err = __tipc_nl_add_link(net, msg,
1860                                          node->links[i].link, NLM_F_MULTI);
1861                 if (err)
1862                         return err;
1863         }
1864         *prev_link = 0;
1865
1866         return 0;
1867 }
1868
1869 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
1870 {
1871         struct net *net = sock_net(skb->sk);
1872         struct tipc_net *tn = net_generic(net, tipc_net_id);
1873         struct tipc_node *node;
1874         struct tipc_nl_msg msg;
1875         u32 prev_node = cb->args[0];
1876         u32 prev_link = cb->args[1];
1877         int done = cb->args[2];
1878         int err;
1879
1880         if (done)
1881                 return 0;
1882
1883         msg.skb = skb;
1884         msg.portid = NETLINK_CB(cb->skb).portid;
1885         msg.seq = cb->nlh->nlmsg_seq;
1886
1887         rcu_read_lock();
1888         if (prev_node) {
1889                 node = tipc_node_find(net, prev_node);
1890                 if (!node) {
1891                         /* We never set seq or call nl_dump_check_consistent()
1892                          * this means that setting prev_seq here will cause the
1893                          * consistence check to fail in the netlink callback
1894                          * handler. Resulting in the last NLMSG_DONE message
1895                          * having the NLM_F_DUMP_INTR flag set.
1896                          */
1897                         cb->prev_seq = 1;
1898                         goto out;
1899                 }
1900                 tipc_node_put(node);
1901
1902                 list_for_each_entry_continue_rcu(node, &tn->node_list,
1903                                                  list) {
1904                         tipc_node_lock(node);
1905                         err = __tipc_nl_add_node_links(net, &msg, node,
1906                                                        &prev_link);
1907                         tipc_node_unlock(node);
1908                         if (err)
1909                                 goto out;
1910
1911                         prev_node = node->addr;
1912                 }
1913         } else {
1914                 err = tipc_nl_add_bc_link(net, &msg);
1915                 if (err)
1916                         goto out;
1917
1918                 list_for_each_entry_rcu(node, &tn->node_list, list) {
1919                         tipc_node_lock(node);
1920                         err = __tipc_nl_add_node_links(net, &msg, node,
1921                                                        &prev_link);
1922                         tipc_node_unlock(node);
1923                         if (err)
1924                                 goto out;
1925
1926                         prev_node = node->addr;
1927                 }
1928         }
1929         done = 1;
1930 out:
1931         rcu_read_unlock();
1932
1933         cb->args[0] = prev_node;
1934         cb->args[1] = prev_link;
1935         cb->args[2] = done;
1936
1937         return skb->len;
1938 }
1939
1940 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
1941 {
1942         struct net *net = genl_info_net(info);
1943         struct tipc_nl_msg msg;
1944         char *name;
1945         int err;
1946
1947         msg.portid = info->snd_portid;
1948         msg.seq = info->snd_seq;
1949
1950         if (!info->attrs[TIPC_NLA_LINK_NAME])
1951                 return -EINVAL;
1952         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
1953
1954         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
1955         if (!msg.skb)
1956                 return -ENOMEM;
1957
1958         if (strcmp(name, tipc_bclink_name) == 0) {
1959                 err = tipc_nl_add_bc_link(net, &msg);
1960                 if (err) {
1961                         nlmsg_free(msg.skb);
1962                         return err;
1963                 }
1964         } else {
1965                 int bearer_id;
1966                 struct tipc_node *node;
1967                 struct tipc_link *link;
1968
1969                 node = tipc_link_find_owner(net, name, &bearer_id);
1970                 if (!node)
1971                         return -EINVAL;
1972
1973                 tipc_node_lock(node);
1974                 link = node->links[bearer_id].link;
1975                 if (!link) {
1976                         tipc_node_unlock(node);
1977                         nlmsg_free(msg.skb);
1978                         return -EINVAL;
1979                 }
1980
1981                 err = __tipc_nl_add_link(net, &msg, link, 0);
1982                 tipc_node_unlock(node);
1983                 if (err) {
1984                         nlmsg_free(msg.skb);
1985                         return err;
1986                 }
1987         }
1988
1989         return genlmsg_reply(msg.skb, info);
1990 }
1991
1992 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
1993 {
1994         int err;
1995         char *link_name;
1996         unsigned int bearer_id;
1997         struct tipc_link *link;
1998         struct tipc_node *node;
1999         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2000         struct net *net = sock_net(skb->sk);
2001
2002         if (!info->attrs[TIPC_NLA_LINK])
2003                 return -EINVAL;
2004
2005         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2006                                info->attrs[TIPC_NLA_LINK],
2007                                tipc_nl_link_policy);
2008         if (err)
2009                 return err;
2010
2011         if (!attrs[TIPC_NLA_LINK_NAME])
2012                 return -EINVAL;
2013
2014         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2015
2016         if (strcmp(link_name, tipc_bclink_name) == 0) {
2017                 err = tipc_bclink_reset_stats(net);
2018                 if (err)
2019                         return err;
2020                 return 0;
2021         }
2022
2023         node = tipc_link_find_owner(net, link_name, &bearer_id);
2024         if (!node)
2025                 return -EINVAL;
2026
2027         tipc_node_lock(node);
2028
2029         link = node->links[bearer_id].link;
2030         if (!link) {
2031                 tipc_node_unlock(node);
2032                 return -EINVAL;
2033         }
2034
2035         link_reset_statistics(link);
2036
2037         tipc_node_unlock(node);
2038
2039         return 0;
2040 }