net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, 2012-2016, 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 #include "monitor.h"
  46 #include "trace.h"
  47 #include "crypto.h"
  48
  49 #include <linux/pkt_sched.h>
  50
  51 struct tipc_stats {
  52         u32 sent_pkts;
  53         u32 recv_pkts;
  54         u32 sent_states;
  55         u32 recv_states;
  56         u32 sent_probes;
  57         u32 recv_probes;
  58         u32 sent_nacks;
  59         u32 recv_nacks;
  60         u32 sent_acks;
  61         u32 sent_bundled;
  62         u32 sent_bundles;
  63         u32 recv_bundled;
  64         u32 recv_bundles;
  65         u32 retransmitted;
  66         u32 sent_fragmented;
  67         u32 sent_fragments;
  68         u32 recv_fragmented;
  69         u32 recv_fragments;
  70         u32 link_congs;         /* # port sends blocked by congestion */
  71         u32 deferred_recv;
  72         u32 duplicates;
  73         u32 max_queue_sz;       /* send queue size high water mark */
  74         u32 accu_queue_sz;      /* used for send queue size profiling */
  75         u32 queue_sz_counts;    /* used for send queue size profiling */
  76         u32 msg_length_counts;  /* used for message length profiling */
  77         u32 msg_lengths_total;  /* used for message length profiling */
  78         u32 msg_length_profile[7]; /* used for msg. length profiling */
  79 };
  80
  81 /**
  82  * struct tipc_link - TIPC link data structure
  83  * @addr: network address of link's peer node
  84  * @name: link name character string
  85  * @media_addr: media address to use when sending messages over link
  86  * @timer: link timer
  87  * @net: pointer to namespace struct
  88  * @refcnt: reference counter for permanent references (owner node & timer)
  89  * @peer_session: link session # being used by peer end of link
  90  * @peer_bearer_id: bearer id used by link's peer endpoint
  91  * @bearer_id: local bearer id used by link
  92  * @tolerance: minimum link continuity loss needed to reset link [in ms]
  93  * @abort_limit: # of unacknowledged continuity probes needed to reset link
  94  * @state: current state of link FSM
  95  * @peer_caps: bitmap describing capabilities of peer node
  96  * @silent_intv_cnt: # of timer intervals without any reception from peer
  97  * @proto_msg: template for control messages generated by link
  98  * @pmsg: convenience pointer to "proto_msg" field
  99  * @priority: current link priority
 100  * @net_plane: current link network plane ('A' through 'H')
 101  * @mon_state: cookie with information needed by link monitor
 102  * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
 103  * @exp_msg_count: # of tunnelled messages expected during link changeover
 104  * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
 105  * @mtu: current maximum packet size for this link
 106  * @advertised_mtu: advertised own mtu when link is being established
 107  * @transmitq: queue for sent, non-acked messages
 108  * @backlogq: queue for messages waiting to be sent
 109  * @snt_nxt: next sequence number to use for outbound messages
 110  * @ackers: # of peers that needs to ack each packet before it can be released
 111  * @acked: # last packet acked by a certain peer. Used for broadcast.
 112  * @rcv_nxt: next sequence number to expect for inbound messages
 113  * @deferred_queue: deferred queue saved OOS b'cast message received from node
 114  * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
 115  * @inputq: buffer queue for messages to be delivered upwards
 116  * @namedq: buffer queue for name table messages to be delivered upwards
 117  * @next_out: ptr to first unsent outbound message in queue
 118  * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
 119  * @long_msg_seq_no: next identifier to use for outbound fragmented messages
 120  * @reasm_buf: head of partially reassembled inbound message fragments
 121  * @bc_rcvr: marks that this is a broadcast receiver link
 122  * @stats: collects statistics regarding link activity
 123  */
 124 struct tipc_link {
 125         u32 addr;
 126         char name[TIPC_MAX_LINK_NAME];
 127         struct net *net;
 128
 129         /* Management and link supervision data */
 130         u16 peer_session;
 131         u16 session;
 132         u16 snd_nxt_state;
 133         u16 rcv_nxt_state;
 134         u32 peer_bearer_id;
 135         u32 bearer_id;
 136         u32 tolerance;
 137         u32 abort_limit;
 138         u32 state;
 139         u16 peer_caps;
 140         bool in_session;
 141         bool active;
 142         u32 silent_intv_cnt;
 143         char if_name[TIPC_MAX_IF_NAME];
 144         u32 priority;
 145         char net_plane;
 146         struct tipc_mon_state mon_state;
 147         u16 rst_cnt;
 148
 149         /* Failover/synch */
 150         u16 drop_point;
 151         struct sk_buff *failover_reasm_skb;
 152         struct sk_buff_head failover_deferdq;
 153
 154         /* Max packet negotiation */
 155         u16 mtu;
 156         u16 advertised_mtu;
 157
 158         /* Sending */
 159         struct sk_buff_head transmq;
 160         struct sk_buff_head backlogq;
 161         struct {
 162                 u16 len;
 163                 u16 limit;
 164                 struct sk_buff *target_bskb;
 165         } backlog[5];
 166         u16 snd_nxt;
 167
 168         /* Reception */
 169         u16 rcv_nxt;
 170         u32 rcv_unacked;
 171         struct sk_buff_head deferdq;
 172         struct sk_buff_head *inputq;
 173         struct sk_buff_head *namedq;
 174
 175         /* Congestion handling */
 176         struct sk_buff_head wakeupq;
 177         u16 window;
 178         u16 min_win;
 179         u16 ssthresh;
 180         u16 max_win;
 181         u16 cong_acks;
 182         u16 checkpoint;
 183
 184         /* Fragmentation/reassembly */
 185         struct sk_buff *reasm_buf;
 186         struct sk_buff *reasm_tnlmsg;
 187
 188         /* Broadcast */
 189         u16 ackers;
 190         u16 acked;
 191         struct tipc_link *bc_rcvlink;
 192         struct tipc_link *bc_sndlink;
 193         u8 nack_state;
 194         bool bc_peer_is_up;
 195
 196         /* Statistics */
 197         struct tipc_stats stats;
 198 };
 199
 200 /*
 201  * Error message prefixes
 202  */
 203 static const char *link_co_err = "Link tunneling error, ";
 204 static const char *link_rst_msg = "Resetting link ";
 205
 206 /* Send states for broadcast NACKs
 207  */
 208 enum {
 209         BC_NACK_SND_CONDITIONAL,
 210         BC_NACK_SND_UNCONDITIONAL,
 211         BC_NACK_SND_SUPPRESS,
 212 };
 213
 214 #define TIPC_BC_RETR_LIM  (jiffies + msecs_to_jiffies(10))
 215 #define TIPC_UC_RETR_TIME (jiffies + msecs_to_jiffies(1))
 216
 217 /*
 218  * Interval between NACKs when packets arrive out of order
 219  */
 220 #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
 221
 222 /* Link FSM states:
 223  */
 224 enum {
 225         LINK_ESTABLISHED     = 0xe,
 226         LINK_ESTABLISHING    = 0xe  << 4,
 227         LINK_RESET           = 0x1  << 8,
 228         LINK_RESETTING       = 0x2  << 12,
 229         LINK_PEER_RESET      = 0xd  << 16,
 230         LINK_FAILINGOVER     = 0xf  << 20,
 231         LINK_SYNCHING        = 0xc  << 24
 232 };
 233
 234 /* Link FSM state checking routines
 235  */
 236 static int link_is_up(struct tipc_link *l)
 237 {
 238         return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
 239 }
 240
 241 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 242                                struct sk_buff_head *xmitq);
 243 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 244                                       bool probe_reply, u16 rcvgap,
 245                                       int tolerance, int priority,
 246                                       struct sk_buff_head *xmitq);
 247 static void link_print(struct tipc_link *l, const char *str);
 248 static int tipc_link_build_nack_msg(struct tipc_link *l,
 249                                     struct sk_buff_head *xmitq);
 250 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
 251                                         struct sk_buff_head *xmitq);
 252 static int tipc_link_release_pkts(struct tipc_link *l, u16 to);
 253 static u16 tipc_build_gap_ack_blks(struct tipc_link *l, void *data, u16 gap);
 254 static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,
 255                                      struct tipc_gap_ack_blks *ga,
 256                                      struct sk_buff_head *xmitq);
 257 static void tipc_link_update_cwin(struct tipc_link *l, int released,
 258                                   bool retransmitted);
 259 /*
 260  *  Simple non-static link routines (i.e. referenced outside this file)
 261  */
 262 bool tipc_link_is_up(struct tipc_link *l)
 263 {
 264         return link_is_up(l);
 265 }
 266
 267 bool tipc_link_peer_is_down(struct tipc_link *l)
 268 {
 269         return l->state == LINK_PEER_RESET;
 270 }
 271
 272 bool tipc_link_is_reset(struct tipc_link *l)
 273 {
 274         return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
 275 }
 276
 277 bool tipc_link_is_establishing(struct tipc_link *l)
 278 {
 279         return l->state == LINK_ESTABLISHING;
 280 }
 281
 282 bool tipc_link_is_synching(struct tipc_link *l)
 283 {
 284         return l->state == LINK_SYNCHING;
 285 }
 286
 287 bool tipc_link_is_failingover(struct tipc_link *l)
 288 {
 289         return l->state == LINK_FAILINGOVER;
 290 }
 291
 292 bool tipc_link_is_blocked(struct tipc_link *l)
 293 {
 294         return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
 295 }
 296
 297 static bool link_is_bc_sndlink(struct tipc_link *l)
 298 {
 299         return !l->bc_sndlink;
 300 }
 301
 302 static bool link_is_bc_rcvlink(struct tipc_link *l)
 303 {
 304         return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
 305 }
 306
 307 void tipc_link_set_active(struct tipc_link *l, bool active)
 308 {
 309         l->active = active;
 310 }
 311
 312 u32 tipc_link_id(struct tipc_link *l)
 313 {
 314         return l->peer_bearer_id << 16 | l->bearer_id;
 315 }
 316
 317 int tipc_link_min_win(struct tipc_link *l)
 318 {
 319         return l->min_win;
 320 }
 321
 322 int tipc_link_max_win(struct tipc_link *l)
 323 {
 324         return l->max_win;
 325 }
 326
 327 int tipc_link_prio(struct tipc_link *l)
 328 {
 329         return l->priority;
 330 }
 331
 332 unsigned long tipc_link_tolerance(struct tipc_link *l)
 333 {
 334         return l->tolerance;
 335 }
 336
 337 struct sk_buff_head *tipc_link_inputq(struct tipc_link *l)
 338 {
 339         return l->inputq;
 340 }
 341
 342 char tipc_link_plane(struct tipc_link *l)
 343 {
 344         return l->net_plane;
 345 }
 346
 347 void tipc_link_update_caps(struct tipc_link *l, u16 capabilities)
 348 {
 349         l->peer_caps = capabilities;
 350 }
 351
 352 void tipc_link_add_bc_peer(struct tipc_link *snd_l,
 353                            struct tipc_link *uc_l,
 354                            struct sk_buff_head *xmitq)
 355 {
 356         struct tipc_link *rcv_l = uc_l->bc_rcvlink;
 357
 358         snd_l->ackers++;
 359         rcv_l->acked = snd_l->snd_nxt - 1;
 360         snd_l->state = LINK_ESTABLISHED;
 361         tipc_link_build_bc_init_msg(uc_l, xmitq);
 362 }
 363
 364 void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
 365                               struct tipc_link *rcv_l,
 366                               struct sk_buff_head *xmitq)
 367 {
 368         u16 ack = snd_l->snd_nxt - 1;
 369
 370         snd_l->ackers--;
 371         rcv_l->bc_peer_is_up = true;
 372         rcv_l->state = LINK_ESTABLISHED;
 373         tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
 374         trace_tipc_link_reset(rcv_l, TIPC_DUMP_ALL, "bclink removed!");
 375         tipc_link_reset(rcv_l);
 376         rcv_l->state = LINK_RESET;
 377         if (!snd_l->ackers) {
 378                 trace_tipc_link_reset(snd_l, TIPC_DUMP_ALL, "zero ackers!");
 379                 tipc_link_reset(snd_l);
 380                 snd_l->state = LINK_RESET;
 381                 __skb_queue_purge(xmitq);
 382         }
 383 }
 384
 385 int tipc_link_bc_peers(struct tipc_link *l)
 386 {
 387         return l->ackers;
 388 }
 389
 390 static u16 link_bc_rcv_gap(struct tipc_link *l)
 391 {
 392         struct sk_buff *skb = skb_peek(&l->deferdq);
 393         u16 gap = 0;
 394
 395         if (more(l->snd_nxt, l->rcv_nxt))
 396                 gap = l->snd_nxt - l->rcv_nxt;
 397         if (skb)
 398                 gap = buf_seqno(skb) - l->rcv_nxt;
 399         return gap;
 400 }
 401
 402 void tipc_link_set_mtu(struct tipc_link *l, int mtu)
 403 {
 404         l->mtu = mtu;
 405 }
 406
 407 int tipc_link_mtu(struct tipc_link *l)
 408 {
 409         return l->mtu;
 410 }
 411
 412 int tipc_link_mss(struct tipc_link *l)
 413 {
 414 #ifdef CONFIG_TIPC_CRYPTO
 415         return l->mtu - INT_H_SIZE - EMSG_OVERHEAD;
 416 #else
 417         return l->mtu - INT_H_SIZE;
 418 #endif
 419 }
 420
 421 u16 tipc_link_rcv_nxt(struct tipc_link *l)
 422 {
 423         return l->rcv_nxt;
 424 }
 425
 426 u16 tipc_link_acked(struct tipc_link *l)
 427 {
 428         return l->acked;
 429 }
 430
 431 char *tipc_link_name(struct tipc_link *l)
 432 {
 433         return l->name;
 434 }
 435
 436 u32 tipc_link_state(struct tipc_link *l)
 437 {
 438         return l->state;
 439 }
 440
 441 /**
 442  * tipc_link_create - create a new link
 443  * @n: pointer to associated node
 444  * @if_name: associated interface name
 445  * @bearer_id: id (index) of associated bearer
 446  * @tolerance: link tolerance to be used by link
 447  * @net_plane: network plane (A,B,c..) this link belongs to
 448  * @mtu: mtu to be advertised by link
 449  * @priority: priority to be used by link
 450  * @min_win: minimal send window to be used by link
 451  * @max_win: maximal send window to be used by link
 452  * @session: session to be used by link
 453  * @ownnode: identity of own node
 454  * @peer: node id of peer node
 455  * @peer_caps: bitmap describing peer node capabilities
 456  * @bc_sndlink: the namespace global link used for broadcast sending
 457  * @bc_rcvlink: the peer specific link used for broadcast reception
 458  * @inputq: queue to put messages ready for delivery
 459  * @namedq: queue to put binding table update messages ready for delivery
 460  * @link: return value, pointer to put the created link
 461  *
 462  * Returns true if link was created, otherwise false
 463  */
 464 bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
 465                       int tolerance, char net_plane, u32 mtu, int priority,
 466                       u32 min_win, u32 max_win, u32 session, u32 self,
 467                       u32 peer, u8 *peer_id, u16 peer_caps,
 468                       struct tipc_link *bc_sndlink,
 469                       struct tipc_link *bc_rcvlink,
 470                       struct sk_buff_head *inputq,
 471                       struct sk_buff_head *namedq,
 472                       struct tipc_link **link)
 473 {
 474         char peer_str[NODE_ID_STR_LEN] = {0,};
 475         char self_str[NODE_ID_STR_LEN] = {0,};
 476         struct tipc_link *l;
 477
 478         l = kzalloc(sizeof(*l), GFP_ATOMIC);
 479         if (!l)
 480                 return false;
 481         *link = l;
 482         l->session = session;
 483
 484         /* Set link name for unicast links only */
 485         if (peer_id) {
 486                 tipc_nodeid2string(self_str, tipc_own_id(net));
 487                 if (strlen(self_str) > 16)
 488                         sprintf(self_str, "%x", self);
 489                 tipc_nodeid2string(peer_str, peer_id);
 490                 if (strlen(peer_str) > 16)
 491                         sprintf(peer_str, "%x", peer);
 492         }
 493         /* Peer i/f name will be completed by reset/activate message */
 494         snprintf(l->name, sizeof(l->name), "%s:%s-%s:unknown",
 495                  self_str, if_name, peer_str);
 496
 497         strcpy(l->if_name, if_name);
 498         l->addr = peer;
 499         l->peer_caps = peer_caps;
 500         l->net = net;
 501         l->in_session = false;
 502         l->bearer_id = bearer_id;
 503         l->tolerance = tolerance;
 504         if (bc_rcvlink)
 505                 bc_rcvlink->tolerance = tolerance;
 506         l->net_plane = net_plane;
 507         l->advertised_mtu = mtu;
 508         l->mtu = mtu;
 509         l->priority = priority;
 510         tipc_link_set_queue_limits(l, min_win, max_win);
 511         l->ackers = 1;
 512         l->bc_sndlink = bc_sndlink;
 513         l->bc_rcvlink = bc_rcvlink;
 514         l->inputq = inputq;
 515         l->namedq = namedq;
 516         l->state = LINK_RESETTING;
 517         __skb_queue_head_init(&l->transmq);
 518         __skb_queue_head_init(&l->backlogq);
 519         __skb_queue_head_init(&l->deferdq);
 520         __skb_queue_head_init(&l->failover_deferdq);
 521         skb_queue_head_init(&l->wakeupq);
 522         skb_queue_head_init(l->inputq);
 523         return true;
 524 }
 525
 526 /**
 527  * tipc_link_bc_create - create new link to be used for broadcast
 528  * @n: pointer to associated node
 529  * @mtu: mtu to be used initially if no peers
 530  * @window: send window to be used
 531  * @inputq: queue to put messages ready for delivery
 532  * @namedq: queue to put binding table update messages ready for delivery
 533  * @link: return value, pointer to put the created link
 534  *
 535  * Returns true if link was created, otherwise false
 536  */
 537 bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
 538                          int mtu, u32 min_win, u32 max_win, u16 peer_caps,
 539                          struct sk_buff_head *inputq,
 540                          struct sk_buff_head *namedq,
 541                          struct tipc_link *bc_sndlink,
 542                          struct tipc_link **link)
 543 {
 544         struct tipc_link *l;
 545
 546         if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, min_win,
 547                               max_win, 0, ownnode, peer, NULL, peer_caps,
 548                               bc_sndlink, NULL, inputq, namedq, link))
 549                 return false;
 550
 551         l = *link;
 552         strcpy(l->name, tipc_bclink_name);
 553         trace_tipc_link_reset(l, TIPC_DUMP_ALL, "bclink created!");
 554         tipc_link_reset(l);
 555         l->state = LINK_RESET;
 556         l->ackers = 0;
 557         l->bc_rcvlink = l;
 558
 559         /* Broadcast send link is always up */
 560         if (link_is_bc_sndlink(l))
 561                 l->state = LINK_ESTABLISHED;
 562
 563         /* Disable replicast if even a single peer doesn't support it */
 564         if (link_is_bc_rcvlink(l) && !(peer_caps & TIPC_BCAST_RCAST))
 565                 tipc_bcast_toggle_rcast(net, false);
 566
 567         return true;
 568 }
 569
 570 /**
 571  * tipc_link_fsm_evt - link finite state machine
 572  * @l: pointer to link
 573  * @evt: state machine event to be processed
 574  */
 575 int tipc_link_fsm_evt(struct tipc_link *l, int evt)
 576 {
 577         int rc = 0;
 578         int old_state = l->state;
 579
 580         switch (l->state) {
 581         case LINK_RESETTING:
 582                 switch (evt) {
 583                 case LINK_PEER_RESET_EVT:
 584                         l->state = LINK_PEER_RESET;
 585                         break;
 586                 case LINK_RESET_EVT:
 587                         l->state = LINK_RESET;
 588                         break;
 589                 case LINK_FAILURE_EVT:
 590                 case LINK_FAILOVER_BEGIN_EVT:
 591                 case LINK_ESTABLISH_EVT:
 592                 case LINK_FAILOVER_END_EVT:
 593                 case LINK_SYNCH_BEGIN_EVT:
 594                 case LINK_SYNCH_END_EVT:
 595                 default:
 596                         goto illegal_evt;
 597                 }
 598                 break;
 599         case LINK_RESET:
 600                 switch (evt) {
 601                 case LINK_PEER_RESET_EVT:
 602                         l->state = LINK_ESTABLISHING;
 603                         break;
 604                 case LINK_FAILOVER_BEGIN_EVT:
 605                         l->state = LINK_FAILINGOVER;
 606                 case LINK_FAILURE_EVT:
 607                 case LINK_RESET_EVT:
 608                 case LINK_ESTABLISH_EVT:
 609                 case LINK_FAILOVER_END_EVT:
 610                         break;
 611                 case LINK_SYNCH_BEGIN_EVT:
 612                 case LINK_SYNCH_END_EVT:
 613                 default:
 614                         goto illegal_evt;
 615                 }
 616                 break;
 617         case LINK_PEER_RESET:
 618                 switch (evt) {
 619                 case LINK_RESET_EVT:
 620                         l->state = LINK_ESTABLISHING;
 621                         break;
 622                 case LINK_PEER_RESET_EVT:
 623                 case LINK_ESTABLISH_EVT:
 624                 case LINK_FAILURE_EVT:
 625                         break;
 626                 case LINK_SYNCH_BEGIN_EVT:
 627                 case LINK_SYNCH_END_EVT:
 628                 case LINK_FAILOVER_BEGIN_EVT:
 629                 case LINK_FAILOVER_END_EVT:
 630                 default:
 631                         goto illegal_evt;
 632                 }
 633                 break;
 634         case LINK_FAILINGOVER:
 635                 switch (evt) {
 636                 case LINK_FAILOVER_END_EVT:
 637                         l->state = LINK_RESET;
 638                         break;
 639                 case LINK_PEER_RESET_EVT:
 640                 case LINK_RESET_EVT:
 641                 case LINK_ESTABLISH_EVT:
 642                 case LINK_FAILURE_EVT:
 643                         break;
 644                 case LINK_FAILOVER_BEGIN_EVT:
 645                 case LINK_SYNCH_BEGIN_EVT:
 646                 case LINK_SYNCH_END_EVT:
 647                 default:
 648                         goto illegal_evt;
 649                 }
 650                 break;
 651         case LINK_ESTABLISHING:
 652                 switch (evt) {
 653                 case LINK_ESTABLISH_EVT:
 654                         l->state = LINK_ESTABLISHED;
 655                         break;
 656                 case LINK_FAILOVER_BEGIN_EVT:
 657                         l->state = LINK_FAILINGOVER;
 658                         break;
 659                 case LINK_RESET_EVT:
 660                         l->state = LINK_RESET;
 661                         break;
 662                 case LINK_FAILURE_EVT:
 663                 case LINK_PEER_RESET_EVT:
 664                 case LINK_SYNCH_BEGIN_EVT:
 665                 case LINK_FAILOVER_END_EVT:
 666                         break;
 667                 case LINK_SYNCH_END_EVT:
 668                 default:
 669                         goto illegal_evt;
 670                 }
 671                 break;
 672         case LINK_ESTABLISHED:
 673                 switch (evt) {
 674                 case LINK_PEER_RESET_EVT:
 675                         l->state = LINK_PEER_RESET;
 676                         rc |= TIPC_LINK_DOWN_EVT;
 677                         break;
 678                 case LINK_FAILURE_EVT:
 679                         l->state = LINK_RESETTING;
 680                         rc |= TIPC_LINK_DOWN_EVT;
 681                         break;
 682                 case LINK_RESET_EVT:
 683                         l->state = LINK_RESET;
 684                         break;
 685                 case LINK_ESTABLISH_EVT:
 686                 case LINK_SYNCH_END_EVT:
 687                         break;
 688                 case LINK_SYNCH_BEGIN_EVT:
 689                         l->state = LINK_SYNCHING;
 690                         break;
 691                 case LINK_FAILOVER_BEGIN_EVT:
 692                 case LINK_FAILOVER_END_EVT:
 693                 default:
 694                         goto illegal_evt;
 695                 }
 696                 break;
 697         case LINK_SYNCHING:
 698                 switch (evt) {
 699                 case LINK_PEER_RESET_EVT:
 700                         l->state = LINK_PEER_RESET;
 701                         rc |= TIPC_LINK_DOWN_EVT;
 702                         break;
 703                 case LINK_FAILURE_EVT:
 704                         l->state = LINK_RESETTING;
 705                         rc |= TIPC_LINK_DOWN_EVT;
 706                         break;
 707                 case LINK_RESET_EVT:
 708                         l->state = LINK_RESET;
 709                         break;
 710                 case LINK_ESTABLISH_EVT:
 711                 case LINK_SYNCH_BEGIN_EVT:
 712                         break;
 713                 case LINK_SYNCH_END_EVT:
 714                         l->state = LINK_ESTABLISHED;
 715                         break;
 716                 case LINK_FAILOVER_BEGIN_EVT:
 717                 case LINK_FAILOVER_END_EVT:
 718                 default:
 719                         goto illegal_evt;
 720                 }
 721                 break;
 722         default:
 723                 pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
 724         }
 725         trace_tipc_link_fsm(l->name, old_state, l->state, evt);
 726         return rc;
 727 illegal_evt:
 728         pr_err("Illegal FSM event %x in state %x on link %s\n",
 729                evt, l->state, l->name);
 730         trace_tipc_link_fsm(l->name, old_state, l->state, evt);
 731         return rc;
 732 }
 733
 734 /* link_profile_stats - update statistical profiling of traffic
 735  */
 736 static void link_profile_stats(struct tipc_link *l)
 737 {
 738         struct sk_buff *skb;
 739         struct tipc_msg *msg;
 740         int length;
 741
 742         /* Update counters used in statistical profiling of send traffic */
 743         l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 744         l->stats.queue_sz_counts++;
 745
 746         skb = skb_peek(&l->transmq);
 747         if (!skb)
 748                 return;
 749         msg = buf_msg(skb);
 750         length = msg_size(msg);
 751
 752         if (msg_user(msg) == MSG_FRAGMENTER) {
 753                 if (msg_type(msg) != FIRST_FRAGMENT)
 754                         return;
 755                 length = msg_size(msg_inner_hdr(msg));
 756         }
 757         l->stats.msg_lengths_total += length;
 758         l->stats.msg_length_counts++;
 759         if (length <= 64)
 760                 l->stats.msg_length_profile[0]++;
 761         else if (length <= 256)
 762                 l->stats.msg_length_profile[1]++;
 763         else if (length <= 1024)
 764                 l->stats.msg_length_profile[2]++;
 765         else if (length <= 4096)
 766                 l->stats.msg_length_profile[3]++;
 767         else if (length <= 16384)
 768                 l->stats.msg_length_profile[4]++;
 769         else if (length <= 32768)
 770                 l->stats.msg_length_profile[5]++;
 771         else
 772                 l->stats.msg_length_profile[6]++;
 773 }
 774
 775 /**
 776  * tipc_link_too_silent - check if link is "too silent"
 777  * @l: tipc link to be checked
 778  *
 779  * Returns true if the link 'silent_intv_cnt' is about to reach the
 780  * 'abort_limit' value, otherwise false
 781  */
 782 bool tipc_link_too_silent(struct tipc_link *l)
 783 {
 784         return (l->silent_intv_cnt + 2 > l->abort_limit);
 785 }
 786
 787 static int tipc_link_bc_retrans(struct tipc_link *l, struct tipc_link *r,
 788                                 u16 from, u16 to, struct sk_buff_head *xmitq);
 789 /* tipc_link_timeout - perform periodic task as instructed from node timeout
 790  */
 791 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 792 {
 793         int mtyp = 0;
 794         int rc = 0;
 795         bool state = false;
 796         bool probe = false;
 797         bool setup = false;
 798         u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
 799         u16 bc_acked = l->bc_rcvlink->acked;
 800         struct tipc_mon_state *mstate = &l->mon_state;
 801
 802         trace_tipc_link_timeout(l, TIPC_DUMP_NONE, " ");
 803         trace_tipc_link_too_silent(l, TIPC_DUMP_ALL, " ");
 804         switch (l->state) {
 805         case LINK_ESTABLISHED:
 806         case LINK_SYNCHING:
 807                 mtyp = STATE_MSG;
 808                 link_profile_stats(l);
 809                 tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id);
 810                 if (mstate->reset || (l->silent_intv_cnt > l->abort_limit))
 811                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 812                 state = bc_acked != bc_snt;
 813                 state |= l->bc_rcvlink->rcv_unacked;
 814                 state |= l->rcv_unacked;
 815                 state |= !skb_queue_empty(&l->transmq);
 816                 state |= !skb_queue_empty(&l->deferdq);
 817                 probe = mstate->probing;
 818                 probe |= l->silent_intv_cnt;
 819                 if (probe || mstate->monitoring)
 820                         l->silent_intv_cnt++;
 821                 if (l->snd_nxt == l->checkpoint) {
 822                         tipc_link_update_cwin(l, 0, 0);
 823                         probe = true;
 824                 }
 825                 l->checkpoint = l->snd_nxt;
 826                 break;
 827         case LINK_RESET:
 828                 setup = l->rst_cnt++ <= 4;
 829                 setup |= !(l->rst_cnt % 16);
 830                 mtyp = RESET_MSG;
 831                 break;
 832         case LINK_ESTABLISHING:
 833                 setup = true;
 834                 mtyp = ACTIVATE_MSG;
 835                 break;
 836         case LINK_PEER_RESET:
 837         case LINK_RESETTING:
 838         case LINK_FAILINGOVER:
 839                 break;
 840         default:
 841                 break;
 842         }
 843
 844         if (state || probe || setup)
 845                 tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, 0, xmitq);
 846
 847         return rc;
 848 }
 849
 850 /**
 851  * link_schedule_user - schedule a message sender for wakeup after congestion
 852  * @l: congested link
 853  * @hdr: header of message that is being sent
 854  * Create pseudo msg to send back to user when congestion abates
 855  */
 856 static int link_schedule_user(struct tipc_link *l, struct tipc_msg *hdr)
 857 {
 858         u32 dnode = tipc_own_addr(l->net);
 859         u32 dport = msg_origport(hdr);
 860         struct sk_buff *skb;
 861
 862         /* Create and schedule wakeup pseudo message */
 863         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 864                               dnode, l->addr, dport, 0, 0);
 865         if (!skb)
 866                 return -ENOBUFS;
 867         msg_set_dest_droppable(buf_msg(skb), true);
 868         TIPC_SKB_CB(skb)->chain_imp = msg_importance(hdr);
 869         skb_queue_tail(&l->wakeupq, skb);
 870         l->stats.link_congs++;
 871         trace_tipc_link_conges(l, TIPC_DUMP_ALL, "wakeup scheduled!");
 872         return -ELINKCONG;
 873 }
 874
 875 /**
 876  * link_prepare_wakeup - prepare users for wakeup after congestion
 877  * @l: congested link
 878  * Wake up a number of waiting users, as permitted by available space
 879  * in the send queue
 880  */
 881 static void link_prepare_wakeup(struct tipc_link *l)
 882 {
 883         struct sk_buff_head *wakeupq = &l->wakeupq;
 884         struct sk_buff_head *inputq = l->inputq;
 885         struct sk_buff *skb, *tmp;
 886         struct sk_buff_head tmpq;
 887         int avail[5] = {0,};
 888         int imp = 0;
 889
 890         __skb_queue_head_init(&tmpq);
 891
 892         for (; imp <= TIPC_SYSTEM_IMPORTANCE; imp++)
 893                 avail[imp] = l->backlog[imp].limit - l->backlog[imp].len;
 894
 895         skb_queue_walk_safe(wakeupq, skb, tmp) {
 896                 imp = TIPC_SKB_CB(skb)->chain_imp;
 897                 if (avail[imp] <= 0)
 898                         continue;
 899                 avail[imp]--;
 900                 __skb_unlink(skb, wakeupq);
 901                 __skb_queue_tail(&tmpq, skb);
 902         }
 903
 904         spin_lock_bh(&inputq->lock);
 905         skb_queue_splice_tail(&tmpq, inputq);
 906         spin_unlock_bh(&inputq->lock);
 907
 908 }
 909
 910 void tipc_link_reset(struct tipc_link *l)
 911 {
 912         struct sk_buff_head list;
 913         u32 imp;
 914
 915         __skb_queue_head_init(&list);
 916
 917         l->in_session = false;
 918         /* Force re-synch of peer session number before establishing */
 919         l->peer_session--;
 920         l->session++;
 921         l->mtu = l->advertised_mtu;
 922
 923         spin_lock_bh(&l->wakeupq.lock);
 924         skb_queue_splice_init(&l->wakeupq, &list);
 925         spin_unlock_bh(&l->wakeupq.lock);
 926
 927         spin_lock_bh(&l->inputq->lock);
 928         skb_queue_splice_init(&list, l->inputq);
 929         spin_unlock_bh(&l->inputq->lock);
 930
 931         __skb_queue_purge(&l->transmq);
 932         __skb_queue_purge(&l->deferdq);
 933         __skb_queue_purge(&l->backlogq);
 934         __skb_queue_purge(&l->failover_deferdq);
 935         for (imp = 0; imp <= TIPC_SYSTEM_IMPORTANCE; imp++) {
 936                 l->backlog[imp].len = 0;
 937                 l->backlog[imp].target_bskb = NULL;
 938         }
 939         kfree_skb(l->reasm_buf);
 940         kfree_skb(l->reasm_tnlmsg);
 941         kfree_skb(l->failover_reasm_skb);
 942         l->reasm_buf = NULL;
 943         l->reasm_tnlmsg = NULL;
 944         l->failover_reasm_skb = NULL;
 945         l->rcv_unacked = 0;
 946         l->snd_nxt = 1;
 947         l->rcv_nxt = 1;
 948         l->snd_nxt_state = 1;
 949         l->rcv_nxt_state = 1;
 950         l->acked = 0;
 951         l->silent_intv_cnt = 0;
 952         l->rst_cnt = 0;
 953         l->bc_peer_is_up = false;
 954         memset(&l->mon_state, 0, sizeof(l->mon_state));
 955         tipc_link_reset_stats(l);
 956 }
 957
 958 /**
 959  * tipc_link_xmit(): enqueue buffer list according to queue situation
 960  * @link: link to use
 961  * @list: chain of buffers containing message
 962  * @xmitq: returned list of packets to be sent by caller
 963  *
 964  * Consumes the buffer chain.
 965  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 966  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 967  */
 968 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 969                    struct sk_buff_head *xmitq)
 970 {
 971         struct tipc_msg *hdr = buf_msg(skb_peek(list));
 972         struct sk_buff_head *backlogq = &l->backlogq;
 973         struct sk_buff_head *transmq = &l->transmq;
 974         struct sk_buff *skb, *_skb;
 975         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 976         u16 ack = l->rcv_nxt - 1;
 977         u16 seqno = l->snd_nxt;
 978         int pkt_cnt = skb_queue_len(list);
 979         int imp = msg_importance(hdr);
 980         unsigned int mss = tipc_link_mss(l);
 981         unsigned int cwin = l->window;
 982         unsigned int mtu = l->mtu;
 983         bool new_bundle;
 984         int rc = 0;
 985
 986         if (unlikely(msg_size(hdr) > mtu)) {
 987                 pr_warn("Too large msg, purging xmit list %d %d %d %d %d!\n",
 988                         skb_queue_len(list), msg_user(hdr),
 989                         msg_type(hdr), msg_size(hdr), mtu);
 990                 __skb_queue_purge(list);
 991                 return -EMSGSIZE;
 992         }
 993
 994         /* Allow oversubscription of one data msg per source at congestion */
 995         if (unlikely(l->backlog[imp].len >= l->backlog[imp].limit)) {
 996                 if (imp == TIPC_SYSTEM_IMPORTANCE) {
 997                         pr_warn("%s<%s>, link overflow", link_rst_msg, l->name);
 998                         return -ENOBUFS;
 999                 }
1000                 rc = link_schedule_user(l, hdr);
1001         }
1002
1003         if (pkt_cnt > 1) {
1004                 l->stats.sent_fragmented++;
1005                 l->stats.sent_fragments += pkt_cnt;
1006         }
1007
1008         /* Prepare each packet for sending, and add to relevant queue: */
1009         while ((skb = __skb_dequeue(list))) {
1010                 if (likely(skb_queue_len(transmq) < cwin)) {
1011                         hdr = buf_msg(skb);
1012                         msg_set_seqno(hdr, seqno);
1013                         msg_set_ack(hdr, ack);
1014                         msg_set_bcast_ack(hdr, bc_ack);
1015                         _skb = skb_clone(skb, GFP_ATOMIC);
1016                         if (!_skb) {
1017                                 kfree_skb(skb);
1018                                 __skb_queue_purge(list);
1019                                 return -ENOBUFS;
1020                         }
1021                         __skb_queue_tail(transmq, skb);
1022                         /* next retransmit attempt */
1023                         if (link_is_bc_sndlink(l))
1024                                 TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
1025                         __skb_queue_tail(xmitq, _skb);
1026                         TIPC_SKB_CB(skb)->ackers = l->ackers;
1027                         l->rcv_unacked = 0;
1028                         l->stats.sent_pkts++;
1029                         seqno++;
1030                         continue;
1031                 }
1032                 if (tipc_msg_try_bundle(l->backlog[imp].target_bskb, &skb,
1033                                         mss, l->addr, &new_bundle)) {
1034                         if (skb) {
1035                                 /* Keep a ref. to the skb for next try */
1036                                 l->backlog[imp].target_bskb = skb;
1037                                 l->backlog[imp].len++;
1038                                 __skb_queue_tail(backlogq, skb);
1039                         } else {
1040                                 if (new_bundle) {
1041                                         l->stats.sent_bundles++;
1042                                         l->stats.sent_bundled++;
1043                                 }
1044                                 l->stats.sent_bundled++;
1045                         }
1046                         continue;
1047                 }
1048                 l->backlog[imp].target_bskb = NULL;
1049                 l->backlog[imp].len += (1 + skb_queue_len(list));
1050                 __skb_queue_tail(backlogq, skb);
1051                 skb_queue_splice_tail_init(list, backlogq);
1052         }
1053         l->snd_nxt = seqno;
1054         return rc;
1055 }
1056
1057 static void tipc_link_update_cwin(struct tipc_link *l, int released,
1058                                   bool retransmitted)
1059 {
1060         int bklog_len = skb_queue_len(&l->backlogq);
1061         struct sk_buff_head *txq = &l->transmq;
1062         int txq_len = skb_queue_len(txq);
1063         u16 cwin = l->window;
1064
1065         /* Enter fast recovery */
1066         if (unlikely(retransmitted)) {
1067                 l->ssthresh = max_t(u16, l->window / 2, 300);
1068                 l->window = min_t(u16, l->ssthresh, l->window);
1069                 return;
1070         }
1071         /* Enter slow start */
1072         if (unlikely(!released)) {
1073                 l->ssthresh = max_t(u16, l->window / 2, 300);
1074                 l->window = l->min_win;
1075                 return;
1076         }
1077         /* Don't increase window if no pressure on the transmit queue */
1078         if (txq_len + bklog_len < cwin)
1079                 return;
1080
1081         /* Don't increase window if there are holes the transmit queue */
1082         if (txq_len && l->snd_nxt - buf_seqno(skb_peek(txq)) != txq_len)
1083                 return;
1084
1085         l->cong_acks += released;
1086
1087         /* Slow start  */
1088         if (cwin <= l->ssthresh) {
1089                 l->window = min_t(u16, cwin + released, l->max_win);
1090                 return;
1091         }
1092         /* Congestion avoidance */
1093         if (l->cong_acks < cwin)
1094                 return;
1095         l->window = min_t(u16, ++cwin, l->max_win);
1096         l->cong_acks = 0;
1097 }
1098
1099 static void tipc_link_advance_backlog(struct tipc_link *l,
1100                                       struct sk_buff_head *xmitq)
1101 {
1102         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1103         struct sk_buff_head *txq = &l->transmq;
1104         struct sk_buff *skb, *_skb;
1105         u16 ack = l->rcv_nxt - 1;
1106         u16 seqno = l->snd_nxt;
1107         struct tipc_msg *hdr;
1108         u16 cwin = l->window;
1109         u32 imp;
1110
1111         while (skb_queue_len(txq) < cwin) {
1112                 skb = skb_peek(&l->backlogq);
1113                 if (!skb)
1114                         break;
1115                 _skb = skb_clone(skb, GFP_ATOMIC);
1116                 if (!_skb)
1117                         break;
1118                 __skb_dequeue(&l->backlogq);
1119                 hdr = buf_msg(skb);
1120                 imp = msg_importance(hdr);
1121                 l->backlog[imp].len--;
1122                 if (unlikely(skb == l->backlog[imp].target_bskb))
1123                         l->backlog[imp].target_bskb = NULL;
1124                 __skb_queue_tail(&l->transmq, skb);
1125                 /* next retransmit attempt */
1126                 if (link_is_bc_sndlink(l))
1127                         TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
1128
1129                 __skb_queue_tail(xmitq, _skb);
1130                 TIPC_SKB_CB(skb)->ackers = l->ackers;
1131                 msg_set_seqno(hdr, seqno);
1132                 msg_set_ack(hdr, ack);
1133                 msg_set_bcast_ack(hdr, bc_ack);
1134                 l->rcv_unacked = 0;
1135                 l->stats.sent_pkts++;
1136                 seqno++;
1137         }
1138         l->snd_nxt = seqno;
1139 }
1140
1141 /**
1142  * link_retransmit_failure() - Detect repeated retransmit failures
1143  * @l: tipc link sender
1144  * @r: tipc link receiver (= l in case of unicast)
1145  * @rc: returned code
1146  *
1147  * Return: true if the repeated retransmit failures happens, otherwise
1148  * false
1149  */
1150 static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r,
1151                                     int *rc)
1152 {
1153         struct sk_buff *skb = skb_peek(&l->transmq);
1154         struct tipc_msg *hdr;
1155
1156         if (!skb)
1157                 return false;
1158
1159         if (!TIPC_SKB_CB(skb)->retr_cnt)
1160                 return false;
1161
1162         if (!time_after(jiffies, TIPC_SKB_CB(skb)->retr_stamp +
1163                         msecs_to_jiffies(r->tolerance * 10)))
1164                 return false;
1165
1166         hdr = buf_msg(skb);
1167         if (link_is_bc_sndlink(l) && !less(r->acked, msg_seqno(hdr)))
1168                 return false;
1169
1170         pr_warn("Retransmission failure on link <%s>\n", l->name);
1171         link_print(l, "State of link ");
1172         pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
1173                 msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
1174         pr_info("sqno %u, prev: %x, dest: %x\n",
1175                 msg_seqno(hdr), msg_prevnode(hdr), msg_destnode(hdr));
1176         pr_info("retr_stamp %d, retr_cnt %d\n",
1177                 jiffies_to_msecs(TIPC_SKB_CB(skb)->retr_stamp),
1178                 TIPC_SKB_CB(skb)->retr_cnt);
1179
1180         trace_tipc_list_dump(&l->transmq, true, "retrans failure!");
1181         trace_tipc_link_dump(l, TIPC_DUMP_NONE, "retrans failure!");
1182         trace_tipc_link_dump(r, TIPC_DUMP_NONE, "retrans failure!");
1183
1184         if (link_is_bc_sndlink(l)) {
1185                 r->state = LINK_RESET;
1186                 *rc = TIPC_LINK_DOWN_EVT;
1187         } else {
1188                 *rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1189         }
1190
1191         return true;
1192 }
1193
1194 /* tipc_link_bc_retrans() - retransmit zero or more packets
1195  * @l: the link to transmit on
1196  * @r: the receiving link ordering the retransmit. Same as l if unicast
1197  * @from: retransmit from (inclusive) this sequence number
1198  * @to: retransmit to (inclusive) this sequence number
1199  * xmitq: queue for accumulating the retransmitted packets
1200  */
1201 static int tipc_link_bc_retrans(struct tipc_link *l, struct tipc_link *r,
1202                                 u16 from, u16 to, struct sk_buff_head *xmitq)
1203 {
1204         struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
1205         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1206         u16 ack = l->rcv_nxt - 1;
1207         int retransmitted = 0;
1208         struct tipc_msg *hdr;
1209         int rc = 0;
1210
1211         if (!skb)
1212                 return 0;
1213         if (less(to, from))
1214                 return 0;
1215
1216         trace_tipc_link_retrans(r, from, to, &l->transmq);
1217
1218         if (link_retransmit_failure(l, r, &rc))
1219                 return rc;
1220
1221         skb_queue_walk(&l->transmq, skb) {
1222                 hdr = buf_msg(skb);
1223                 if (less(msg_seqno(hdr), from))
1224                         continue;
1225                 if (more(msg_seqno(hdr), to))
1226                         break;
1227                 if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
1228                         continue;
1229                 TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
1230                 _skb = pskb_copy(skb, GFP_ATOMIC);
1231                 if (!_skb)
1232                         return 0;
1233                 hdr = buf_msg(_skb);
1234                 msg_set_ack(hdr, ack);
1235                 msg_set_bcast_ack(hdr, bc_ack);
1236                 _skb->priority = TC_PRIO_CONTROL;
1237                 __skb_queue_tail(xmitq, _skb);
1238                 l->stats.retransmitted++;
1239                 retransmitted++;
1240                 /* Increase actual retrans counter & mark first time */
1241                 if (!TIPC_SKB_CB(skb)->retr_cnt++)
1242                         TIPC_SKB_CB(skb)->retr_stamp = jiffies;
1243         }
1244         tipc_link_update_cwin(l, 0, retransmitted);
1245         return 0;
1246 }
1247
1248 /* tipc_data_input - deliver data and name distr msgs to upper layer
1249  *
1250  * Consumes buffer if message is of right type
1251  * Node lock must be held
1252  */
1253 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1254                             struct sk_buff_head *inputq)
1255 {
1256         struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq;
1257         struct tipc_msg *hdr = buf_msg(skb);
1258
1259         switch (msg_user(hdr)) {
1260         case TIPC_LOW_IMPORTANCE:
1261         case TIPC_MEDIUM_IMPORTANCE:
1262         case TIPC_HIGH_IMPORTANCE:
1263         case TIPC_CRITICAL_IMPORTANCE:
1264                 if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) {
1265                         skb_queue_tail(mc_inputq, skb);
1266                         return true;
1267                 }
1268                 /* fall through */
1269         case CONN_MANAGER:
1270                 skb_queue_tail(inputq, skb);
1271                 return true;
1272         case GROUP_PROTOCOL:
1273                 skb_queue_tail(mc_inputq, skb);
1274                 return true;
1275         case NAME_DISTRIBUTOR:
1276                 l->bc_rcvlink->state = LINK_ESTABLISHED;
1277                 skb_queue_tail(l->namedq, skb);
1278                 return true;
1279         case MSG_BUNDLER:
1280         case TUNNEL_PROTOCOL:
1281         case MSG_FRAGMENTER:
1282         case BCAST_PROTOCOL:
1283                 return false;
1284         default:
1285                 pr_warn("Dropping received illegal msg type\n");
1286                 kfree_skb(skb);
1287                 return true;
1288         };
1289 }
1290
1291 /* tipc_link_input - process packet that has passed link protocol check
1292  *
1293  * Consumes buffer
1294  */
1295 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1296                            struct sk_buff_head *inputq,
1297                            struct sk_buff **reasm_skb)
1298 {
1299         struct tipc_msg *hdr = buf_msg(skb);
1300         struct sk_buff *iskb;
1301         struct sk_buff_head tmpq;
1302         int usr = msg_user(hdr);
1303         int pos = 0;
1304
1305         if (usr == MSG_BUNDLER) {
1306                 skb_queue_head_init(&tmpq);
1307                 l->stats.recv_bundles++;
1308                 l->stats.recv_bundled += msg_msgcnt(hdr);
1309                 while (tipc_msg_extract(skb, &iskb, &pos))
1310                         tipc_data_input(l, iskb, &tmpq);
1311                 tipc_skb_queue_splice_tail(&tmpq, inputq);
1312                 return 0;
1313         } else if (usr == MSG_FRAGMENTER) {
1314                 l->stats.recv_fragments++;
1315                 if (tipc_buf_append(reasm_skb, &skb)) {
1316                         l->stats.recv_fragmented++;
1317                         tipc_data_input(l, skb, inputq);
1318                 } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1319                         pr_warn_ratelimited("Unable to build fragment list\n");
1320                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1321                 }
1322                 return 0;
1323         } else if (usr == BCAST_PROTOCOL) {
1324                 tipc_bcast_lock(l->net);
1325                 tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1326                 tipc_bcast_unlock(l->net);
1327         }
1328
1329         kfree_skb(skb);
1330         return 0;
1331 }
1332
1333 /* tipc_link_tnl_rcv() - receive TUNNEL_PROTOCOL message, drop or process the
1334  *                       inner message along with the ones in the old link's
1335  *                       deferdq
1336  * @l: tunnel link
1337  * @skb: TUNNEL_PROTOCOL message
1338  * @inputq: queue to put messages ready for delivery
1339  */
1340 static int tipc_link_tnl_rcv(struct tipc_link *l, struct sk_buff *skb,
1341                              struct sk_buff_head *inputq)
1342 {
1343         struct sk_buff **reasm_skb = &l->failover_reasm_skb;
1344         struct sk_buff **reasm_tnlmsg = &l->reasm_tnlmsg;
1345         struct sk_buff_head *fdefq = &l->failover_deferdq;
1346         struct tipc_msg *hdr = buf_msg(skb);
1347         struct sk_buff *iskb;
1348         int ipos = 0;
1349         int rc = 0;
1350         u16 seqno;
1351
1352         if (msg_type(hdr) == SYNCH_MSG) {
1353                 kfree_skb(skb);
1354                 return 0;
1355         }
1356
1357         /* Not a fragment? */
1358         if (likely(!msg_nof_fragms(hdr))) {
1359                 if (unlikely(!tipc_msg_extract(skb, &iskb, &ipos))) {
1360                         pr_warn_ratelimited("Unable to extract msg, defq: %d\n",
1361                                             skb_queue_len(fdefq));
1362                         return 0;
1363                 }
1364                 kfree_skb(skb);
1365         } else {
1366                 /* Set fragment type for buf_append */
1367                 if (msg_fragm_no(hdr) == 1)
1368                         msg_set_type(hdr, FIRST_FRAGMENT);
1369                 else if (msg_fragm_no(hdr) < msg_nof_fragms(hdr))
1370                         msg_set_type(hdr, FRAGMENT);
1371                 else
1372                         msg_set_type(hdr, LAST_FRAGMENT);
1373
1374                 if (!tipc_buf_append(reasm_tnlmsg, &skb)) {
1375                         /* Successful but non-complete reassembly? */
1376                         if (*reasm_tnlmsg || link_is_bc_rcvlink(l))
1377                                 return 0;
1378                         pr_warn_ratelimited("Unable to reassemble tunnel msg\n");
1379                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1380                 }
1381                 iskb = skb;
1382         }
1383
1384         do {
1385                 seqno = buf_seqno(iskb);
1386                 if (unlikely(less(seqno, l->drop_point))) {
1387                         kfree_skb(iskb);
1388                         continue;
1389                 }
1390                 if (unlikely(seqno != l->drop_point)) {
1391                         __tipc_skb_queue_sorted(fdefq, seqno, iskb);
1392                         continue;
1393                 }
1394
1395                 l->drop_point++;
1396                 if (!tipc_data_input(l, iskb, inputq))
1397                         rc |= tipc_link_input(l, iskb, inputq, reasm_skb);
1398                 if (unlikely(rc))
1399                         break;
1400         } while ((iskb = __tipc_skb_dequeue(fdefq, l->drop_point)));
1401
1402         return rc;
1403 }
1404
1405 static int tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1406 {
1407         int released = 0;
1408         struct sk_buff *skb, *tmp;
1409
1410         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1411                 if (more(buf_seqno(skb), acked))
1412                         break;
1413                 __skb_unlink(skb, &l->transmq);
1414                 kfree_skb(skb);
1415                 released++;
1416         }
1417         return released;
1418 }
1419
1420 /* tipc_build_gap_ack_blks - build Gap ACK blocks
1421  * @l: tipc link that data have come with gaps in sequence if any
1422  * @data: data buffer to store the Gap ACK blocks after built
1423  *
1424  * returns the actual allocated memory size
1425  */
1426 static u16 tipc_build_gap_ack_blks(struct tipc_link *l, void *data, u16 gap)
1427 {
1428         struct sk_buff *skb = skb_peek(&l->deferdq);
1429         struct tipc_gap_ack_blks *ga = data;
1430         u16 len, expect, seqno = 0;
1431         u8 n = 0;
1432
1433         if (!skb || !gap)
1434                 goto exit;
1435
1436         expect = buf_seqno(skb);
1437         skb_queue_walk(&l->deferdq, skb) {
1438                 seqno = buf_seqno(skb);
1439                 if (unlikely(more(seqno, expect))) {
1440                         ga->gacks[n].ack = htons(expect - 1);
1441                         ga->gacks[n].gap = htons(seqno - expect);
1442                         if (++n >= MAX_GAP_ACK_BLKS) {
1443                                 pr_info_ratelimited("Too few Gap ACK blocks!\n");
1444                                 goto exit;
1445                         }
1446                 } else if (unlikely(less(seqno, expect))) {
1447                         pr_warn("Unexpected skb in deferdq!\n");
1448                         continue;
1449                 }
1450                 expect = seqno + 1;
1451         }
1452
1453         /* last block */
1454         ga->gacks[n].ack = htons(seqno);
1455         ga->gacks[n].gap = 0;
1456         n++;
1457
1458 exit:
1459         len = tipc_gap_ack_blks_sz(n);
1460         ga->len = htons(len);
1461         ga->gack_cnt = n;
1462         return len;
1463 }
1464
1465 /* tipc_link_advance_transmq - advance TIPC link transmq queue by releasing
1466  *                             acked packets, also doing retransmissions if
1467  *                             gaps found
1468  * @l: tipc link with transmq queue to be advanced
1469  * @acked: seqno of last packet acked by peer without any gaps before
1470  * @gap: # of gap packets
1471  * @ga: buffer pointer to Gap ACK blocks from peer
1472  * @xmitq: queue for accumulating the retransmitted packets if any
1473  *
1474  * In case of a repeated retransmit failures, the call will return shortly
1475  * with a returned code (e.g. TIPC_LINK_DOWN_EVT)
1476  */
1477 static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,
1478                                      struct tipc_gap_ack_blks *ga,
1479                                      struct sk_buff_head *xmitq)
1480 {
1481         struct sk_buff *skb, *_skb, *tmp;
1482         struct tipc_msg *hdr;
1483         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1484         bool retransmitted = false;
1485         u16 ack = l->rcv_nxt - 1;
1486         bool passed = false;
1487         u16 released = 0;
1488         u16 seqno, n = 0;
1489         int rc = 0;
1490
1491         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1492                 seqno = buf_seqno(skb);
1493
1494 next_gap_ack:
1495                 if (less_eq(seqno, acked)) {
1496                         /* release skb */
1497                         __skb_unlink(skb, &l->transmq);
1498                         kfree_skb(skb);
1499                         released++;
1500                 } else if (less_eq(seqno, acked + gap)) {
1501                         /* First, check if repeated retrans failures occurs? */
1502                         if (!passed && link_retransmit_failure(l, l, &rc))
1503                                 return rc;
1504                         passed = true;
1505
1506                         /* retransmit skb if unrestricted*/
1507                         if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
1508                                 continue;
1509                         TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
1510                         _skb = pskb_copy(skb, GFP_ATOMIC);
1511                         if (!_skb)
1512                                 continue;
1513                         hdr = buf_msg(_skb);
1514                         msg_set_ack(hdr, ack);
1515                         msg_set_bcast_ack(hdr, bc_ack);
1516                         _skb->priority = TC_PRIO_CONTROL;
1517                         __skb_queue_tail(xmitq, _skb);
1518                         l->stats.retransmitted++;
1519                         retransmitted = true;
1520                         /* Increase actual retrans counter & mark first time */
1521                         if (!TIPC_SKB_CB(skb)->retr_cnt++)
1522                                 TIPC_SKB_CB(skb)->retr_stamp = jiffies;
1523                 } else {
1524                         /* retry with Gap ACK blocks if any */
1525                         if (!ga || n >= ga->gack_cnt)
1526                                 break;
1527                         acked = ntohs(ga->gacks[n].ack);
1528                         gap = ntohs(ga->gacks[n].gap);
1529                         n++;
1530                         goto next_gap_ack;
1531                 }
1532         }
1533         if (released || retransmitted)
1534                 tipc_link_update_cwin(l, released, retransmitted);
1535         if (released)
1536                 tipc_link_advance_backlog(l, xmitq);
1537         return 0;
1538 }
1539
1540 /* tipc_link_build_state_msg: prepare link state message for transmission
1541  *
1542  * Note that sending of broadcast ack is coordinated among nodes, to reduce
1543  * risk of ack storms towards the sender
1544  */
1545 int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1546 {
1547         if (!l)
1548                 return 0;
1549
1550         /* Broadcast ACK must be sent via a unicast link => defer to caller */
1551         if (link_is_bc_rcvlink(l)) {
1552                 if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1553                         return 0;
1554                 l->rcv_unacked = 0;
1555
1556                 /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
1557                 l->snd_nxt = l->rcv_nxt;
1558                 return TIPC_LINK_SND_STATE;
1559         }
1560         /* Unicast ACK */
1561         l->rcv_unacked = 0;
1562         l->stats.sent_acks++;
1563         tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
1564         return 0;
1565 }
1566
1567 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1568  */
1569 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1570 {
1571         int mtyp = RESET_MSG;
1572         struct sk_buff *skb;
1573
1574         if (l->state == LINK_ESTABLISHING)
1575                 mtyp = ACTIVATE_MSG;
1576
1577         tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, 0, xmitq);
1578
1579         /* Inform peer that this endpoint is going down if applicable */
1580         skb = skb_peek_tail(xmitq);
1581         if (skb && (l->state == LINK_RESET))
1582                 msg_set_peer_stopping(buf_msg(skb), 1);
1583 }
1584
1585 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1586  * Note that sending of broadcast NACK is coordinated among nodes, to
1587  * reduce the risk of NACK storms towards the sender
1588  */
1589 static int tipc_link_build_nack_msg(struct tipc_link *l,
1590                                     struct sk_buff_head *xmitq)
1591 {
1592         u32 def_cnt = ++l->stats.deferred_recv;
1593         struct sk_buff_head *dfq = &l->deferdq;
1594         u32 defq_len = skb_queue_len(dfq);
1595         int match1, match2;
1596
1597         if (link_is_bc_rcvlink(l)) {
1598                 match1 = def_cnt & 0xf;
1599                 match2 = tipc_own_addr(l->net) & 0xf;
1600                 if (match1 == match2)
1601                         return TIPC_LINK_SND_STATE;
1602                 return 0;
1603         }
1604
1605         if (defq_len >= 3 && !((defq_len - 3) % 16)) {
1606                 u16 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1607
1608                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0,
1609                                           rcvgap, 0, 0, xmitq);
1610         }
1611         return 0;
1612 }
1613
1614 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1615  * @l: the link that should handle the message
1616  * @skb: TIPC packet
1617  * @xmitq: queue to place packets to be sent after this call
1618  */
1619 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1620                   struct sk_buff_head *xmitq)
1621 {
1622         struct sk_buff_head *defq = &l->deferdq;
1623         struct tipc_msg *hdr = buf_msg(skb);
1624         u16 seqno, rcv_nxt, win_lim;
1625         int released = 0;
1626         int rc = 0;
1627
1628         /* Verify and update link state */
1629         if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1630                 return tipc_link_proto_rcv(l, skb, xmitq);
1631
1632         /* Don't send probe at next timeout expiration */
1633         l->silent_intv_cnt = 0;
1634
1635         do {
1636                 hdr = buf_msg(skb);
1637                 seqno = msg_seqno(hdr);
1638                 rcv_nxt = l->rcv_nxt;
1639                 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1640
1641                 if (unlikely(!link_is_up(l))) {
1642                         if (l->state == LINK_ESTABLISHING)
1643                                 rc = TIPC_LINK_UP_EVT;
1644                         kfree_skb(skb);
1645                         break;
1646                 }
1647
1648                 /* Drop if outside receive window */
1649                 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1650                         l->stats.duplicates++;
1651                         kfree_skb(skb);
1652                         break;
1653                 }
1654                 released += tipc_link_release_pkts(l, msg_ack(hdr));
1655
1656                 /* Defer delivery if sequence gap */
1657                 if (unlikely(seqno != rcv_nxt)) {
1658                         __tipc_skb_queue_sorted(defq, seqno, skb);
1659                         rc |= tipc_link_build_nack_msg(l, xmitq);
1660                         break;
1661                 }
1662
1663                 /* Deliver packet */
1664                 l->rcv_nxt++;
1665                 l->stats.recv_pkts++;
1666
1667                 if (unlikely(msg_user(hdr) == TUNNEL_PROTOCOL))
1668                         rc |= tipc_link_tnl_rcv(l, skb, l->inputq);
1669                 else if (!tipc_data_input(l, skb, l->inputq))
1670                         rc |= tipc_link_input(l, skb, l->inputq, &l->reasm_buf);
1671                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1672                         rc |= tipc_link_build_state_msg(l, xmitq);
1673                 if (unlikely(rc & ~TIPC_LINK_SND_STATE))
1674                         break;
1675         } while ((skb = __tipc_skb_dequeue(defq, l->rcv_nxt)));
1676
1677         /* Forward queues and wake up waiting users */
1678         if (released) {
1679                 tipc_link_update_cwin(l, released, 0);
1680                 tipc_link_advance_backlog(l, xmitq);
1681                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1682                         link_prepare_wakeup(l);
1683         }
1684         return rc;
1685 }
1686
1687 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1688                                       bool probe_reply, u16 rcvgap,
1689                                       int tolerance, int priority,
1690                                       struct sk_buff_head *xmitq)
1691 {
1692         struct tipc_link *bcl = l->bc_rcvlink;
1693         struct sk_buff *skb;
1694         struct tipc_msg *hdr;
1695         struct sk_buff_head *dfq = &l->deferdq;
1696         bool node_up = link_is_up(bcl);
1697         struct tipc_mon_state *mstate = &l->mon_state;
1698         int dlen = 0;
1699         void *data;
1700         u16 glen = 0;
1701
1702         /* Don't send protocol message during reset or link failover */
1703         if (tipc_link_is_blocked(l))
1704                 return;
1705
1706         if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1707                 return;
1708
1709         if ((probe || probe_reply) && !skb_queue_empty(dfq))
1710                 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1711
1712         skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1713                               tipc_max_domain_size + MAX_GAP_ACK_BLKS_SZ,
1714                               l->addr, tipc_own_addr(l->net), 0, 0, 0);
1715         if (!skb)
1716                 return;
1717
1718         hdr = buf_msg(skb);
1719         data = msg_data(hdr);
1720         msg_set_session(hdr, l->session);
1721         msg_set_bearer_id(hdr, l->bearer_id);
1722         msg_set_net_plane(hdr, l->net_plane);
1723         msg_set_next_sent(hdr, l->snd_nxt);
1724         msg_set_ack(hdr, l->rcv_nxt - 1);
1725         msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1726         msg_set_bc_ack_invalid(hdr, !node_up);
1727         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1728         msg_set_link_tolerance(hdr, tolerance);
1729         msg_set_linkprio(hdr, priority);
1730         msg_set_redundant_link(hdr, node_up);
1731         msg_set_seq_gap(hdr, 0);
1732         msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1733
1734         if (mtyp == STATE_MSG) {
1735                 if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
1736                         msg_set_seqno(hdr, l->snd_nxt_state++);
1737                 msg_set_seq_gap(hdr, rcvgap);
1738                 msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
1739                 msg_set_probe(hdr, probe);
1740                 msg_set_is_keepalive(hdr, probe || probe_reply);
1741                 if (l->peer_caps & TIPC_GAP_ACK_BLOCK)
1742                         glen = tipc_build_gap_ack_blks(l, data, rcvgap);
1743                 tipc_mon_prep(l->net, data + glen, &dlen, mstate, l->bearer_id);
1744                 msg_set_size(hdr, INT_H_SIZE + glen + dlen);
1745                 skb_trim(skb, INT_H_SIZE + glen + dlen);
1746                 l->stats.sent_states++;
1747                 l->rcv_unacked = 0;
1748         } else {
1749                 /* RESET_MSG or ACTIVATE_MSG */
1750                 if (mtyp == ACTIVATE_MSG) {
1751                         msg_set_dest_session_valid(hdr, 1);
1752                         msg_set_dest_session(hdr, l->peer_session);
1753                 }
1754                 msg_set_max_pkt(hdr, l->advertised_mtu);
1755                 strcpy(data, l->if_name);
1756                 msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
1757                 skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
1758         }
1759         if (probe)
1760                 l->stats.sent_probes++;
1761         if (rcvgap)
1762                 l->stats.sent_nacks++;
1763         skb->priority = TC_PRIO_CONTROL;
1764         __skb_queue_tail(xmitq, skb);
1765         trace_tipc_proto_build(skb, false, l->name);
1766 }
1767
1768 void tipc_link_create_dummy_tnl_msg(struct tipc_link *l,
1769                                     struct sk_buff_head *xmitq)
1770 {
1771         u32 onode = tipc_own_addr(l->net);
1772         struct tipc_msg *hdr, *ihdr;
1773         struct sk_buff_head tnlq;
1774         struct sk_buff *skb;
1775         u32 dnode = l->addr;
1776
1777         __skb_queue_head_init(&tnlq);
1778         skb = tipc_msg_create(TUNNEL_PROTOCOL, FAILOVER_MSG,
1779                               INT_H_SIZE, BASIC_H_SIZE,
1780                               dnode, onode, 0, 0, 0);
1781         if (!skb) {
1782                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1783                 return;
1784         }
1785
1786         hdr = buf_msg(skb);
1787         msg_set_msgcnt(hdr, 1);
1788         msg_set_bearer_id(hdr, l->peer_bearer_id);
1789
1790         ihdr = (struct tipc_msg *)msg_data(hdr);
1791         tipc_msg_init(onode, ihdr, TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1792                       BASIC_H_SIZE, dnode);
1793         msg_set_errcode(ihdr, TIPC_ERR_NO_PORT);
1794         __skb_queue_tail(&tnlq, skb);
1795         tipc_link_xmit(l, &tnlq, xmitq);
1796 }
1797
1798 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1799  * with contents of the link's transmit and backlog queues.
1800  */
1801 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1802                            int mtyp, struct sk_buff_head *xmitq)
1803 {
1804         struct sk_buff_head *fdefq = &tnl->failover_deferdq;
1805         struct sk_buff *skb, *tnlskb;
1806         struct tipc_msg *hdr, tnlhdr;
1807         struct sk_buff_head *queue = &l->transmq;
1808         struct sk_buff_head tmpxq, tnlq, frags;
1809         u16 pktlen, pktcnt, seqno = l->snd_nxt;
1810         bool pktcnt_need_update = false;
1811         u16 syncpt;
1812         int rc;
1813
1814         if (!tnl)
1815                 return;
1816
1817         __skb_queue_head_init(&tnlq);
1818         /* Link Synching:
1819          * From now on, send only one single ("dummy") SYNCH message
1820          * to peer. The SYNCH message does not contain any data, just
1821          * a header conveying the synch point to the peer.
1822          */
1823         if (mtyp == SYNCH_MSG && (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
1824                 tnlskb = tipc_msg_create(TUNNEL_PROTOCOL, SYNCH_MSG,
1825                                          INT_H_SIZE, 0, l->addr,
1826                                          tipc_own_addr(l->net),
1827                                          0, 0, 0);
1828                 if (!tnlskb) {
1829                         pr_warn("%sunable to create dummy SYNCH_MSG\n",
1830                                 link_co_err);
1831                         return;
1832                 }
1833
1834                 hdr = buf_msg(tnlskb);
1835                 syncpt = l->snd_nxt + skb_queue_len(&l->backlogq) - 1;
1836                 msg_set_syncpt(hdr, syncpt);
1837                 msg_set_bearer_id(hdr, l->peer_bearer_id);
1838                 __skb_queue_tail(&tnlq, tnlskb);
1839                 tipc_link_xmit(tnl, &tnlq, xmitq);
1840                 return;
1841         }
1842
1843         __skb_queue_head_init(&tmpxq);
1844         __skb_queue_head_init(&frags);
1845         /* At least one packet required for safe algorithm => add dummy */
1846         skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1847                               BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
1848                               0, 0, TIPC_ERR_NO_PORT);
1849         if (!skb) {
1850                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1851                 return;
1852         }
1853         __skb_queue_tail(&tnlq, skb);
1854         tipc_link_xmit(l, &tnlq, &tmpxq);
1855         __skb_queue_purge(&tmpxq);
1856
1857         /* Initialize reusable tunnel packet header */
1858         tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
1859                       mtyp, INT_H_SIZE, l->addr);
1860         if (mtyp == SYNCH_MSG)
1861                 pktcnt = l->snd_nxt - buf_seqno(skb_peek(&l->transmq));
1862         else
1863                 pktcnt = skb_queue_len(&l->transmq);
1864         pktcnt += skb_queue_len(&l->backlogq);
1865         msg_set_msgcnt(&tnlhdr, pktcnt);
1866         msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1867 tnl:
1868         /* Wrap each packet into a tunnel packet */
1869         skb_queue_walk(queue, skb) {
1870                 hdr = buf_msg(skb);
1871                 if (queue == &l->backlogq)
1872                         msg_set_seqno(hdr, seqno++);
1873                 pktlen = msg_size(hdr);
1874
1875                 /* Tunnel link MTU is not large enough? This could be
1876                  * due to:
1877                  * 1) Link MTU has just changed or set differently;
1878                  * 2) Or FAILOVER on the top of a SYNCH message
1879                  *
1880                  * The 2nd case should not happen if peer supports
1881                  * TIPC_TUNNEL_ENHANCED
1882                  */
1883                 if (pktlen > tnl->mtu - INT_H_SIZE) {
1884                         if (mtyp == FAILOVER_MSG &&
1885                             (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
1886                                 rc = tipc_msg_fragment(skb, &tnlhdr, tnl->mtu,
1887                                                        &frags);
1888                                 if (rc) {
1889                                         pr_warn("%sunable to frag msg: rc %d\n",
1890                                                 link_co_err, rc);
1891                                         return;
1892                                 }
1893                                 pktcnt += skb_queue_len(&frags) - 1;
1894                                 pktcnt_need_update = true;
1895                                 skb_queue_splice_tail_init(&frags, &tnlq);
1896                                 continue;
1897                         }
1898                         /* Unluckily, peer doesn't have TIPC_TUNNEL_ENHANCED
1899                          * => Just warn it and return!
1900                          */
1901                         pr_warn_ratelimited("%stoo large msg <%d, %d>: %d!\n",
1902                                             link_co_err, msg_user(hdr),
1903                                             msg_type(hdr), msg_size(hdr));
1904                         return;
1905                 }
1906
1907                 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1908                 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
1909                 if (!tnlskb) {
1910                         pr_warn("%sunable to send packet\n", link_co_err);
1911                         return;
1912                 }
1913                 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1914                 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1915                 __skb_queue_tail(&tnlq, tnlskb);
1916         }
1917         if (queue != &l->backlogq) {
1918                 queue = &l->backlogq;
1919                 goto tnl;
1920         }
1921
1922         if (pktcnt_need_update)
1923                 skb_queue_walk(&tnlq, skb) {
1924                         hdr = buf_msg(skb);
1925                         msg_set_msgcnt(hdr, pktcnt);
1926                 }
1927
1928         tipc_link_xmit(tnl, &tnlq, xmitq);
1929
1930         if (mtyp == FAILOVER_MSG) {
1931                 tnl->drop_point = l->rcv_nxt;
1932                 tnl->failover_reasm_skb = l->reasm_buf;
1933                 l->reasm_buf = NULL;
1934
1935                 /* Failover the link's deferdq */
1936                 if (unlikely(!skb_queue_empty(fdefq))) {
1937                         pr_warn("Link failover deferdq not empty: %d!\n",
1938                                 skb_queue_len(fdefq));
1939                         __skb_queue_purge(fdefq);
1940                 }
1941                 skb_queue_splice_init(&l->deferdq, fdefq);
1942         }
1943 }
1944
1945 /**
1946  * tipc_link_failover_prepare() - prepare tnl for link failover
1947  *
1948  * This is a special version of the precursor - tipc_link_tnl_prepare(),
1949  * see the tipc_node_link_failover() for details
1950  *
1951  * @l: failover link
1952  * @tnl: tunnel link
1953  * @xmitq: queue for messages to be xmited
1954  */
1955 void tipc_link_failover_prepare(struct tipc_link *l, struct tipc_link *tnl,
1956                                 struct sk_buff_head *xmitq)
1957 {
1958         struct sk_buff_head *fdefq = &tnl->failover_deferdq;
1959
1960         tipc_link_create_dummy_tnl_msg(tnl, xmitq);
1961
1962         /* This failover link endpoint was never established before,
1963          * so it has not received anything from peer.
1964          * Otherwise, it must be a normal failover situation or the
1965          * node has entered SELF_DOWN_PEER_LEAVING and both peer nodes
1966          * would have to start over from scratch instead.
1967          */
1968         tnl->drop_point = 1;
1969         tnl->failover_reasm_skb = NULL;
1970
1971         /* Initiate the link's failover deferdq */
1972         if (unlikely(!skb_queue_empty(fdefq))) {
1973                 pr_warn("Link failover deferdq not empty: %d!\n",
1974                         skb_queue_len(fdefq));
1975                 __skb_queue_purge(fdefq);
1976         }
1977 }
1978
1979 /* tipc_link_validate_msg(): validate message against current link state
1980  * Returns true if message should be accepted, otherwise false
1981  */
1982 bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr)
1983 {
1984         u16 curr_session = l->peer_session;
1985         u16 session = msg_session(hdr);
1986         int mtyp = msg_type(hdr);
1987
1988         if (msg_user(hdr) != LINK_PROTOCOL)
1989                 return true;
1990
1991         switch (mtyp) {
1992         case RESET_MSG:
1993                 if (!l->in_session)
1994                         return true;
1995                 /* Accept only RESET with new session number */
1996                 return more(session, curr_session);
1997         case ACTIVATE_MSG:
1998                 if (!l->in_session)
1999                         return true;
2000                 /* Accept only ACTIVATE with new or current session number */
2001                 return !less(session, curr_session);
2002         case STATE_MSG:
2003                 /* Accept only STATE with current session number */
2004                 if (!l->in_session)
2005                         return false;
2006                 if (session != curr_session)
2007                         return false;
2008                 /* Extra sanity check */
2009                 if (!link_is_up(l) && msg_ack(hdr))
2010                         return false;
2011                 if (!(l->peer_caps & TIPC_LINK_PROTO_SEQNO))
2012                         return true;
2013                 /* Accept only STATE with new sequence number */
2014                 return !less(msg_seqno(hdr), l->rcv_nxt_state);
2015         default:
2016                 return false;
2017         }
2018 }
2019
2020 /* tipc_link_proto_rcv(): receive link level protocol message :
2021  * Note that network plane id propagates through the network, and may
2022  * change at any time. The node with lowest numerical id determines
2023  * network plane
2024  */
2025 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
2026                                struct sk_buff_head *xmitq)
2027 {
2028         struct tipc_msg *hdr = buf_msg(skb);
2029         struct tipc_gap_ack_blks *ga = NULL;
2030         u16 rcvgap = 0;
2031         u16 ack = msg_ack(hdr);
2032         u16 gap = msg_seq_gap(hdr);
2033         u16 peers_snd_nxt =  msg_next_sent(hdr);
2034         u16 peers_tol = msg_link_tolerance(hdr);
2035         u16 peers_prio = msg_linkprio(hdr);
2036         u16 rcv_nxt = l->rcv_nxt;
2037         u16 dlen = msg_data_sz(hdr);
2038         int mtyp = msg_type(hdr);
2039         bool reply = msg_probe(hdr);
2040         u16 glen = 0;
2041         void *data;
2042         char *if_name;
2043         int rc = 0;
2044
2045         trace_tipc_proto_rcv(skb, false, l->name);
2046         if (tipc_link_is_blocked(l) || !xmitq)
2047                 goto exit;
2048
2049         if (tipc_own_addr(l->net) > msg_prevnode(hdr))
2050                 l->net_plane = msg_net_plane(hdr);
2051
2052         skb_linearize(skb);
2053         hdr = buf_msg(skb);
2054         data = msg_data(hdr);
2055
2056         if (!tipc_link_validate_msg(l, hdr)) {
2057                 trace_tipc_skb_dump(skb, false, "PROTO invalid (1)!");
2058                 trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (1)!");
2059                 goto exit;
2060         }
2061
2062         switch (mtyp) {
2063         case RESET_MSG:
2064         case ACTIVATE_MSG:
2065                 /* Complete own link name with peer's interface name */
2066                 if_name =  strrchr(l->name, ':') + 1;
2067                 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
2068                         break;
2069                 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
2070                         break;
2071                 strncpy(if_name, data, TIPC_MAX_IF_NAME);
2072
2073                 /* Update own tolerance if peer indicates a non-zero value */
2074                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2075                         l->tolerance = peers_tol;
2076                         l->bc_rcvlink->tolerance = peers_tol;
2077                 }
2078                 /* Update own priority if peer's priority is higher */
2079                 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
2080                         l->priority = peers_prio;
2081
2082                 /* If peer is going down we want full re-establish cycle */
2083                 if (msg_peer_stopping(hdr)) {
2084                         rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2085                         break;
2086                 }
2087
2088                 /* If this endpoint was re-created while peer was ESTABLISHING
2089                  * it doesn't know current session number. Force re-synch.
2090                  */
2091                 if (mtyp == ACTIVATE_MSG && msg_dest_session_valid(hdr) &&
2092                     l->session != msg_dest_session(hdr)) {
2093                         if (less(l->session, msg_dest_session(hdr)))
2094                                 l->session = msg_dest_session(hdr) + 1;
2095                         break;
2096                 }
2097
2098                 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
2099                 if (mtyp == RESET_MSG || !link_is_up(l))
2100                         rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
2101
2102                 /* ACTIVATE_MSG takes up link if it was already locally reset */
2103                 if (mtyp == ACTIVATE_MSG && l->state == LINK_ESTABLISHING)
2104                         rc = TIPC_LINK_UP_EVT;
2105
2106                 l->peer_session = msg_session(hdr);
2107                 l->in_session = true;
2108                 l->peer_bearer_id = msg_bearer_id(hdr);
2109                 if (l->mtu > msg_max_pkt(hdr))
2110                         l->mtu = msg_max_pkt(hdr);
2111                 break;
2112
2113         case STATE_MSG:
2114                 l->rcv_nxt_state = msg_seqno(hdr) + 1;
2115
2116                 /* Update own tolerance if peer indicates a non-zero value */
2117                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2118                         l->tolerance = peers_tol;
2119                         l->bc_rcvlink->tolerance = peers_tol;
2120                 }
2121                 /* Update own prio if peer indicates a different value */
2122                 if ((peers_prio != l->priority) &&
2123                     in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) {
2124                         l->priority = peers_prio;
2125                         rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2126                 }
2127
2128                 l->silent_intv_cnt = 0;
2129                 l->stats.recv_states++;
2130                 if (msg_probe(hdr))
2131                         l->stats.recv_probes++;
2132
2133                 if (!link_is_up(l)) {
2134                         if (l->state == LINK_ESTABLISHING)
2135                                 rc = TIPC_LINK_UP_EVT;
2136                         break;
2137                 }
2138
2139                 /* Receive Gap ACK blocks from peer if any */
2140                 if (l->peer_caps & TIPC_GAP_ACK_BLOCK) {
2141                         ga = (struct tipc_gap_ack_blks *)data;
2142                         glen = ntohs(ga->len);
2143                         /* sanity check: if failed, ignore Gap ACK blocks */
2144                         if (glen != tipc_gap_ack_blks_sz(ga->gack_cnt))
2145                                 ga = NULL;
2146                 }
2147
2148                 tipc_mon_rcv(l->net, data + glen, dlen - glen, l->addr,
2149                              &l->mon_state, l->bearer_id);
2150
2151                 /* Send NACK if peer has sent pkts we haven't received yet */
2152                 if ((reply || msg_is_keepalive(hdr)) &&
2153                     more(peers_snd_nxt, rcv_nxt) &&
2154                     !tipc_link_is_synching(l) &&
2155                     skb_queue_empty(&l->deferdq))
2156                         rcvgap = peers_snd_nxt - l->rcv_nxt;
2157                 if (rcvgap || reply)
2158                         tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,
2159                                                   rcvgap, 0, 0, xmitq);
2160
2161                 rc |= tipc_link_advance_transmq(l, ack, gap, ga, xmitq);
2162                 if (gap)
2163                         l->stats.recv_nacks++;
2164                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
2165                         link_prepare_wakeup(l);
2166         }
2167 exit:
2168         kfree_skb(skb);
2169         return rc;
2170 }
2171
2172 /* tipc_link_build_bc_proto_msg() - create broadcast protocol message
2173  */
2174 static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
2175                                          u16 peers_snd_nxt,
2176                                          struct sk_buff_head *xmitq)
2177 {
2178         struct sk_buff *skb;
2179         struct tipc_msg *hdr;
2180         struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
2181         u16 ack = l->rcv_nxt - 1;
2182         u16 gap_to = peers_snd_nxt - 1;
2183
2184         skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
2185                               0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
2186         if (!skb)
2187                 return false;
2188         hdr = buf_msg(skb);
2189         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
2190         msg_set_bcast_ack(hdr, ack);
2191         msg_set_bcgap_after(hdr, ack);
2192         if (dfrd_skb)
2193                 gap_to = buf_seqno(dfrd_skb) - 1;
2194         msg_set_bcgap_to(hdr, gap_to);
2195         msg_set_non_seq(hdr, bcast);
2196         __skb_queue_tail(xmitq, skb);
2197         return true;
2198 }
2199
2200 /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
2201  *
2202  * Give a newly added peer node the sequence number where it should
2203  * start receiving and acking broadcast packets.
2204  */
2205 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
2206                                         struct sk_buff_head *xmitq)
2207 {
2208         struct sk_buff_head list;
2209
2210         __skb_queue_head_init(&list);
2211         if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
2212                 return;
2213         msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true);
2214         tipc_link_xmit(l, &list, xmitq);
2215 }
2216
2217 /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
2218  */
2219 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
2220 {
2221         int mtyp = msg_type(hdr);
2222         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2223
2224         if (link_is_up(l))
2225                 return;
2226
2227         if (msg_user(hdr) == BCAST_PROTOCOL) {
2228                 l->rcv_nxt = peers_snd_nxt;
2229                 l->state = LINK_ESTABLISHED;
2230                 return;
2231         }
2232
2233         if (l->peer_caps & TIPC_BCAST_SYNCH)
2234                 return;
2235
2236         if (msg_peer_node_is_up(hdr))
2237                 return;
2238
2239         /* Compatibility: accept older, less safe initial synch data */
2240         if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
2241                 l->rcv_nxt = peers_snd_nxt;
2242 }
2243
2244 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
2245  */
2246 int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
2247                           struct sk_buff_head *xmitq)
2248 {
2249         struct tipc_link *snd_l = l->bc_sndlink;
2250         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2251         u16 from = msg_bcast_ack(hdr) + 1;
2252         u16 to = from + msg_bc_gap(hdr) - 1;
2253         int rc = 0;
2254
2255         if (!link_is_up(l))
2256                 return rc;
2257
2258         if (!msg_peer_node_is_up(hdr))
2259                 return rc;
2260
2261         /* Open when peer ackowledges our bcast init msg (pkt #1) */
2262         if (msg_ack(hdr))
2263                 l->bc_peer_is_up = true;
2264
2265         if (!l->bc_peer_is_up)
2266                 return rc;
2267
2268         l->stats.recv_nacks++;
2269
2270         /* Ignore if peers_snd_nxt goes beyond receive window */
2271         if (more(peers_snd_nxt, l->rcv_nxt + l->window))
2272                 return rc;
2273
2274         rc = tipc_link_bc_retrans(snd_l, l, from, to, xmitq);
2275
2276         l->snd_nxt = peers_snd_nxt;
2277         if (link_bc_rcv_gap(l))
2278                 rc |= TIPC_LINK_SND_STATE;
2279
2280         /* Return now if sender supports nack via STATE messages */
2281         if (l->peer_caps & TIPC_BCAST_STATE_NACK)
2282                 return rc;
2283
2284         /* Otherwise, be backwards compatible */
2285
2286         if (!more(peers_snd_nxt, l->rcv_nxt)) {
2287                 l->nack_state = BC_NACK_SND_CONDITIONAL;
2288                 return 0;
2289         }
2290
2291         /* Don't NACK if one was recently sent or peeked */
2292         if (l->nack_state == BC_NACK_SND_SUPPRESS) {
2293                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2294                 return 0;
2295         }
2296
2297         /* Conditionally delay NACK sending until next synch rcv */
2298         if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
2299                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2300                 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
2301                         return 0;
2302         }
2303
2304         /* Send NACK now but suppress next one */
2305         tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
2306         l->nack_state = BC_NACK_SND_SUPPRESS;
2307         return 0;
2308 }
2309
2310 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
2311                           struct sk_buff_head *xmitq)
2312 {
2313         struct sk_buff *skb, *tmp;
2314         struct tipc_link *snd_l = l->bc_sndlink;
2315
2316         if (!link_is_up(l) || !l->bc_peer_is_up)
2317                 return;
2318
2319         if (!more(acked, l->acked))
2320                 return;
2321
2322         trace_tipc_link_bc_ack(l, l->acked, acked, &snd_l->transmq);
2323         /* Skip over packets peer has already acked */
2324         skb_queue_walk(&snd_l->transmq, skb) {
2325                 if (more(buf_seqno(skb), l->acked))
2326                         break;
2327         }
2328
2329         /* Update/release the packets peer is acking now */
2330         skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
2331                 if (more(buf_seqno(skb), acked))
2332                         break;
2333                 if (!--TIPC_SKB_CB(skb)->ackers) {
2334                         __skb_unlink(skb, &snd_l->transmq);
2335                         kfree_skb(skb);
2336                 }
2337         }
2338         l->acked = acked;
2339         tipc_link_advance_backlog(snd_l, xmitq);
2340         if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
2341                 link_prepare_wakeup(snd_l);
2342 }
2343
2344 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
2345  * This function is here for backwards compatibility, since
2346  * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
2347  */
2348 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
2349                           struct sk_buff_head *xmitq)
2350 {
2351         struct tipc_msg *hdr = buf_msg(skb);
2352         u32 dnode = msg_destnode(hdr);
2353         int mtyp = msg_type(hdr);
2354         u16 acked = msg_bcast_ack(hdr);
2355         u16 from = acked + 1;
2356         u16 to = msg_bcgap_to(hdr);
2357         u16 peers_snd_nxt = to + 1;
2358         int rc = 0;
2359
2360         kfree_skb(skb);
2361
2362         if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
2363                 return 0;
2364
2365         if (mtyp != STATE_MSG)
2366                 return 0;
2367
2368         if (dnode == tipc_own_addr(l->net)) {
2369                 tipc_link_bc_ack_rcv(l, acked, xmitq);
2370                 rc = tipc_link_bc_retrans(l->bc_sndlink, l, from, to, xmitq);
2371                 l->stats.recv_nacks++;
2372                 return rc;
2373         }
2374
2375         /* Msg for other node => suppress own NACK at next sync if applicable */
2376         if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
2377                 l->nack_state = BC_NACK_SND_SUPPRESS;
2378
2379         return 0;
2380 }
2381
2382 void tipc_link_set_queue_limits(struct tipc_link *l, u32 min_win, u32 max_win)
2383 {
2384         int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE);
2385
2386         l->min_win = min_win;
2387         l->ssthresh = max_win;
2388         l->max_win = max_win;
2389         l->window = min_win;
2390         l->backlog[TIPC_LOW_IMPORTANCE].limit      = min_win * 2;
2391         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = min_win * 4;
2392         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = min_win * 6;
2393         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = min_win * 8;
2394         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
2395 }
2396
2397 /**
2398  * link_reset_stats - reset link statistics
2399  * @l: pointer to link
2400  */
2401 void tipc_link_reset_stats(struct tipc_link *l)
2402 {
2403         memset(&l->stats, 0, sizeof(l->stats));
2404 }
2405
2406 static void link_print(struct tipc_link *l, const char *str)
2407 {
2408         struct sk_buff *hskb = skb_peek(&l->transmq);
2409         u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
2410         u16 tail = l->snd_nxt - 1;
2411
2412         pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
2413         pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
2414                 skb_queue_len(&l->transmq), head, tail,
2415                 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
2416 }
2417
2418 /* Parse and validate nested (link) properties valid for media, bearer and link
2419  */
2420 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
2421 {
2422         int err;
2423
2424         err = nla_parse_nested_deprecated(props, TIPC_NLA_PROP_MAX, prop,
2425                                           tipc_nl_prop_policy, NULL);
2426         if (err)
2427                 return err;
2428
2429         if (props[TIPC_NLA_PROP_PRIO]) {
2430                 u32 prio;
2431
2432                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2433                 if (prio > TIPC_MAX_LINK_PRI)
2434                         return -EINVAL;
2435         }
2436
2437         if (props[TIPC_NLA_PROP_TOL]) {
2438                 u32 tol;
2439
2440                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2441                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
2442                         return -EINVAL;
2443         }
2444
2445         if (props[TIPC_NLA_PROP_WIN]) {
2446                 u32 max_win;
2447
2448                 max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2449                 if (max_win < TIPC_DEF_LINK_WIN || max_win > TIPC_MAX_LINK_WIN)
2450                         return -EINVAL;
2451         }
2452
2453         return 0;
2454 }
2455
2456 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
2457 {
2458         int i;
2459         struct nlattr *stats;
2460
2461         struct nla_map {
2462                 u32 key;
2463                 u32 val;
2464         };
2465
2466         struct nla_map map[] = {
2467                 {TIPC_NLA_STATS_RX_INFO, 0},
2468                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
2469                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
2470                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
2471                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
2472                 {TIPC_NLA_STATS_TX_INFO, 0},
2473                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
2474                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
2475                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
2476                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
2477                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
2478                         s->msg_length_counts : 1},
2479                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
2480                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
2481                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
2482                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
2483                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
2484                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
2485                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
2486                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
2487                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
2488                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
2489                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
2490                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
2491                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
2492                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
2493                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
2494                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
2495                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
2496                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
2497                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
2498                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
2499                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
2500                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
2501                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
2502         };
2503
2504         stats = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2505         if (!stats)
2506                 return -EMSGSIZE;
2507
2508         for (i = 0; i <  ARRAY_SIZE(map); i++)
2509                 if (nla_put_u32(skb, map[i].key, map[i].val))
2510                         goto msg_full;
2511
2512         nla_nest_end(skb, stats);
2513
2514         return 0;
2515 msg_full:
2516         nla_nest_cancel(skb, stats);
2517
2518         return -EMSGSIZE;
2519 }
2520
2521 /* Caller should hold appropriate locks to protect the link */
2522 int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
2523                        struct tipc_link *link, int nlflags)
2524 {
2525         u32 self = tipc_own_addr(net);
2526         struct nlattr *attrs;
2527         struct nlattr *prop;
2528         void *hdr;
2529         int err;
2530
2531         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2532                           nlflags, TIPC_NL_LINK_GET);
2533         if (!hdr)
2534                 return -EMSGSIZE;
2535
2536         attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2537         if (!attrs)
2538                 goto msg_full;
2539
2540         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2541                 goto attr_msg_full;
2542         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, tipc_cluster_mask(self)))
2543                 goto attr_msg_full;
2544         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2545                 goto attr_msg_full;
2546         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
2547                 goto attr_msg_full;
2548         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
2549                 goto attr_msg_full;
2550
2551         if (tipc_link_is_up(link))
2552                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2553                         goto attr_msg_full;
2554         if (link->active)
2555                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2556                         goto attr_msg_full;
2557
2558         prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2559         if (!prop)
2560                 goto attr_msg_full;
2561         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2562                 goto prop_msg_full;
2563         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2564                 goto prop_msg_full;
2565         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2566                         link->window))
2567                 goto prop_msg_full;
2568         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2569                 goto prop_msg_full;
2570         nla_nest_end(msg->skb, prop);
2571
2572         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2573         if (err)
2574                 goto attr_msg_full;
2575
2576         nla_nest_end(msg->skb, attrs);
2577         genlmsg_end(msg->skb, hdr);
2578
2579         return 0;
2580
2581 prop_msg_full:
2582         nla_nest_cancel(msg->skb, prop);
2583 attr_msg_full:
2584         nla_nest_cancel(msg->skb, attrs);
2585 msg_full:
2586         genlmsg_cancel(msg->skb, hdr);
2587
2588         return -EMSGSIZE;
2589 }
2590
2591 static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
2592                                       struct tipc_stats *stats)
2593 {
2594         int i;
2595         struct nlattr *nest;
2596
2597         struct nla_map {
2598                 __u32 key;
2599                 __u32 val;
2600         };
2601
2602         struct nla_map map[] = {
2603                 {TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
2604                 {TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
2605                 {TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
2606                 {TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
2607                 {TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
2608                 {TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
2609                 {TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
2610                 {TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
2611                 {TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
2612                 {TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
2613                 {TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
2614                 {TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
2615                 {TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
2616                 {TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
2617                 {TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
2618                 {TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
2619                 {TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
2620                 {TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
2621                 {TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
2622                         (stats->accu_queue_sz / stats->queue_sz_counts) : 0}
2623         };
2624
2625         nest = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2626         if (!nest)
2627                 return -EMSGSIZE;
2628
2629         for (i = 0; i <  ARRAY_SIZE(map); i++)
2630                 if (nla_put_u32(skb, map[i].key, map[i].val))
2631                         goto msg_full;
2632
2633         nla_nest_end(skb, nest);
2634
2635         return 0;
2636 msg_full:
2637         nla_nest_cancel(skb, nest);
2638
2639         return -EMSGSIZE;
2640 }
2641
2642 int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
2643 {
2644         int err;
2645         void *hdr;
2646         struct nlattr *attrs;
2647         struct nlattr *prop;
2648         struct tipc_net *tn = net_generic(net, tipc_net_id);
2649         u32 bc_mode = tipc_bcast_get_broadcast_mode(net);
2650         u32 bc_ratio = tipc_bcast_get_broadcast_ratio(net);
2651         struct tipc_link *bcl = tn->bcl;
2652
2653         if (!bcl)
2654                 return 0;
2655
2656         tipc_bcast_lock(net);
2657
2658         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2659                           NLM_F_MULTI, TIPC_NL_LINK_GET);
2660         if (!hdr) {
2661                 tipc_bcast_unlock(net);
2662                 return -EMSGSIZE;
2663         }
2664
2665         attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2666         if (!attrs)
2667                 goto msg_full;
2668
2669         /* The broadcast link is always up */
2670         if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2671                 goto attr_msg_full;
2672
2673         if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
2674                 goto attr_msg_full;
2675         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
2676                 goto attr_msg_full;
2677         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
2678                 goto attr_msg_full;
2679         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
2680                 goto attr_msg_full;
2681
2682         prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2683         if (!prop)
2684                 goto attr_msg_full;
2685         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->max_win))
2686                 goto prop_msg_full;
2687         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST, bc_mode))
2688                 goto prop_msg_full;
2689         if (bc_mode & BCLINK_MODE_SEL)
2690                 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST_RATIO,
2691                                 bc_ratio))
2692                         goto prop_msg_full;
2693         nla_nest_end(msg->skb, prop);
2694
2695         err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
2696         if (err)
2697                 goto attr_msg_full;
2698
2699         tipc_bcast_unlock(net);
2700         nla_nest_end(msg->skb, attrs);
2701         genlmsg_end(msg->skb, hdr);
2702
2703         return 0;
2704
2705 prop_msg_full:
2706         nla_nest_cancel(msg->skb, prop);
2707 attr_msg_full:
2708         nla_nest_cancel(msg->skb, attrs);
2709 msg_full:
2710         tipc_bcast_unlock(net);
2711         genlmsg_cancel(msg->skb, hdr);
2712
2713         return -EMSGSIZE;
2714 }
2715
2716 void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
2717                              struct sk_buff_head *xmitq)
2718 {
2719         l->tolerance = tol;
2720         if (l->bc_rcvlink)
2721                 l->bc_rcvlink->tolerance = tol;
2722         if (link_is_up(l))
2723                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
2724 }
2725
2726 void tipc_link_set_prio(struct tipc_link *l, u32 prio,
2727                         struct sk_buff_head *xmitq)
2728 {
2729         l->priority = prio;
2730         tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, prio, xmitq);
2731 }
2732
2733 void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
2734 {
2735         l->abort_limit = limit;
2736 }
2737
2738 char *tipc_link_name_ext(struct tipc_link *l, char *buf)
2739 {
2740         if (!l)
2741                 scnprintf(buf, TIPC_MAX_LINK_NAME, "null");
2742         else if (link_is_bc_sndlink(l))
2743                 scnprintf(buf, TIPC_MAX_LINK_NAME, "broadcast-sender");
2744         else if (link_is_bc_rcvlink(l))
2745                 scnprintf(buf, TIPC_MAX_LINK_NAME,
2746                           "broadcast-receiver, peer %x", l->addr);
2747         else
2748                 memcpy(buf, l->name, TIPC_MAX_LINK_NAME);
2749
2750         return buf;
2751 }
2752
2753 /**
2754  * tipc_link_dump - dump TIPC link data
2755  * @l: tipc link to be dumped
2756  * @dqueues: bitmask to decide if any link queue to be dumped?
2757  *           - TIPC_DUMP_NONE: don't dump link queues
2758  *           - TIPC_DUMP_TRANSMQ: dump link transmq queue
2759  *           - TIPC_DUMP_BACKLOGQ: dump link backlog queue
2760  *           - TIPC_DUMP_DEFERDQ: dump link deferd queue
2761  *           - TIPC_DUMP_INPUTQ: dump link input queue
2762  *           - TIPC_DUMP_WAKEUP: dump link wakeup queue
2763  *           - TIPC_DUMP_ALL: dump all the link queues above
2764  * @buf: returned buffer of dump data in format
2765  */
2766 int tipc_link_dump(struct tipc_link *l, u16 dqueues, char *buf)
2767 {
2768         int i = 0;
2769         size_t sz = (dqueues) ? LINK_LMAX : LINK_LMIN;
2770         struct sk_buff_head *list;
2771         struct sk_buff *hskb, *tskb;
2772         u32 len;
2773
2774         if (!l) {
2775                 i += scnprintf(buf, sz, "link data: (null)\n");
2776                 return i;
2777         }
2778
2779         i += scnprintf(buf, sz, "link data: %x", l->addr);
2780         i += scnprintf(buf + i, sz - i, " %x", l->state);
2781         i += scnprintf(buf + i, sz - i, " %u", l->in_session);
2782         i += scnprintf(buf + i, sz - i, " %u", l->session);
2783         i += scnprintf(buf + i, sz - i, " %u", l->peer_session);
2784         i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt);
2785         i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt);
2786         i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt_state);
2787         i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt_state);
2788         i += scnprintf(buf + i, sz - i, " %x", l->peer_caps);
2789         i += scnprintf(buf + i, sz - i, " %u", l->silent_intv_cnt);
2790         i += scnprintf(buf + i, sz - i, " %u", l->rst_cnt);
2791         i += scnprintf(buf + i, sz - i, " %u", 0);
2792         i += scnprintf(buf + i, sz - i, " %u", 0);
2793         i += scnprintf(buf + i, sz - i, " %u", l->acked);
2794
2795         list = &l->transmq;
2796         len = skb_queue_len(list);
2797         hskb = skb_peek(list);
2798         tskb = skb_peek_tail(list);
2799         i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2800                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2801                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2802
2803         list = &l->deferdq;
2804         len = skb_queue_len(list);
2805         hskb = skb_peek(list);
2806         tskb = skb_peek_tail(list);
2807         i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2808                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2809                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2810
2811         list = &l->backlogq;
2812         len = skb_queue_len(list);
2813         hskb = skb_peek(list);
2814         tskb = skb_peek_tail(list);
2815         i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2816                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2817                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2818
2819         list = l->inputq;
2820         len = skb_queue_len(list);
2821         hskb = skb_peek(list);
2822         tskb = skb_peek_tail(list);
2823         i += scnprintf(buf + i, sz - i, " | %u %u %u\n", len,
2824                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2825                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2826
2827         if (dqueues & TIPC_DUMP_TRANSMQ) {
2828                 i += scnprintf(buf + i, sz - i, "transmq: ");
2829                 i += tipc_list_dump(&l->transmq, false, buf + i);
2830         }
2831         if (dqueues & TIPC_DUMP_BACKLOGQ) {
2832                 i += scnprintf(buf + i, sz - i,
2833                                "backlogq: <%u %u %u %u %u>, ",
2834                                l->backlog[TIPC_LOW_IMPORTANCE].len,
2835                                l->backlog[TIPC_MEDIUM_IMPORTANCE].len,
2836                                l->backlog[TIPC_HIGH_IMPORTANCE].len,
2837                                l->backlog[TIPC_CRITICAL_IMPORTANCE].len,
2838                                l->backlog[TIPC_SYSTEM_IMPORTANCE].len);
2839                 i += tipc_list_dump(&l->backlogq, false, buf + i);
2840         }
2841         if (dqueues & TIPC_DUMP_DEFERDQ) {
2842                 i += scnprintf(buf + i, sz - i, "deferdq: ");
2843                 i += tipc_list_dump(&l->deferdq, false, buf + i);
2844         }
2845         if (dqueues & TIPC_DUMP_INPUTQ) {
2846                 i += scnprintf(buf + i, sz - i, "inputq: ");
2847                 i += tipc_list_dump(l->inputq, false, buf + i);
2848         }
2849         if (dqueues & TIPC_DUMP_WAKEUP) {
2850                 i += scnprintf(buf + i, sz - i, "wakeup: ");
2851                 i += tipc_list_dump(&l->wakeupq, false, buf + i);
2852         }
2853
2854         return i;
2855 }