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         u16 last_gap;
 192         struct tipc_gap_ack_blks *last_ga;
 193         struct tipc_link *bc_rcvlink;
 194         struct tipc_link *bc_sndlink;
 195         u8 nack_state;
 196         bool bc_peer_is_up;
 197
 198         /* Statistics */
 199         struct tipc_stats stats;
 200 };
 201
 202 /*
 203  * Error message prefixes
 204  */
 205 static const char *link_co_err = "Link tunneling error, ";
 206 static const char *link_rst_msg = "Resetting link ";
 207
 208 /* Send states for broadcast NACKs
 209  */
 210 enum {
 211         BC_NACK_SND_CONDITIONAL,
 212         BC_NACK_SND_UNCONDITIONAL,
 213         BC_NACK_SND_SUPPRESS,
 214 };
 215
 216 #define TIPC_BC_RETR_LIM  (jiffies + msecs_to_jiffies(10))
 217 #define TIPC_UC_RETR_TIME (jiffies + msecs_to_jiffies(1))
 218
 219 /* Link FSM states:
 220  */
 221 enum {
 222         LINK_ESTABLISHED     = 0xe,
 223         LINK_ESTABLISHING    = 0xe  << 4,
 224         LINK_RESET           = 0x1  << 8,
 225         LINK_RESETTING       = 0x2  << 12,
 226         LINK_PEER_RESET      = 0xd  << 16,
 227         LINK_FAILINGOVER     = 0xf  << 20,
 228         LINK_SYNCHING        = 0xc  << 24
 229 };
 230
 231 /* Link FSM state checking routines
 232  */
 233 static int link_is_up(struct tipc_link *l)
 234 {
 235         return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
 236 }
 237
 238 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 239                                struct sk_buff_head *xmitq);
 240 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 241                                       bool probe_reply, u16 rcvgap,
 242                                       int tolerance, int priority,
 243                                       struct sk_buff_head *xmitq);
 244 static void link_print(struct tipc_link *l, const char *str);
 245 static int tipc_link_build_nack_msg(struct tipc_link *l,
 246                                     struct sk_buff_head *xmitq);
 247 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
 248                                         struct sk_buff_head *xmitq);
 249 static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
 250                                     struct tipc_link *l, u8 start_index);
 251 static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr);
 252 static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
 253                                      u16 acked, u16 gap,
 254                                      struct tipc_gap_ack_blks *ga,
 255                                      struct sk_buff_head *xmitq,
 256                                      bool *retransmitted, int *rc);
 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 struct net *tipc_link_net(struct tipc_link *l)
 348 {
 349         return l->net;
 350 }
 351
 352 void tipc_link_update_caps(struct tipc_link *l, u16 capabilities)
 353 {
 354         l->peer_caps = capabilities;
 355 }
 356
 357 void tipc_link_add_bc_peer(struct tipc_link *snd_l,
 358                            struct tipc_link *uc_l,
 359                            struct sk_buff_head *xmitq)
 360 {
 361         struct tipc_link *rcv_l = uc_l->bc_rcvlink;
 362
 363         snd_l->ackers++;
 364         rcv_l->acked = snd_l->snd_nxt - 1;
 365         snd_l->state = LINK_ESTABLISHED;
 366         tipc_link_build_bc_init_msg(uc_l, xmitq);
 367 }
 368
 369 void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
 370                               struct tipc_link *rcv_l,
 371                               struct sk_buff_head *xmitq)
 372 {
 373         u16 ack = snd_l->snd_nxt - 1;
 374
 375         snd_l->ackers--;
 376         rcv_l->bc_peer_is_up = true;
 377         rcv_l->state = LINK_ESTABLISHED;
 378         tipc_link_bc_ack_rcv(rcv_l, ack, 0, NULL, xmitq, NULL);
 379         trace_tipc_link_reset(rcv_l, TIPC_DUMP_ALL, "bclink removed!");
 380         tipc_link_reset(rcv_l);
 381         rcv_l->state = LINK_RESET;
 382         if (!snd_l->ackers) {
 383                 trace_tipc_link_reset(snd_l, TIPC_DUMP_ALL, "zero ackers!");
 384                 tipc_link_reset(snd_l);
 385                 snd_l->state = LINK_RESET;
 386                 __skb_queue_purge(xmitq);
 387         }
 388 }
 389
 390 int tipc_link_bc_peers(struct tipc_link *l)
 391 {
 392         return l->ackers;
 393 }
 394
 395 static u16 link_bc_rcv_gap(struct tipc_link *l)
 396 {
 397         struct sk_buff *skb = skb_peek(&l->deferdq);
 398         u16 gap = 0;
 399
 400         if (more(l->snd_nxt, l->rcv_nxt))
 401                 gap = l->snd_nxt - l->rcv_nxt;
 402         if (skb)
 403                 gap = buf_seqno(skb) - l->rcv_nxt;
 404         return gap;
 405 }
 406
 407 void tipc_link_set_mtu(struct tipc_link *l, int mtu)
 408 {
 409         l->mtu = mtu;
 410 }
 411
 412 int tipc_link_mtu(struct tipc_link *l)
 413 {
 414         return l->mtu;
 415 }
 416
 417 int tipc_link_mss(struct tipc_link *l)
 418 {
 419 #ifdef CONFIG_TIPC_CRYPTO
 420         return l->mtu - INT_H_SIZE - EMSG_OVERHEAD;
 421 #else
 422         return l->mtu - INT_H_SIZE;
 423 #endif
 424 }
 425
 426 u16 tipc_link_rcv_nxt(struct tipc_link *l)
 427 {
 428         return l->rcv_nxt;
 429 }
 430
 431 u16 tipc_link_acked(struct tipc_link *l)
 432 {
 433         return l->acked;
 434 }
 435
 436 char *tipc_link_name(struct tipc_link *l)
 437 {
 438         return l->name;
 439 }
 440
 441 u32 tipc_link_state(struct tipc_link *l)
 442 {
 443         return l->state;
 444 }
 445
 446 /**
 447  * tipc_link_create - create a new link
 448  * @net: pointer to associated network namespace
 449  * @if_name: associated interface name
 450  * @bearer_id: id (index) of associated bearer
 451  * @tolerance: link tolerance to be used by link
 452  * @net_plane: network plane (A,B,c..) this link belongs to
 453  * @mtu: mtu to be advertised by link
 454  * @priority: priority to be used by link
 455  * @min_win: minimal send window to be used by link
 456  * @max_win: maximal send window to be used by link
 457  * @session: session to be used by link
 458  * @ownnode: identity of own node
 459  * @peer: node id of peer node
 460  * @peer_caps: bitmap describing peer node capabilities
 461  * @bc_sndlink: the namespace global link used for broadcast sending
 462  * @bc_rcvlink: the peer specific link used for broadcast reception
 463  * @inputq: queue to put messages ready for delivery
 464  * @namedq: queue to put binding table update messages ready for delivery
 465  * @link: return value, pointer to put the created link
 466  *
 467  * Returns true if link was created, otherwise false
 468  */
 469 bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
 470                       int tolerance, char net_plane, u32 mtu, int priority,
 471                       u32 min_win, u32 max_win, u32 session, u32 self,
 472                       u32 peer, u8 *peer_id, u16 peer_caps,
 473                       struct tipc_link *bc_sndlink,
 474                       struct tipc_link *bc_rcvlink,
 475                       struct sk_buff_head *inputq,
 476                       struct sk_buff_head *namedq,
 477                       struct tipc_link **link)
 478 {
 479         char peer_str[NODE_ID_STR_LEN] = {0,};
 480         char self_str[NODE_ID_STR_LEN] = {0,};
 481         struct tipc_link *l;
 482
 483         l = kzalloc(sizeof(*l), GFP_ATOMIC);
 484         if (!l)
 485                 return false;
 486         *link = l;
 487         l->session = session;
 488
 489         /* Set link name for unicast links only */
 490         if (peer_id) {
 491                 tipc_nodeid2string(self_str, tipc_own_id(net));
 492                 if (strlen(self_str) > 16)
 493                         sprintf(self_str, "%x", self);
 494                 tipc_nodeid2string(peer_str, peer_id);
 495                 if (strlen(peer_str) > 16)
 496                         sprintf(peer_str, "%x", peer);
 497         }
 498         /* Peer i/f name will be completed by reset/activate message */
 499         snprintf(l->name, sizeof(l->name), "%s:%s-%s:unknown",
 500                  self_str, if_name, peer_str);
 501
 502         strcpy(l->if_name, if_name);
 503         l->addr = peer;
 504         l->peer_caps = peer_caps;
 505         l->net = net;
 506         l->in_session = false;
 507         l->bearer_id = bearer_id;
 508         l->tolerance = tolerance;
 509         if (bc_rcvlink)
 510                 bc_rcvlink->tolerance = tolerance;
 511         l->net_plane = net_plane;
 512         l->advertised_mtu = mtu;
 513         l->mtu = mtu;
 514         l->priority = priority;
 515         tipc_link_set_queue_limits(l, min_win, max_win);
 516         l->ackers = 1;
 517         l->bc_sndlink = bc_sndlink;
 518         l->bc_rcvlink = bc_rcvlink;
 519         l->inputq = inputq;
 520         l->namedq = namedq;
 521         l->state = LINK_RESETTING;
 522         __skb_queue_head_init(&l->transmq);
 523         __skb_queue_head_init(&l->backlogq);
 524         __skb_queue_head_init(&l->deferdq);
 525         __skb_queue_head_init(&l->failover_deferdq);
 526         skb_queue_head_init(&l->wakeupq);
 527         skb_queue_head_init(l->inputq);
 528         return true;
 529 }
 530
 531 /**
 532  * tipc_link_bc_create - create new link to be used for broadcast
 533  * @net: pointer to associated network namespace
 534  * @mtu: mtu to be used initially if no peers
 535  * @min_win: minimal send window to be used by link
 536  * @max_win: maximal send window to be used by link
 537  * @inputq: queue to put messages ready for delivery
 538  * @namedq: queue to put binding table update messages ready for delivery
 539  * @link: return value, pointer to put the created link
 540  *
 541  * Returns true if link was created, otherwise false
 542  */
 543 bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, u8 *peer_id,
 544                          int mtu, u32 min_win, u32 max_win, u16 peer_caps,
 545                          struct sk_buff_head *inputq,
 546                          struct sk_buff_head *namedq,
 547                          struct tipc_link *bc_sndlink,
 548                          struct tipc_link **link)
 549 {
 550         struct tipc_link *l;
 551
 552         if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, min_win,
 553                               max_win, 0, ownnode, peer, NULL, peer_caps,
 554                               bc_sndlink, NULL, inputq, namedq, link))
 555                 return false;
 556
 557         l = *link;
 558         if (peer_id) {
 559                 char peer_str[NODE_ID_STR_LEN] = {0,};
 560
 561                 tipc_nodeid2string(peer_str, peer_id);
 562                 if (strlen(peer_str) > 16)
 563                         sprintf(peer_str, "%x", peer);
 564                 /* Broadcast receiver link name: "broadcast-link:<peer>" */
 565                 snprintf(l->name, sizeof(l->name), "%s:%s", tipc_bclink_name,
 566                          peer_str);
 567         } else {
 568                 strcpy(l->name, tipc_bclink_name);
 569         }
 570         trace_tipc_link_reset(l, TIPC_DUMP_ALL, "bclink created!");
 571         tipc_link_reset(l);
 572         l->state = LINK_RESET;
 573         l->ackers = 0;
 574         l->bc_rcvlink = l;
 575
 576         /* Broadcast send link is always up */
 577         if (link_is_bc_sndlink(l))
 578                 l->state = LINK_ESTABLISHED;
 579
 580         /* Disable replicast if even a single peer doesn't support it */
 581         if (link_is_bc_rcvlink(l) && !(peer_caps & TIPC_BCAST_RCAST))
 582                 tipc_bcast_toggle_rcast(net, false);
 583
 584         return true;
 585 }
 586
 587 /**
 588  * tipc_link_fsm_evt - link finite state machine
 589  * @l: pointer to link
 590  * @evt: state machine event to be processed
 591  */
 592 int tipc_link_fsm_evt(struct tipc_link *l, int evt)
 593 {
 594         int rc = 0;
 595         int old_state = l->state;
 596
 597         switch (l->state) {
 598         case LINK_RESETTING:
 599                 switch (evt) {
 600                 case LINK_PEER_RESET_EVT:
 601                         l->state = LINK_PEER_RESET;
 602                         break;
 603                 case LINK_RESET_EVT:
 604                         l->state = LINK_RESET;
 605                         break;
 606                 case LINK_FAILURE_EVT:
 607                 case LINK_FAILOVER_BEGIN_EVT:
 608                 case LINK_ESTABLISH_EVT:
 609                 case LINK_FAILOVER_END_EVT:
 610                 case LINK_SYNCH_BEGIN_EVT:
 611                 case LINK_SYNCH_END_EVT:
 612                 default:
 613                         goto illegal_evt;
 614                 }
 615                 break;
 616         case LINK_RESET:
 617                 switch (evt) {
 618                 case LINK_PEER_RESET_EVT:
 619                         l->state = LINK_ESTABLISHING;
 620                         break;
 621                 case LINK_FAILOVER_BEGIN_EVT:
 622                         l->state = LINK_FAILINGOVER;
 623                 case LINK_FAILURE_EVT:
 624                 case LINK_RESET_EVT:
 625                 case LINK_ESTABLISH_EVT:
 626                 case LINK_FAILOVER_END_EVT:
 627                         break;
 628                 case LINK_SYNCH_BEGIN_EVT:
 629                 case LINK_SYNCH_END_EVT:
 630                 default:
 631                         goto illegal_evt;
 632                 }
 633                 break;
 634         case LINK_PEER_RESET:
 635                 switch (evt) {
 636                 case LINK_RESET_EVT:
 637                         l->state = LINK_ESTABLISHING;
 638                         break;
 639                 case LINK_PEER_RESET_EVT:
 640                 case LINK_ESTABLISH_EVT:
 641                 case LINK_FAILURE_EVT:
 642                         break;
 643                 case LINK_SYNCH_BEGIN_EVT:
 644                 case LINK_SYNCH_END_EVT:
 645                 case LINK_FAILOVER_BEGIN_EVT:
 646                 case LINK_FAILOVER_END_EVT:
 647                 default:
 648                         goto illegal_evt;
 649                 }
 650                 break;
 651         case LINK_FAILINGOVER:
 652                 switch (evt) {
 653                 case LINK_FAILOVER_END_EVT:
 654                         l->state = LINK_RESET;
 655                         break;
 656                 case LINK_PEER_RESET_EVT:
 657                 case LINK_RESET_EVT:
 658                 case LINK_ESTABLISH_EVT:
 659                 case LINK_FAILURE_EVT:
 660                         break;
 661                 case LINK_FAILOVER_BEGIN_EVT:
 662                 case LINK_SYNCH_BEGIN_EVT:
 663                 case LINK_SYNCH_END_EVT:
 664                 default:
 665                         goto illegal_evt;
 666                 }
 667                 break;
 668         case LINK_ESTABLISHING:
 669                 switch (evt) {
 670                 case LINK_ESTABLISH_EVT:
 671                         l->state = LINK_ESTABLISHED;
 672                         break;
 673                 case LINK_FAILOVER_BEGIN_EVT:
 674                         l->state = LINK_FAILINGOVER;
 675                         break;
 676                 case LINK_RESET_EVT:
 677                         l->state = LINK_RESET;
 678                         break;
 679                 case LINK_FAILURE_EVT:
 680                 case LINK_PEER_RESET_EVT:
 681                 case LINK_SYNCH_BEGIN_EVT:
 682                 case LINK_FAILOVER_END_EVT:
 683                         break;
 684                 case LINK_SYNCH_END_EVT:
 685                 default:
 686                         goto illegal_evt;
 687                 }
 688                 break;
 689         case LINK_ESTABLISHED:
 690                 switch (evt) {
 691                 case LINK_PEER_RESET_EVT:
 692                         l->state = LINK_PEER_RESET;
 693                         rc |= TIPC_LINK_DOWN_EVT;
 694                         break;
 695                 case LINK_FAILURE_EVT:
 696                         l->state = LINK_RESETTING;
 697                         rc |= TIPC_LINK_DOWN_EVT;
 698                         break;
 699                 case LINK_RESET_EVT:
 700                         l->state = LINK_RESET;
 701                         break;
 702                 case LINK_ESTABLISH_EVT:
 703                 case LINK_SYNCH_END_EVT:
 704                         break;
 705                 case LINK_SYNCH_BEGIN_EVT:
 706                         l->state = LINK_SYNCHING;
 707                         break;
 708                 case LINK_FAILOVER_BEGIN_EVT:
 709                 case LINK_FAILOVER_END_EVT:
 710                 default:
 711                         goto illegal_evt;
 712                 }
 713                 break;
 714         case LINK_SYNCHING:
 715                 switch (evt) {
 716                 case LINK_PEER_RESET_EVT:
 717                         l->state = LINK_PEER_RESET;
 718                         rc |= TIPC_LINK_DOWN_EVT;
 719                         break;
 720                 case LINK_FAILURE_EVT:
 721                         l->state = LINK_RESETTING;
 722                         rc |= TIPC_LINK_DOWN_EVT;
 723                         break;
 724                 case LINK_RESET_EVT:
 725                         l->state = LINK_RESET;
 726                         break;
 727                 case LINK_ESTABLISH_EVT:
 728                 case LINK_SYNCH_BEGIN_EVT:
 729                         break;
 730                 case LINK_SYNCH_END_EVT:
 731                         l->state = LINK_ESTABLISHED;
 732                         break;
 733                 case LINK_FAILOVER_BEGIN_EVT:
 734                 case LINK_FAILOVER_END_EVT:
 735                 default:
 736                         goto illegal_evt;
 737                 }
 738                 break;
 739         default:
 740                 pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
 741         }
 742         trace_tipc_link_fsm(l->name, old_state, l->state, evt);
 743         return rc;
 744 illegal_evt:
 745         pr_err("Illegal FSM event %x in state %x on link %s\n",
 746                evt, l->state, l->name);
 747         trace_tipc_link_fsm(l->name, old_state, l->state, evt);
 748         return rc;
 749 }
 750
 751 /* link_profile_stats - update statistical profiling of traffic
 752  */
 753 static void link_profile_stats(struct tipc_link *l)
 754 {
 755         struct sk_buff *skb;
 756         struct tipc_msg *msg;
 757         int length;
 758
 759         /* Update counters used in statistical profiling of send traffic */
 760         l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 761         l->stats.queue_sz_counts++;
 762
 763         skb = skb_peek(&l->transmq);
 764         if (!skb)
 765                 return;
 766         msg = buf_msg(skb);
 767         length = msg_size(msg);
 768
 769         if (msg_user(msg) == MSG_FRAGMENTER) {
 770                 if (msg_type(msg) != FIRST_FRAGMENT)
 771                         return;
 772                 length = msg_size(msg_inner_hdr(msg));
 773         }
 774         l->stats.msg_lengths_total += length;
 775         l->stats.msg_length_counts++;
 776         if (length <= 64)
 777                 l->stats.msg_length_profile[0]++;
 778         else if (length <= 256)
 779                 l->stats.msg_length_profile[1]++;
 780         else if (length <= 1024)
 781                 l->stats.msg_length_profile[2]++;
 782         else if (length <= 4096)
 783                 l->stats.msg_length_profile[3]++;
 784         else if (length <= 16384)
 785                 l->stats.msg_length_profile[4]++;
 786         else if (length <= 32768)
 787                 l->stats.msg_length_profile[5]++;
 788         else
 789                 l->stats.msg_length_profile[6]++;
 790 }
 791
 792 /**
 793  * tipc_link_too_silent - check if link is "too silent"
 794  * @l: tipc link to be checked
 795  *
 796  * Returns true if the link 'silent_intv_cnt' is about to reach the
 797  * 'abort_limit' value, otherwise false
 798  */
 799 bool tipc_link_too_silent(struct tipc_link *l)
 800 {
 801         return (l->silent_intv_cnt + 2 > l->abort_limit);
 802 }
 803
 804 /* tipc_link_timeout - perform periodic task as instructed from node timeout
 805  */
 806 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 807 {
 808         int mtyp = 0;
 809         int rc = 0;
 810         bool state = false;
 811         bool probe = false;
 812         bool setup = false;
 813         u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
 814         u16 bc_acked = l->bc_rcvlink->acked;
 815         struct tipc_mon_state *mstate = &l->mon_state;
 816
 817         trace_tipc_link_timeout(l, TIPC_DUMP_NONE, " ");
 818         trace_tipc_link_too_silent(l, TIPC_DUMP_ALL, " ");
 819         switch (l->state) {
 820         case LINK_ESTABLISHED:
 821         case LINK_SYNCHING:
 822                 mtyp = STATE_MSG;
 823                 link_profile_stats(l);
 824                 tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id);
 825                 if (mstate->reset || (l->silent_intv_cnt > l->abort_limit))
 826                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 827                 state = bc_acked != bc_snt;
 828                 state |= l->bc_rcvlink->rcv_unacked;
 829                 state |= l->rcv_unacked;
 830                 state |= !skb_queue_empty(&l->transmq);
 831                 probe = mstate->probing;
 832                 probe |= l->silent_intv_cnt;
 833                 if (probe || mstate->monitoring)
 834                         l->silent_intv_cnt++;
 835                 probe |= !skb_queue_empty(&l->deferdq);
 836                 if (l->snd_nxt == l->checkpoint) {
 837                         tipc_link_update_cwin(l, 0, 0);
 838                         probe = true;
 839                 }
 840                 l->checkpoint = l->snd_nxt;
 841                 break;
 842         case LINK_RESET:
 843                 setup = l->rst_cnt++ <= 4;
 844                 setup |= !(l->rst_cnt % 16);
 845                 mtyp = RESET_MSG;
 846                 break;
 847         case LINK_ESTABLISHING:
 848                 setup = true;
 849                 mtyp = ACTIVATE_MSG;
 850                 break;
 851         case LINK_PEER_RESET:
 852         case LINK_RESETTING:
 853         case LINK_FAILINGOVER:
 854                 break;
 855         default:
 856                 break;
 857         }
 858
 859         if (state || probe || setup)
 860                 tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, 0, xmitq);
 861
 862         return rc;
 863 }
 864
 865 /**
 866  * link_schedule_user - schedule a message sender for wakeup after congestion
 867  * @l: congested link
 868  * @hdr: header of message that is being sent
 869  * Create pseudo msg to send back to user when congestion abates
 870  */
 871 static int link_schedule_user(struct tipc_link *l, struct tipc_msg *hdr)
 872 {
 873         u32 dnode = tipc_own_addr(l->net);
 874         u32 dport = msg_origport(hdr);
 875         struct sk_buff *skb;
 876
 877         /* Create and schedule wakeup pseudo message */
 878         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 879                               dnode, l->addr, dport, 0, 0);
 880         if (!skb)
 881                 return -ENOBUFS;
 882         msg_set_dest_droppable(buf_msg(skb), true);
 883         TIPC_SKB_CB(skb)->chain_imp = msg_importance(hdr);
 884         skb_queue_tail(&l->wakeupq, skb);
 885         l->stats.link_congs++;
 886         trace_tipc_link_conges(l, TIPC_DUMP_ALL, "wakeup scheduled!");
 887         return -ELINKCONG;
 888 }
 889
 890 /**
 891  * link_prepare_wakeup - prepare users for wakeup after congestion
 892  * @l: congested link
 893  * Wake up a number of waiting users, as permitted by available space
 894  * in the send queue
 895  */
 896 static void link_prepare_wakeup(struct tipc_link *l)
 897 {
 898         struct sk_buff_head *wakeupq = &l->wakeupq;
 899         struct sk_buff_head *inputq = l->inputq;
 900         struct sk_buff *skb, *tmp;
 901         struct sk_buff_head tmpq;
 902         int avail[5] = {0,};
 903         int imp = 0;
 904
 905         __skb_queue_head_init(&tmpq);
 906
 907         for (; imp <= TIPC_SYSTEM_IMPORTANCE; imp++)
 908                 avail[imp] = l->backlog[imp].limit - l->backlog[imp].len;
 909
 910         skb_queue_walk_safe(wakeupq, skb, tmp) {
 911                 imp = TIPC_SKB_CB(skb)->chain_imp;
 912                 if (avail[imp] <= 0)
 913                         continue;
 914                 avail[imp]--;
 915                 __skb_unlink(skb, wakeupq);
 916                 __skb_queue_tail(&tmpq, skb);
 917         }
 918
 919         spin_lock_bh(&inputq->lock);
 920         skb_queue_splice_tail(&tmpq, inputq);
 921         spin_unlock_bh(&inputq->lock);
 922
 923 }
 924
 925 /**
 926  * tipc_link_set_skb_retransmit_time - set the time at which retransmission of
 927  *                                     the given skb should be next attempted
 928  * @skb: skb to set a future retransmission time for
 929  * @l: link the skb will be transmitted on
 930  */
 931 static void tipc_link_set_skb_retransmit_time(struct sk_buff *skb,
 932                                               struct tipc_link *l)
 933 {
 934         if (link_is_bc_sndlink(l))
 935                 TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
 936         else
 937                 TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
 938 }
 939
 940 void tipc_link_reset(struct tipc_link *l)
 941 {
 942         struct sk_buff_head list;
 943         u32 imp;
 944
 945         __skb_queue_head_init(&list);
 946
 947         l->in_session = false;
 948         /* Force re-synch of peer session number before establishing */
 949         l->peer_session--;
 950         l->session++;
 951         l->mtu = l->advertised_mtu;
 952
 953         spin_lock_bh(&l->wakeupq.lock);
 954         skb_queue_splice_init(&l->wakeupq, &list);
 955         spin_unlock_bh(&l->wakeupq.lock);
 956
 957         spin_lock_bh(&l->inputq->lock);
 958         skb_queue_splice_init(&list, l->inputq);
 959         spin_unlock_bh(&l->inputq->lock);
 960
 961         __skb_queue_purge(&l->transmq);
 962         __skb_queue_purge(&l->deferdq);
 963         __skb_queue_purge(&l->backlogq);
 964         __skb_queue_purge(&l->failover_deferdq);
 965         for (imp = 0; imp <= TIPC_SYSTEM_IMPORTANCE; imp++) {
 966                 l->backlog[imp].len = 0;
 967                 l->backlog[imp].target_bskb = NULL;
 968         }
 969         kfree_skb(l->reasm_buf);
 970         kfree_skb(l->reasm_tnlmsg);
 971         kfree_skb(l->failover_reasm_skb);
 972         l->reasm_buf = NULL;
 973         l->reasm_tnlmsg = NULL;
 974         l->failover_reasm_skb = NULL;
 975         l->rcv_unacked = 0;
 976         l->snd_nxt = 1;
 977         l->rcv_nxt = 1;
 978         l->snd_nxt_state = 1;
 979         l->rcv_nxt_state = 1;
 980         l->acked = 0;
 981         l->last_gap = 0;
 982         kfree(l->last_ga);
 983         l->last_ga = NULL;
 984         l->silent_intv_cnt = 0;
 985         l->rst_cnt = 0;
 986         l->bc_peer_is_up = false;
 987         memset(&l->mon_state, 0, sizeof(l->mon_state));
 988         tipc_link_reset_stats(l);
 989 }
 990
 991 /**
 992  * tipc_link_xmit(): enqueue buffer list according to queue situation
 993  * @l: link to use
 994  * @list: chain of buffers containing message
 995  * @xmitq: returned list of packets to be sent by caller
 996  *
 997  * Consumes the buffer chain.
 998  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 999  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
1000  */
1001 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
1002                    struct sk_buff_head *xmitq)
1003 {
1004         struct sk_buff_head *backlogq = &l->backlogq;
1005         struct sk_buff_head *transmq = &l->transmq;
1006         struct sk_buff *skb, *_skb;
1007         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1008         u16 ack = l->rcv_nxt - 1;
1009         u16 seqno = l->snd_nxt;
1010         int pkt_cnt = skb_queue_len(list);
1011         unsigned int mss = tipc_link_mss(l);
1012         unsigned int cwin = l->window;
1013         unsigned int mtu = l->mtu;
1014         struct tipc_msg *hdr;
1015         bool new_bundle;
1016         int rc = 0;
1017         int imp;
1018
1019         if (pkt_cnt <= 0)
1020                 return 0;
1021
1022         hdr = buf_msg(skb_peek(list));
1023         if (unlikely(msg_size(hdr) > mtu)) {
1024                 pr_warn("Too large msg, purging xmit list %d %d %d %d %d!\n",
1025                         skb_queue_len(list), msg_user(hdr),
1026                         msg_type(hdr), msg_size(hdr), mtu);
1027                 __skb_queue_purge(list);
1028                 return -EMSGSIZE;
1029         }
1030
1031         imp = msg_importance(hdr);
1032         /* Allow oversubscription of one data msg per source at congestion */
1033         if (unlikely(l->backlog[imp].len >= l->backlog[imp].limit)) {
1034                 if (imp == TIPC_SYSTEM_IMPORTANCE) {
1035                         pr_warn("%s<%s>, link overflow", link_rst_msg, l->name);
1036                         return -ENOBUFS;
1037                 }
1038                 rc = link_schedule_user(l, hdr);
1039         }
1040
1041         if (pkt_cnt > 1) {
1042                 l->stats.sent_fragmented++;
1043                 l->stats.sent_fragments += pkt_cnt;
1044         }
1045
1046         /* Prepare each packet for sending, and add to relevant queue: */
1047         while ((skb = __skb_dequeue(list))) {
1048                 if (likely(skb_queue_len(transmq) < cwin)) {
1049                         hdr = buf_msg(skb);
1050                         msg_set_seqno(hdr, seqno);
1051                         msg_set_ack(hdr, ack);
1052                         msg_set_bcast_ack(hdr, bc_ack);
1053                         _skb = skb_clone(skb, GFP_ATOMIC);
1054                         if (!_skb) {
1055                                 kfree_skb(skb);
1056                                 __skb_queue_purge(list);
1057                                 return -ENOBUFS;
1058                         }
1059                         __skb_queue_tail(transmq, skb);
1060                         tipc_link_set_skb_retransmit_time(skb, l);
1061                         __skb_queue_tail(xmitq, _skb);
1062                         TIPC_SKB_CB(skb)->ackers = l->ackers;
1063                         l->rcv_unacked = 0;
1064                         l->stats.sent_pkts++;
1065                         seqno++;
1066                         continue;
1067                 }
1068                 if (tipc_msg_try_bundle(l->backlog[imp].target_bskb, &skb,
1069                                         mss, l->addr, &new_bundle)) {
1070                         if (skb) {
1071                                 /* Keep a ref. to the skb for next try */
1072                                 l->backlog[imp].target_bskb = skb;
1073                                 l->backlog[imp].len++;
1074                                 __skb_queue_tail(backlogq, skb);
1075                         } else {
1076                                 if (new_bundle) {
1077                                         l->stats.sent_bundles++;
1078                                         l->stats.sent_bundled++;
1079                                 }
1080                                 l->stats.sent_bundled++;
1081                         }
1082                         continue;
1083                 }
1084                 l->backlog[imp].target_bskb = NULL;
1085                 l->backlog[imp].len += (1 + skb_queue_len(list));
1086                 __skb_queue_tail(backlogq, skb);
1087                 skb_queue_splice_tail_init(list, backlogq);
1088         }
1089         l->snd_nxt = seqno;
1090         return rc;
1091 }
1092
1093 static void tipc_link_update_cwin(struct tipc_link *l, int released,
1094                                   bool retransmitted)
1095 {
1096         int bklog_len = skb_queue_len(&l->backlogq);
1097         struct sk_buff_head *txq = &l->transmq;
1098         int txq_len = skb_queue_len(txq);
1099         u16 cwin = l->window;
1100
1101         /* Enter fast recovery */
1102         if (unlikely(retransmitted)) {
1103                 l->ssthresh = max_t(u16, l->window / 2, 300);
1104                 l->window = min_t(u16, l->ssthresh, l->window);
1105                 return;
1106         }
1107         /* Enter slow start */
1108         if (unlikely(!released)) {
1109                 l->ssthresh = max_t(u16, l->window / 2, 300);
1110                 l->window = l->min_win;
1111                 return;
1112         }
1113         /* Don't increase window if no pressure on the transmit queue */
1114         if (txq_len + bklog_len < cwin)
1115                 return;
1116
1117         /* Don't increase window if there are holes the transmit queue */
1118         if (txq_len && l->snd_nxt - buf_seqno(skb_peek(txq)) != txq_len)
1119                 return;
1120
1121         l->cong_acks += released;
1122
1123         /* Slow start  */
1124         if (cwin <= l->ssthresh) {
1125                 l->window = min_t(u16, cwin + released, l->max_win);
1126                 return;
1127         }
1128         /* Congestion avoidance */
1129         if (l->cong_acks < cwin)
1130                 return;
1131         l->window = min_t(u16, ++cwin, l->max_win);
1132         l->cong_acks = 0;
1133 }
1134
1135 static void tipc_link_advance_backlog(struct tipc_link *l,
1136                                       struct sk_buff_head *xmitq)
1137 {
1138         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1139         struct sk_buff_head *txq = &l->transmq;
1140         struct sk_buff *skb, *_skb;
1141         u16 ack = l->rcv_nxt - 1;
1142         u16 seqno = l->snd_nxt;
1143         struct tipc_msg *hdr;
1144         u16 cwin = l->window;
1145         u32 imp;
1146
1147         while (skb_queue_len(txq) < cwin) {
1148                 skb = skb_peek(&l->backlogq);
1149                 if (!skb)
1150                         break;
1151                 _skb = skb_clone(skb, GFP_ATOMIC);
1152                 if (!_skb)
1153                         break;
1154                 __skb_dequeue(&l->backlogq);
1155                 hdr = buf_msg(skb);
1156                 imp = msg_importance(hdr);
1157                 l->backlog[imp].len--;
1158                 if (unlikely(skb == l->backlog[imp].target_bskb))
1159                         l->backlog[imp].target_bskb = NULL;
1160                 __skb_queue_tail(&l->transmq, skb);
1161                 tipc_link_set_skb_retransmit_time(skb, l);
1162
1163                 __skb_queue_tail(xmitq, _skb);
1164                 TIPC_SKB_CB(skb)->ackers = l->ackers;
1165                 msg_set_seqno(hdr, seqno);
1166                 msg_set_ack(hdr, ack);
1167                 msg_set_bcast_ack(hdr, bc_ack);
1168                 l->rcv_unacked = 0;
1169                 l->stats.sent_pkts++;
1170                 seqno++;
1171         }
1172         l->snd_nxt = seqno;
1173 }
1174
1175 /**
1176  * link_retransmit_failure() - Detect repeated retransmit failures
1177  * @l: tipc link sender
1178  * @r: tipc link receiver (= l in case of unicast)
1179  * @rc: returned code
1180  *
1181  * Return: true if the repeated retransmit failures happens, otherwise
1182  * false
1183  */
1184 static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r,
1185                                     int *rc)
1186 {
1187         struct sk_buff *skb = skb_peek(&l->transmq);
1188         struct tipc_msg *hdr;
1189
1190         if (!skb)
1191                 return false;
1192
1193         if (!TIPC_SKB_CB(skb)->retr_cnt)
1194                 return false;
1195
1196         if (!time_after(jiffies, TIPC_SKB_CB(skb)->retr_stamp +
1197                         msecs_to_jiffies(r->tolerance * 10)))
1198                 return false;
1199
1200         hdr = buf_msg(skb);
1201         if (link_is_bc_sndlink(l) && !less(r->acked, msg_seqno(hdr)))
1202                 return false;
1203
1204         pr_warn("Retransmission failure on link <%s>\n", l->name);
1205         link_print(l, "State of link ");
1206         pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
1207                 msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
1208         pr_info("sqno %u, prev: %x, dest: %x\n",
1209                 msg_seqno(hdr), msg_prevnode(hdr), msg_destnode(hdr));
1210         pr_info("retr_stamp %d, retr_cnt %d\n",
1211                 jiffies_to_msecs(TIPC_SKB_CB(skb)->retr_stamp),
1212                 TIPC_SKB_CB(skb)->retr_cnt);
1213
1214         trace_tipc_list_dump(&l->transmq, true, "retrans failure!");
1215         trace_tipc_link_dump(l, TIPC_DUMP_NONE, "retrans failure!");
1216         trace_tipc_link_dump(r, TIPC_DUMP_NONE, "retrans failure!");
1217
1218         if (link_is_bc_sndlink(l)) {
1219                 r->state = LINK_RESET;
1220                 *rc |= TIPC_LINK_DOWN_EVT;
1221         } else {
1222                 *rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1223         }
1224
1225         return true;
1226 }
1227
1228 /* tipc_data_input - deliver data and name distr msgs to upper layer
1229  *
1230  * Consumes buffer if message is of right type
1231  * Node lock must be held
1232  */
1233 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1234                             struct sk_buff_head *inputq)
1235 {
1236         struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq;
1237         struct tipc_msg *hdr = buf_msg(skb);
1238
1239         switch (msg_user(hdr)) {
1240         case TIPC_LOW_IMPORTANCE:
1241         case TIPC_MEDIUM_IMPORTANCE:
1242         case TIPC_HIGH_IMPORTANCE:
1243         case TIPC_CRITICAL_IMPORTANCE:
1244                 if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) {
1245                         skb_queue_tail(mc_inputq, skb);
1246                         return true;
1247                 }
1248                 fallthrough;
1249         case CONN_MANAGER:
1250                 skb_queue_tail(inputq, skb);
1251                 return true;
1252         case GROUP_PROTOCOL:
1253                 skb_queue_tail(mc_inputq, skb);
1254                 return true;
1255         case NAME_DISTRIBUTOR:
1256                 l->bc_rcvlink->state = LINK_ESTABLISHED;
1257                 skb_queue_tail(l->namedq, skb);
1258                 return true;
1259         case MSG_BUNDLER:
1260         case TUNNEL_PROTOCOL:
1261         case MSG_FRAGMENTER:
1262         case BCAST_PROTOCOL:
1263                 return false;
1264 #ifdef CONFIG_TIPC_CRYPTO
1265         case MSG_CRYPTO:
1266                 if (TIPC_SKB_CB(skb)->decrypted) {
1267                         tipc_crypto_msg_rcv(l->net, skb);
1268                         return true;
1269                 }
1270                 fallthrough;
1271 #endif
1272         default:
1273                 pr_warn("Dropping received illegal msg type\n");
1274                 kfree_skb(skb);
1275                 return true;
1276         };
1277 }
1278
1279 /* tipc_link_input - process packet that has passed link protocol check
1280  *
1281  * Consumes buffer
1282  */
1283 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1284                            struct sk_buff_head *inputq,
1285                            struct sk_buff **reasm_skb)
1286 {
1287         struct tipc_msg *hdr = buf_msg(skb);
1288         struct sk_buff *iskb;
1289         struct sk_buff_head tmpq;
1290         int usr = msg_user(hdr);
1291         int pos = 0;
1292
1293         if (usr == MSG_BUNDLER) {
1294                 skb_queue_head_init(&tmpq);
1295                 l->stats.recv_bundles++;
1296                 l->stats.recv_bundled += msg_msgcnt(hdr);
1297                 while (tipc_msg_extract(skb, &iskb, &pos))
1298                         tipc_data_input(l, iskb, &tmpq);
1299                 tipc_skb_queue_splice_tail(&tmpq, inputq);
1300                 return 0;
1301         } else if (usr == MSG_FRAGMENTER) {
1302                 l->stats.recv_fragments++;
1303                 if (tipc_buf_append(reasm_skb, &skb)) {
1304                         l->stats.recv_fragmented++;
1305                         tipc_data_input(l, skb, inputq);
1306                 } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1307                         pr_warn_ratelimited("Unable to build fragment list\n");
1308                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1309                 }
1310                 return 0;
1311         } else if (usr == BCAST_PROTOCOL) {
1312                 tipc_bcast_lock(l->net);
1313                 tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1314                 tipc_bcast_unlock(l->net);
1315         }
1316
1317         kfree_skb(skb);
1318         return 0;
1319 }
1320
1321 /* tipc_link_tnl_rcv() - receive TUNNEL_PROTOCOL message, drop or process the
1322  *                       inner message along with the ones in the old link's
1323  *                       deferdq
1324  * @l: tunnel link
1325  * @skb: TUNNEL_PROTOCOL message
1326  * @inputq: queue to put messages ready for delivery
1327  */
1328 static int tipc_link_tnl_rcv(struct tipc_link *l, struct sk_buff *skb,
1329                              struct sk_buff_head *inputq)
1330 {
1331         struct sk_buff **reasm_skb = &l->failover_reasm_skb;
1332         struct sk_buff **reasm_tnlmsg = &l->reasm_tnlmsg;
1333         struct sk_buff_head *fdefq = &l->failover_deferdq;
1334         struct tipc_msg *hdr = buf_msg(skb);
1335         struct sk_buff *iskb;
1336         int ipos = 0;
1337         int rc = 0;
1338         u16 seqno;
1339
1340         if (msg_type(hdr) == SYNCH_MSG) {
1341                 kfree_skb(skb);
1342                 return 0;
1343         }
1344
1345         /* Not a fragment? */
1346         if (likely(!msg_nof_fragms(hdr))) {
1347                 if (unlikely(!tipc_msg_extract(skb, &iskb, &ipos))) {
1348                         pr_warn_ratelimited("Unable to extract msg, defq: %d\n",
1349                                             skb_queue_len(fdefq));
1350                         return 0;
1351                 }
1352                 kfree_skb(skb);
1353         } else {
1354                 /* Set fragment type for buf_append */
1355                 if (msg_fragm_no(hdr) == 1)
1356                         msg_set_type(hdr, FIRST_FRAGMENT);
1357                 else if (msg_fragm_no(hdr) < msg_nof_fragms(hdr))
1358                         msg_set_type(hdr, FRAGMENT);
1359                 else
1360                         msg_set_type(hdr, LAST_FRAGMENT);
1361
1362                 if (!tipc_buf_append(reasm_tnlmsg, &skb)) {
1363                         /* Successful but non-complete reassembly? */
1364                         if (*reasm_tnlmsg || link_is_bc_rcvlink(l))
1365                                 return 0;
1366                         pr_warn_ratelimited("Unable to reassemble tunnel msg\n");
1367                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1368                 }
1369                 iskb = skb;
1370         }
1371
1372         do {
1373                 seqno = buf_seqno(iskb);
1374                 if (unlikely(less(seqno, l->drop_point))) {
1375                         kfree_skb(iskb);
1376                         continue;
1377                 }
1378                 if (unlikely(seqno != l->drop_point)) {
1379                         __tipc_skb_queue_sorted(fdefq, seqno, iskb);
1380                         continue;
1381                 }
1382
1383                 l->drop_point++;
1384                 if (!tipc_data_input(l, iskb, inputq))
1385                         rc |= tipc_link_input(l, iskb, inputq, reasm_skb);
1386                 if (unlikely(rc))
1387                         break;
1388         } while ((iskb = __tipc_skb_dequeue(fdefq, l->drop_point)));
1389
1390         return rc;
1391 }
1392
1393 /**
1394  * tipc_get_gap_ack_blks - get Gap ACK blocks from PROTOCOL/STATE_MSG
1395  * @ga: returned pointer to the Gap ACK blocks if any
1396  * @l: the tipc link
1397  * @hdr: the PROTOCOL/STATE_MSG header
1398  * @uc: desired Gap ACK blocks type, i.e. unicast (= 1) or broadcast (= 0)
1399  *
1400  * Return: the total Gap ACK blocks size
1401  */
1402 u16 tipc_get_gap_ack_blks(struct tipc_gap_ack_blks **ga, struct tipc_link *l,
1403                           struct tipc_msg *hdr, bool uc)
1404 {
1405         struct tipc_gap_ack_blks *p;
1406         u16 sz = 0;
1407
1408         /* Does peer support the Gap ACK blocks feature? */
1409         if (l->peer_caps & TIPC_GAP_ACK_BLOCK) {
1410                 p = (struct tipc_gap_ack_blks *)msg_data(hdr);
1411                 sz = ntohs(p->len);
1412                 /* Sanity check */
1413                 if (sz == struct_size(p, gacks, size_add(p->ugack_cnt, p->bgack_cnt))) {
1414                         /* Good, check if the desired type exists */
1415                         if ((uc && p->ugack_cnt) || (!uc && p->bgack_cnt))
1416                                 goto ok;
1417                 /* Backward compatible: peer might not support bc, but uc? */
1418                 } else if (uc && sz == struct_size(p, gacks, p->ugack_cnt)) {
1419                         if (p->ugack_cnt) {
1420                                 p->bgack_cnt = 0;
1421                                 goto ok;
1422                         }
1423                 }
1424         }
1425         /* Other cases: ignore! */
1426         p = NULL;
1427
1428 ok:
1429         *ga = p;
1430         return sz;
1431 }
1432
1433 static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
1434                                     struct tipc_link *l, u8 start_index)
1435 {
1436         struct tipc_gap_ack *gacks = &ga->gacks[start_index];
1437         struct sk_buff *skb = skb_peek(&l->deferdq);
1438         u16 expect, seqno = 0;
1439         u8 n = 0;
1440
1441         if (!skb)
1442                 return 0;
1443
1444         expect = buf_seqno(skb);
1445         skb_queue_walk(&l->deferdq, skb) {
1446                 seqno = buf_seqno(skb);
1447                 if (unlikely(more(seqno, expect))) {
1448                         gacks[n].ack = htons(expect - 1);
1449                         gacks[n].gap = htons(seqno - expect);
1450                         if (++n >= MAX_GAP_ACK_BLKS / 2) {
1451                                 pr_info_ratelimited("Gacks on %s: %d, ql: %d!\n",
1452                                                     l->name, n,
1453                                                     skb_queue_len(&l->deferdq));
1454                                 return n;
1455                         }
1456                 } else if (unlikely(less(seqno, expect))) {
1457                         pr_warn("Unexpected skb in deferdq!\n");
1458                         continue;
1459                 }
1460                 expect = seqno + 1;
1461         }
1462
1463         /* last block */
1464         gacks[n].ack = htons(seqno);
1465         gacks[n].gap = 0;
1466         n++;
1467         return n;
1468 }
1469
1470 /* tipc_build_gap_ack_blks - build Gap ACK blocks
1471  * @l: tipc unicast link
1472  * @hdr: the tipc message buffer to store the Gap ACK blocks after built
1473  *
1474  * The function builds Gap ACK blocks for both the unicast & broadcast receiver
1475  * links of a certain peer, the buffer after built has the network data format
1476  * as found at the struct tipc_gap_ack_blks definition.
1477  *
1478  * returns the actual allocated memory size
1479  */
1480 static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr)
1481 {
1482         struct tipc_link *bcl = l->bc_rcvlink;
1483         struct tipc_gap_ack_blks *ga;
1484         u16 len;
1485
1486         ga = (struct tipc_gap_ack_blks *)msg_data(hdr);
1487
1488         /* Start with broadcast link first */
1489         tipc_bcast_lock(bcl->net);
1490         msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1491         msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
1492         ga->bgack_cnt = __tipc_build_gap_ack_blks(ga, bcl, 0);
1493         tipc_bcast_unlock(bcl->net);
1494
1495         /* Now for unicast link, but an explicit NACK only (???) */
1496         ga->ugack_cnt = (msg_seq_gap(hdr)) ?
1497                         __tipc_build_gap_ack_blks(ga, l, ga->bgack_cnt) : 0;
1498
1499         /* Total len */
1500         len = struct_size(ga, gacks, size_add(ga->bgack_cnt, ga->ugack_cnt));
1501         ga->len = htons(len);
1502         return len;
1503 }
1504
1505 /* tipc_link_advance_transmq - advance TIPC link transmq queue by releasing
1506  *                             acked packets, also doing retransmissions if
1507  *                             gaps found
1508  * @l: tipc link with transmq queue to be advanced
1509  * @r: tipc link "receiver" i.e. in case of broadcast (= "l" if unicast)
1510  * @acked: seqno of last packet acked by peer without any gaps before
1511  * @gap: # of gap packets
1512  * @ga: buffer pointer to Gap ACK blocks from peer
1513  * @xmitq: queue for accumulating the retransmitted packets if any
1514  * @retransmitted: returned boolean value if a retransmission is really issued
1515  * @rc: returned code e.g. TIPC_LINK_DOWN_EVT if a repeated retransmit failures
1516  *      happens (- unlikely case)
1517  *
1518  * Return: the number of packets released from the link transmq
1519  */
1520 static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
1521                                      u16 acked, u16 gap,
1522                                      struct tipc_gap_ack_blks *ga,
1523                                      struct sk_buff_head *xmitq,
1524                                      bool *retransmitted, int *rc)
1525 {
1526         struct tipc_gap_ack_blks *last_ga = r->last_ga, *this_ga = NULL;
1527         struct tipc_gap_ack *gacks = NULL;
1528         struct sk_buff *skb, *_skb, *tmp;
1529         struct tipc_msg *hdr;
1530         u32 qlen = skb_queue_len(&l->transmq);
1531         u16 nacked = acked, ngap = gap, gack_cnt = 0;
1532         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1533         u16 ack = l->rcv_nxt - 1;
1534         u16 seqno, n = 0;
1535         u16 end = r->acked, start = end, offset = r->last_gap;
1536         u16 si = (last_ga) ? last_ga->start_index : 0;
1537         bool is_uc = !link_is_bc_sndlink(l);
1538         bool bc_has_acked = false;
1539
1540         trace_tipc_link_retrans(r, acked + 1, acked + gap, &l->transmq);
1541
1542         /* Determine Gap ACK blocks if any for the particular link */
1543         if (ga && is_uc) {
1544                 /* Get the Gap ACKs, uc part */
1545                 gack_cnt = ga->ugack_cnt;
1546                 gacks = &ga->gacks[ga->bgack_cnt];
1547         } else if (ga) {
1548                 /* Copy the Gap ACKs, bc part, for later renewal if needed */
1549                 this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt),
1550                                   GFP_ATOMIC);
1551                 if (likely(this_ga)) {
1552                         this_ga->start_index = 0;
1553                         /* Start with the bc Gap ACKs */
1554                         gack_cnt = this_ga->bgack_cnt;
1555                         gacks = &this_ga->gacks[0];
1556                 } else {
1557                         /* Hmm, we can get in trouble..., simply ignore it */
1558                         pr_warn_ratelimited("Ignoring bc Gap ACKs, no memory\n");
1559                 }
1560         }
1561
1562         /* Advance the link transmq */
1563         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1564                 seqno = buf_seqno(skb);
1565
1566 next_gap_ack:
1567                 if (less_eq(seqno, nacked)) {
1568                         if (is_uc)
1569                                 goto release;
1570                         /* Skip packets peer has already acked */
1571                         if (!more(seqno, r->acked))
1572                                 continue;
1573                         /* Get the next of last Gap ACK blocks */
1574                         while (more(seqno, end)) {
1575                                 if (!last_ga || si >= last_ga->bgack_cnt)
1576                                         break;
1577                                 start = end + offset + 1;
1578                                 end = ntohs(last_ga->gacks[si].ack);
1579                                 offset = ntohs(last_ga->gacks[si].gap);
1580                                 si++;
1581                                 WARN_ONCE(more(start, end) ||
1582                                           (!offset &&
1583                                            si < last_ga->bgack_cnt) ||
1584                                           si > MAX_GAP_ACK_BLKS,
1585                                           "Corrupted Gap ACK: %d %d %d %d %d\n",
1586                                           start, end, offset, si,
1587                                           last_ga->bgack_cnt);
1588                         }
1589                         /* Check against the last Gap ACK block */
1590                         if (in_range(seqno, start, end))
1591                                 continue;
1592                         /* Update/release the packet peer is acking */
1593                         bc_has_acked = true;
1594                         if (--TIPC_SKB_CB(skb)->ackers)
1595                                 continue;
1596 release:
1597                         /* release skb */
1598                         __skb_unlink(skb, &l->transmq);
1599                         kfree_skb(skb);
1600                 } else if (less_eq(seqno, nacked + ngap)) {
1601                         /* First gap: check if repeated retrans failures? */
1602                         if (unlikely(seqno == acked + 1 &&
1603                                      link_retransmit_failure(l, r, rc))) {
1604                                 /* Ignore this bc Gap ACKs if any */
1605                                 kfree(this_ga);
1606                                 this_ga = NULL;
1607                                 break;
1608                         }
1609                         /* retransmit skb if unrestricted*/
1610                         if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
1611                                 continue;
1612                         tipc_link_set_skb_retransmit_time(skb, l);
1613                         _skb = pskb_copy(skb, GFP_ATOMIC);
1614                         if (!_skb)
1615                                 continue;
1616                         hdr = buf_msg(_skb);
1617                         msg_set_ack(hdr, ack);
1618                         msg_set_bcast_ack(hdr, bc_ack);
1619                         _skb->priority = TC_PRIO_CONTROL;
1620                         __skb_queue_tail(xmitq, _skb);
1621                         l->stats.retransmitted++;
1622                         if (!is_uc)
1623                                 r->stats.retransmitted++;
1624                         *retransmitted = true;
1625                         /* Increase actual retrans counter & mark first time */
1626                         if (!TIPC_SKB_CB(skb)->retr_cnt++)
1627                                 TIPC_SKB_CB(skb)->retr_stamp = jiffies;
1628                 } else {
1629                         /* retry with Gap ACK blocks if any */
1630                         if (n >= gack_cnt)
1631                                 break;
1632                         nacked = ntohs(gacks[n].ack);
1633                         ngap = ntohs(gacks[n].gap);
1634                         n++;
1635                         goto next_gap_ack;
1636                 }
1637         }
1638
1639         /* Renew last Gap ACK blocks for bc if needed */
1640         if (bc_has_acked) {
1641                 if (this_ga) {
1642                         kfree(last_ga);
1643                         r->last_ga = this_ga;
1644                         r->last_gap = gap;
1645                 } else if (last_ga) {
1646                         if (less(acked, start)) {
1647                                 si--;
1648                                 offset = start - acked - 1;
1649                         } else if (less(acked, end)) {
1650                                 acked = end;
1651                         }
1652                         if (si < last_ga->bgack_cnt) {
1653                                 last_ga->start_index = si;
1654                                 r->last_gap = offset;
1655                         } else {
1656                                 kfree(last_ga);
1657                                 r->last_ga = NULL;
1658                                 r->last_gap = 0;
1659                         }
1660                 } else {
1661                         r->last_gap = 0;
1662                 }
1663                 r->acked = acked;
1664         } else {
1665                 kfree(this_ga);
1666         }
1667
1668         return qlen - skb_queue_len(&l->transmq);
1669 }
1670
1671 /* tipc_link_build_state_msg: prepare link state message for transmission
1672  *
1673  * Note that sending of broadcast ack is coordinated among nodes, to reduce
1674  * risk of ack storms towards the sender
1675  */
1676 int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1677 {
1678         if (!l)
1679                 return 0;
1680
1681         /* Broadcast ACK must be sent via a unicast link => defer to caller */
1682         if (link_is_bc_rcvlink(l)) {
1683                 if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1684                         return 0;
1685                 l->rcv_unacked = 0;
1686
1687                 /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
1688                 l->snd_nxt = l->rcv_nxt;
1689                 return TIPC_LINK_SND_STATE;
1690         }
1691         /* Unicast ACK */
1692         l->rcv_unacked = 0;
1693         l->stats.sent_acks++;
1694         tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
1695         return 0;
1696 }
1697
1698 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1699  */
1700 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1701 {
1702         int mtyp = RESET_MSG;
1703         struct sk_buff *skb;
1704
1705         if (l->state == LINK_ESTABLISHING)
1706                 mtyp = ACTIVATE_MSG;
1707
1708         tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, 0, xmitq);
1709
1710         /* Inform peer that this endpoint is going down if applicable */
1711         skb = skb_peek_tail(xmitq);
1712         if (skb && (l->state == LINK_RESET))
1713                 msg_set_peer_stopping(buf_msg(skb), 1);
1714 }
1715
1716 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1717  * Note that sending of broadcast NACK is coordinated among nodes, to
1718  * reduce the risk of NACK storms towards the sender
1719  */
1720 static int tipc_link_build_nack_msg(struct tipc_link *l,
1721                                     struct sk_buff_head *xmitq)
1722 {
1723         u32 def_cnt = ++l->stats.deferred_recv;
1724         struct sk_buff_head *dfq = &l->deferdq;
1725         u32 defq_len = skb_queue_len(dfq);
1726         int match1, match2;
1727
1728         if (link_is_bc_rcvlink(l)) {
1729                 match1 = def_cnt & 0xf;
1730                 match2 = tipc_own_addr(l->net) & 0xf;
1731                 if (match1 == match2)
1732                         return TIPC_LINK_SND_STATE;
1733                 return 0;
1734         }
1735
1736         if (defq_len >= 3 && !((defq_len - 3) % 16)) {
1737                 u16 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1738
1739                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0,
1740                                           rcvgap, 0, 0, xmitq);
1741         }
1742         return 0;
1743 }
1744
1745 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1746  * @l: the link that should handle the message
1747  * @skb: TIPC packet
1748  * @xmitq: queue to place packets to be sent after this call
1749  */
1750 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1751                   struct sk_buff_head *xmitq)
1752 {
1753         struct sk_buff_head *defq = &l->deferdq;
1754         struct tipc_msg *hdr = buf_msg(skb);
1755         u16 seqno, rcv_nxt, win_lim;
1756         int released = 0;
1757         int rc = 0;
1758
1759         /* Verify and update link state */
1760         if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1761                 return tipc_link_proto_rcv(l, skb, xmitq);
1762
1763         /* Don't send probe at next timeout expiration */
1764         l->silent_intv_cnt = 0;
1765
1766         do {
1767                 hdr = buf_msg(skb);
1768                 seqno = msg_seqno(hdr);
1769                 rcv_nxt = l->rcv_nxt;
1770                 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1771
1772                 if (unlikely(!link_is_up(l))) {
1773                         if (l->state == LINK_ESTABLISHING)
1774                                 rc = TIPC_LINK_UP_EVT;
1775                         kfree_skb(skb);
1776                         break;
1777                 }
1778
1779                 /* Drop if outside receive window */
1780                 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1781                         l->stats.duplicates++;
1782                         kfree_skb(skb);
1783                         break;
1784                 }
1785                 released += tipc_link_advance_transmq(l, l, msg_ack(hdr), 0,
1786                                                       NULL, NULL, NULL, NULL);
1787
1788                 /* Defer delivery if sequence gap */
1789                 if (unlikely(seqno != rcv_nxt)) {
1790                         if (!__tipc_skb_queue_sorted(defq, seqno, skb))
1791                                 l->stats.duplicates++;
1792                         rc |= tipc_link_build_nack_msg(l, xmitq);
1793                         break;
1794                 }
1795
1796                 /* Deliver packet */
1797                 l->rcv_nxt++;
1798                 l->stats.recv_pkts++;
1799
1800                 if (unlikely(msg_user(hdr) == TUNNEL_PROTOCOL))
1801                         rc |= tipc_link_tnl_rcv(l, skb, l->inputq);
1802                 else if (!tipc_data_input(l, skb, l->inputq))
1803                         rc |= tipc_link_input(l, skb, l->inputq, &l->reasm_buf);
1804                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1805                         rc |= tipc_link_build_state_msg(l, xmitq);
1806                 if (unlikely(rc & ~TIPC_LINK_SND_STATE))
1807                         break;
1808         } while ((skb = __tipc_skb_dequeue(defq, l->rcv_nxt)));
1809
1810         /* Forward queues and wake up waiting users */
1811         if (released) {
1812                 tipc_link_update_cwin(l, released, 0);
1813                 tipc_link_advance_backlog(l, xmitq);
1814                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1815                         link_prepare_wakeup(l);
1816         }
1817         return rc;
1818 }
1819
1820 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1821                                       bool probe_reply, u16 rcvgap,
1822                                       int tolerance, int priority,
1823                                       struct sk_buff_head *xmitq)
1824 {
1825         struct tipc_mon_state *mstate = &l->mon_state;
1826         struct sk_buff_head *dfq = &l->deferdq;
1827         struct tipc_link *bcl = l->bc_rcvlink;
1828         struct tipc_msg *hdr;
1829         struct sk_buff *skb;
1830         bool node_up = link_is_up(bcl);
1831         u16 glen = 0, bc_rcvgap = 0;
1832         int dlen = 0;
1833         void *data;
1834
1835         /* Don't send protocol message during reset or link failover */
1836         if (tipc_link_is_blocked(l))
1837                 return;
1838
1839         if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1840                 return;
1841
1842         if ((probe || probe_reply) && !skb_queue_empty(dfq))
1843                 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1844
1845         skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1846                               tipc_max_domain_size + MAX_GAP_ACK_BLKS_SZ,
1847                               l->addr, tipc_own_addr(l->net), 0, 0, 0);
1848         if (!skb)
1849                 return;
1850
1851         hdr = buf_msg(skb);
1852         data = msg_data(hdr);
1853         msg_set_session(hdr, l->session);
1854         msg_set_bearer_id(hdr, l->bearer_id);
1855         msg_set_net_plane(hdr, l->net_plane);
1856         msg_set_next_sent(hdr, l->snd_nxt);
1857         msg_set_ack(hdr, l->rcv_nxt - 1);
1858         msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1859         msg_set_bc_ack_invalid(hdr, !node_up);
1860         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1861         msg_set_link_tolerance(hdr, tolerance);
1862         msg_set_linkprio(hdr, priority);
1863         msg_set_redundant_link(hdr, node_up);
1864         msg_set_seq_gap(hdr, 0);
1865         msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1866
1867         if (mtyp == STATE_MSG) {
1868                 if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
1869                         msg_set_seqno(hdr, l->snd_nxt_state++);
1870                 msg_set_seq_gap(hdr, rcvgap);
1871                 bc_rcvgap = link_bc_rcv_gap(bcl);
1872                 msg_set_bc_gap(hdr, bc_rcvgap);
1873                 msg_set_probe(hdr, probe);
1874                 msg_set_is_keepalive(hdr, probe || probe_reply);
1875                 if (l->peer_caps & TIPC_GAP_ACK_BLOCK)
1876                         glen = tipc_build_gap_ack_blks(l, hdr);
1877                 tipc_mon_prep(l->net, data + glen, &dlen, mstate, l->bearer_id);
1878                 msg_set_size(hdr, INT_H_SIZE + glen + dlen);
1879                 skb_trim(skb, INT_H_SIZE + glen + dlen);
1880                 l->stats.sent_states++;
1881                 l->rcv_unacked = 0;
1882         } else {
1883                 /* RESET_MSG or ACTIVATE_MSG */
1884                 if (mtyp == ACTIVATE_MSG) {
1885                         msg_set_dest_session_valid(hdr, 1);
1886                         msg_set_dest_session(hdr, l->peer_session);
1887                 }
1888                 msg_set_max_pkt(hdr, l->advertised_mtu);
1889                 strcpy(data, l->if_name);
1890                 msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
1891                 skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
1892         }
1893         if (probe)
1894                 l->stats.sent_probes++;
1895         if (rcvgap)
1896                 l->stats.sent_nacks++;
1897         if (bc_rcvgap)
1898                 bcl->stats.sent_nacks++;
1899         skb->priority = TC_PRIO_CONTROL;
1900         __skb_queue_tail(xmitq, skb);
1901         trace_tipc_proto_build(skb, false, l->name);
1902 }
1903
1904 void tipc_link_create_dummy_tnl_msg(struct tipc_link *l,
1905                                     struct sk_buff_head *xmitq)
1906 {
1907         u32 onode = tipc_own_addr(l->net);
1908         struct tipc_msg *hdr, *ihdr;
1909         struct sk_buff_head tnlq;
1910         struct sk_buff *skb;
1911         u32 dnode = l->addr;
1912
1913         __skb_queue_head_init(&tnlq);
1914         skb = tipc_msg_create(TUNNEL_PROTOCOL, FAILOVER_MSG,
1915                               INT_H_SIZE, BASIC_H_SIZE,
1916                               dnode, onode, 0, 0, 0);
1917         if (!skb) {
1918                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1919                 return;
1920         }
1921
1922         hdr = buf_msg(skb);
1923         msg_set_msgcnt(hdr, 1);
1924         msg_set_bearer_id(hdr, l->peer_bearer_id);
1925
1926         ihdr = (struct tipc_msg *)msg_data(hdr);
1927         tipc_msg_init(onode, ihdr, TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1928                       BASIC_H_SIZE, dnode);
1929         msg_set_errcode(ihdr, TIPC_ERR_NO_PORT);
1930         __skb_queue_tail(&tnlq, skb);
1931         tipc_link_xmit(l, &tnlq, xmitq);
1932 }
1933
1934 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1935  * with contents of the link's transmit and backlog queues.
1936  */
1937 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1938                            int mtyp, struct sk_buff_head *xmitq)
1939 {
1940         struct sk_buff_head *fdefq = &tnl->failover_deferdq;
1941         struct sk_buff *skb, *tnlskb;
1942         struct tipc_msg *hdr, tnlhdr;
1943         struct sk_buff_head *queue = &l->transmq;
1944         struct sk_buff_head tmpxq, tnlq, frags;
1945         u16 pktlen, pktcnt, seqno = l->snd_nxt;
1946         bool pktcnt_need_update = false;
1947         u16 syncpt;
1948         int rc;
1949
1950         if (!tnl)
1951                 return;
1952
1953         __skb_queue_head_init(&tnlq);
1954         /* Link Synching:
1955          * From now on, send only one single ("dummy") SYNCH message
1956          * to peer. The SYNCH message does not contain any data, just
1957          * a header conveying the synch point to the peer.
1958          */
1959         if (mtyp == SYNCH_MSG && (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
1960                 tnlskb = tipc_msg_create(TUNNEL_PROTOCOL, SYNCH_MSG,
1961                                          INT_H_SIZE, 0, l->addr,
1962                                          tipc_own_addr(l->net),
1963                                          0, 0, 0);
1964                 if (!tnlskb) {
1965                         pr_warn("%sunable to create dummy SYNCH_MSG\n",
1966                                 link_co_err);
1967                         return;
1968                 }
1969
1970                 hdr = buf_msg(tnlskb);
1971                 syncpt = l->snd_nxt + skb_queue_len(&l->backlogq) - 1;
1972                 msg_set_syncpt(hdr, syncpt);
1973                 msg_set_bearer_id(hdr, l->peer_bearer_id);
1974                 __skb_queue_tail(&tnlq, tnlskb);
1975                 tipc_link_xmit(tnl, &tnlq, xmitq);
1976                 return;
1977         }
1978
1979         __skb_queue_head_init(&tmpxq);
1980         __skb_queue_head_init(&frags);
1981         /* At least one packet required for safe algorithm => add dummy */
1982         skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1983                               BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
1984                               0, 0, TIPC_ERR_NO_PORT);
1985         if (!skb) {
1986                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1987                 return;
1988         }
1989         __skb_queue_tail(&tnlq, skb);
1990         tipc_link_xmit(l, &tnlq, &tmpxq);
1991         __skb_queue_purge(&tmpxq);
1992
1993         /* Initialize reusable tunnel packet header */
1994         tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
1995                       mtyp, INT_H_SIZE, l->addr);
1996         if (mtyp == SYNCH_MSG)
1997                 pktcnt = l->snd_nxt - buf_seqno(skb_peek(&l->transmq));
1998         else
1999                 pktcnt = skb_queue_len(&l->transmq);
2000         pktcnt += skb_queue_len(&l->backlogq);
2001         msg_set_msgcnt(&tnlhdr, pktcnt);
2002         msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
2003 tnl:
2004         /* Wrap each packet into a tunnel packet */
2005         skb_queue_walk(queue, skb) {
2006                 hdr = buf_msg(skb);
2007                 if (queue == &l->backlogq)
2008                         msg_set_seqno(hdr, seqno++);
2009                 pktlen = msg_size(hdr);
2010
2011                 /* Tunnel link MTU is not large enough? This could be
2012                  * due to:
2013                  * 1) Link MTU has just changed or set differently;
2014                  * 2) Or FAILOVER on the top of a SYNCH message
2015                  *
2016                  * The 2nd case should not happen if peer supports
2017                  * TIPC_TUNNEL_ENHANCED
2018                  */
2019                 if (pktlen > tnl->mtu - INT_H_SIZE) {
2020                         if (mtyp == FAILOVER_MSG &&
2021                             (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
2022                                 rc = tipc_msg_fragment(skb, &tnlhdr, tnl->mtu,
2023                                                        &frags);
2024                                 if (rc) {
2025                                         pr_warn("%sunable to frag msg: rc %d\n",
2026                                                 link_co_err, rc);
2027                                         return;
2028                                 }
2029                                 pktcnt += skb_queue_len(&frags) - 1;
2030                                 pktcnt_need_update = true;
2031                                 skb_queue_splice_tail_init(&frags, &tnlq);
2032                                 continue;
2033                         }
2034                         /* Unluckily, peer doesn't have TIPC_TUNNEL_ENHANCED
2035                          * => Just warn it and return!
2036                          */
2037                         pr_warn_ratelimited("%stoo large msg <%d, %d>: %d!\n",
2038                                             link_co_err, msg_user(hdr),
2039                                             msg_type(hdr), msg_size(hdr));
2040                         return;
2041                 }
2042
2043                 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
2044                 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
2045                 if (!tnlskb) {
2046                         pr_warn("%sunable to send packet\n", link_co_err);
2047                         return;
2048                 }
2049                 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
2050                 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
2051                 __skb_queue_tail(&tnlq, tnlskb);
2052         }
2053         if (queue != &l->backlogq) {
2054                 queue = &l->backlogq;
2055                 goto tnl;
2056         }
2057
2058         if (pktcnt_need_update)
2059                 skb_queue_walk(&tnlq, skb) {
2060                         hdr = buf_msg(skb);
2061                         msg_set_msgcnt(hdr, pktcnt);
2062                 }
2063
2064         tipc_link_xmit(tnl, &tnlq, xmitq);
2065
2066         if (mtyp == FAILOVER_MSG) {
2067                 tnl->drop_point = l->rcv_nxt;
2068                 tnl->failover_reasm_skb = l->reasm_buf;
2069                 l->reasm_buf = NULL;
2070
2071                 /* Failover the link's deferdq */
2072                 if (unlikely(!skb_queue_empty(fdefq))) {
2073                         pr_warn("Link failover deferdq not empty: %d!\n",
2074                                 skb_queue_len(fdefq));
2075                         __skb_queue_purge(fdefq);
2076                 }
2077                 skb_queue_splice_init(&l->deferdq, fdefq);
2078         }
2079 }
2080
2081 /**
2082  * tipc_link_failover_prepare() - prepare tnl for link failover
2083  *
2084  * This is a special version of the precursor - tipc_link_tnl_prepare(),
2085  * see the tipc_node_link_failover() for details
2086  *
2087  * @l: failover link
2088  * @tnl: tunnel link
2089  * @xmitq: queue for messages to be xmited
2090  */
2091 void tipc_link_failover_prepare(struct tipc_link *l, struct tipc_link *tnl,
2092                                 struct sk_buff_head *xmitq)
2093 {
2094         struct sk_buff_head *fdefq = &tnl->failover_deferdq;
2095
2096         tipc_link_create_dummy_tnl_msg(tnl, xmitq);
2097
2098         /* This failover link endpoint was never established before,
2099          * so it has not received anything from peer.
2100          * Otherwise, it must be a normal failover situation or the
2101          * node has entered SELF_DOWN_PEER_LEAVING and both peer nodes
2102          * would have to start over from scratch instead.
2103          */
2104         tnl->drop_point = 1;
2105         tnl->failover_reasm_skb = NULL;
2106
2107         /* Initiate the link's failover deferdq */
2108         if (unlikely(!skb_queue_empty(fdefq))) {
2109                 pr_warn("Link failover deferdq not empty: %d!\n",
2110                         skb_queue_len(fdefq));
2111                 __skb_queue_purge(fdefq);
2112         }
2113 }
2114
2115 /* tipc_link_validate_msg(): validate message against current link state
2116  * Returns true if message should be accepted, otherwise false
2117  */
2118 bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr)
2119 {
2120         u16 curr_session = l->peer_session;
2121         u16 session = msg_session(hdr);
2122         int mtyp = msg_type(hdr);
2123
2124         if (msg_user(hdr) != LINK_PROTOCOL)
2125                 return true;
2126
2127         switch (mtyp) {
2128         case RESET_MSG:
2129                 if (!l->in_session)
2130                         return true;
2131                 /* Accept only RESET with new session number */
2132                 return more(session, curr_session);
2133         case ACTIVATE_MSG:
2134                 if (!l->in_session)
2135                         return true;
2136                 /* Accept only ACTIVATE with new or current session number */
2137                 return !less(session, curr_session);
2138         case STATE_MSG:
2139                 /* Accept only STATE with current session number */
2140                 if (!l->in_session)
2141                         return false;
2142                 if (session != curr_session)
2143                         return false;
2144                 /* Extra sanity check */
2145                 if (!link_is_up(l) && msg_ack(hdr))
2146                         return false;
2147                 if (!(l->peer_caps & TIPC_LINK_PROTO_SEQNO))
2148                         return true;
2149                 /* Accept only STATE with new sequence number */
2150                 return !less(msg_seqno(hdr), l->rcv_nxt_state);
2151         default:
2152                 return false;
2153         }
2154 }
2155
2156 /* tipc_link_proto_rcv(): receive link level protocol message :
2157  * Note that network plane id propagates through the network, and may
2158  * change at any time. The node with lowest numerical id determines
2159  * network plane
2160  */
2161 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
2162                                struct sk_buff_head *xmitq)
2163 {
2164         struct tipc_msg *hdr = buf_msg(skb);
2165         struct tipc_gap_ack_blks *ga = NULL;
2166         bool reply = msg_probe(hdr), retransmitted = false;
2167         u32 dlen = msg_data_sz(hdr), glen = 0, msg_max;
2168         u16 peers_snd_nxt =  msg_next_sent(hdr);
2169         u16 peers_tol = msg_link_tolerance(hdr);
2170         u16 peers_prio = msg_linkprio(hdr);
2171         u16 gap = msg_seq_gap(hdr);
2172         u16 ack = msg_ack(hdr);
2173         u16 rcv_nxt = l->rcv_nxt;
2174         u16 rcvgap = 0;
2175         int mtyp = msg_type(hdr);
2176         int rc = 0, released;
2177         char *if_name;
2178         void *data;
2179
2180         trace_tipc_proto_rcv(skb, false, l->name);
2181
2182         if (dlen > U16_MAX)
2183                 goto exit;
2184
2185         if (tipc_link_is_blocked(l) || !xmitq)
2186                 goto exit;
2187
2188         if (tipc_own_addr(l->net) > msg_prevnode(hdr))
2189                 l->net_plane = msg_net_plane(hdr);
2190
2191         if (skb_linearize(skb))
2192                 goto exit;
2193
2194         hdr = buf_msg(skb);
2195         data = msg_data(hdr);
2196
2197         if (!tipc_link_validate_msg(l, hdr)) {
2198                 trace_tipc_skb_dump(skb, false, "PROTO invalid (1)!");
2199                 trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (1)!");
2200                 goto exit;
2201         }
2202
2203         switch (mtyp) {
2204         case RESET_MSG:
2205         case ACTIVATE_MSG:
2206                 msg_max = msg_max_pkt(hdr);
2207                 if (msg_max < tipc_bearer_min_mtu(l->net, l->bearer_id))
2208                         break;
2209                 /* Complete own link name with peer's interface name */
2210                 if_name =  strrchr(l->name, ':') + 1;
2211                 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
2212                         break;
2213                 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
2214                         break;
2215                 strncpy(if_name, data, TIPC_MAX_IF_NAME);
2216
2217                 /* Update own tolerance if peer indicates a non-zero value */
2218                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2219                         l->tolerance = peers_tol;
2220                         l->bc_rcvlink->tolerance = peers_tol;
2221                 }
2222                 /* Update own priority if peer's priority is higher */
2223                 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
2224                         l->priority = peers_prio;
2225
2226                 /* If peer is going down we want full re-establish cycle */
2227                 if (msg_peer_stopping(hdr)) {
2228                         rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2229                         break;
2230                 }
2231
2232                 /* If this endpoint was re-created while peer was ESTABLISHING
2233                  * it doesn't know current session number. Force re-synch.
2234                  */
2235                 if (mtyp == ACTIVATE_MSG && msg_dest_session_valid(hdr) &&
2236                     l->session != msg_dest_session(hdr)) {
2237                         if (less(l->session, msg_dest_session(hdr)))
2238                                 l->session = msg_dest_session(hdr) + 1;
2239                         break;
2240                 }
2241
2242                 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
2243                 if (mtyp == RESET_MSG || !link_is_up(l))
2244                         rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
2245
2246                 /* ACTIVATE_MSG takes up link if it was already locally reset */
2247                 if (mtyp == ACTIVATE_MSG && l->state == LINK_ESTABLISHING)
2248                         rc = TIPC_LINK_UP_EVT;
2249
2250                 l->peer_session = msg_session(hdr);
2251                 l->in_session = true;
2252                 l->peer_bearer_id = msg_bearer_id(hdr);
2253                 if (l->mtu > msg_max)
2254                         l->mtu = msg_max;
2255                 break;
2256
2257         case STATE_MSG:
2258                 /* Validate Gap ACK blocks, drop if invalid */
2259                 glen = tipc_get_gap_ack_blks(&ga, l, hdr, true);
2260                 if (glen > dlen)
2261                         break;
2262
2263                 l->rcv_nxt_state = msg_seqno(hdr) + 1;
2264
2265                 /* Update own tolerance if peer indicates a non-zero value */
2266                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2267                         l->tolerance = peers_tol;
2268                         l->bc_rcvlink->tolerance = peers_tol;
2269                 }
2270                 /* Update own prio if peer indicates a different value */
2271                 if ((peers_prio != l->priority) &&
2272                     in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) {
2273                         l->priority = peers_prio;
2274                         rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2275                 }
2276
2277                 l->silent_intv_cnt = 0;
2278                 l->stats.recv_states++;
2279                 if (msg_probe(hdr))
2280                         l->stats.recv_probes++;
2281
2282                 if (!link_is_up(l)) {
2283                         if (l->state == LINK_ESTABLISHING)
2284                                 rc = TIPC_LINK_UP_EVT;
2285                         break;
2286                 }
2287
2288                 tipc_mon_rcv(l->net, data + glen, dlen - glen, l->addr,
2289                              &l->mon_state, l->bearer_id);
2290
2291                 /* Send NACK if peer has sent pkts we haven't received yet */
2292                 if ((reply || msg_is_keepalive(hdr)) &&
2293                     more(peers_snd_nxt, rcv_nxt) &&
2294                     !tipc_link_is_synching(l) &&
2295                     skb_queue_empty(&l->deferdq))
2296                         rcvgap = peers_snd_nxt - l->rcv_nxt;
2297                 if (rcvgap || reply)
2298                         tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,
2299                                                   rcvgap, 0, 0, xmitq);
2300
2301                 released = tipc_link_advance_transmq(l, l, ack, gap, ga, xmitq,
2302                                                      &retransmitted, &rc);
2303                 if (gap)
2304                         l->stats.recv_nacks++;
2305                 if (released || retransmitted)
2306                         tipc_link_update_cwin(l, released, retransmitted);
2307                 if (released)
2308                         tipc_link_advance_backlog(l, xmitq);
2309                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
2310                         link_prepare_wakeup(l);
2311         }
2312 exit:
2313         kfree_skb(skb);
2314         return rc;
2315 }
2316
2317 /* tipc_link_build_bc_proto_msg() - create broadcast protocol message
2318  */
2319 static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
2320                                          u16 peers_snd_nxt,
2321                                          struct sk_buff_head *xmitq)
2322 {
2323         struct sk_buff *skb;
2324         struct tipc_msg *hdr;
2325         struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
2326         u16 ack = l->rcv_nxt - 1;
2327         u16 gap_to = peers_snd_nxt - 1;
2328
2329         skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
2330                               0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
2331         if (!skb)
2332                 return false;
2333         hdr = buf_msg(skb);
2334         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
2335         msg_set_bcast_ack(hdr, ack);
2336         msg_set_bcgap_after(hdr, ack);
2337         if (dfrd_skb)
2338                 gap_to = buf_seqno(dfrd_skb) - 1;
2339         msg_set_bcgap_to(hdr, gap_to);
2340         msg_set_non_seq(hdr, bcast);
2341         __skb_queue_tail(xmitq, skb);
2342         return true;
2343 }
2344
2345 /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
2346  *
2347  * Give a newly added peer node the sequence number where it should
2348  * start receiving and acking broadcast packets.
2349  */
2350 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
2351                                         struct sk_buff_head *xmitq)
2352 {
2353         struct sk_buff_head list;
2354
2355         __skb_queue_head_init(&list);
2356         if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
2357                 return;
2358         msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true);
2359         tipc_link_xmit(l, &list, xmitq);
2360 }
2361
2362 /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
2363  */
2364 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
2365 {
2366         int mtyp = msg_type(hdr);
2367         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2368
2369         if (link_is_up(l))
2370                 return;
2371
2372         if (msg_user(hdr) == BCAST_PROTOCOL) {
2373                 l->rcv_nxt = peers_snd_nxt;
2374                 l->state = LINK_ESTABLISHED;
2375                 return;
2376         }
2377
2378         if (l->peer_caps & TIPC_BCAST_SYNCH)
2379                 return;
2380
2381         if (msg_peer_node_is_up(hdr))
2382                 return;
2383
2384         /* Compatibility: accept older, less safe initial synch data */
2385         if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
2386                 l->rcv_nxt = peers_snd_nxt;
2387 }
2388
2389 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
2390  */
2391 int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
2392                           struct sk_buff_head *xmitq)
2393 {
2394         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2395         int rc = 0;
2396
2397         if (!link_is_up(l))
2398                 return rc;
2399
2400         if (!msg_peer_node_is_up(hdr))
2401                 return rc;
2402
2403         /* Open when peer ackowledges our bcast init msg (pkt #1) */
2404         if (msg_ack(hdr))
2405                 l->bc_peer_is_up = true;
2406
2407         if (!l->bc_peer_is_up)
2408                 return rc;
2409
2410         /* Ignore if peers_snd_nxt goes beyond receive window */
2411         if (more(peers_snd_nxt, l->rcv_nxt + l->window))
2412                 return rc;
2413
2414         l->snd_nxt = peers_snd_nxt;
2415         if (link_bc_rcv_gap(l))
2416                 rc |= TIPC_LINK_SND_STATE;
2417
2418         /* Return now if sender supports nack via STATE messages */
2419         if (l->peer_caps & TIPC_BCAST_STATE_NACK)
2420                 return rc;
2421
2422         /* Otherwise, be backwards compatible */
2423
2424         if (!more(peers_snd_nxt, l->rcv_nxt)) {
2425                 l->nack_state = BC_NACK_SND_CONDITIONAL;
2426                 return 0;
2427         }
2428
2429         /* Don't NACK if one was recently sent or peeked */
2430         if (l->nack_state == BC_NACK_SND_SUPPRESS) {
2431                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2432                 return 0;
2433         }
2434
2435         /* Conditionally delay NACK sending until next synch rcv */
2436         if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
2437                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2438                 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
2439                         return 0;
2440         }
2441
2442         /* Send NACK now but suppress next one */
2443         tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
2444         l->nack_state = BC_NACK_SND_SUPPRESS;
2445         return 0;
2446 }
2447
2448 int tipc_link_bc_ack_rcv(struct tipc_link *r, u16 acked, u16 gap,
2449                          struct tipc_gap_ack_blks *ga,
2450                          struct sk_buff_head *xmitq,
2451                          struct sk_buff_head *retrq)
2452 {
2453         struct tipc_link *l = r->bc_sndlink;
2454         bool unused = false;
2455         int rc = 0;
2456
2457         if (!link_is_up(r) || !r->bc_peer_is_up)
2458                 return 0;
2459
2460         if (gap) {
2461                 l->stats.recv_nacks++;
2462                 r->stats.recv_nacks++;
2463         }
2464
2465         if (less(acked, r->acked) || (acked == r->acked && !gap && !ga))
2466                 return 0;
2467
2468         trace_tipc_link_bc_ack(r, acked, gap, &l->transmq);
2469         tipc_link_advance_transmq(l, r, acked, gap, ga, retrq, &unused, &rc);
2470
2471         tipc_link_advance_backlog(l, xmitq);
2472         if (unlikely(!skb_queue_empty(&l->wakeupq)))
2473                 link_prepare_wakeup(l);
2474
2475         return rc;
2476 }
2477
2478 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
2479  * This function is here for backwards compatibility, since
2480  * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
2481  */
2482 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
2483                           struct sk_buff_head *xmitq)
2484 {
2485         struct tipc_msg *hdr = buf_msg(skb);
2486         u32 dnode = msg_destnode(hdr);
2487         int mtyp = msg_type(hdr);
2488         u16 acked = msg_bcast_ack(hdr);
2489         u16 from = acked + 1;
2490         u16 to = msg_bcgap_to(hdr);
2491         u16 peers_snd_nxt = to + 1;
2492         int rc = 0;
2493
2494         kfree_skb(skb);
2495
2496         if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
2497                 return 0;
2498
2499         if (mtyp != STATE_MSG)
2500                 return 0;
2501
2502         if (dnode == tipc_own_addr(l->net)) {
2503                 rc = tipc_link_bc_ack_rcv(l, acked, to - acked, NULL, xmitq,
2504                                           xmitq);
2505                 l->stats.recv_nacks++;
2506                 return rc;
2507         }
2508
2509         /* Msg for other node => suppress own NACK at next sync if applicable */
2510         if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
2511                 l->nack_state = BC_NACK_SND_SUPPRESS;
2512
2513         return 0;
2514 }
2515
2516 void tipc_link_set_queue_limits(struct tipc_link *l, u32 min_win, u32 max_win)
2517 {
2518         int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE);
2519
2520         l->min_win = min_win;
2521         l->ssthresh = max_win;
2522         l->max_win = max_win;
2523         l->window = min_win;
2524         l->backlog[TIPC_LOW_IMPORTANCE].limit      = min_win * 2;
2525         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = min_win * 4;
2526         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = min_win * 6;
2527         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = min_win * 8;
2528         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
2529 }
2530
2531 /**
2532  * link_reset_stats - reset link statistics
2533  * @l: pointer to link
2534  */
2535 void tipc_link_reset_stats(struct tipc_link *l)
2536 {
2537         memset(&l->stats, 0, sizeof(l->stats));
2538 }
2539
2540 static void link_print(struct tipc_link *l, const char *str)
2541 {
2542         struct sk_buff *hskb = skb_peek(&l->transmq);
2543         u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
2544         u16 tail = l->snd_nxt - 1;
2545
2546         pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
2547         pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
2548                 skb_queue_len(&l->transmq), head, tail,
2549                 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
2550 }
2551
2552 /* Parse and validate nested (link) properties valid for media, bearer and link
2553  */
2554 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
2555 {
2556         int err;
2557
2558         err = nla_parse_nested_deprecated(props, TIPC_NLA_PROP_MAX, prop,
2559                                           tipc_nl_prop_policy, NULL);
2560         if (err)
2561                 return err;
2562
2563         if (props[TIPC_NLA_PROP_PRIO]) {
2564                 u32 prio;
2565
2566                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2567                 if (prio > TIPC_MAX_LINK_PRI)
2568                         return -EINVAL;
2569         }
2570
2571         if (props[TIPC_NLA_PROP_TOL]) {
2572                 u32 tol;
2573
2574                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2575                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
2576                         return -EINVAL;
2577         }
2578
2579         if (props[TIPC_NLA_PROP_WIN]) {
2580                 u32 max_win;
2581
2582                 max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2583                 if (max_win < TIPC_DEF_LINK_WIN || max_win > TIPC_MAX_LINK_WIN)
2584                         return -EINVAL;
2585         }
2586
2587         return 0;
2588 }
2589
2590 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
2591 {
2592         int i;
2593         struct nlattr *stats;
2594
2595         struct nla_map {
2596                 u32 key;
2597                 u32 val;
2598         };
2599
2600         struct nla_map map[] = {
2601                 {TIPC_NLA_STATS_RX_INFO, 0},
2602                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
2603                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
2604                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
2605                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
2606                 {TIPC_NLA_STATS_TX_INFO, 0},
2607                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
2608                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
2609                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
2610                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
2611                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
2612                         s->msg_length_counts : 1},
2613                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
2614                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
2615                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
2616                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
2617                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
2618                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
2619                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
2620                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
2621                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
2622                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
2623                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
2624                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
2625                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
2626                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
2627                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
2628                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
2629                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
2630                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
2631                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
2632                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
2633                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
2634                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
2635                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
2636         };
2637
2638         stats = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2639         if (!stats)
2640                 return -EMSGSIZE;
2641
2642         for (i = 0; i <  ARRAY_SIZE(map); i++)
2643                 if (nla_put_u32(skb, map[i].key, map[i].val))
2644                         goto msg_full;
2645
2646         nla_nest_end(skb, stats);
2647
2648         return 0;
2649 msg_full:
2650         nla_nest_cancel(skb, stats);
2651
2652         return -EMSGSIZE;
2653 }
2654
2655 /* Caller should hold appropriate locks to protect the link */
2656 int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
2657                        struct tipc_link *link, int nlflags)
2658 {
2659         u32 self = tipc_own_addr(net);
2660         struct nlattr *attrs;
2661         struct nlattr *prop;
2662         void *hdr;
2663         int err;
2664
2665         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2666                           nlflags, TIPC_NL_LINK_GET);
2667         if (!hdr)
2668                 return -EMSGSIZE;
2669
2670         attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2671         if (!attrs)
2672                 goto msg_full;
2673
2674         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2675                 goto attr_msg_full;
2676         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, tipc_cluster_mask(self)))
2677                 goto attr_msg_full;
2678         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2679                 goto attr_msg_full;
2680         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
2681                 goto attr_msg_full;
2682         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
2683                 goto attr_msg_full;
2684
2685         if (tipc_link_is_up(link))
2686                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2687                         goto attr_msg_full;
2688         if (link->active)
2689                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2690                         goto attr_msg_full;
2691
2692         prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2693         if (!prop)
2694                 goto attr_msg_full;
2695         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2696                 goto prop_msg_full;
2697         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2698                 goto prop_msg_full;
2699         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2700                         link->window))
2701                 goto prop_msg_full;
2702         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2703                 goto prop_msg_full;
2704         nla_nest_end(msg->skb, prop);
2705
2706         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2707         if (err)
2708                 goto attr_msg_full;
2709
2710         nla_nest_end(msg->skb, attrs);
2711         genlmsg_end(msg->skb, hdr);
2712
2713         return 0;
2714
2715 prop_msg_full:
2716         nla_nest_cancel(msg->skb, prop);
2717 attr_msg_full:
2718         nla_nest_cancel(msg->skb, attrs);
2719 msg_full:
2720         genlmsg_cancel(msg->skb, hdr);
2721
2722         return -EMSGSIZE;
2723 }
2724
2725 static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
2726                                       struct tipc_stats *stats)
2727 {
2728         int i;
2729         struct nlattr *nest;
2730
2731         struct nla_map {
2732                 __u32 key;
2733                 __u32 val;
2734         };
2735
2736         struct nla_map map[] = {
2737                 {TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
2738                 {TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
2739                 {TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
2740                 {TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
2741                 {TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
2742                 {TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
2743                 {TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
2744                 {TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
2745                 {TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
2746                 {TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
2747                 {TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
2748                 {TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
2749                 {TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
2750                 {TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
2751                 {TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
2752                 {TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
2753                 {TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
2754                 {TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
2755                 {TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
2756                         (stats->accu_queue_sz / stats->queue_sz_counts) : 0}
2757         };
2758
2759         nest = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2760         if (!nest)
2761                 return -EMSGSIZE;
2762
2763         for (i = 0; i <  ARRAY_SIZE(map); i++)
2764                 if (nla_put_u32(skb, map[i].key, map[i].val))
2765                         goto msg_full;
2766
2767         nla_nest_end(skb, nest);
2768
2769         return 0;
2770 msg_full:
2771         nla_nest_cancel(skb, nest);
2772
2773         return -EMSGSIZE;
2774 }
2775
2776 int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg,
2777                         struct tipc_link *bcl)
2778 {
2779         int err;
2780         void *hdr;
2781         struct nlattr *attrs;
2782         struct nlattr *prop;
2783         u32 bc_mode = tipc_bcast_get_mode(net);
2784         u32 bc_ratio = tipc_bcast_get_broadcast_ratio(net);
2785
2786         if (!bcl)
2787                 return 0;
2788
2789         tipc_bcast_lock(net);
2790
2791         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2792                           NLM_F_MULTI, TIPC_NL_LINK_GET);
2793         if (!hdr) {
2794                 tipc_bcast_unlock(net);
2795                 return -EMSGSIZE;
2796         }
2797
2798         attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2799         if (!attrs)
2800                 goto msg_full;
2801
2802         /* The broadcast link is always up */
2803         if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2804                 goto attr_msg_full;
2805
2806         if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
2807                 goto attr_msg_full;
2808         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
2809                 goto attr_msg_full;
2810         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
2811                 goto attr_msg_full;
2812         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
2813                 goto attr_msg_full;
2814
2815         prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2816         if (!prop)
2817                 goto attr_msg_full;
2818         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->max_win))
2819                 goto prop_msg_full;
2820         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST, bc_mode))
2821                 goto prop_msg_full;
2822         if (bc_mode & BCLINK_MODE_SEL)
2823                 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST_RATIO,
2824                                 bc_ratio))
2825                         goto prop_msg_full;
2826         nla_nest_end(msg->skb, prop);
2827
2828         err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
2829         if (err)
2830                 goto attr_msg_full;
2831
2832         tipc_bcast_unlock(net);
2833         nla_nest_end(msg->skb, attrs);
2834         genlmsg_end(msg->skb, hdr);
2835
2836         return 0;
2837
2838 prop_msg_full:
2839         nla_nest_cancel(msg->skb, prop);
2840 attr_msg_full:
2841         nla_nest_cancel(msg->skb, attrs);
2842 msg_full:
2843         tipc_bcast_unlock(net);
2844         genlmsg_cancel(msg->skb, hdr);
2845
2846         return -EMSGSIZE;
2847 }
2848
2849 void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
2850                              struct sk_buff_head *xmitq)
2851 {
2852         l->tolerance = tol;
2853         if (l->bc_rcvlink)
2854                 l->bc_rcvlink->tolerance = tol;
2855         if (link_is_up(l))
2856                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
2857 }
2858
2859 void tipc_link_set_prio(struct tipc_link *l, u32 prio,
2860                         struct sk_buff_head *xmitq)
2861 {
2862         l->priority = prio;
2863         tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, prio, xmitq);
2864 }
2865
2866 void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
2867 {
2868         l->abort_limit = limit;
2869 }
2870
2871 /**
2872  * tipc_link_dump - dump TIPC link data
2873  * @l: tipc link to be dumped
2874  * @dqueues: bitmask to decide if any link queue to be dumped?
2875  *           - TIPC_DUMP_NONE: don't dump link queues
2876  *           - TIPC_DUMP_TRANSMQ: dump link transmq queue
2877  *           - TIPC_DUMP_BACKLOGQ: dump link backlog queue
2878  *           - TIPC_DUMP_DEFERDQ: dump link deferd queue
2879  *           - TIPC_DUMP_INPUTQ: dump link input queue
2880  *           - TIPC_DUMP_WAKEUP: dump link wakeup queue
2881  *           - TIPC_DUMP_ALL: dump all the link queues above
2882  * @buf: returned buffer of dump data in format
2883  */
2884 int tipc_link_dump(struct tipc_link *l, u16 dqueues, char *buf)
2885 {
2886         int i = 0;
2887         size_t sz = (dqueues) ? LINK_LMAX : LINK_LMIN;
2888         struct sk_buff_head *list;
2889         struct sk_buff *hskb, *tskb;
2890         u32 len;
2891
2892         if (!l) {
2893                 i += scnprintf(buf, sz, "link data: (null)\n");
2894                 return i;
2895         }
2896
2897         i += scnprintf(buf, sz, "link data: %x", l->addr);
2898         i += scnprintf(buf + i, sz - i, " %x", l->state);
2899         i += scnprintf(buf + i, sz - i, " %u", l->in_session);
2900         i += scnprintf(buf + i, sz - i, " %u", l->session);
2901         i += scnprintf(buf + i, sz - i, " %u", l->peer_session);
2902         i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt);
2903         i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt);
2904         i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt_state);
2905         i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt_state);
2906         i += scnprintf(buf + i, sz - i, " %x", l->peer_caps);
2907         i += scnprintf(buf + i, sz - i, " %u", l->silent_intv_cnt);
2908         i += scnprintf(buf + i, sz - i, " %u", l->rst_cnt);
2909         i += scnprintf(buf + i, sz - i, " %u", 0);
2910         i += scnprintf(buf + i, sz - i, " %u", 0);
2911         i += scnprintf(buf + i, sz - i, " %u", l->acked);
2912
2913         list = &l->transmq;
2914         len = skb_queue_len(list);
2915         hskb = skb_peek(list);
2916         tskb = skb_peek_tail(list);
2917         i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2918                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2919                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2920
2921         list = &l->deferdq;
2922         len = skb_queue_len(list);
2923         hskb = skb_peek(list);
2924         tskb = skb_peek_tail(list);
2925         i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2926                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2927                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2928
2929         list = &l->backlogq;
2930         len = skb_queue_len(list);
2931         hskb = skb_peek(list);
2932         tskb = skb_peek_tail(list);
2933         i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2934                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2935                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2936
2937         list = l->inputq;
2938         len = skb_queue_len(list);
2939         hskb = skb_peek(list);
2940         tskb = skb_peek_tail(list);
2941         i += scnprintf(buf + i, sz - i, " | %u %u %u\n", len,
2942                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2943                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2944
2945         if (dqueues & TIPC_DUMP_TRANSMQ) {
2946                 i += scnprintf(buf + i, sz - i, "transmq: ");
2947                 i += tipc_list_dump(&l->transmq, false, buf + i);
2948         }
2949         if (dqueues & TIPC_DUMP_BACKLOGQ) {
2950                 i += scnprintf(buf + i, sz - i,
2951                                "backlogq: <%u %u %u %u %u>, ",
2952                                l->backlog[TIPC_LOW_IMPORTANCE].len,
2953                                l->backlog[TIPC_MEDIUM_IMPORTANCE].len,
2954                                l->backlog[TIPC_HIGH_IMPORTANCE].len,
2955                                l->backlog[TIPC_CRITICAL_IMPORTANCE].len,
2956                                l->backlog[TIPC_SYSTEM_IMPORTANCE].len);
2957                 i += tipc_list_dump(&l->backlogq, false, buf + i);
2958         }
2959         if (dqueues & TIPC_DUMP_DEFERDQ) {
2960                 i += scnprintf(buf + i, sz - i, "deferdq: ");
2961                 i += tipc_list_dump(&l->deferdq, false, buf + i);
2962         }
2963         if (dqueues & TIPC_DUMP_INPUTQ) {
2964                 i += scnprintf(buf + i, sz - i, "inputq: ");
2965                 i += tipc_list_dump(l->inputq, false, buf + i);
2966         }
2967         if (dqueues & TIPC_DUMP_WAKEUP) {
2968                 i += scnprintf(buf + i, sz - i, "wakeup: ");
2969                 i += tipc_list_dump(&l->wakeupq, false, buf + i);
2970         }
2971
2972         return i;
2973 }