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         unsigned int maxwin = l->window;
 943         unsigned int mtu = l->mtu;
 944         u16 ack = l->rcv_nxt - 1;
 945         u16 seqno = l->snd_nxt;
 946         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 947         struct sk_buff_head *transmq = &l->transmq;
 948         struct sk_buff_head *backlogq = &l->backlogq;
 949         struct sk_buff *skb, *_skb, **tskb;
 950         int pkt_cnt = skb_queue_len(list);
 951         struct tipc_msg *hdr;
 952         int rc = 0;
 953         int imp;
 954
 955         if (pkt_cnt <= 0)
 956                 return 0;
 957
 958         hdr = buf_msg(skb_peek(list));
 959         if (unlikely(msg_size(hdr) > mtu)) {
 960                 pr_warn("Too large msg, purging xmit list %d %d %d %d %d!\n",
 961                         skb_queue_len(list), msg_user(hdr),
 962                         msg_type(hdr), msg_size(hdr), mtu);
 963                 __skb_queue_purge(list);
 964                 return -EMSGSIZE;
 965         }
 966
 967         imp = msg_importance(hdr);
 968         /* Allow oversubscription of one data msg per source at congestion */
 969         if (unlikely(l->backlog[imp].len >= l->backlog[imp].limit)) {
 970                 if (imp == TIPC_SYSTEM_IMPORTANCE) {
 971                         pr_warn("%s<%s>, link overflow", link_rst_msg, l->name);
 972                         return -ENOBUFS;
 973                 }
 974                 rc = link_schedule_user(l, hdr);
 975         }
 976
 977         if (pkt_cnt > 1) {
 978                 l->stats.sent_fragmented++;
 979                 l->stats.sent_fragments += pkt_cnt;
 980         }
 981
 982         /* Prepare each packet for sending, and add to relevant queue: */
 983         while (skb_queue_len(list)) {
 984                 skb = skb_peek(list);
 985                 hdr = buf_msg(skb);
 986                 msg_set_seqno(hdr, seqno);
 987                 msg_set_ack(hdr, ack);
 988                 msg_set_bcast_ack(hdr, bc_ack);
 989
 990                 if (likely(skb_queue_len(transmq) < maxwin)) {
 991                         _skb = skb_clone(skb, GFP_ATOMIC);
 992                         if (!_skb) {
 993                                 __skb_queue_purge(list);
 994                                 return -ENOBUFS;
 995                         }
 996                         __skb_dequeue(list);
 997                         __skb_queue_tail(transmq, skb);
 998                         /* next retransmit attempt */
 999                         if (link_is_bc_sndlink(l))
1000                                 TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
1001                         __skb_queue_tail(xmitq, _skb);
1002                         TIPC_SKB_CB(skb)->ackers = l->ackers;
1003                         l->rcv_unacked = 0;
1004                         l->stats.sent_pkts++;
1005                         seqno++;
1006                         continue;
1007                 }
1008                 tskb = &l->backlog[imp].target_bskb;
1009                 if (tipc_msg_bundle(*tskb, hdr, mtu)) {
1010                         kfree_skb(__skb_dequeue(list));
1011                         l->stats.sent_bundled++;
1012                         continue;
1013                 }
1014                 if (tipc_msg_make_bundle(tskb, hdr, mtu, l->addr)) {
1015                         kfree_skb(__skb_dequeue(list));
1016                         __skb_queue_tail(backlogq, *tskb);
1017                         l->backlog[imp].len++;
1018                         l->stats.sent_bundled++;
1019                         l->stats.sent_bundles++;
1020                         continue;
1021                 }
1022                 l->backlog[imp].target_bskb = NULL;
1023                 l->backlog[imp].len += skb_queue_len(list);
1024                 skb_queue_splice_tail_init(list, backlogq);
1025         }
1026         l->snd_nxt = seqno;
1027         return rc;
1028 }
1029
1030 static void tipc_link_advance_backlog(struct tipc_link *l,
1031                                       struct sk_buff_head *xmitq)
1032 {
1033         struct sk_buff *skb, *_skb;
1034         struct tipc_msg *hdr;
1035         u16 seqno = l->snd_nxt;
1036         u16 ack = l->rcv_nxt - 1;
1037         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1038         u32 imp;
1039
1040         while (skb_queue_len(&l->transmq) < l->window) {
1041                 skb = skb_peek(&l->backlogq);
1042                 if (!skb)
1043                         break;
1044                 _skb = skb_clone(skb, GFP_ATOMIC);
1045                 if (!_skb)
1046                         break;
1047                 __skb_dequeue(&l->backlogq);
1048                 hdr = buf_msg(skb);
1049                 imp = msg_importance(hdr);
1050                 l->backlog[imp].len--;
1051                 if (unlikely(skb == l->backlog[imp].target_bskb))
1052                         l->backlog[imp].target_bskb = NULL;
1053                 __skb_queue_tail(&l->transmq, skb);
1054                 /* next retransmit attempt */
1055                 if (link_is_bc_sndlink(l))
1056                         TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
1057
1058                 __skb_queue_tail(xmitq, _skb);
1059                 TIPC_SKB_CB(skb)->ackers = l->ackers;
1060                 msg_set_seqno(hdr, seqno);
1061                 msg_set_ack(hdr, ack);
1062                 msg_set_bcast_ack(hdr, bc_ack);
1063                 l->rcv_unacked = 0;
1064                 l->stats.sent_pkts++;
1065                 seqno++;
1066         }
1067         l->snd_nxt = seqno;
1068 }
1069
1070 /**
1071  * link_retransmit_failure() - Detect repeated retransmit failures
1072  * @l: tipc link sender
1073  * @r: tipc link receiver (= l in case of unicast)
1074  * @rc: returned code
1075  *
1076  * Return: true if the repeated retransmit failures happens, otherwise
1077  * false
1078  */
1079 static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r,
1080                                     int *rc)
1081 {
1082         struct sk_buff *skb = skb_peek(&l->transmq);
1083         struct tipc_msg *hdr;
1084
1085         if (!skb)
1086                 return false;
1087
1088         if (!TIPC_SKB_CB(skb)->retr_cnt)
1089                 return false;
1090
1091         if (!time_after(jiffies, TIPC_SKB_CB(skb)->retr_stamp +
1092                         msecs_to_jiffies(r->tolerance * 10)))
1093                 return false;
1094
1095         hdr = buf_msg(skb);
1096         if (link_is_bc_sndlink(l) && !less(r->acked, msg_seqno(hdr)))
1097                 return false;
1098
1099         pr_warn("Retransmission failure on link <%s>\n", l->name);
1100         link_print(l, "State of link ");
1101         pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
1102                 msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
1103         pr_info("sqno %u, prev: %x, dest: %x\n",
1104                 msg_seqno(hdr), msg_prevnode(hdr), msg_destnode(hdr));
1105         pr_info("retr_stamp %d, retr_cnt %d\n",
1106                 jiffies_to_msecs(TIPC_SKB_CB(skb)->retr_stamp),
1107                 TIPC_SKB_CB(skb)->retr_cnt);
1108
1109         trace_tipc_list_dump(&l->transmq, true, "retrans failure!");
1110         trace_tipc_link_dump(l, TIPC_DUMP_NONE, "retrans failure!");
1111         trace_tipc_link_dump(r, TIPC_DUMP_NONE, "retrans failure!");
1112
1113         if (link_is_bc_sndlink(l)) {
1114                 r->state = LINK_RESET;
1115                 *rc = TIPC_LINK_DOWN_EVT;
1116         } else {
1117                 *rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1118         }
1119
1120         return true;
1121 }
1122
1123 /* tipc_link_bc_retrans() - retransmit zero or more packets
1124  * @l: the link to transmit on
1125  * @r: the receiving link ordering the retransmit. Same as l if unicast
1126  * @from: retransmit from (inclusive) this sequence number
1127  * @to: retransmit to (inclusive) this sequence number
1128  * xmitq: queue for accumulating the retransmitted packets
1129  */
1130 static int tipc_link_bc_retrans(struct tipc_link *l, struct tipc_link *r,
1131                                 u16 from, u16 to, struct sk_buff_head *xmitq)
1132 {
1133         struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
1134         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1135         u16 ack = l->rcv_nxt - 1;
1136         struct tipc_msg *hdr;
1137         int rc = 0;
1138
1139         if (!skb)
1140                 return 0;
1141         if (less(to, from))
1142                 return 0;
1143
1144         trace_tipc_link_retrans(r, from, to, &l->transmq);
1145
1146         if (link_retransmit_failure(l, r, &rc))
1147                 return rc;
1148
1149         skb_queue_walk(&l->transmq, skb) {
1150                 hdr = buf_msg(skb);
1151                 if (less(msg_seqno(hdr), from))
1152                         continue;
1153                 if (more(msg_seqno(hdr), to))
1154                         break;
1155
1156                 if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
1157                         continue;
1158                 TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
1159                 _skb = __pskb_copy(skb, LL_MAX_HEADER + MIN_H_SIZE, GFP_ATOMIC);
1160                 if (!_skb)
1161                         return 0;
1162                 hdr = buf_msg(_skb);
1163                 msg_set_ack(hdr, ack);
1164                 msg_set_bcast_ack(hdr, bc_ack);
1165                 _skb->priority = TC_PRIO_CONTROL;
1166                 __skb_queue_tail(xmitq, _skb);
1167                 l->stats.retransmitted++;
1168
1169                 /* Increase actual retrans counter & mark first time */
1170                 if (!TIPC_SKB_CB(skb)->retr_cnt++)
1171                         TIPC_SKB_CB(skb)->retr_stamp = jiffies;
1172         }
1173         return 0;
1174 }
1175
1176 /* tipc_data_input - deliver data and name distr msgs to upper layer
1177  *
1178  * Consumes buffer if message is of right type
1179  * Node lock must be held
1180  */
1181 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1182                             struct sk_buff_head *inputq)
1183 {
1184         struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq;
1185         struct tipc_msg *hdr = buf_msg(skb);
1186
1187         switch (msg_user(hdr)) {
1188         case TIPC_LOW_IMPORTANCE:
1189         case TIPC_MEDIUM_IMPORTANCE:
1190         case TIPC_HIGH_IMPORTANCE:
1191         case TIPC_CRITICAL_IMPORTANCE:
1192                 if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) {
1193                         skb_queue_tail(mc_inputq, skb);
1194                         return true;
1195                 }
1196                 /* fall through */
1197         case CONN_MANAGER:
1198                 skb_queue_tail(inputq, skb);
1199                 return true;
1200         case GROUP_PROTOCOL:
1201                 skb_queue_tail(mc_inputq, skb);
1202                 return true;
1203         case NAME_DISTRIBUTOR:
1204                 l->bc_rcvlink->state = LINK_ESTABLISHED;
1205                 skb_queue_tail(l->namedq, skb);
1206                 return true;
1207         case MSG_BUNDLER:
1208         case TUNNEL_PROTOCOL:
1209         case MSG_FRAGMENTER:
1210         case BCAST_PROTOCOL:
1211                 return false;
1212         default:
1213                 pr_warn("Dropping received illegal msg type\n");
1214                 kfree_skb(skb);
1215                 return true;
1216         };
1217 }
1218
1219 /* tipc_link_input - process packet that has passed link protocol check
1220  *
1221  * Consumes buffer
1222  */
1223 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1224                            struct sk_buff_head *inputq,
1225                            struct sk_buff **reasm_skb)
1226 {
1227         struct tipc_msg *hdr = buf_msg(skb);
1228         struct sk_buff *iskb;
1229         struct sk_buff_head tmpq;
1230         int usr = msg_user(hdr);
1231         int pos = 0;
1232
1233         if (usr == MSG_BUNDLER) {
1234                 skb_queue_head_init(&tmpq);
1235                 l->stats.recv_bundles++;
1236                 l->stats.recv_bundled += msg_msgcnt(hdr);
1237                 while (tipc_msg_extract(skb, &iskb, &pos))
1238                         tipc_data_input(l, iskb, &tmpq);
1239                 tipc_skb_queue_splice_tail(&tmpq, inputq);
1240                 return 0;
1241         } else if (usr == MSG_FRAGMENTER) {
1242                 l->stats.recv_fragments++;
1243                 if (tipc_buf_append(reasm_skb, &skb)) {
1244                         l->stats.recv_fragmented++;
1245                         tipc_data_input(l, skb, inputq);
1246                 } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1247                         pr_warn_ratelimited("Unable to build fragment list\n");
1248                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1249                 }
1250                 return 0;
1251         } else if (usr == BCAST_PROTOCOL) {
1252                 tipc_bcast_lock(l->net);
1253                 tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1254                 tipc_bcast_unlock(l->net);
1255         }
1256
1257         kfree_skb(skb);
1258         return 0;
1259 }
1260
1261 /* tipc_link_tnl_rcv() - receive TUNNEL_PROTOCOL message, drop or process the
1262  *                       inner message along with the ones in the old link's
1263  *                       deferdq
1264  * @l: tunnel link
1265  * @skb: TUNNEL_PROTOCOL message
1266  * @inputq: queue to put messages ready for delivery
1267  */
1268 static int tipc_link_tnl_rcv(struct tipc_link *l, struct sk_buff *skb,
1269                              struct sk_buff_head *inputq)
1270 {
1271         struct sk_buff **reasm_skb = &l->failover_reasm_skb;
1272         struct sk_buff **reasm_tnlmsg = &l->reasm_tnlmsg;
1273         struct sk_buff_head *fdefq = &l->failover_deferdq;
1274         struct tipc_msg *hdr = buf_msg(skb);
1275         struct sk_buff *iskb;
1276         int ipos = 0;
1277         int rc = 0;
1278         u16 seqno;
1279
1280         if (msg_type(hdr) == SYNCH_MSG) {
1281                 kfree_skb(skb);
1282                 return 0;
1283         }
1284
1285         /* Not a fragment? */
1286         if (likely(!msg_nof_fragms(hdr))) {
1287                 if (unlikely(!tipc_msg_extract(skb, &iskb, &ipos))) {
1288                         pr_warn_ratelimited("Unable to extract msg, defq: %d\n",
1289                                             skb_queue_len(fdefq));
1290                         return 0;
1291                 }
1292                 kfree_skb(skb);
1293         } else {
1294                 /* Set fragment type for buf_append */
1295                 if (msg_fragm_no(hdr) == 1)
1296                         msg_set_type(hdr, FIRST_FRAGMENT);
1297                 else if (msg_fragm_no(hdr) < msg_nof_fragms(hdr))
1298                         msg_set_type(hdr, FRAGMENT);
1299                 else
1300                         msg_set_type(hdr, LAST_FRAGMENT);
1301
1302                 if (!tipc_buf_append(reasm_tnlmsg, &skb)) {
1303                         /* Successful but non-complete reassembly? */
1304                         if (*reasm_tnlmsg || link_is_bc_rcvlink(l))
1305                                 return 0;
1306                         pr_warn_ratelimited("Unable to reassemble tunnel msg\n");
1307                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1308                 }
1309                 iskb = skb;
1310         }
1311
1312         do {
1313                 seqno = buf_seqno(iskb);
1314                 if (unlikely(less(seqno, l->drop_point))) {
1315                         kfree_skb(iskb);
1316                         continue;
1317                 }
1318                 if (unlikely(seqno != l->drop_point)) {
1319                         __tipc_skb_queue_sorted(fdefq, seqno, iskb);
1320                         continue;
1321                 }
1322
1323                 l->drop_point++;
1324                 if (!tipc_data_input(l, iskb, inputq))
1325                         rc |= tipc_link_input(l, iskb, inputq, reasm_skb);
1326                 if (unlikely(rc))
1327                         break;
1328         } while ((iskb = __tipc_skb_dequeue(fdefq, l->drop_point)));
1329
1330         return rc;
1331 }
1332
1333 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1334 {
1335         bool released = false;
1336         struct sk_buff *skb, *tmp;
1337
1338         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1339                 if (more(buf_seqno(skb), acked))
1340                         break;
1341                 __skb_unlink(skb, &l->transmq);
1342                 kfree_skb(skb);
1343                 released = true;
1344         }
1345         return released;
1346 }
1347
1348 /* tipc_build_gap_ack_blks - build Gap ACK blocks
1349  * @l: tipc link that data have come with gaps in sequence if any
1350  * @data: data buffer to store the Gap ACK blocks after built
1351  *
1352  * returns the actual allocated memory size
1353  */
1354 static u16 tipc_build_gap_ack_blks(struct tipc_link *l, void *data)
1355 {
1356         struct sk_buff *skb = skb_peek(&l->deferdq);
1357         struct tipc_gap_ack_blks *ga = data;
1358         u16 len, expect, seqno = 0;
1359         u8 n = 0;
1360
1361         if (!skb)
1362                 goto exit;
1363
1364         expect = buf_seqno(skb);
1365         skb_queue_walk(&l->deferdq, skb) {
1366                 seqno = buf_seqno(skb);
1367                 if (unlikely(more(seqno, expect))) {
1368                         ga->gacks[n].ack = htons(expect - 1);
1369                         ga->gacks[n].gap = htons(seqno - expect);
1370                         if (++n >= MAX_GAP_ACK_BLKS) {
1371                                 pr_info_ratelimited("Too few Gap ACK blocks!\n");
1372                                 goto exit;
1373                         }
1374                 } else if (unlikely(less(seqno, expect))) {
1375                         pr_warn("Unexpected skb in deferdq!\n");
1376                         continue;
1377                 }
1378                 expect = seqno + 1;
1379         }
1380
1381         /* last block */
1382         ga->gacks[n].ack = htons(seqno);
1383         ga->gacks[n].gap = 0;
1384         n++;
1385
1386 exit:
1387         len = tipc_gap_ack_blks_sz(n);
1388         ga->len = htons(len);
1389         ga->gack_cnt = n;
1390         return len;
1391 }
1392
1393 /* tipc_link_advance_transmq - advance TIPC link transmq queue by releasing
1394  *                             acked packets, also doing retransmissions if
1395  *                             gaps found
1396  * @l: tipc link with transmq queue to be advanced
1397  * @acked: seqno of last packet acked by peer without any gaps before
1398  * @gap: # of gap packets
1399  * @ga: buffer pointer to Gap ACK blocks from peer
1400  * @xmitq: queue for accumulating the retransmitted packets if any
1401  *
1402  * In case of a repeated retransmit failures, the call will return shortly
1403  * with a returned code (e.g. TIPC_LINK_DOWN_EVT)
1404  */
1405 static int tipc_link_advance_transmq(struct tipc_link *l, u16 acked, u16 gap,
1406                                      struct tipc_gap_ack_blks *ga,
1407                                      struct sk_buff_head *xmitq)
1408 {
1409         struct sk_buff *skb, *_skb, *tmp;
1410         struct tipc_msg *hdr;
1411         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1412         u16 ack = l->rcv_nxt - 1;
1413         bool passed = false;
1414         u16 seqno, n = 0;
1415         int rc = 0;
1416
1417         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1418                 seqno = buf_seqno(skb);
1419
1420 next_gap_ack:
1421                 if (less_eq(seqno, acked)) {
1422                         /* release skb */
1423                         __skb_unlink(skb, &l->transmq);
1424                         kfree_skb(skb);
1425                 } else if (less_eq(seqno, acked + gap)) {
1426                         /* First, check if repeated retrans failures occurs? */
1427                         if (!passed && link_retransmit_failure(l, l, &rc))
1428                                 return rc;
1429                         passed = true;
1430
1431                         /* retransmit skb if unrestricted*/
1432                         if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
1433                                 continue;
1434                         TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
1435                         _skb = __pskb_copy(skb, LL_MAX_HEADER + MIN_H_SIZE,
1436                                            GFP_ATOMIC);
1437                         if (!_skb)
1438                                 continue;
1439                         hdr = buf_msg(_skb);
1440                         msg_set_ack(hdr, ack);
1441                         msg_set_bcast_ack(hdr, bc_ack);
1442                         _skb->priority = TC_PRIO_CONTROL;
1443                         __skb_queue_tail(xmitq, _skb);
1444                         l->stats.retransmitted++;
1445
1446                         /* Increase actual retrans counter & mark first time */
1447                         if (!TIPC_SKB_CB(skb)->retr_cnt++)
1448                                 TIPC_SKB_CB(skb)->retr_stamp = jiffies;
1449                 } else {
1450                         /* retry with Gap ACK blocks if any */
1451                         if (!ga || n >= ga->gack_cnt)
1452                                 break;
1453                         acked = ntohs(ga->gacks[n].ack);
1454                         gap = ntohs(ga->gacks[n].gap);
1455                         n++;
1456                         goto next_gap_ack;
1457                 }
1458         }
1459
1460         return 0;
1461 }
1462
1463 /* tipc_link_build_state_msg: prepare link state message for transmission
1464  *
1465  * Note that sending of broadcast ack is coordinated among nodes, to reduce
1466  * risk of ack storms towards the sender
1467  */
1468 int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1469 {
1470         if (!l)
1471                 return 0;
1472
1473         /* Broadcast ACK must be sent via a unicast link => defer to caller */
1474         if (link_is_bc_rcvlink(l)) {
1475                 if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1476                         return 0;
1477                 l->rcv_unacked = 0;
1478
1479                 /* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
1480                 l->snd_nxt = l->rcv_nxt;
1481                 return TIPC_LINK_SND_STATE;
1482         }
1483
1484         /* Unicast ACK */
1485         l->rcv_unacked = 0;
1486         l->stats.sent_acks++;
1487         tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
1488         return 0;
1489 }
1490
1491 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1492  */
1493 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1494 {
1495         int mtyp = RESET_MSG;
1496         struct sk_buff *skb;
1497
1498         if (l->state == LINK_ESTABLISHING)
1499                 mtyp = ACTIVATE_MSG;
1500
1501         tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, 0, xmitq);
1502
1503         /* Inform peer that this endpoint is going down if applicable */
1504         skb = skb_peek_tail(xmitq);
1505         if (skb && (l->state == LINK_RESET))
1506                 msg_set_peer_stopping(buf_msg(skb), 1);
1507 }
1508
1509 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1510  * Note that sending of broadcast NACK is coordinated among nodes, to
1511  * reduce the risk of NACK storms towards the sender
1512  */
1513 static int tipc_link_build_nack_msg(struct tipc_link *l,
1514                                     struct sk_buff_head *xmitq)
1515 {
1516         u32 def_cnt = ++l->stats.deferred_recv;
1517         u32 defq_len = skb_queue_len(&l->deferdq);
1518         int match1, match2;
1519
1520         if (link_is_bc_rcvlink(l)) {
1521                 match1 = def_cnt & 0xf;
1522                 match2 = tipc_own_addr(l->net) & 0xf;
1523                 if (match1 == match2)
1524                         return TIPC_LINK_SND_STATE;
1525                 return 0;
1526         }
1527
1528         if (defq_len >= 3 && !((defq_len - 3) % 16))
1529                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
1530         return 0;
1531 }
1532
1533 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1534  * @l: the link that should handle the message
1535  * @skb: TIPC packet
1536  * @xmitq: queue to place packets to be sent after this call
1537  */
1538 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1539                   struct sk_buff_head *xmitq)
1540 {
1541         struct sk_buff_head *defq = &l->deferdq;
1542         struct tipc_msg *hdr = buf_msg(skb);
1543         u16 seqno, rcv_nxt, win_lim;
1544         int rc = 0;
1545
1546         /* Verify and update link state */
1547         if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1548                 return tipc_link_proto_rcv(l, skb, xmitq);
1549
1550         /* Don't send probe at next timeout expiration */
1551         l->silent_intv_cnt = 0;
1552
1553         do {
1554                 hdr = buf_msg(skb);
1555                 seqno = msg_seqno(hdr);
1556                 rcv_nxt = l->rcv_nxt;
1557                 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1558
1559                 if (unlikely(!link_is_up(l))) {
1560                         if (l->state == LINK_ESTABLISHING)
1561                                 rc = TIPC_LINK_UP_EVT;
1562                         goto drop;
1563                 }
1564
1565                 /* Drop if outside receive window */
1566                 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1567                         l->stats.duplicates++;
1568                         goto drop;
1569                 }
1570
1571                 /* Forward queues and wake up waiting users */
1572                 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1573                         tipc_link_advance_backlog(l, xmitq);
1574                         if (unlikely(!skb_queue_empty(&l->wakeupq)))
1575                                 link_prepare_wakeup(l);
1576                 }
1577
1578                 /* Defer delivery if sequence gap */
1579                 if (unlikely(seqno != rcv_nxt)) {
1580                         __tipc_skb_queue_sorted(defq, seqno, skb);
1581                         rc |= tipc_link_build_nack_msg(l, xmitq);
1582                         break;
1583                 }
1584
1585                 /* Deliver packet */
1586                 l->rcv_nxt++;
1587                 l->stats.recv_pkts++;
1588
1589                 if (unlikely(msg_user(hdr) == TUNNEL_PROTOCOL))
1590                         rc |= tipc_link_tnl_rcv(l, skb, l->inputq);
1591                 else if (!tipc_data_input(l, skb, l->inputq))
1592                         rc |= tipc_link_input(l, skb, l->inputq, &l->reasm_buf);
1593                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1594                         rc |= tipc_link_build_state_msg(l, xmitq);
1595                 if (unlikely(rc & ~TIPC_LINK_SND_STATE))
1596                         break;
1597         } while ((skb = __tipc_skb_dequeue(defq, l->rcv_nxt)));
1598
1599         return rc;
1600 drop:
1601         kfree_skb(skb);
1602         return rc;
1603 }
1604
1605 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1606                                       bool probe_reply, u16 rcvgap,
1607                                       int tolerance, int priority,
1608                                       struct sk_buff_head *xmitq)
1609 {
1610         struct tipc_link *bcl = l->bc_rcvlink;
1611         struct sk_buff *skb;
1612         struct tipc_msg *hdr;
1613         struct sk_buff_head *dfq = &l->deferdq;
1614         bool node_up = link_is_up(bcl);
1615         struct tipc_mon_state *mstate = &l->mon_state;
1616         int dlen = 0;
1617         void *data;
1618         u16 glen = 0;
1619
1620         /* Don't send protocol message during reset or link failover */
1621         if (tipc_link_is_blocked(l))
1622                 return;
1623
1624         if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1625                 return;
1626
1627         if (!skb_queue_empty(dfq))
1628                 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1629
1630         skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1631                               tipc_max_domain_size + MAX_GAP_ACK_BLKS_SZ,
1632                               l->addr, tipc_own_addr(l->net), 0, 0, 0);
1633         if (!skb)
1634                 return;
1635
1636         hdr = buf_msg(skb);
1637         data = msg_data(hdr);
1638         msg_set_session(hdr, l->session);
1639         msg_set_bearer_id(hdr, l->bearer_id);
1640         msg_set_net_plane(hdr, l->net_plane);
1641         msg_set_next_sent(hdr, l->snd_nxt);
1642         msg_set_ack(hdr, l->rcv_nxt - 1);
1643         msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1644         msg_set_bc_ack_invalid(hdr, !node_up);
1645         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1646         msg_set_link_tolerance(hdr, tolerance);
1647         msg_set_linkprio(hdr, priority);
1648         msg_set_redundant_link(hdr, node_up);
1649         msg_set_seq_gap(hdr, 0);
1650         msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1651
1652         if (mtyp == STATE_MSG) {
1653                 if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
1654                         msg_set_seqno(hdr, l->snd_nxt_state++);
1655                 msg_set_seq_gap(hdr, rcvgap);
1656                 msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
1657                 msg_set_probe(hdr, probe);
1658                 msg_set_is_keepalive(hdr, probe || probe_reply);
1659                 if (l->peer_caps & TIPC_GAP_ACK_BLOCK)
1660                         glen = tipc_build_gap_ack_blks(l, data);
1661                 tipc_mon_prep(l->net, data + glen, &dlen, mstate, l->bearer_id);
1662                 msg_set_size(hdr, INT_H_SIZE + glen + dlen);
1663                 skb_trim(skb, INT_H_SIZE + glen + dlen);
1664                 l->stats.sent_states++;
1665                 l->rcv_unacked = 0;
1666         } else {
1667                 /* RESET_MSG or ACTIVATE_MSG */
1668                 if (mtyp == ACTIVATE_MSG) {
1669                         msg_set_dest_session_valid(hdr, 1);
1670                         msg_set_dest_session(hdr, l->peer_session);
1671                 }
1672                 msg_set_max_pkt(hdr, l->advertised_mtu);
1673                 strcpy(data, l->if_name);
1674                 msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
1675                 skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
1676         }
1677         if (probe)
1678                 l->stats.sent_probes++;
1679         if (rcvgap)
1680                 l->stats.sent_nacks++;
1681         skb->priority = TC_PRIO_CONTROL;
1682         __skb_queue_tail(xmitq, skb);
1683         trace_tipc_proto_build(skb, false, l->name);
1684 }
1685
1686 void tipc_link_create_dummy_tnl_msg(struct tipc_link *l,
1687                                     struct sk_buff_head *xmitq)
1688 {
1689         u32 onode = tipc_own_addr(l->net);
1690         struct tipc_msg *hdr, *ihdr;
1691         struct sk_buff_head tnlq;
1692         struct sk_buff *skb;
1693         u32 dnode = l->addr;
1694
1695         __skb_queue_head_init(&tnlq);
1696         skb = tipc_msg_create(TUNNEL_PROTOCOL, FAILOVER_MSG,
1697                               INT_H_SIZE, BASIC_H_SIZE,
1698                               dnode, onode, 0, 0, 0);
1699         if (!skb) {
1700                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1701                 return;
1702         }
1703
1704         hdr = buf_msg(skb);
1705         msg_set_msgcnt(hdr, 1);
1706         msg_set_bearer_id(hdr, l->peer_bearer_id);
1707
1708         ihdr = (struct tipc_msg *)msg_data(hdr);
1709         tipc_msg_init(onode, ihdr, TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1710                       BASIC_H_SIZE, dnode);
1711         msg_set_errcode(ihdr, TIPC_ERR_NO_PORT);
1712         __skb_queue_tail(&tnlq, skb);
1713         tipc_link_xmit(l, &tnlq, xmitq);
1714 }
1715
1716 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1717  * with contents of the link's transmit and backlog queues.
1718  */
1719 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1720                            int mtyp, struct sk_buff_head *xmitq)
1721 {
1722         struct sk_buff_head *fdefq = &tnl->failover_deferdq;
1723         struct sk_buff *skb, *tnlskb;
1724         struct tipc_msg *hdr, tnlhdr;
1725         struct sk_buff_head *queue = &l->transmq;
1726         struct sk_buff_head tmpxq, tnlq, frags;
1727         u16 pktlen, pktcnt, seqno = l->snd_nxt;
1728         bool pktcnt_need_update = false;
1729         u16 syncpt;
1730         int rc;
1731
1732         if (!tnl)
1733                 return;
1734
1735         __skb_queue_head_init(&tnlq);
1736         __skb_queue_head_init(&tmpxq);
1737         __skb_queue_head_init(&frags);
1738
1739         /* At least one packet required for safe algorithm => add dummy */
1740         skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1741                               BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
1742                               0, 0, TIPC_ERR_NO_PORT);
1743         if (!skb) {
1744                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1745                 return;
1746         }
1747         __skb_queue_tail(&tnlq, skb);
1748         tipc_link_xmit(l, &tnlq, &tmpxq);
1749         __skb_queue_purge(&tmpxq);
1750
1751         /* Link Synching:
1752          * From now on, send only one single ("dummy") SYNCH message
1753          * to peer. The SYNCH message does not contain any data, just
1754          * a header conveying the synch point to the peer.
1755          */
1756         if (mtyp == SYNCH_MSG && (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
1757                 tnlskb = tipc_msg_create(TUNNEL_PROTOCOL, SYNCH_MSG,
1758                                          INT_H_SIZE, 0, l->addr,
1759                                          tipc_own_addr(l->net),
1760                                          0, 0, 0);
1761                 if (!tnlskb) {
1762                         pr_warn("%sunable to create dummy SYNCH_MSG\n",
1763                                 link_co_err);
1764                         return;
1765                 }
1766
1767                 hdr = buf_msg(tnlskb);
1768                 syncpt = l->snd_nxt + skb_queue_len(&l->backlogq) - 1;
1769                 msg_set_syncpt(hdr, syncpt);
1770                 msg_set_bearer_id(hdr, l->peer_bearer_id);
1771                 __skb_queue_tail(&tnlq, tnlskb);
1772                 tipc_link_xmit(tnl, &tnlq, xmitq);
1773                 return;
1774         }
1775
1776         /* Initialize reusable tunnel packet header */
1777         tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
1778                       mtyp, INT_H_SIZE, l->addr);
1779         if (mtyp == SYNCH_MSG)
1780                 pktcnt = l->snd_nxt - buf_seqno(skb_peek(&l->transmq));
1781         else
1782                 pktcnt = skb_queue_len(&l->transmq);
1783         pktcnt += skb_queue_len(&l->backlogq);
1784         msg_set_msgcnt(&tnlhdr, pktcnt);
1785         msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1786 tnl:
1787         /* Wrap each packet into a tunnel packet */
1788         skb_queue_walk(queue, skb) {
1789                 hdr = buf_msg(skb);
1790                 if (queue == &l->backlogq)
1791                         msg_set_seqno(hdr, seqno++);
1792                 pktlen = msg_size(hdr);
1793
1794                 /* Tunnel link MTU is not large enough? This could be
1795                  * due to:
1796                  * 1) Link MTU has just changed or set differently;
1797                  * 2) Or FAILOVER on the top of a SYNCH message
1798                  *
1799                  * The 2nd case should not happen if peer supports
1800                  * TIPC_TUNNEL_ENHANCED
1801                  */
1802                 if (pktlen > tnl->mtu - INT_H_SIZE) {
1803                         if (mtyp == FAILOVER_MSG &&
1804                             (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
1805                                 rc = tipc_msg_fragment(skb, &tnlhdr, tnl->mtu,
1806                                                        &frags);
1807                                 if (rc) {
1808                                         pr_warn("%sunable to frag msg: rc %d\n",
1809                                                 link_co_err, rc);
1810                                         return;
1811                                 }
1812                                 pktcnt += skb_queue_len(&frags) - 1;
1813                                 pktcnt_need_update = true;
1814                                 skb_queue_splice_tail_init(&frags, &tnlq);
1815                                 continue;
1816                         }
1817                         /* Unluckily, peer doesn't have TIPC_TUNNEL_ENHANCED
1818                          * => Just warn it and return!
1819                          */
1820                         pr_warn_ratelimited("%stoo large msg <%d, %d>: %d!\n",
1821                                             link_co_err, msg_user(hdr),
1822                                             msg_type(hdr), msg_size(hdr));
1823                         return;
1824                 }
1825
1826                 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1827                 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
1828                 if (!tnlskb) {
1829                         pr_warn("%sunable to send packet\n", link_co_err);
1830                         return;
1831                 }
1832                 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1833                 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1834                 __skb_queue_tail(&tnlq, tnlskb);
1835         }
1836         if (queue != &l->backlogq) {
1837                 queue = &l->backlogq;
1838                 goto tnl;
1839         }
1840
1841         if (pktcnt_need_update)
1842                 skb_queue_walk(&tnlq, skb) {
1843                         hdr = buf_msg(skb);
1844                         msg_set_msgcnt(hdr, pktcnt);
1845                 }
1846
1847         tipc_link_xmit(tnl, &tnlq, xmitq);
1848
1849         if (mtyp == FAILOVER_MSG) {
1850                 tnl->drop_point = l->rcv_nxt;
1851                 tnl->failover_reasm_skb = l->reasm_buf;
1852                 l->reasm_buf = NULL;
1853
1854                 /* Failover the link's deferdq */
1855                 if (unlikely(!skb_queue_empty(fdefq))) {
1856                         pr_warn("Link failover deferdq not empty: %d!\n",
1857                                 skb_queue_len(fdefq));
1858                         __skb_queue_purge(fdefq);
1859                 }
1860                 skb_queue_splice_init(&l->deferdq, fdefq);
1861         }
1862 }
1863
1864 /**
1865  * tipc_link_failover_prepare() - prepare tnl for link failover
1866  *
1867  * This is a special version of the precursor - tipc_link_tnl_prepare(),
1868  * see the tipc_node_link_failover() for details
1869  *
1870  * @l: failover link
1871  * @tnl: tunnel link
1872  * @xmitq: queue for messages to be xmited
1873  */
1874 void tipc_link_failover_prepare(struct tipc_link *l, struct tipc_link *tnl,
1875                                 struct sk_buff_head *xmitq)
1876 {
1877         struct sk_buff_head *fdefq = &tnl->failover_deferdq;
1878
1879         tipc_link_create_dummy_tnl_msg(tnl, xmitq);
1880
1881         /* This failover link enpoint was never established before,
1882          * so it has not received anything from peer.
1883          * Otherwise, it must be a normal failover situation or the
1884          * node has entered SELF_DOWN_PEER_LEAVING and both peer nodes
1885          * would have to start over from scratch instead.
1886          */
1887         tnl->drop_point = 1;
1888         tnl->failover_reasm_skb = NULL;
1889
1890         /* Initiate the link's failover deferdq */
1891         if (unlikely(!skb_queue_empty(fdefq))) {
1892                 pr_warn("Link failover deferdq not empty: %d!\n",
1893                         skb_queue_len(fdefq));
1894                 __skb_queue_purge(fdefq);
1895         }
1896 }
1897
1898 /* tipc_link_validate_msg(): validate message against current link state
1899  * Returns true if message should be accepted, otherwise false
1900  */
1901 bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr)
1902 {
1903         u16 curr_session = l->peer_session;
1904         u16 session = msg_session(hdr);
1905         int mtyp = msg_type(hdr);
1906
1907         if (msg_user(hdr) != LINK_PROTOCOL)
1908                 return true;
1909
1910         switch (mtyp) {
1911         case RESET_MSG:
1912                 if (!l->in_session)
1913                         return true;
1914                 /* Accept only RESET with new session number */
1915                 return more(session, curr_session);
1916         case ACTIVATE_MSG:
1917                 if (!l->in_session)
1918                         return true;
1919                 /* Accept only ACTIVATE with new or current session number */
1920                 return !less(session, curr_session);
1921         case STATE_MSG:
1922                 /* Accept only STATE with current session number */
1923                 if (!l->in_session)
1924                         return false;
1925                 if (session != curr_session)
1926                         return false;
1927                 /* Extra sanity check */
1928                 if (!link_is_up(l) && msg_ack(hdr))
1929                         return false;
1930                 if (!(l->peer_caps & TIPC_LINK_PROTO_SEQNO))
1931                         return true;
1932                 /* Accept only STATE with new sequence number */
1933                 return !less(msg_seqno(hdr), l->rcv_nxt_state);
1934         default:
1935                 return false;
1936         }
1937 }
1938
1939 /* tipc_link_proto_rcv(): receive link level protocol message :
1940  * Note that network plane id propagates through the network, and may
1941  * change at any time. The node with lowest numerical id determines
1942  * network plane
1943  */
1944 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1945                                struct sk_buff_head *xmitq)
1946 {
1947         struct tipc_msg *hdr = buf_msg(skb);
1948         struct tipc_gap_ack_blks *ga = NULL;
1949         u16 rcvgap = 0;
1950         u16 ack = msg_ack(hdr);
1951         u16 gap = msg_seq_gap(hdr);
1952         u16 peers_snd_nxt =  msg_next_sent(hdr);
1953         u16 peers_tol = msg_link_tolerance(hdr);
1954         u16 peers_prio = msg_linkprio(hdr);
1955         u16 rcv_nxt = l->rcv_nxt;
1956         u32 dlen = msg_data_sz(hdr), glen = 0;
1957         int mtyp = msg_type(hdr);
1958         bool reply = msg_probe(hdr);
1959         void *data;
1960         char *if_name;
1961         int rc = 0;
1962
1963         trace_tipc_proto_rcv(skb, false, l->name);
1964
1965         if (dlen > U16_MAX)
1966                 goto exit;
1967
1968         if (tipc_link_is_blocked(l) || !xmitq)
1969                 goto exit;
1970
1971         if (tipc_own_addr(l->net) > msg_prevnode(hdr))
1972                 l->net_plane = msg_net_plane(hdr);
1973
1974         if (skb_linearize(skb))
1975                 goto exit;
1976
1977         hdr = buf_msg(skb);
1978         data = msg_data(hdr);
1979
1980         if (!tipc_link_validate_msg(l, hdr)) {
1981                 trace_tipc_skb_dump(skb, false, "PROTO invalid (1)!");
1982                 trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (1)!");
1983                 goto exit;
1984         }
1985
1986         switch (mtyp) {
1987         case RESET_MSG:
1988         case ACTIVATE_MSG:
1989                 /* Complete own link name with peer's interface name */
1990                 if_name =  strrchr(l->name, ':') + 1;
1991                 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1992                         break;
1993                 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1994                         break;
1995                 strncpy(if_name, data, TIPC_MAX_IF_NAME);
1996
1997                 /* Update own tolerance if peer indicates a non-zero value */
1998                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
1999                         l->tolerance = peers_tol;
2000                         l->bc_rcvlink->tolerance = peers_tol;
2001                 }
2002                 /* Update own priority if peer's priority is higher */
2003                 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
2004                         l->priority = peers_prio;
2005
2006                 /* If peer is going down we want full re-establish cycle */
2007                 if (msg_peer_stopping(hdr)) {
2008                         rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2009                         break;
2010                 }
2011
2012                 /* If this endpoint was re-created while peer was ESTABLISHING
2013                  * it doesn't know current session number. Force re-synch.
2014                  */
2015                 if (mtyp == ACTIVATE_MSG && msg_dest_session_valid(hdr) &&
2016                     l->session != msg_dest_session(hdr)) {
2017                         if (less(l->session, msg_dest_session(hdr)))
2018                                 l->session = msg_dest_session(hdr) + 1;
2019                         break;
2020                 }
2021
2022                 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
2023                 if (mtyp == RESET_MSG || !link_is_up(l))
2024                         rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
2025
2026                 /* ACTIVATE_MSG takes up link if it was already locally reset */
2027                 if (mtyp == ACTIVATE_MSG && l->state == LINK_ESTABLISHING)
2028                         rc = TIPC_LINK_UP_EVT;
2029
2030                 l->peer_session = msg_session(hdr);
2031                 l->in_session = true;
2032                 l->peer_bearer_id = msg_bearer_id(hdr);
2033                 if (l->mtu > msg_max_pkt(hdr))
2034                         l->mtu = msg_max_pkt(hdr);
2035                 break;
2036
2037         case STATE_MSG:
2038                 l->rcv_nxt_state = msg_seqno(hdr) + 1;
2039
2040                 /* Update own tolerance if peer indicates a non-zero value */
2041                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2042                         l->tolerance = peers_tol;
2043                         l->bc_rcvlink->tolerance = peers_tol;
2044                 }
2045                 /* Update own prio if peer indicates a different value */
2046                 if ((peers_prio != l->priority) &&
2047                     in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) {
2048                         l->priority = peers_prio;
2049                         rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2050                 }
2051
2052                 l->silent_intv_cnt = 0;
2053                 l->stats.recv_states++;
2054                 if (msg_probe(hdr))
2055                         l->stats.recv_probes++;
2056
2057                 if (!link_is_up(l)) {
2058                         if (l->state == LINK_ESTABLISHING)
2059                                 rc = TIPC_LINK_UP_EVT;
2060                         break;
2061                 }
2062
2063                 /* Receive Gap ACK blocks from peer if any */
2064                 if (l->peer_caps & TIPC_GAP_ACK_BLOCK) {
2065                         ga = (struct tipc_gap_ack_blks *)data;
2066                         glen = ntohs(ga->len);
2067                         /* sanity check: if failed, ignore Gap ACK blocks */
2068                         if (glen != tipc_gap_ack_blks_sz(ga->gack_cnt))
2069                                 ga = NULL;
2070                 }
2071                 if(glen > dlen)
2072                         break;
2073                 tipc_mon_rcv(l->net, data + glen, dlen - glen, l->addr,
2074                              &l->mon_state, l->bearer_id);
2075
2076                 /* Send NACK if peer has sent pkts we haven't received yet */
2077                 if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
2078                         rcvgap = peers_snd_nxt - l->rcv_nxt;
2079                 if (rcvgap || reply)
2080                         tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,
2081                                                   rcvgap, 0, 0, xmitq);
2082
2083                 rc |= tipc_link_advance_transmq(l, ack, gap, ga, xmitq);
2084
2085                 /* If NACK, retransmit will now start at right position */
2086                 if (gap)
2087                         l->stats.recv_nacks++;
2088
2089                 tipc_link_advance_backlog(l, xmitq);
2090                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
2091                         link_prepare_wakeup(l);
2092         }
2093 exit:
2094         kfree_skb(skb);
2095         return rc;
2096 }
2097
2098 /* tipc_link_build_bc_proto_msg() - create broadcast protocol message
2099  */
2100 static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
2101                                          u16 peers_snd_nxt,
2102                                          struct sk_buff_head *xmitq)
2103 {
2104         struct sk_buff *skb;
2105         struct tipc_msg *hdr;
2106         struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
2107         u16 ack = l->rcv_nxt - 1;
2108         u16 gap_to = peers_snd_nxt - 1;
2109
2110         skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
2111                               0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
2112         if (!skb)
2113                 return false;
2114         hdr = buf_msg(skb);
2115         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
2116         msg_set_bcast_ack(hdr, ack);
2117         msg_set_bcgap_after(hdr, ack);
2118         if (dfrd_skb)
2119                 gap_to = buf_seqno(dfrd_skb) - 1;
2120         msg_set_bcgap_to(hdr, gap_to);
2121         msg_set_non_seq(hdr, bcast);
2122         __skb_queue_tail(xmitq, skb);
2123         return true;
2124 }
2125
2126 /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
2127  *
2128  * Give a newly added peer node the sequence number where it should
2129  * start receiving and acking broadcast packets.
2130  */
2131 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
2132                                         struct sk_buff_head *xmitq)
2133 {
2134         struct sk_buff_head list;
2135
2136         __skb_queue_head_init(&list);
2137         if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
2138                 return;
2139         msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true);
2140         tipc_link_xmit(l, &list, xmitq);
2141 }
2142
2143 /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
2144  */
2145 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
2146 {
2147         int mtyp = msg_type(hdr);
2148         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2149
2150         if (link_is_up(l))
2151                 return;
2152
2153         if (msg_user(hdr) == BCAST_PROTOCOL) {
2154                 l->rcv_nxt = peers_snd_nxt;
2155                 l->state = LINK_ESTABLISHED;
2156                 return;
2157         }
2158
2159         if (l->peer_caps & TIPC_BCAST_SYNCH)
2160                 return;
2161
2162         if (msg_peer_node_is_up(hdr))
2163                 return;
2164
2165         /* Compatibility: accept older, less safe initial synch data */
2166         if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
2167                 l->rcv_nxt = peers_snd_nxt;
2168 }
2169
2170 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
2171  */
2172 int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
2173                           struct sk_buff_head *xmitq)
2174 {
2175         struct tipc_link *snd_l = l->bc_sndlink;
2176         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2177         u16 from = msg_bcast_ack(hdr) + 1;
2178         u16 to = from + msg_bc_gap(hdr) - 1;
2179         int rc = 0;
2180
2181         if (!link_is_up(l))
2182                 return rc;
2183
2184         if (!msg_peer_node_is_up(hdr))
2185                 return rc;
2186
2187         /* Open when peer ackowledges our bcast init msg (pkt #1) */
2188         if (msg_ack(hdr))
2189                 l->bc_peer_is_up = true;
2190
2191         if (!l->bc_peer_is_up)
2192                 return rc;
2193
2194         l->stats.recv_nacks++;
2195
2196         /* Ignore if peers_snd_nxt goes beyond receive window */
2197         if (more(peers_snd_nxt, l->rcv_nxt + l->window))
2198                 return rc;
2199
2200         rc = tipc_link_bc_retrans(snd_l, l, from, to, xmitq);
2201
2202         l->snd_nxt = peers_snd_nxt;
2203         if (link_bc_rcv_gap(l))
2204                 rc |= TIPC_LINK_SND_STATE;
2205
2206         /* Return now if sender supports nack via STATE messages */
2207         if (l->peer_caps & TIPC_BCAST_STATE_NACK)
2208                 return rc;
2209
2210         /* Otherwise, be backwards compatible */
2211
2212         if (!more(peers_snd_nxt, l->rcv_nxt)) {
2213                 l->nack_state = BC_NACK_SND_CONDITIONAL;
2214                 return 0;
2215         }
2216
2217         /* Don't NACK if one was recently sent or peeked */
2218         if (l->nack_state == BC_NACK_SND_SUPPRESS) {
2219                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2220                 return 0;
2221         }
2222
2223         /* Conditionally delay NACK sending until next synch rcv */
2224         if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
2225                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2226                 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
2227                         return 0;
2228         }
2229
2230         /* Send NACK now but suppress next one */
2231         tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
2232         l->nack_state = BC_NACK_SND_SUPPRESS;
2233         return 0;
2234 }
2235
2236 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
2237                           struct sk_buff_head *xmitq)
2238 {
2239         struct sk_buff *skb, *tmp;
2240         struct tipc_link *snd_l = l->bc_sndlink;
2241
2242         if (!link_is_up(l) || !l->bc_peer_is_up)
2243                 return;
2244
2245         if (!more(acked, l->acked))
2246                 return;
2247
2248         trace_tipc_link_bc_ack(l, l->acked, acked, &snd_l->transmq);
2249         /* Skip over packets peer has already acked */
2250         skb_queue_walk(&snd_l->transmq, skb) {
2251                 if (more(buf_seqno(skb), l->acked))
2252                         break;
2253         }
2254
2255         /* Update/release the packets peer is acking now */
2256         skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
2257                 if (more(buf_seqno(skb), acked))
2258                         break;
2259                 if (!--TIPC_SKB_CB(skb)->ackers) {
2260                         __skb_unlink(skb, &snd_l->transmq);
2261                         kfree_skb(skb);
2262                 }
2263         }
2264         l->acked = acked;
2265         tipc_link_advance_backlog(snd_l, xmitq);
2266         if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
2267                 link_prepare_wakeup(snd_l);
2268 }
2269
2270 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
2271  * This function is here for backwards compatibility, since
2272  * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
2273  */
2274 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
2275                           struct sk_buff_head *xmitq)
2276 {
2277         struct tipc_msg *hdr = buf_msg(skb);
2278         u32 dnode = msg_destnode(hdr);
2279         int mtyp = msg_type(hdr);
2280         u16 acked = msg_bcast_ack(hdr);
2281         u16 from = acked + 1;
2282         u16 to = msg_bcgap_to(hdr);
2283         u16 peers_snd_nxt = to + 1;
2284         int rc = 0;
2285
2286         kfree_skb(skb);
2287
2288         if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
2289                 return 0;
2290
2291         if (mtyp != STATE_MSG)
2292                 return 0;
2293
2294         if (dnode == tipc_own_addr(l->net)) {
2295                 tipc_link_bc_ack_rcv(l, acked, xmitq);
2296                 rc = tipc_link_bc_retrans(l->bc_sndlink, l, from, to, xmitq);
2297                 l->stats.recv_nacks++;
2298                 return rc;
2299         }
2300
2301         /* Msg for other node => suppress own NACK at next sync if applicable */
2302         if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
2303                 l->nack_state = BC_NACK_SND_SUPPRESS;
2304
2305         return 0;
2306 }
2307
2308 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
2309 {
2310         int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE);
2311
2312         l->window = win;
2313         l->backlog[TIPC_LOW_IMPORTANCE].limit      = max_t(u16, 50, win);
2314         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = max_t(u16, 100, win * 2);
2315         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = max_t(u16, 150, win * 3);
2316         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = max_t(u16, 200, win * 4);
2317         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
2318 }
2319
2320 /**
2321  * link_reset_stats - reset link statistics
2322  * @l: pointer to link
2323  */
2324 void tipc_link_reset_stats(struct tipc_link *l)
2325 {
2326         memset(&l->stats, 0, sizeof(l->stats));
2327 }
2328
2329 static void link_print(struct tipc_link *l, const char *str)
2330 {
2331         struct sk_buff *hskb = skb_peek(&l->transmq);
2332         u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
2333         u16 tail = l->snd_nxt - 1;
2334
2335         pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
2336         pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
2337                 skb_queue_len(&l->transmq), head, tail,
2338                 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
2339 }
2340
2341 /* Parse and validate nested (link) properties valid for media, bearer and link
2342  */
2343 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
2344 {
2345         int err;
2346
2347         err = nla_parse_nested_deprecated(props, TIPC_NLA_PROP_MAX, prop,
2348                                           tipc_nl_prop_policy, NULL);
2349         if (err)
2350                 return err;
2351
2352         if (props[TIPC_NLA_PROP_PRIO]) {
2353                 u32 prio;
2354
2355                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2356                 if (prio > TIPC_MAX_LINK_PRI)
2357                         return -EINVAL;
2358         }
2359
2360         if (props[TIPC_NLA_PROP_TOL]) {
2361                 u32 tol;
2362
2363                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2364                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
2365                         return -EINVAL;
2366         }
2367
2368         if (props[TIPC_NLA_PROP_WIN]) {
2369                 u32 win;
2370
2371                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2372                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
2373                         return -EINVAL;
2374         }
2375
2376         return 0;
2377 }
2378
2379 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
2380 {
2381         int i;
2382         struct nlattr *stats;
2383
2384         struct nla_map {
2385                 u32 key;
2386                 u32 val;
2387         };
2388
2389         struct nla_map map[] = {
2390                 {TIPC_NLA_STATS_RX_INFO, 0},
2391                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
2392                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
2393                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
2394                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
2395                 {TIPC_NLA_STATS_TX_INFO, 0},
2396                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
2397                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
2398                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
2399                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
2400                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
2401                         s->msg_length_counts : 1},
2402                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
2403                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
2404                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
2405                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
2406                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
2407                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
2408                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
2409                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
2410                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
2411                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
2412                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
2413                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
2414                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
2415                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
2416                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
2417                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
2418                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
2419                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
2420                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
2421                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
2422                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
2423                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
2424                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
2425         };
2426
2427         stats = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2428         if (!stats)
2429                 return -EMSGSIZE;
2430
2431         for (i = 0; i <  ARRAY_SIZE(map); i++)
2432                 if (nla_put_u32(skb, map[i].key, map[i].val))
2433                         goto msg_full;
2434
2435         nla_nest_end(skb, stats);
2436
2437         return 0;
2438 msg_full:
2439         nla_nest_cancel(skb, stats);
2440
2441         return -EMSGSIZE;
2442 }
2443
2444 /* Caller should hold appropriate locks to protect the link */
2445 int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
2446                        struct tipc_link *link, int nlflags)
2447 {
2448         u32 self = tipc_own_addr(net);
2449         struct nlattr *attrs;
2450         struct nlattr *prop;
2451         void *hdr;
2452         int err;
2453
2454         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2455                           nlflags, TIPC_NL_LINK_GET);
2456         if (!hdr)
2457                 return -EMSGSIZE;
2458
2459         attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2460         if (!attrs)
2461                 goto msg_full;
2462
2463         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2464                 goto attr_msg_full;
2465         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, tipc_cluster_mask(self)))
2466                 goto attr_msg_full;
2467         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2468                 goto attr_msg_full;
2469         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
2470                 goto attr_msg_full;
2471         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
2472                 goto attr_msg_full;
2473
2474         if (tipc_link_is_up(link))
2475                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2476                         goto attr_msg_full;
2477         if (link->active)
2478                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2479                         goto attr_msg_full;
2480
2481         prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2482         if (!prop)
2483                 goto attr_msg_full;
2484         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2485                 goto prop_msg_full;
2486         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2487                 goto prop_msg_full;
2488         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2489                         link->window))
2490                 goto prop_msg_full;
2491         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2492                 goto prop_msg_full;
2493         nla_nest_end(msg->skb, prop);
2494
2495         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2496         if (err)
2497                 goto attr_msg_full;
2498
2499         nla_nest_end(msg->skb, attrs);
2500         genlmsg_end(msg->skb, hdr);
2501
2502         return 0;
2503
2504 prop_msg_full:
2505         nla_nest_cancel(msg->skb, prop);
2506 attr_msg_full:
2507         nla_nest_cancel(msg->skb, attrs);
2508 msg_full:
2509         genlmsg_cancel(msg->skb, hdr);
2510
2511         return -EMSGSIZE;
2512 }
2513
2514 static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
2515                                       struct tipc_stats *stats)
2516 {
2517         int i;
2518         struct nlattr *nest;
2519
2520         struct nla_map {
2521                 __u32 key;
2522                 __u32 val;
2523         };
2524
2525         struct nla_map map[] = {
2526                 {TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
2527                 {TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
2528                 {TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
2529                 {TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
2530                 {TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
2531                 {TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
2532                 {TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
2533                 {TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
2534                 {TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
2535                 {TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
2536                 {TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
2537                 {TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
2538                 {TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
2539                 {TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
2540                 {TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
2541                 {TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
2542                 {TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
2543                 {TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
2544                 {TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
2545                         (stats->accu_queue_sz / stats->queue_sz_counts) : 0}
2546         };
2547
2548         nest = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2549         if (!nest)
2550                 return -EMSGSIZE;
2551
2552         for (i = 0; i <  ARRAY_SIZE(map); i++)
2553                 if (nla_put_u32(skb, map[i].key, map[i].val))
2554                         goto msg_full;
2555
2556         nla_nest_end(skb, nest);
2557
2558         return 0;
2559 msg_full:
2560         nla_nest_cancel(skb, nest);
2561
2562         return -EMSGSIZE;
2563 }
2564
2565 int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
2566 {
2567         int err;
2568         void *hdr;
2569         struct nlattr *attrs;
2570         struct nlattr *prop;
2571         struct tipc_net *tn = net_generic(net, tipc_net_id);
2572         u32 bc_mode = tipc_bcast_get_broadcast_mode(net);
2573         u32 bc_ratio = tipc_bcast_get_broadcast_ratio(net);
2574         struct tipc_link *bcl = tn->bcl;
2575
2576         if (!bcl)
2577                 return 0;
2578
2579         tipc_bcast_lock(net);
2580
2581         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2582                           NLM_F_MULTI, TIPC_NL_LINK_GET);
2583         if (!hdr) {
2584                 tipc_bcast_unlock(net);
2585                 return -EMSGSIZE;
2586         }
2587
2588         attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2589         if (!attrs)
2590                 goto msg_full;
2591
2592         /* The broadcast link is always up */
2593         if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2594                 goto attr_msg_full;
2595
2596         if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
2597                 goto attr_msg_full;
2598         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
2599                 goto attr_msg_full;
2600         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
2601                 goto attr_msg_full;
2602         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
2603                 goto attr_msg_full;
2604
2605         prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2606         if (!prop)
2607                 goto attr_msg_full;
2608         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->window))
2609                 goto prop_msg_full;
2610         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST, bc_mode))
2611                 goto prop_msg_full;
2612         if (bc_mode & BCLINK_MODE_SEL)
2613                 if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST_RATIO,
2614                                 bc_ratio))
2615                         goto prop_msg_full;
2616         nla_nest_end(msg->skb, prop);
2617
2618         err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
2619         if (err)
2620                 goto attr_msg_full;
2621
2622         tipc_bcast_unlock(net);
2623         nla_nest_end(msg->skb, attrs);
2624         genlmsg_end(msg->skb, hdr);
2625
2626         return 0;
2627
2628 prop_msg_full:
2629         nla_nest_cancel(msg->skb, prop);
2630 attr_msg_full:
2631         nla_nest_cancel(msg->skb, attrs);
2632 msg_full:
2633         tipc_bcast_unlock(net);
2634         genlmsg_cancel(msg->skb, hdr);
2635
2636         return -EMSGSIZE;
2637 }
2638
2639 void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
2640                              struct sk_buff_head *xmitq)
2641 {
2642         l->tolerance = tol;
2643         if (l->bc_rcvlink)
2644                 l->bc_rcvlink->tolerance = tol;
2645         if (link_is_up(l))
2646                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
2647 }
2648
2649 void tipc_link_set_prio(struct tipc_link *l, u32 prio,
2650                         struct sk_buff_head *xmitq)
2651 {
2652         l->priority = prio;
2653         tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, prio, xmitq);
2654 }
2655
2656 void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
2657 {
2658         l->abort_limit = limit;
2659 }
2660
2661 char *tipc_link_name_ext(struct tipc_link *l, char *buf)
2662 {
2663         if (!l)
2664                 scnprintf(buf, TIPC_MAX_LINK_NAME, "null");
2665         else if (link_is_bc_sndlink(l))
2666                 scnprintf(buf, TIPC_MAX_LINK_NAME, "broadcast-sender");
2667         else if (link_is_bc_rcvlink(l))
2668                 scnprintf(buf, TIPC_MAX_LINK_NAME,
2669                           "broadcast-receiver, peer %x", l->addr);
2670         else
2671                 memcpy(buf, l->name, TIPC_MAX_LINK_NAME);
2672
2673         return buf;
2674 }
2675
2676 /**
2677  * tipc_link_dump - dump TIPC link data
2678  * @l: tipc link to be dumped
2679  * @dqueues: bitmask to decide if any link queue to be dumped?
2680  *           - TIPC_DUMP_NONE: don't dump link queues
2681  *           - TIPC_DUMP_TRANSMQ: dump link transmq queue
2682  *           - TIPC_DUMP_BACKLOGQ: dump link backlog queue
2683  *           - TIPC_DUMP_DEFERDQ: dump link deferd queue
2684  *           - TIPC_DUMP_INPUTQ: dump link input queue
2685  *           - TIPC_DUMP_WAKEUP: dump link wakeup queue
2686  *           - TIPC_DUMP_ALL: dump all the link queues above
2687  * @buf: returned buffer of dump data in format
2688  */
2689 int tipc_link_dump(struct tipc_link *l, u16 dqueues, char *buf)
2690 {
2691         int i = 0;
2692         size_t sz = (dqueues) ? LINK_LMAX : LINK_LMIN;
2693         struct sk_buff_head *list;
2694         struct sk_buff *hskb, *tskb;
2695         u32 len;
2696
2697         if (!l) {
2698                 i += scnprintf(buf, sz, "link data: (null)\n");
2699                 return i;
2700         }
2701
2702         i += scnprintf(buf, sz, "link data: %x", l->addr);
2703         i += scnprintf(buf + i, sz - i, " %x", l->state);
2704         i += scnprintf(buf + i, sz - i, " %u", l->in_session);
2705         i += scnprintf(buf + i, sz - i, " %u", l->session);
2706         i += scnprintf(buf + i, sz - i, " %u", l->peer_session);
2707         i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt);
2708         i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt);
2709         i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt_state);
2710         i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt_state);
2711         i += scnprintf(buf + i, sz - i, " %x", l->peer_caps);
2712         i += scnprintf(buf + i, sz - i, " %u", l->silent_intv_cnt);
2713         i += scnprintf(buf + i, sz - i, " %u", l->rst_cnt);
2714         i += scnprintf(buf + i, sz - i, " %u", 0);
2715         i += scnprintf(buf + i, sz - i, " %u", 0);
2716         i += scnprintf(buf + i, sz - i, " %u", l->acked);
2717
2718         list = &l->transmq;
2719         len = skb_queue_len(list);
2720         hskb = skb_peek(list);
2721         tskb = skb_peek_tail(list);
2722         i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2723                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2724                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2725
2726         list = &l->deferdq;
2727         len = skb_queue_len(list);
2728         hskb = skb_peek(list);
2729         tskb = skb_peek_tail(list);
2730         i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2731                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2732                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2733
2734         list = &l->backlogq;
2735         len = skb_queue_len(list);
2736         hskb = skb_peek(list);
2737         tskb = skb_peek_tail(list);
2738         i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2739                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2740                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2741
2742         list = l->inputq;
2743         len = skb_queue_len(list);
2744         hskb = skb_peek(list);
2745         tskb = skb_peek_tail(list);
2746         i += scnprintf(buf + i, sz - i, " | %u %u %u\n", len,
2747                        (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2748                        (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2749
2750         if (dqueues & TIPC_DUMP_TRANSMQ) {
2751                 i += scnprintf(buf + i, sz - i, "transmq: ");
2752                 i += tipc_list_dump(&l->transmq, false, buf + i);
2753         }
2754         if (dqueues & TIPC_DUMP_BACKLOGQ) {
2755                 i += scnprintf(buf + i, sz - i,
2756                                "backlogq: <%u %u %u %u %u>, ",
2757                                l->backlog[TIPC_LOW_IMPORTANCE].len,
2758                                l->backlog[TIPC_MEDIUM_IMPORTANCE].len,
2759                                l->backlog[TIPC_HIGH_IMPORTANCE].len,
2760                                l->backlog[TIPC_CRITICAL_IMPORTANCE].len,
2761                                l->backlog[TIPC_SYSTEM_IMPORTANCE].len);
2762                 i += tipc_list_dump(&l->backlogq, false, buf + i);
2763         }
2764         if (dqueues & TIPC_DUMP_DEFERDQ) {
2765                 i += scnprintf(buf + i, sz - i, "deferdq: ");
2766                 i += tipc_list_dump(&l->deferdq, false, buf + i);
2767         }
2768         if (dqueues & TIPC_DUMP_INPUTQ) {
2769                 i += scnprintf(buf + i, sz - i, "inputq: ");
2770                 i += tipc_list_dump(l->inputq, false, buf + i);
2771         }
2772         if (dqueues & TIPC_DUMP_WAKEUP) {
2773                 i += scnprintf(buf + i, sz - i, "wakeup: ");
2774                 i += tipc_list_dump(&l->wakeupq, false, buf + i);
2775         }
2776
2777         return i;
2778 }