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