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