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