link.c

   1/*
   2 * net/tipc/link.c: TIPC link code
   3 *
   4 * Copyright (c) 1996-2007, 2012-2016, Ericsson AB
   5 * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
   6 * All rights reserved.
   7 *
   8 * Redistribution and use in source and binary forms, with or without
   9 * modification, are permitted provided that the following conditions are met:
  10 *
  11 * 1. Redistributions of source code must retain the above copyright
  12 *    notice, this list of conditions and the following disclaimer.
  13 * 2. Redistributions in binary form must reproduce the above copyright
  14 *    notice, this list of conditions and the following disclaimer in the
  15 *    documentation and/or other materials provided with the distribution.
  16 * 3. Neither the names of the copyright holders nor the names of its
  17 *    contributors may be used to endorse or promote products derived from
  18 *    this software without specific prior written permission.
  19 *
  20 * Alternatively, this software may be distributed under the terms of the
  21 * GNU General Public License ("GPL") version 2 as published by the Free
  22 * Software Foundation.
  23 *
  24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34 * POSSIBILITY OF SUCH DAMAGE.
  35 */
  36
  37#include "core.h"
  38#include "subscr.h"
  39#include "link.h"
  40#include "bcast.h"
  41#include "socket.h"
  42#include "name_distr.h"
  43#include "discover.h"
  44#include "netlink.h"
  45#include "monitor.h"
  46#include "trace.h"
  47#include "crypto.h"
  48
  49#include <linux/pkt_sched.h>
  50
  51struct tipc_stats {
  52	u32 sent_pkts;
  53	u32 recv_pkts;
  54	u32 sent_states;
  55	u32 recv_states;
  56	u32 sent_probes;
  57	u32 recv_probes;
  58	u32 sent_nacks;
  59	u32 recv_nacks;
  60	u32 sent_acks;
  61	u32 sent_bundled;
  62	u32 sent_bundles;
  63	u32 recv_bundled;
  64	u32 recv_bundles;
  65	u32 retransmitted;
  66	u32 sent_fragmented;
  67	u32 sent_fragments;
  68	u32 recv_fragmented;
  69	u32 recv_fragments;
  70	u32 link_congs;		/* # port sends blocked by congestion */
  71	u32 deferred_recv;
  72	u32 duplicates;
  73	u32 max_queue_sz;	/* send queue size high water mark */
  74	u32 accu_queue_sz;	/* used for send queue size profiling */
  75	u32 queue_sz_counts;	/* used for send queue size profiling */
  76	u32 msg_length_counts;	/* used for message length profiling */
  77	u32 msg_lengths_total;	/* used for message length profiling */
  78	u32 msg_length_profile[7]; /* used for msg. length profiling */
  79};
  80
  81/**
  82 * struct tipc_link - TIPC link data structure
  83 * @addr: network address of link's peer node
  84 * @name: link name character string
  85 * @net: pointer to namespace struct
  86 * @peer_session: link session # being used by peer end of link
  87 * @peer_bearer_id: bearer id used by link's peer endpoint
  88 * @bearer_id: local bearer id used by link
  89 * @tolerance: minimum link continuity loss needed to reset link [in ms]
  90 * @abort_limit: # of unacknowledged continuity probes needed to reset link
  91 * @state: current state of link FSM
  92 * @peer_caps: bitmap describing capabilities of peer node
  93 * @silent_intv_cnt: # of timer intervals without any reception from peer
  94 * @priority: current link priority
  95 * @net_plane: current link network plane ('A' through 'H')
  96 * @mon_state: cookie with information needed by link monitor
  97 * @mtu: current maximum packet size for this link
  98 * @advertised_mtu: advertised own mtu when link is being established
  99 * @backlogq: queue for messages waiting to be sent
 100 * @ackers: # of peers that needs to ack each packet before it can be released
 101 * @acked: # last packet acked by a certain peer. Used for broadcast.
 102 * @rcv_nxt: next sequence number to expect for inbound messages
 103 * @inputq: buffer queue for messages to be delivered upwards
 104 * @namedq: buffer queue for name table messages to be delivered upwards
 105 * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
 106 * @reasm_buf: head of partially reassembled inbound message fragments
 107 * @stats: collects statistics regarding link activity
 108 * @session: session to be used by link
 109 * @snd_nxt_state: next send seq number
 110 * @rcv_nxt_state: next rcv seq number
 111 * @in_session: have received ACTIVATE_MSG from peer
 112 * @active: link is active
 113 * @if_name: associated interface name
 114 * @rst_cnt: link reset counter
 115 * @drop_point: seq number for failover handling (FIXME)
 116 * @failover_reasm_skb: saved failover msg ptr (FIXME)
 117 * @failover_deferdq: deferred message queue for failover processing (FIXME)
 118 * @transmq: the link's transmit queue
 119 * @backlog: link's backlog by priority (importance)
 120 * @snd_nxt: next sequence number to be used
 121 * @rcv_unacked: # messages read by user, but not yet acked back to peer
 122 * @deferdq: deferred receive queue
 123 * @window: sliding window size for congestion handling
 124 * @min_win: minimal send window to be used by link
 125 * @ssthresh: slow start threshold for congestion handling
 126 * @max_win: maximal send window to be used by link
 127 * @cong_acks: congestion acks for congestion avoidance (FIXME)
 128 * @checkpoint: seq number for congestion window size handling
 129 * @reasm_tnlmsg: fragmentation/reassembly area for tunnel protocol message
 130 * @last_gap: last gap ack blocks for bcast (FIXME)
 131 * @last_ga: ptr to gap ack blocks
 132 * @bc_rcvlink: the peer specific link used for broadcast reception
 133 * @bc_sndlink: the namespace global link used for broadcast sending
 134 * @nack_state: bcast nack state
 135 * @bc_peer_is_up: peer has acked the bcast init msg
 136 */
 137struct tipc_link {
 138	u32 addr;
 139	char name[TIPC_MAX_LINK_NAME];
 140	struct net *net;
 141
 142	/* Management and link supervision data */
 143	u16 peer_session;
 144	u16 session;
 145	u16 snd_nxt_state;
 146	u16 rcv_nxt_state;
 147	u32 peer_bearer_id;
 148	u32 bearer_id;
 149	u32 tolerance;
 150	u32 abort_limit;
 151	u32 state;
 152	u16 peer_caps;
 153	bool in_session;
 154	bool active;
 155	u32 silent_intv_cnt;
 156	char if_name[TIPC_MAX_IF_NAME];
 157	u32 priority;
 158	char net_plane;
 159	struct tipc_mon_state mon_state;
 160	u16 rst_cnt;
 161
 162	/* Failover/synch */
 163	u16 drop_point;
 164	struct sk_buff *failover_reasm_skb;
 165	struct sk_buff_head failover_deferdq;
 166
 167	/* Max packet negotiation */
 168	u16 mtu;
 169	u16 advertised_mtu;
 170
 171	/* Sending */
 172	struct sk_buff_head transmq;
 173	struct sk_buff_head backlogq;
 174	struct {
 175		u16 len;
 176		u16 limit;
 177		struct sk_buff *target_bskb;
 178	} backlog[5];
 179	u16 snd_nxt;
 180
 181	/* Reception */
 182	u16 rcv_nxt;
 183	u32 rcv_unacked;
 184	struct sk_buff_head deferdq;
 185	struct sk_buff_head *inputq;
 186	struct sk_buff_head *namedq;
 187
 188	/* Congestion handling */
 189	struct sk_buff_head wakeupq;
 190	u16 window;
 191	u16 min_win;
 192	u16 ssthresh;
 193	u16 max_win;
 194	u16 cong_acks;
 195	u16 checkpoint;
 196
 197	/* Fragmentation/reassembly */
 198	struct sk_buff *reasm_buf;
 199	struct sk_buff *reasm_tnlmsg;
 200
 201	/* Broadcast */
 202	u16 ackers;
 203	u16 acked;
 204	u16 last_gap;
 205	struct tipc_gap_ack_blks *last_ga;
 206	struct tipc_link *bc_rcvlink;
 207	struct tipc_link *bc_sndlink;
 208	u8 nack_state;
 209	bool bc_peer_is_up;
 210
 211	/* Statistics */
 212	struct tipc_stats stats;
 213};
 214
 215/*
 216 * Error message prefixes
 217 */
 218static const char *link_co_err = "Link tunneling error, ";
 219static const char *link_rst_msg = "Resetting link ";
 220
 221/* Send states for broadcast NACKs
 222 */
 223enum {
 224	BC_NACK_SND_CONDITIONAL,
 225	BC_NACK_SND_UNCONDITIONAL,
 226	BC_NACK_SND_SUPPRESS,
 227};
 228
 229#define TIPC_BC_RETR_LIM  (jiffies + msecs_to_jiffies(10))
 230#define TIPC_UC_RETR_TIME (jiffies + msecs_to_jiffies(1))
 231
 232/* Link FSM states:
 233 */
 234enum {
 235	LINK_ESTABLISHED     = 0xe,
 236	LINK_ESTABLISHING    = 0xe  << 4,
 237	LINK_RESET           = 0x1  << 8,
 238	LINK_RESETTING       = 0x2  << 12,
 239	LINK_PEER_RESET      = 0xd  << 16,
 240	LINK_FAILINGOVER     = 0xf  << 20,
 241	LINK_SYNCHING        = 0xc  << 24
 242};
 243
 244static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 245			       struct sk_buff_head *xmitq);
 246static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 247				      bool probe_reply, u16 rcvgap,
 248				      int tolerance, int priority,
 249				      struct sk_buff_head *xmitq);
 250static void link_print(struct tipc_link *l, const char *str);
 251static int tipc_link_build_nack_msg(struct tipc_link *l,
 252				    struct sk_buff_head *xmitq);
 253static void tipc_link_build_bc_init_msg(struct tipc_link *l,
 254					struct sk_buff_head *xmitq);
 255static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
 256				    struct tipc_link *l, u8 start_index);
 257static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr);
 258static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
 259				     u16 acked, u16 gap,
 260				     struct tipc_gap_ack_blks *ga,
 261				     struct sk_buff_head *xmitq,
 262				     bool *retransmitted, int *rc);
 263static void tipc_link_update_cwin(struct tipc_link *l, int released,
 264				  bool retransmitted);
 265/*
 266 *  Simple non-static link routines (i.e. referenced outside this file)
 267 */
 268bool tipc_link_is_up(struct tipc_link *l)
 269{
 270	return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
 271}
 272
 273bool tipc_link_peer_is_down(struct tipc_link *l)
 274{
 275	return l->state == LINK_PEER_RESET;
 276}
 277
 278bool tipc_link_is_reset(struct tipc_link *l)
 279{
 280	return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
 281}
 282
 283bool tipc_link_is_establishing(struct tipc_link *l)
 284{
 285	return l->state == LINK_ESTABLISHING;
 286}
 287
 288bool tipc_link_is_synching(struct tipc_link *l)
 289{
 290	return l->state == LINK_SYNCHING;
 291}
 292
 293bool tipc_link_is_failingover(struct tipc_link *l)
 294{
 295	return l->state == LINK_FAILINGOVER;
 296}
 297
 298bool tipc_link_is_blocked(struct tipc_link *l)
 299{
 300	return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
 301}
 302
 303static bool link_is_bc_sndlink(struct tipc_link *l)
 304{
 305	return !l->bc_sndlink;
 306}
 307
 308static bool link_is_bc_rcvlink(struct tipc_link *l)
 309{
 310	return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
 311}
 312
 313void tipc_link_set_active(struct tipc_link *l, bool active)
 314{
 315	l->active = active;
 316}
 317
 318u32 tipc_link_id(struct tipc_link *l)
 319{
 320	return l->peer_bearer_id << 16 | l->bearer_id;
 321}
 322
 323int tipc_link_min_win(struct tipc_link *l)
 324{
 325	return l->min_win;
 326}
 327
 328int tipc_link_max_win(struct tipc_link *l)
 329{
 330	return l->max_win;
 331}
 332
 333int tipc_link_prio(struct tipc_link *l)
 334{
 335	return l->priority;
 336}
 337
 338unsigned long tipc_link_tolerance(struct tipc_link *l)
 339{
 340	return l->tolerance;
 341}
 342
 343struct sk_buff_head *tipc_link_inputq(struct tipc_link *l)
 344{
 345	return l->inputq;
 346}
 347
 348char tipc_link_plane(struct tipc_link *l)
 349{
 350	return l->net_plane;
 351}
 352
 353struct net *tipc_link_net(struct tipc_link *l)
 354{
 355	return l->net;
 356}
 357
 358void tipc_link_update_caps(struct tipc_link *l, u16 capabilities)
 359{
 360	l->peer_caps = capabilities;
 361}
 362
 363void tipc_link_add_bc_peer(struct tipc_link *snd_l,
 364			   struct tipc_link *uc_l,
 365			   struct sk_buff_head *xmitq)
 366{
 367	struct tipc_link *rcv_l = uc_l->bc_rcvlink;
 368
 369	snd_l->ackers++;
 370	rcv_l->acked = snd_l->snd_nxt - 1;
 371	snd_l->state = LINK_ESTABLISHED;
 372	tipc_link_build_bc_init_msg(uc_l, xmitq);
 373}
 374
 375void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
 376			      struct tipc_link *rcv_l,
 377			      struct sk_buff_head *xmitq)
 378{
 379	u16 ack = snd_l->snd_nxt - 1;
 380
 381	snd_l->ackers--;
 382	rcv_l->bc_peer_is_up = true;
 383	rcv_l->state = LINK_ESTABLISHED;
 384	tipc_link_bc_ack_rcv(rcv_l, ack, 0, NULL, xmitq, NULL);
 385	trace_tipc_link_reset(rcv_l, TIPC_DUMP_ALL, "bclink removed!");
 386	tipc_link_reset(rcv_l);
 387	rcv_l->state = LINK_RESET;
 388	if (!snd_l->ackers) {
 389		trace_tipc_link_reset(snd_l, TIPC_DUMP_ALL, "zero ackers!");
 390		tipc_link_reset(snd_l);
 391		snd_l->state = LINK_RESET;
 392		__skb_queue_purge(xmitq);
 393	}
 394}
 395
 396int tipc_link_bc_peers(struct tipc_link *l)
 397{
 398	return l->ackers;
 399}
 400
 401static u16 link_bc_rcv_gap(struct tipc_link *l)
 402{
 403	struct sk_buff *skb = skb_peek(&l->deferdq);
 404	u16 gap = 0;
 405
 406	if (more(l->snd_nxt, l->rcv_nxt))
 407		gap = l->snd_nxt - l->rcv_nxt;
 408	if (skb)
 409		gap = buf_seqno(skb) - l->rcv_nxt;
 410	return gap;
 411}
 412
 413void tipc_link_set_mtu(struct tipc_link *l, int mtu)
 414{
 415	l->mtu = mtu;
 416}
 417
 418int tipc_link_mtu(struct tipc_link *l)
 419{
 420	return l->mtu;
 421}
 422
 423int tipc_link_mss(struct tipc_link *l)
 424{
 425#ifdef CONFIG_TIPC_CRYPTO
 426	return l->mtu - INT_H_SIZE - EMSG_OVERHEAD;
 427#else
 428	return l->mtu - INT_H_SIZE;
 429#endif
 430}
 431
 432u16 tipc_link_rcv_nxt(struct tipc_link *l)
 433{
 434	return l->rcv_nxt;
 435}
 436
 437u16 tipc_link_acked(struct tipc_link *l)
 438{
 439	return l->acked;
 440}
 441
 442char *tipc_link_name(struct tipc_link *l)
 443{
 444	return l->name;
 445}
 446
 447u32 tipc_link_state(struct tipc_link *l)
 448{
 449	return l->state;
 450}
 451
 452/**
 453 * tipc_link_create - create a new link
 454 * @net: pointer to associated network namespace
 455 * @if_name: associated interface name
 456 * @bearer_id: id (index) of associated bearer
 457 * @tolerance: link tolerance to be used by link
 458 * @net_plane: network plane (A,B,c..) this link belongs to
 459 * @mtu: mtu to be advertised by link
 460 * @priority: priority to be used by link
 461 * @min_win: minimal send window to be used by link
 462 * @max_win: maximal send window to be used by link
 463 * @session: session to be used by link
 464 * @peer: node id of peer node
 465 * @peer_caps: bitmap describing peer node capabilities
 466 * @bc_sndlink: the namespace global link used for broadcast sending
 467 * @bc_rcvlink: the peer specific link used for broadcast reception
 468 * @inputq: queue to put messages ready for delivery
 469 * @namedq: queue to put binding table update messages ready for delivery
 470 * @link: return value, pointer to put the created link
 471 * @self: local unicast link id
 472 * @peer_id: 128-bit ID of peer
 473 *
 474 * Return: true if link was created, otherwise false
 475 */
 476bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
 477		      int tolerance, char net_plane, u32 mtu, int priority,
 478		      u32 min_win, u32 max_win, u32 session, u32 self,
 479		      u32 peer, u8 *peer_id, u16 peer_caps,
 480		      struct tipc_link *bc_sndlink,
 481		      struct tipc_link *bc_rcvlink,
 482		      struct sk_buff_head *inputq,
 483		      struct sk_buff_head *namedq,
 484		      struct tipc_link **link)
 485{
 486	char peer_str[NODE_ID_STR_LEN] = {0,};
 487	char self_str[NODE_ID_STR_LEN] = {0,};
 488	struct tipc_link *l;
 489
 490	l = kzalloc(sizeof(*l), GFP_ATOMIC);
 491	if (!l)
 492		return false;
 493	*link = l;
 494	l->session = session;
 495
 496	/* Set link name for unicast links only */
 497	if (peer_id) {
 498		if (tipc_nodeid2string(self_str, tipc_own_id(net)) > NODE_ID_LEN)
 499			sprintf(self_str, "%x", self);
 500		if (tipc_nodeid2string(peer_str, peer_id) > NODE_ID_LEN)
 501			sprintf(peer_str, "%x", peer);
 502	}
 503	/* Peer i/f name will be completed by reset/activate message */
 504	snprintf(l->name, sizeof(l->name), "%s:%s-%s:unknown",
 505		 self_str, if_name, peer_str);
 506
 507	strcpy(l->if_name, if_name);
 508	l->addr = peer;
 509	l->peer_caps = peer_caps;
 510	l->net = net;
 511	l->in_session = false;
 512	l->bearer_id = bearer_id;
 513	l->tolerance = tolerance;
 514	if (bc_rcvlink)
 515		bc_rcvlink->tolerance = tolerance;
 516	l->net_plane = net_plane;
 517	l->advertised_mtu = mtu;
 518	l->mtu = mtu;
 519	l->priority = priority;
 520	tipc_link_set_queue_limits(l, min_win, max_win);
 521	l->ackers = 1;
 522	l->bc_sndlink = bc_sndlink;
 523	l->bc_rcvlink = bc_rcvlink;
 524	l->inputq = inputq;
 525	l->namedq = namedq;
 526	l->state = LINK_RESETTING;
 527	__skb_queue_head_init(&l->transmq);
 528	__skb_queue_head_init(&l->backlogq);
 529	__skb_queue_head_init(&l->deferdq);
 530	__skb_queue_head_init(&l->failover_deferdq);
 531	skb_queue_head_init(&l->wakeupq);
 532	skb_queue_head_init(l->inputq);
 533	return true;
 534}
 535
 536/**
 537 * tipc_link_bc_create - create new link to be used for broadcast
 538 * @net: pointer to associated network namespace
 539 * @mtu: mtu to be used initially if no peers
 540 * @min_win: minimal send window to be used by link
 541 * @max_win: maximal send window to be used by link
 542 * @inputq: queue to put messages ready for delivery
 543 * @namedq: queue to put binding table update messages ready for delivery
 544 * @link: return value, pointer to put the created link
 545 * @ownnode: identity of own node
 546 * @peer: node id of peer node
 547 * @peer_id: 128-bit ID of peer
 548 * @peer_caps: bitmap describing peer node capabilities
 549 * @bc_sndlink: the namespace global link used for broadcast sending
 550 *
 551 * Return: true if link was created, otherwise false
 552 */
 553bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer, u8 *peer_id,
 554			 int mtu, u32 min_win, u32 max_win, u16 peer_caps,
 555			 struct sk_buff_head *inputq,
 556			 struct sk_buff_head *namedq,
 557			 struct tipc_link *bc_sndlink,
 558			 struct tipc_link **link)
 559{
 560	struct tipc_link *l;
 561
 562	if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, min_win,
 563			      max_win, 0, ownnode, peer, NULL, peer_caps,
 564			      bc_sndlink, NULL, inputq, namedq, link))
 565		return false;
 566
 567	l = *link;
 568	if (peer_id) {
 569		char peer_str[NODE_ID_STR_LEN] = {0,};
 570
 571		if (tipc_nodeid2string(peer_str, peer_id) > NODE_ID_LEN)
 572			sprintf(peer_str, "%x", peer);
 573		/* Broadcast receiver link name: "broadcast-link:<peer>" */
 574		snprintf(l->name, sizeof(l->name), "%s:%s", tipc_bclink_name,
 575			 peer_str);
 576	} else {
 577		strcpy(l->name, tipc_bclink_name);
 578	}
 579	trace_tipc_link_reset(l, TIPC_DUMP_ALL, "bclink created!");
 580	tipc_link_reset(l);
 581	l->state = LINK_RESET;
 582	l->ackers = 0;
 583	l->bc_rcvlink = l;
 584
 585	/* Broadcast send link is always up */
 586	if (link_is_bc_sndlink(l))
 587		l->state = LINK_ESTABLISHED;
 588
 589	/* Disable replicast if even a single peer doesn't support it */
 590	if (link_is_bc_rcvlink(l) && !(peer_caps & TIPC_BCAST_RCAST))
 591		tipc_bcast_toggle_rcast(net, false);
 592
 593	return true;
 594}
 595
 596/**
 597 * tipc_link_fsm_evt - link finite state machine
 598 * @l: pointer to link
 599 * @evt: state machine event to be processed
 600 */
 601int tipc_link_fsm_evt(struct tipc_link *l, int evt)
 602{
 603	int rc = 0;
 604	int old_state = l->state;
 605
 606	switch (l->state) {
 607	case LINK_RESETTING:
 608		switch (evt) {
 609		case LINK_PEER_RESET_EVT:
 610			l->state = LINK_PEER_RESET;
 611			break;
 612		case LINK_RESET_EVT:
 613			l->state = LINK_RESET;
 614			break;
 615		case LINK_FAILURE_EVT:
 616		case LINK_FAILOVER_BEGIN_EVT:
 617		case LINK_ESTABLISH_EVT:
 618		case LINK_FAILOVER_END_EVT:
 619		case LINK_SYNCH_BEGIN_EVT:
 620		case LINK_SYNCH_END_EVT:
 621		default:
 622			goto illegal_evt;
 623		}
 624		break;
 625	case LINK_RESET:
 626		switch (evt) {
 627		case LINK_PEER_RESET_EVT:
 628			l->state = LINK_ESTABLISHING;
 629			break;
 630		case LINK_FAILOVER_BEGIN_EVT:
 631			l->state = LINK_FAILINGOVER;
 632			break;
 633		case LINK_FAILURE_EVT:
 634		case LINK_RESET_EVT:
 635		case LINK_ESTABLISH_EVT:
 636		case LINK_FAILOVER_END_EVT:
 637			break;
 638		case LINK_SYNCH_BEGIN_EVT:
 639		case LINK_SYNCH_END_EVT:
 640		default:
 641			goto illegal_evt;
 642		}
 643		break;
 644	case LINK_PEER_RESET:
 645		switch (evt) {
 646		case LINK_RESET_EVT:
 647			l->state = LINK_ESTABLISHING;
 648			break;
 649		case LINK_PEER_RESET_EVT:
 650		case LINK_ESTABLISH_EVT:
 651		case LINK_FAILURE_EVT:
 652			break;
 653		case LINK_SYNCH_BEGIN_EVT:
 654		case LINK_SYNCH_END_EVT:
 655		case LINK_FAILOVER_BEGIN_EVT:
 656		case LINK_FAILOVER_END_EVT:
 657		default:
 658			goto illegal_evt;
 659		}
 660		break;
 661	case LINK_FAILINGOVER:
 662		switch (evt) {
 663		case LINK_FAILOVER_END_EVT:
 664			l->state = LINK_RESET;
 665			break;
 666		case LINK_PEER_RESET_EVT:
 667		case LINK_RESET_EVT:
 668		case LINK_ESTABLISH_EVT:
 669		case LINK_FAILURE_EVT:
 670			break;
 671		case LINK_FAILOVER_BEGIN_EVT:
 672		case LINK_SYNCH_BEGIN_EVT:
 673		case LINK_SYNCH_END_EVT:
 674		default:
 675			goto illegal_evt;
 676		}
 677		break;
 678	case LINK_ESTABLISHING:
 679		switch (evt) {
 680		case LINK_ESTABLISH_EVT:
 681			l->state = LINK_ESTABLISHED;
 682			break;
 683		case LINK_FAILOVER_BEGIN_EVT:
 684			l->state = LINK_FAILINGOVER;
 685			break;
 686		case LINK_RESET_EVT:
 687			l->state = LINK_RESET;
 688			break;
 689		case LINK_FAILURE_EVT:
 690		case LINK_PEER_RESET_EVT:
 691		case LINK_SYNCH_BEGIN_EVT:
 692		case LINK_FAILOVER_END_EVT:
 693			break;
 694		case LINK_SYNCH_END_EVT:
 695		default:
 696			goto illegal_evt;
 697		}
 698		break;
 699	case LINK_ESTABLISHED:
 700		switch (evt) {
 701		case LINK_PEER_RESET_EVT:
 702			l->state = LINK_PEER_RESET;
 703			rc |= TIPC_LINK_DOWN_EVT;
 704			break;
 705		case LINK_FAILURE_EVT:
 706			l->state = LINK_RESETTING;
 707			rc |= TIPC_LINK_DOWN_EVT;
 708			break;
 709		case LINK_RESET_EVT:
 710			l->state = LINK_RESET;
 711			break;
 712		case LINK_ESTABLISH_EVT:
 713		case LINK_SYNCH_END_EVT:
 714			break;
 715		case LINK_SYNCH_BEGIN_EVT:
 716			l->state = LINK_SYNCHING;
 717			break;
 718		case LINK_FAILOVER_BEGIN_EVT:
 719		case LINK_FAILOVER_END_EVT:
 720		default:
 721			goto illegal_evt;
 722		}
 723		break;
 724	case LINK_SYNCHING:
 725		switch (evt) {
 726		case LINK_PEER_RESET_EVT:
 727			l->state = LINK_PEER_RESET;
 728			rc |= TIPC_LINK_DOWN_EVT;
 729			break;
 730		case LINK_FAILURE_EVT:
 731			l->state = LINK_RESETTING;
 732			rc |= TIPC_LINK_DOWN_EVT;
 733			break;
 734		case LINK_RESET_EVT:
 735			l->state = LINK_RESET;
 736			break;
 737		case LINK_ESTABLISH_EVT:
 738		case LINK_SYNCH_BEGIN_EVT:
 739			break;
 740		case LINK_SYNCH_END_EVT:
 741			l->state = LINK_ESTABLISHED;
 742			break;
 743		case LINK_FAILOVER_BEGIN_EVT:
 744		case LINK_FAILOVER_END_EVT:
 745		default:
 746			goto illegal_evt;
 747		}
 748		break;
 749	default:
 750		pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
 751	}
 752	trace_tipc_link_fsm(l->name, old_state, l->state, evt);
 753	return rc;
 754illegal_evt:
 755	pr_err("Illegal FSM event %x in state %x on link %s\n",
 756	       evt, l->state, l->name);
 757	trace_tipc_link_fsm(l->name, old_state, l->state, evt);
 758	return rc;
 759}
 760
 761/* link_profile_stats - update statistical profiling of traffic
 762 */
 763static void link_profile_stats(struct tipc_link *l)
 764{
 765	struct sk_buff *skb;
 766	struct tipc_msg *msg;
 767	int length;
 768
 769	/* Update counters used in statistical profiling of send traffic */
 770	l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 771	l->stats.queue_sz_counts++;
 772
 773	skb = skb_peek(&l->transmq);
 774	if (!skb)
 775		return;
 776	msg = buf_msg(skb);
 777	length = msg_size(msg);
 778
 779	if (msg_user(msg) == MSG_FRAGMENTER) {
 780		if (msg_type(msg) != FIRST_FRAGMENT)
 781			return;
 782		length = msg_size(msg_inner_hdr(msg));
 783	}
 784	l->stats.msg_lengths_total += length;
 785	l->stats.msg_length_counts++;
 786	if (length <= 64)
 787		l->stats.msg_length_profile[0]++;
 788	else if (length <= 256)
 789		l->stats.msg_length_profile[1]++;
 790	else if (length <= 1024)
 791		l->stats.msg_length_profile[2]++;
 792	else if (length <= 4096)
 793		l->stats.msg_length_profile[3]++;
 794	else if (length <= 16384)
 795		l->stats.msg_length_profile[4]++;
 796	else if (length <= 32768)
 797		l->stats.msg_length_profile[5]++;
 798	else
 799		l->stats.msg_length_profile[6]++;
 800}
 801
 802/**
 803 * tipc_link_too_silent - check if link is "too silent"
 804 * @l: tipc link to be checked
 805 *
 806 * Return: true if the link 'silent_intv_cnt' is about to reach the
 807 * 'abort_limit' value, otherwise false
 808 */
 809bool tipc_link_too_silent(struct tipc_link *l)
 810{
 811	return (l->silent_intv_cnt + 2 > l->abort_limit);
 812}
 813
 814/* tipc_link_timeout - perform periodic task as instructed from node timeout
 815 */
 816int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 817{
 818	int mtyp = 0;
 819	int rc = 0;
 820	bool state = false;
 821	bool probe = false;
 822	bool setup = false;
 823	u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
 824	u16 bc_acked = l->bc_rcvlink->acked;
 825	struct tipc_mon_state *mstate = &l->mon_state;
 826
 827	trace_tipc_link_timeout(l, TIPC_DUMP_NONE, " ");
 828	trace_tipc_link_too_silent(l, TIPC_DUMP_ALL, " ");
 829	switch (l->state) {
 830	case LINK_ESTABLISHED:
 831	case LINK_SYNCHING:
 832		mtyp = STATE_MSG;
 833		link_profile_stats(l);
 834		tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id);
 835		if (mstate->reset || (l->silent_intv_cnt > l->abort_limit))
 836			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 837		state = bc_acked != bc_snt;
 838		state |= l->bc_rcvlink->rcv_unacked;
 839		state |= l->rcv_unacked;
 840		state |= !skb_queue_empty(&l->transmq);
 841		probe = mstate->probing;
 842		probe |= l->silent_intv_cnt;
 843		if (probe || mstate->monitoring)
 844			l->silent_intv_cnt++;
 845		probe |= !skb_queue_empty(&l->deferdq);
 846		if (l->snd_nxt == l->checkpoint) {
 847			tipc_link_update_cwin(l, 0, 0);
 848			probe = true;
 849		}
 850		l->checkpoint = l->snd_nxt;
 851		break;
 852	case LINK_RESET:
 853		setup = l->rst_cnt++ <= 4;
 854		setup |= !(l->rst_cnt % 16);
 855		mtyp = RESET_MSG;
 856		break;
 857	case LINK_ESTABLISHING:
 858		setup = true;
 859		mtyp = ACTIVATE_MSG;
 860		break;
 861	case LINK_PEER_RESET:
 862	case LINK_RESETTING:
 863	case LINK_FAILINGOVER:
 864		break;
 865	default:
 866		break;
 867	}
 868
 869	if (state || probe || setup)
 870		tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, 0, xmitq);
 871
 872	return rc;
 873}
 874
 875/**
 876 * link_schedule_user - schedule a message sender for wakeup after congestion
 877 * @l: congested link
 878 * @hdr: header of message that is being sent
 879 * Create pseudo msg to send back to user when congestion abates
 880 */
 881static int link_schedule_user(struct tipc_link *l, struct tipc_msg *hdr)
 882{
 883	u32 dnode = tipc_own_addr(l->net);
 884	u32 dport = msg_origport(hdr);
 885	struct sk_buff *skb;
 886
 887	/* Create and schedule wakeup pseudo message */
 888	skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 889			      dnode, l->addr, dport, 0, 0);
 890	if (!skb)
 891		return -ENOBUFS;
 892	msg_set_dest_droppable(buf_msg(skb), true);
 893	TIPC_SKB_CB(skb)->chain_imp = msg_importance(hdr);
 894	skb_queue_tail(&l->wakeupq, skb);
 895	l->stats.link_congs++;
 896	trace_tipc_link_conges(l, TIPC_DUMP_ALL, "wakeup scheduled!");
 897	return -ELINKCONG;
 898}
 899
 900/**
 901 * link_prepare_wakeup - prepare users for wakeup after congestion
 902 * @l: congested link
 903 * Wake up a number of waiting users, as permitted by available space
 904 * in the send queue
 905 */
 906static void link_prepare_wakeup(struct tipc_link *l)
 907{
 908	struct sk_buff_head *wakeupq = &l->wakeupq;
 909	struct sk_buff_head *inputq = l->inputq;
 910	struct sk_buff *skb, *tmp;
 911	struct sk_buff_head tmpq;
 912	int avail[5] = {0,};
 913	int imp = 0;
 914
 915	__skb_queue_head_init(&tmpq);
 916
 917	for (; imp <= TIPC_SYSTEM_IMPORTANCE; imp++)
 918		avail[imp] = l->backlog[imp].limit - l->backlog[imp].len;
 919
 920	skb_queue_walk_safe(wakeupq, skb, tmp) {
 921		imp = TIPC_SKB_CB(skb)->chain_imp;
 922		if (avail[imp] <= 0)
 923			continue;
 924		avail[imp]--;
 925		__skb_unlink(skb, wakeupq);
 926		__skb_queue_tail(&tmpq, skb);
 927	}
 928
 929	spin_lock_bh(&inputq->lock);
 930	skb_queue_splice_tail(&tmpq, inputq);
 931	spin_unlock_bh(&inputq->lock);
 932
 933}
 934
 935/**
 936 * tipc_link_set_skb_retransmit_time - set the time at which retransmission of
 937 *                                     the given skb should be next attempted
 938 * @skb: skb to set a future retransmission time for
 939 * @l: link the skb will be transmitted on
 940 */
 941static void tipc_link_set_skb_retransmit_time(struct sk_buff *skb,
 942					      struct tipc_link *l)
 943{
 944	if (link_is_bc_sndlink(l))
 945		TIPC_SKB_CB(skb)->nxt_retr = TIPC_BC_RETR_LIM;
 946	else
 947		TIPC_SKB_CB(skb)->nxt_retr = TIPC_UC_RETR_TIME;
 948}
 949
 950void tipc_link_reset(struct tipc_link *l)
 951{
 952	struct sk_buff_head list;
 953	u32 imp;
 954
 955	__skb_queue_head_init(&list);
 956
 957	l->in_session = false;
 958	/* Force re-synch of peer session number before establishing */
 959	l->peer_session--;
 960	l->session++;
 961	l->mtu = l->advertised_mtu;
 962
 963	spin_lock_bh(&l->wakeupq.lock);
 964	skb_queue_splice_init(&l->wakeupq, &list);
 965	spin_unlock_bh(&l->wakeupq.lock);
 966
 967	spin_lock_bh(&l->inputq->lock);
 968	skb_queue_splice_init(&list, l->inputq);
 969	spin_unlock_bh(&l->inputq->lock);
 970
 971	__skb_queue_purge(&l->transmq);
 972	__skb_queue_purge(&l->deferdq);
 973	__skb_queue_purge(&l->backlogq);
 974	__skb_queue_purge(&l->failover_deferdq);
 975	for (imp = 0; imp <= TIPC_SYSTEM_IMPORTANCE; imp++) {
 976		l->backlog[imp].len = 0;
 977		l->backlog[imp].target_bskb = NULL;
 978	}
 979	kfree_skb(l->reasm_buf);
 980	kfree_skb(l->reasm_tnlmsg);
 981	kfree_skb(l->failover_reasm_skb);
 982	l->reasm_buf = NULL;
 983	l->reasm_tnlmsg = NULL;
 984	l->failover_reasm_skb = NULL;
 985	l->rcv_unacked = 0;
 986	l->snd_nxt = 1;
 987	l->rcv_nxt = 1;
 988	l->snd_nxt_state = 1;
 989	l->rcv_nxt_state = 1;
 990	l->acked = 0;
 991	l->last_gap = 0;
 992	kfree(l->last_ga);
 993	l->last_ga = NULL;
 994	l->silent_intv_cnt = 0;
 995	l->rst_cnt = 0;
 996	l->bc_peer_is_up = false;
 997	memset(&l->mon_state, 0, sizeof(l->mon_state));
 998	tipc_link_reset_stats(l);
 999}
1000
1001/**
1002 * tipc_link_xmit(): enqueue buffer list according to queue situation
1003 * @l: link to use
1004 * @list: chain of buffers containing message
1005 * @xmitq: returned list of packets to be sent by caller
1006 *
1007 * Consumes the buffer chain.
1008 * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
1009 * Return: 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
1010 */
1011int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
1012		   struct sk_buff_head *xmitq)
1013{
1014	struct sk_buff_head *backlogq = &l->backlogq;
1015	struct sk_buff_head *transmq = &l->transmq;
1016	struct sk_buff *skb, *_skb;
1017	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1018	u16 ack = l->rcv_nxt - 1;
1019	u16 seqno = l->snd_nxt;
1020	int pkt_cnt = skb_queue_len(list);
1021	unsigned int mss = tipc_link_mss(l);
1022	unsigned int cwin = l->window;
1023	unsigned int mtu = l->mtu;
1024	struct tipc_msg *hdr;
1025	bool new_bundle;
1026	int rc = 0;
1027	int imp;
1028
1029	if (pkt_cnt <= 0)
1030		return 0;
1031
1032	hdr = buf_msg(skb_peek(list));
1033	if (unlikely(msg_size(hdr) > mtu)) {
1034		pr_warn("Too large msg, purging xmit list %d %d %d %d %d!\n",
1035			skb_queue_len(list), msg_user(hdr),
1036			msg_type(hdr), msg_size(hdr), mtu);
1037		__skb_queue_purge(list);
1038		return -EMSGSIZE;
1039	}
1040
1041	imp = msg_importance(hdr);
1042	/* Allow oversubscription of one data msg per source at congestion */
1043	if (unlikely(l->backlog[imp].len >= l->backlog[imp].limit)) {
1044		if (imp == TIPC_SYSTEM_IMPORTANCE) {
1045			pr_warn("%s<%s>, link overflow", link_rst_msg, l->name);
1046			__skb_queue_purge(list);
1047			return -ENOBUFS;
1048		}
1049		rc = link_schedule_user(l, hdr);
1050	}
1051
1052	if (pkt_cnt > 1) {
1053		l->stats.sent_fragmented++;
1054		l->stats.sent_fragments += pkt_cnt;
1055	}
1056
1057	/* Prepare each packet for sending, and add to relevant queue: */
1058	while ((skb = __skb_dequeue(list))) {
1059		if (likely(skb_queue_len(transmq) < cwin)) {
1060			hdr = buf_msg(skb);
1061			msg_set_seqno(hdr, seqno);
1062			msg_set_ack(hdr, ack);
1063			msg_set_bcast_ack(hdr, bc_ack);
1064			_skb = skb_clone(skb, GFP_ATOMIC);
1065			if (!_skb) {
1066				kfree_skb(skb);
1067				__skb_queue_purge(list);
1068				return -ENOBUFS;
1069			}
1070			__skb_queue_tail(transmq, skb);
1071			tipc_link_set_skb_retransmit_time(skb, l);
1072			__skb_queue_tail(xmitq, _skb);
1073			TIPC_SKB_CB(skb)->ackers = l->ackers;
1074			l->rcv_unacked = 0;
1075			l->stats.sent_pkts++;
1076			seqno++;
1077			continue;
1078		}
1079		if (tipc_msg_try_bundle(l->backlog[imp].target_bskb, &skb,
1080					mss, l->addr, &new_bundle)) {
1081			if (skb) {
1082				/* Keep a ref. to the skb for next try */
1083				l->backlog[imp].target_bskb = skb;
1084				l->backlog[imp].len++;
1085				__skb_queue_tail(backlogq, skb);
1086			} else {
1087				if (new_bundle) {
1088					l->stats.sent_bundles++;
1089					l->stats.sent_bundled++;
1090				}
1091				l->stats.sent_bundled++;
1092			}
1093			continue;
1094		}
1095		l->backlog[imp].target_bskb = NULL;
1096		l->backlog[imp].len += (1 + skb_queue_len(list));
1097		__skb_queue_tail(backlogq, skb);
1098		skb_queue_splice_tail_init(list, backlogq);
1099	}
1100	l->snd_nxt = seqno;
1101	return rc;
1102}
1103
1104static void tipc_link_update_cwin(struct tipc_link *l, int released,
1105				  bool retransmitted)
1106{
1107	int bklog_len = skb_queue_len(&l->backlogq);
1108	struct sk_buff_head *txq = &l->transmq;
1109	int txq_len = skb_queue_len(txq);
1110	u16 cwin = l->window;
1111
1112	/* Enter fast recovery */
1113	if (unlikely(retransmitted)) {
1114		l->ssthresh = max_t(u16, l->window / 2, 300);
1115		l->window = min_t(u16, l->ssthresh, l->window);
1116		return;
1117	}
1118	/* Enter slow start */
1119	if (unlikely(!released)) {
1120		l->ssthresh = max_t(u16, l->window / 2, 300);
1121		l->window = l->min_win;
1122		return;
1123	}
1124	/* Don't increase window if no pressure on the transmit queue */
1125	if (txq_len + bklog_len < cwin)
1126		return;
1127
1128	/* Don't increase window if there are holes the transmit queue */
1129	if (txq_len && l->snd_nxt - buf_seqno(skb_peek(txq)) != txq_len)
1130		return;
1131
1132	l->cong_acks += released;
1133
1134	/* Slow start  */
1135	if (cwin <= l->ssthresh) {
1136		l->window = min_t(u16, cwin + released, l->max_win);
1137		return;
1138	}
1139	/* Congestion avoidance */
1140	if (l->cong_acks < cwin)
1141		return;
1142	l->window = min_t(u16, ++cwin, l->max_win);
1143	l->cong_acks = 0;
1144}
1145
1146static void tipc_link_advance_backlog(struct tipc_link *l,
1147				      struct sk_buff_head *xmitq)
1148{
1149	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1150	struct sk_buff_head *txq = &l->transmq;
1151	struct sk_buff *skb, *_skb;
1152	u16 ack = l->rcv_nxt - 1;
1153	u16 seqno = l->snd_nxt;
1154	struct tipc_msg *hdr;
1155	u16 cwin = l->window;
1156	u32 imp;
1157
1158	while (skb_queue_len(txq) < cwin) {
1159		skb = skb_peek(&l->backlogq);
1160		if (!skb)
1161			break;
1162		_skb = skb_clone(skb, GFP_ATOMIC);
1163		if (!_skb)
1164			break;
1165		__skb_dequeue(&l->backlogq);
1166		hdr = buf_msg(skb);
1167		imp = msg_importance(hdr);
1168		l->backlog[imp].len--;
1169		if (unlikely(skb == l->backlog[imp].target_bskb))
1170			l->backlog[imp].target_bskb = NULL;
1171		__skb_queue_tail(&l->transmq, skb);
1172		tipc_link_set_skb_retransmit_time(skb, l);
1173
1174		__skb_queue_tail(xmitq, _skb);
1175		TIPC_SKB_CB(skb)->ackers = l->ackers;
1176		msg_set_seqno(hdr, seqno);
1177		msg_set_ack(hdr, ack);
1178		msg_set_bcast_ack(hdr, bc_ack);
1179		l->rcv_unacked = 0;
1180		l->stats.sent_pkts++;
1181		seqno++;
1182	}
1183	l->snd_nxt = seqno;
1184}
1185
1186/**
1187 * link_retransmit_failure() - Detect repeated retransmit failures
1188 * @l: tipc link sender
1189 * @r: tipc link receiver (= l in case of unicast)
1190 * @rc: returned code
1191 *
1192 * Return: true if the repeated retransmit failures happens, otherwise
1193 * false
1194 */
1195static bool link_retransmit_failure(struct tipc_link *l, struct tipc_link *r,
1196				    int *rc)
1197{
1198	struct sk_buff *skb = skb_peek(&l->transmq);
1199	struct tipc_msg *hdr;
1200
1201	if (!skb)
1202		return false;
1203
1204	if (!TIPC_SKB_CB(skb)->retr_cnt)
1205		return false;
1206
1207	if (!time_after(jiffies, TIPC_SKB_CB(skb)->retr_stamp +
1208			msecs_to_jiffies(r->tolerance * 10)))
1209		return false;
1210
1211	hdr = buf_msg(skb);
1212	if (link_is_bc_sndlink(l) && !less(r->acked, msg_seqno(hdr)))
1213		return false;
1214
1215	pr_warn("Retransmission failure on link <%s>\n", l->name);
1216	link_print(l, "State of link ");
1217	pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
1218		msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
1219	pr_info("sqno %u, prev: %x, dest: %x\n",
1220		msg_seqno(hdr), msg_prevnode(hdr), msg_destnode(hdr));
1221	pr_info("retr_stamp %d, retr_cnt %d\n",
1222		jiffies_to_msecs(TIPC_SKB_CB(skb)->retr_stamp),
1223		TIPC_SKB_CB(skb)->retr_cnt);
1224
1225	trace_tipc_list_dump(&l->transmq, true, "retrans failure!");
1226	trace_tipc_link_dump(l, TIPC_DUMP_NONE, "retrans failure!");
1227	trace_tipc_link_dump(r, TIPC_DUMP_NONE, "retrans failure!");
1228
1229	if (link_is_bc_sndlink(l)) {
1230		r->state = LINK_RESET;
1231		*rc |= TIPC_LINK_DOWN_EVT;
1232	} else {
1233		*rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1234	}
1235
1236	return true;
1237}
1238
1239/* tipc_data_input - deliver data and name distr msgs to upper layer
1240 *
1241 * Consumes buffer if message is of right type
1242 * Node lock must be held
1243 */
1244static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1245			    struct sk_buff_head *inputq)
1246{
1247	struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq;
1248	struct tipc_msg *hdr = buf_msg(skb);
1249
1250	switch (msg_user(hdr)) {
1251	case TIPC_LOW_IMPORTANCE:
1252	case TIPC_MEDIUM_IMPORTANCE:
1253	case TIPC_HIGH_IMPORTANCE:
1254	case TIPC_CRITICAL_IMPORTANCE:
1255		if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) {
1256			skb_queue_tail(mc_inputq, skb);
1257			return true;
1258		}
1259		fallthrough;
1260	case CONN_MANAGER:
1261		skb_queue_tail(inputq, skb);
1262		return true;
1263	case GROUP_PROTOCOL:
1264		skb_queue_tail(mc_inputq, skb);
1265		return true;
1266	case NAME_DISTRIBUTOR:
1267		l->bc_rcvlink->state = LINK_ESTABLISHED;
1268		skb_queue_tail(l->namedq, skb);
1269		return true;
1270	case MSG_BUNDLER:
1271	case TUNNEL_PROTOCOL:
1272	case MSG_FRAGMENTER:
1273	case BCAST_PROTOCOL:
1274		return false;
1275#ifdef CONFIG_TIPC_CRYPTO
1276	case MSG_CRYPTO:
1277		if (sysctl_tipc_key_exchange_enabled &&
1278		    TIPC_SKB_CB(skb)->decrypted) {
1279			tipc_crypto_msg_rcv(l->net, skb);
1280			return true;
1281		}
1282		fallthrough;
1283#endif
1284	default:
1285		pr_warn("Dropping received illegal msg type\n");
1286		kfree_skb(skb);
1287		return true;
1288	}
1289}
1290
1291/* tipc_link_input - process packet that has passed link protocol check
1292 *
1293 * Consumes buffer
1294 */
1295static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1296			   struct sk_buff_head *inputq,
1297			   struct sk_buff **reasm_skb)
1298{
1299	struct tipc_msg *hdr = buf_msg(skb);
1300	struct sk_buff *iskb;
1301	struct sk_buff_head tmpq;
1302	int usr = msg_user(hdr);
1303	int pos = 0;
1304
1305	if (usr == MSG_BUNDLER) {
1306		skb_queue_head_init(&tmpq);
1307		l->stats.recv_bundles++;
1308		l->stats.recv_bundled += msg_msgcnt(hdr);
1309		while (tipc_msg_extract(skb, &iskb, &pos))
1310			tipc_data_input(l, iskb, &tmpq);
1311		tipc_skb_queue_splice_tail(&tmpq, inputq);
1312		return 0;
1313	} else if (usr == MSG_FRAGMENTER) {
1314		l->stats.recv_fragments++;
1315		if (tipc_buf_append(reasm_skb, &skb)) {
1316			l->stats.recv_fragmented++;
1317			tipc_data_input(l, skb, inputq);
1318		} else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1319			pr_warn_ratelimited("Unable to build fragment list\n");
1320			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1321		}
1322		return 0;
1323	} else if (usr == BCAST_PROTOCOL) {
1324		tipc_bcast_lock(l->net);
1325		tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1326		tipc_bcast_unlock(l->net);
1327	}
1328
1329	kfree_skb(skb);
1330	return 0;
1331}
1332
1333/* tipc_link_tnl_rcv() - receive TUNNEL_PROTOCOL message, drop or process the
1334 *			 inner message along with the ones in the old link's
1335 *			 deferdq
1336 * @l: tunnel link
1337 * @skb: TUNNEL_PROTOCOL message
1338 * @inputq: queue to put messages ready for delivery
1339 */
1340static int tipc_link_tnl_rcv(struct tipc_link *l, struct sk_buff *skb,
1341			     struct sk_buff_head *inputq)
1342{
1343	struct sk_buff **reasm_skb = &l->failover_reasm_skb;
1344	struct sk_buff **reasm_tnlmsg = &l->reasm_tnlmsg;
1345	struct sk_buff_head *fdefq = &l->failover_deferdq;
1346	struct tipc_msg *hdr = buf_msg(skb);
1347	struct sk_buff *iskb;
1348	int ipos = 0;
1349	int rc = 0;
1350	u16 seqno;
1351
1352	if (msg_type(hdr) == SYNCH_MSG) {
1353		kfree_skb(skb);
1354		return 0;
1355	}
1356
1357	/* Not a fragment? */
1358	if (likely(!msg_nof_fragms(hdr))) {
1359		if (unlikely(!tipc_msg_extract(skb, &iskb, &ipos))) {
1360			pr_warn_ratelimited("Unable to extract msg, defq: %d\n",
1361					    skb_queue_len(fdefq));
1362			return 0;
1363		}
1364		kfree_skb(skb);
1365	} else {
1366		/* Set fragment type for buf_append */
1367		if (msg_fragm_no(hdr) == 1)
1368			msg_set_type(hdr, FIRST_FRAGMENT);
1369		else if (msg_fragm_no(hdr) < msg_nof_fragms(hdr))
1370			msg_set_type(hdr, FRAGMENT);
1371		else
1372			msg_set_type(hdr, LAST_FRAGMENT);
1373
1374		if (!tipc_buf_append(reasm_tnlmsg, &skb)) {
1375			/* Successful but non-complete reassembly? */
1376			if (*reasm_tnlmsg || link_is_bc_rcvlink(l))
1377				return 0;
1378			pr_warn_ratelimited("Unable to reassemble tunnel msg\n");
1379			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1380		}
1381		iskb = skb;
1382	}
1383
1384	do {
1385		seqno = buf_seqno(iskb);
1386		if (unlikely(less(seqno, l->drop_point))) {
1387			kfree_skb(iskb);
1388			continue;
1389		}
1390		if (unlikely(seqno != l->drop_point)) {
1391			__tipc_skb_queue_sorted(fdefq, seqno, iskb);
1392			continue;
1393		}
1394
1395		l->drop_point++;
1396		if (!tipc_data_input(l, iskb, inputq))
1397			rc |= tipc_link_input(l, iskb, inputq, reasm_skb);
1398		if (unlikely(rc))
1399			break;
1400	} while ((iskb = __tipc_skb_dequeue(fdefq, l->drop_point)));
1401
1402	return rc;
1403}
1404
1405/**
1406 * tipc_get_gap_ack_blks - get Gap ACK blocks from PROTOCOL/STATE_MSG
1407 * @ga: returned pointer to the Gap ACK blocks if any
1408 * @l: the tipc link
1409 * @hdr: the PROTOCOL/STATE_MSG header
1410 * @uc: desired Gap ACK blocks type, i.e. unicast (= 1) or broadcast (= 0)
1411 *
1412 * Return: the total Gap ACK blocks size
1413 */
1414u16 tipc_get_gap_ack_blks(struct tipc_gap_ack_blks **ga, struct tipc_link *l,
1415			  struct tipc_msg *hdr, bool uc)
1416{
1417	struct tipc_gap_ack_blks *p;
1418	u16 sz = 0;
1419
1420	/* Does peer support the Gap ACK blocks feature? */
1421	if (l->peer_caps & TIPC_GAP_ACK_BLOCK) {
1422		p = (struct tipc_gap_ack_blks *)msg_data(hdr);
1423		sz = ntohs(p->len);
1424		/* Sanity check */
1425		if (sz == struct_size(p, gacks, size_add(p->ugack_cnt, p->bgack_cnt))) {
1426			/* Good, check if the desired type exists */
1427			if ((uc && p->ugack_cnt) || (!uc && p->bgack_cnt))
1428				goto ok;
1429		/* Backward compatible: peer might not support bc, but uc? */
1430		} else if (uc && sz == struct_size(p, gacks, p->ugack_cnt)) {
1431			if (p->ugack_cnt) {
1432				p->bgack_cnt = 0;
1433				goto ok;
1434			}
1435		}
1436	}
1437	/* Other cases: ignore! */
1438	p = NULL;
1439
1440ok:
1441	*ga = p;
1442	return sz;
1443}
1444
1445static u8 __tipc_build_gap_ack_blks(struct tipc_gap_ack_blks *ga,
1446				    struct tipc_link *l, u8 start_index)
1447{
1448	struct tipc_gap_ack *gacks = &ga->gacks[start_index];
1449	struct sk_buff *skb = skb_peek(&l->deferdq);
1450	u16 expect, seqno = 0;
1451	u8 n = 0;
1452
1453	if (!skb)
1454		return 0;
1455
1456	expect = buf_seqno(skb);
1457	skb_queue_walk(&l->deferdq, skb) {
1458		seqno = buf_seqno(skb);
1459		if (unlikely(more(seqno, expect))) {
1460			gacks[n].ack = htons(expect - 1);
1461			gacks[n].gap = htons(seqno - expect);
1462			if (++n >= MAX_GAP_ACK_BLKS / 2) {
1463				pr_info_ratelimited("Gacks on %s: %d, ql: %d!\n",
1464						    l->name, n,
1465						    skb_queue_len(&l->deferdq));
1466				return n;
1467			}
1468		} else if (unlikely(less(seqno, expect))) {
1469			pr_warn("Unexpected skb in deferdq!\n");
1470			continue;
1471		}
1472		expect = seqno + 1;
1473	}
1474
1475	/* last block */
1476	gacks[n].ack = htons(seqno);
1477	gacks[n].gap = 0;
1478	n++;
1479	return n;
1480}
1481
1482/* tipc_build_gap_ack_blks - build Gap ACK blocks
1483 * @l: tipc unicast link
1484 * @hdr: the tipc message buffer to store the Gap ACK blocks after built
1485 *
1486 * The function builds Gap ACK blocks for both the unicast & broadcast receiver
1487 * links of a certain peer, the buffer after built has the network data format
1488 * as found at the struct tipc_gap_ack_blks definition.
1489 *
1490 * returns the actual allocated memory size
1491 */
1492static u16 tipc_build_gap_ack_blks(struct tipc_link *l, struct tipc_msg *hdr)
1493{
1494	struct tipc_link *bcl = l->bc_rcvlink;
1495	struct tipc_gap_ack_blks *ga;
1496	u16 len;
1497
1498	ga = (struct tipc_gap_ack_blks *)msg_data(hdr);
1499
1500	/* Start with broadcast link first */
1501	tipc_bcast_lock(bcl->net);
1502	msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1503	msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
1504	ga->bgack_cnt = __tipc_build_gap_ack_blks(ga, bcl, 0);
1505	tipc_bcast_unlock(bcl->net);
1506
1507	/* Now for unicast link, but an explicit NACK only (???) */
1508	ga->ugack_cnt = (msg_seq_gap(hdr)) ?
1509			__tipc_build_gap_ack_blks(ga, l, ga->bgack_cnt) : 0;
1510
1511	/* Total len */
1512	len = struct_size(ga, gacks, size_add(ga->bgack_cnt, ga->ugack_cnt));
1513	ga->len = htons(len);
1514	return len;
1515}
1516
1517/* tipc_link_advance_transmq - advance TIPC link transmq queue by releasing
1518 *			       acked packets, also doing retransmissions if
1519 *			       gaps found
1520 * @l: tipc link with transmq queue to be advanced
1521 * @r: tipc link "receiver" i.e. in case of broadcast (= "l" if unicast)
1522 * @acked: seqno of last packet acked by peer without any gaps before
1523 * @gap: # of gap packets
1524 * @ga: buffer pointer to Gap ACK blocks from peer
1525 * @xmitq: queue for accumulating the retransmitted packets if any
1526 * @retransmitted: returned boolean value if a retransmission is really issued
1527 * @rc: returned code e.g. TIPC_LINK_DOWN_EVT if a repeated retransmit failures
1528 *      happens (- unlikely case)
1529 *
1530 * Return: the number of packets released from the link transmq
1531 */
1532static int tipc_link_advance_transmq(struct tipc_link *l, struct tipc_link *r,
1533				     u16 acked, u16 gap,
1534				     struct tipc_gap_ack_blks *ga,
1535				     struct sk_buff_head *xmitq,
1536				     bool *retransmitted, int *rc)
1537{
1538	struct tipc_gap_ack_blks *last_ga = r->last_ga, *this_ga = NULL;
1539	struct tipc_gap_ack *gacks = NULL;
1540	struct sk_buff *skb, *_skb, *tmp;
1541	struct tipc_msg *hdr;
1542	u32 qlen = skb_queue_len(&l->transmq);
1543	u16 nacked = acked, ngap = gap, gack_cnt = 0;
1544	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1545	u16 ack = l->rcv_nxt - 1;
1546	u16 seqno, n = 0;
1547	u16 end = r->acked, start = end, offset = r->last_gap;
1548	u16 si = (last_ga) ? last_ga->start_index : 0;
1549	bool is_uc = !link_is_bc_sndlink(l);
1550	bool bc_has_acked = false;
1551
1552	trace_tipc_link_retrans(r, acked + 1, acked + gap, &l->transmq);
1553
1554	/* Determine Gap ACK blocks if any for the particular link */
1555	if (ga && is_uc) {
1556		/* Get the Gap ACKs, uc part */
1557		gack_cnt = ga->ugack_cnt;
1558		gacks = &ga->gacks[ga->bgack_cnt];
1559	} else if (ga) {
1560		/* Copy the Gap ACKs, bc part, for later renewal if needed */
1561		this_ga = kmemdup(ga, struct_size(ga, gacks, ga->bgack_cnt),
1562				  GFP_ATOMIC);
1563		if (likely(this_ga)) {
1564			this_ga->start_index = 0;
1565			/* Start with the bc Gap ACKs */
1566			gack_cnt = this_ga->bgack_cnt;
1567			gacks = &this_ga->gacks[0];
1568		} else {
1569			/* Hmm, we can get in trouble..., simply ignore it */
1570			pr_warn_ratelimited("Ignoring bc Gap ACKs, no memory\n");
1571		}
1572	}
1573
1574	/* Advance the link transmq */
1575	skb_queue_walk_safe(&l->transmq, skb, tmp) {
1576		seqno = buf_seqno(skb);
1577
1578next_gap_ack:
1579		if (less_eq(seqno, nacked)) {
1580			if (is_uc)
1581				goto release;
1582			/* Skip packets peer has already acked */
1583			if (!more(seqno, r->acked))
1584				continue;
1585			/* Get the next of last Gap ACK blocks */
1586			while (more(seqno, end)) {
1587				if (!last_ga || si >= last_ga->bgack_cnt)
1588					break;
1589				start = end + offset + 1;
1590				end = ntohs(last_ga->gacks[si].ack);
1591				offset = ntohs(last_ga->gacks[si].gap);
1592				si++;
1593				WARN_ONCE(more(start, end) ||
1594					  (!offset &&
1595					   si < last_ga->bgack_cnt) ||
1596					  si > MAX_GAP_ACK_BLKS,
1597					  "Corrupted Gap ACK: %d %d %d %d %d\n",
1598					  start, end, offset, si,
1599					  last_ga->bgack_cnt);
1600			}
1601			/* Check against the last Gap ACK block */
1602			if (tipc_in_range(seqno, start, end))
1603				continue;
1604			/* Update/release the packet peer is acking */
1605			bc_has_acked = true;
1606			if (--TIPC_SKB_CB(skb)->ackers)
1607				continue;
1608release:
1609			/* release skb */
1610			__skb_unlink(skb, &l->transmq);
1611			kfree_skb(skb);
1612		} else if (less_eq(seqno, nacked + ngap)) {
1613			/* First gap: check if repeated retrans failures? */
1614			if (unlikely(seqno == acked + 1 &&
1615				     link_retransmit_failure(l, r, rc))) {
1616				/* Ignore this bc Gap ACKs if any */
1617				kfree(this_ga);
1618				this_ga = NULL;
1619				break;
1620			}
1621			/* retransmit skb if unrestricted*/
1622			if (time_before(jiffies, TIPC_SKB_CB(skb)->nxt_retr))
1623				continue;
1624			tipc_link_set_skb_retransmit_time(skb, l);
1625			_skb = pskb_copy(skb, GFP_ATOMIC);
1626			if (!_skb)
1627				continue;
1628			hdr = buf_msg(_skb);
1629			msg_set_ack(hdr, ack);
1630			msg_set_bcast_ack(hdr, bc_ack);
1631			_skb->priority = TC_PRIO_CONTROL;
1632			__skb_queue_tail(xmitq, _skb);
1633			l->stats.retransmitted++;
1634			if (!is_uc)
1635				r->stats.retransmitted++;
1636			*retransmitted = true;
1637			/* Increase actual retrans counter & mark first time */
1638			if (!TIPC_SKB_CB(skb)->retr_cnt++)
1639				TIPC_SKB_CB(skb)->retr_stamp = jiffies;
1640		} else {
1641			/* retry with Gap ACK blocks if any */
1642			if (n >= gack_cnt)
1643				break;
1644			nacked = ntohs(gacks[n].ack);
1645			ngap = ntohs(gacks[n].gap);
1646			n++;
1647			goto next_gap_ack;
1648		}
1649	}
1650
1651	/* Renew last Gap ACK blocks for bc if needed */
1652	if (bc_has_acked) {
1653		if (this_ga) {
1654			kfree(last_ga);
1655			r->last_ga = this_ga;
1656			r->last_gap = gap;
1657		} else if (last_ga) {
1658			if (less(acked, start)) {
1659				si--;
1660				offset = start - acked - 1;
1661			} else if (less(acked, end)) {
1662				acked = end;
1663			}
1664			if (si < last_ga->bgack_cnt) {
1665				last_ga->start_index = si;
1666				r->last_gap = offset;
1667			} else {
1668				kfree(last_ga);
1669				r->last_ga = NULL;
1670				r->last_gap = 0;
1671			}
1672		} else {
1673			r->last_gap = 0;
1674		}
1675		r->acked = acked;
1676	} else {
1677		kfree(this_ga);
1678	}
1679
1680	return qlen - skb_queue_len(&l->transmq);
1681}
1682
1683/* tipc_link_build_state_msg: prepare link state message for transmission
1684 *
1685 * Note that sending of broadcast ack is coordinated among nodes, to reduce
1686 * risk of ack storms towards the sender
1687 */
1688int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1689{
1690	if (!l)
1691		return 0;
1692
1693	/* Broadcast ACK must be sent via a unicast link => defer to caller */
1694	if (link_is_bc_rcvlink(l)) {
1695		if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1696			return 0;
1697		l->rcv_unacked = 0;
1698
1699		/* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
1700		l->snd_nxt = l->rcv_nxt;
1701		return TIPC_LINK_SND_STATE;
1702	}
1703	/* Unicast ACK */
1704	l->rcv_unacked = 0;
1705	l->stats.sent_acks++;
1706	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
1707	return 0;
1708}
1709
1710/* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1711 */
1712void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1713{
1714	int mtyp = RESET_MSG;
1715	struct sk_buff *skb;
1716
1717	if (l->state == LINK_ESTABLISHING)
1718		mtyp = ACTIVATE_MSG;
1719
1720	tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, 0, xmitq);
1721
1722	/* Inform peer that this endpoint is going down if applicable */
1723	skb = skb_peek_tail(xmitq);
1724	if (skb && (l->state == LINK_RESET))
1725		msg_set_peer_stopping(buf_msg(skb), 1);
1726}
1727
1728/* tipc_link_build_nack_msg: prepare link nack message for transmission
1729 * Note that sending of broadcast NACK is coordinated among nodes, to
1730 * reduce the risk of NACK storms towards the sender
1731 */
1732static int tipc_link_build_nack_msg(struct tipc_link *l,
1733				    struct sk_buff_head *xmitq)
1734{
1735	u32 def_cnt = ++l->stats.deferred_recv;
1736	struct sk_buff_head *dfq = &l->deferdq;
1737	u32 defq_len = skb_queue_len(dfq);
1738	int match1, match2;
1739
1740	if (link_is_bc_rcvlink(l)) {
1741		match1 = def_cnt & 0xf;
1742		match2 = tipc_own_addr(l->net) & 0xf;
1743		if (match1 == match2)
1744			return TIPC_LINK_SND_STATE;
1745		return 0;
1746	}
1747
1748	if (defq_len >= 3 && !((defq_len - 3) % 16)) {
1749		u16 rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1750
1751		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0,
1752					  rcvgap, 0, 0, xmitq);
1753	}
1754	return 0;
1755}
1756
1757/* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1758 * @l: the link that should handle the message
1759 * @skb: TIPC packet
1760 * @xmitq: queue to place packets to be sent after this call
1761 */
1762int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1763		  struct sk_buff_head *xmitq)
1764{
1765	struct sk_buff_head *defq = &l->deferdq;
1766	struct tipc_msg *hdr = buf_msg(skb);
1767	u16 seqno, rcv_nxt, win_lim;
1768	int released = 0;
1769	int rc = 0;
1770
1771	/* Verify and update link state */
1772	if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1773		return tipc_link_proto_rcv(l, skb, xmitq);
1774
1775	/* Don't send probe at next timeout expiration */
1776	l->silent_intv_cnt = 0;
1777
1778	do {
1779		hdr = buf_msg(skb);
1780		seqno = msg_seqno(hdr);
1781		rcv_nxt = l->rcv_nxt;
1782		win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1783
1784		if (unlikely(!tipc_link_is_up(l))) {
1785			if (l->state == LINK_ESTABLISHING)
1786				rc = TIPC_LINK_UP_EVT;
1787			kfree_skb(skb);
1788			break;
1789		}
1790
1791		/* Drop if outside receive window */
1792		if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1793			l->stats.duplicates++;
1794			kfree_skb(skb);
1795			break;
1796		}
1797		released += tipc_link_advance_transmq(l, l, msg_ack(hdr), 0,
1798						      NULL, NULL, NULL, NULL);
1799
1800		/* Defer delivery if sequence gap */
1801		if (unlikely(seqno != rcv_nxt)) {
1802			if (!__tipc_skb_queue_sorted(defq, seqno, skb))
1803				l->stats.duplicates++;
1804			rc |= tipc_link_build_nack_msg(l, xmitq);
1805			break;
1806		}
1807
1808		/* Deliver packet */
1809		l->rcv_nxt++;
1810		l->stats.recv_pkts++;
1811
1812		if (unlikely(msg_user(hdr) == TUNNEL_PROTOCOL))
1813			rc |= tipc_link_tnl_rcv(l, skb, l->inputq);
1814		else if (!tipc_data_input(l, skb, l->inputq))
1815			rc |= tipc_link_input(l, skb, l->inputq, &l->reasm_buf);
1816		if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1817			rc |= tipc_link_build_state_msg(l, xmitq);
1818		if (unlikely(rc & ~TIPC_LINK_SND_STATE))
1819			break;
1820	} while ((skb = __tipc_skb_dequeue(defq, l->rcv_nxt)));
1821
1822	/* Forward queues and wake up waiting users */
1823	if (released) {
1824		tipc_link_update_cwin(l, released, 0);
1825		tipc_link_advance_backlog(l, xmitq);
1826		if (unlikely(!skb_queue_empty(&l->wakeupq)))
1827			link_prepare_wakeup(l);
1828	}
1829	return rc;
1830}
1831
1832static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1833				      bool probe_reply, u16 rcvgap,
1834				      int tolerance, int priority,
1835				      struct sk_buff_head *xmitq)
1836{
1837	struct tipc_mon_state *mstate = &l->mon_state;
1838	struct sk_buff_head *dfq = &l->deferdq;
1839	struct tipc_link *bcl = l->bc_rcvlink;
1840	struct tipc_msg *hdr;
1841	struct sk_buff *skb;
1842	bool node_up = tipc_link_is_up(bcl);
1843	u16 glen = 0, bc_rcvgap = 0;
1844	int dlen = 0;
1845	void *data;
1846
1847	/* Don't send protocol message during reset or link failover */
1848	if (tipc_link_is_blocked(l))
1849		return;
1850
1851	if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1852		return;
1853
1854	if ((probe || probe_reply) && !skb_queue_empty(dfq))
1855		rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1856
1857	skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1858			      tipc_max_domain_size + MAX_GAP_ACK_BLKS_SZ,
1859			      l->addr, tipc_own_addr(l->net), 0, 0, 0);
1860	if (!skb)
1861		return;
1862
1863	hdr = buf_msg(skb);
1864	data = msg_data(hdr);
1865	msg_set_session(hdr, l->session);
1866	msg_set_bearer_id(hdr, l->bearer_id);
1867	msg_set_net_plane(hdr, l->net_plane);
1868	msg_set_next_sent(hdr, l->snd_nxt);
1869	msg_set_ack(hdr, l->rcv_nxt - 1);
1870	msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1871	msg_set_bc_ack_invalid(hdr, !node_up);
1872	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1873	msg_set_link_tolerance(hdr, tolerance);
1874	msg_set_linkprio(hdr, priority);
1875	msg_set_redundant_link(hdr, node_up);
1876	msg_set_seq_gap(hdr, 0);
1877	msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1878
1879	if (mtyp == STATE_MSG) {
1880		if (l->peer_caps & TIPC_LINK_PROTO_SEQNO)
1881			msg_set_seqno(hdr, l->snd_nxt_state++);
1882		msg_set_seq_gap(hdr, rcvgap);
1883		bc_rcvgap = link_bc_rcv_gap(bcl);
1884		msg_set_bc_gap(hdr, bc_rcvgap);
1885		msg_set_probe(hdr, probe);
1886		msg_set_is_keepalive(hdr, probe || probe_reply);
1887		if (l->peer_caps & TIPC_GAP_ACK_BLOCK)
1888			glen = tipc_build_gap_ack_blks(l, hdr);
1889		tipc_mon_prep(l->net, data + glen, &dlen, mstate, l->bearer_id);
1890		msg_set_size(hdr, INT_H_SIZE + glen + dlen);
1891		skb_trim(skb, INT_H_SIZE + glen + dlen);
1892		l->stats.sent_states++;
1893		l->rcv_unacked = 0;
1894	} else {
1895		/* RESET_MSG or ACTIVATE_MSG */
1896		if (mtyp == ACTIVATE_MSG) {
1897			msg_set_dest_session_valid(hdr, 1);
1898			msg_set_dest_session(hdr, l->peer_session);
1899		}
1900		msg_set_max_pkt(hdr, l->advertised_mtu);
1901		strcpy(data, l->if_name);
1902		msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
1903		skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
1904	}
1905	if (probe)
1906		l->stats.sent_probes++;
1907	if (rcvgap)
1908		l->stats.sent_nacks++;
1909	if (bc_rcvgap)
1910		bcl->stats.sent_nacks++;
1911	skb->priority = TC_PRIO_CONTROL;
1912	__skb_queue_tail(xmitq, skb);
1913	trace_tipc_proto_build(skb, false, l->name);
1914}
1915
1916void tipc_link_create_dummy_tnl_msg(struct tipc_link *l,
1917				    struct sk_buff_head *xmitq)
1918{
1919	u32 onode = tipc_own_addr(l->net);
1920	struct tipc_msg *hdr, *ihdr;
1921	struct sk_buff_head tnlq;
1922	struct sk_buff *skb;
1923	u32 dnode = l->addr;
1924
1925	__skb_queue_head_init(&tnlq);
1926	skb = tipc_msg_create(TUNNEL_PROTOCOL, FAILOVER_MSG,
1927			      INT_H_SIZE, BASIC_H_SIZE,
1928			      dnode, onode, 0, 0, 0);
1929	if (!skb) {
1930		pr_warn("%sunable to create tunnel packet\n", link_co_err);
1931		return;
1932	}
1933
1934	hdr = buf_msg(skb);
1935	msg_set_msgcnt(hdr, 1);
1936	msg_set_bearer_id(hdr, l->peer_bearer_id);
1937
1938	ihdr = (struct tipc_msg *)msg_data(hdr);
1939	tipc_msg_init(onode, ihdr, TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1940		      BASIC_H_SIZE, dnode);
1941	msg_set_errcode(ihdr, TIPC_ERR_NO_PORT);
1942	__skb_queue_tail(&tnlq, skb);
1943	tipc_link_xmit(l, &tnlq, xmitq);
1944}
1945
1946/* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1947 * with contents of the link's transmit and backlog queues.
1948 */
1949void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1950			   int mtyp, struct sk_buff_head *xmitq)
1951{
1952	struct sk_buff *skb, *tnlskb;
1953	struct tipc_msg *hdr, tnlhdr;
1954	struct sk_buff_head *queue = &l->transmq;
1955	struct sk_buff_head tmpxq, tnlq, frags;
1956	u16 pktlen, pktcnt, seqno = l->snd_nxt;
1957	bool pktcnt_need_update = false;
1958	u16 syncpt;
1959	int rc;
1960
1961	if (!tnl)
1962		return;
1963
1964	__skb_queue_head_init(&tnlq);
1965	/* Link Synching:
1966	 * From now on, send only one single ("dummy") SYNCH message
1967	 * to peer. The SYNCH message does not contain any data, just
1968	 * a header conveying the synch point to the peer.
1969	 */
1970	if (mtyp == SYNCH_MSG && (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
1971		tnlskb = tipc_msg_create(TUNNEL_PROTOCOL, SYNCH_MSG,
1972					 INT_H_SIZE, 0, l->addr,
1973					 tipc_own_addr(l->net),
1974					 0, 0, 0);
1975		if (!tnlskb) {
1976			pr_warn("%sunable to create dummy SYNCH_MSG\n",
1977				link_co_err);
1978			return;
1979		}
1980
1981		hdr = buf_msg(tnlskb);
1982		syncpt = l->snd_nxt + skb_queue_len(&l->backlogq) - 1;
1983		msg_set_syncpt(hdr, syncpt);
1984		msg_set_bearer_id(hdr, l->peer_bearer_id);
1985		__skb_queue_tail(&tnlq, tnlskb);
1986		tipc_link_xmit(tnl, &tnlq, xmitq);
1987		return;
1988	}
1989
1990	__skb_queue_head_init(&tmpxq);
1991	__skb_queue_head_init(&frags);
1992	/* At least one packet required for safe algorithm => add dummy */
1993	skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1994			      BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
1995			      0, 0, TIPC_ERR_NO_PORT);
1996	if (!skb) {
1997		pr_warn("%sunable to create tunnel packet\n", link_co_err);
1998		return;
1999	}
2000	__skb_queue_tail(&tnlq, skb);
2001	tipc_link_xmit(l, &tnlq, &tmpxq);
2002	__skb_queue_purge(&tmpxq);
2003
2004	/* Initialize reusable tunnel packet header */
2005	tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
2006		      mtyp, INT_H_SIZE, l->addr);
2007	if (mtyp == SYNCH_MSG)
2008		pktcnt = l->snd_nxt - buf_seqno(skb_peek(&l->transmq));
2009	else
2010		pktcnt = skb_queue_len(&l->transmq);
2011	pktcnt += skb_queue_len(&l->backlogq);
2012	msg_set_msgcnt(&tnlhdr, pktcnt);
2013	msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
2014tnl:
2015	/* Wrap each packet into a tunnel packet */
2016	skb_queue_walk(queue, skb) {
2017		hdr = buf_msg(skb);
2018		if (queue == &l->backlogq)
2019			msg_set_seqno(hdr, seqno++);
2020		pktlen = msg_size(hdr);
2021
2022		/* Tunnel link MTU is not large enough? This could be
2023		 * due to:
2024		 * 1) Link MTU has just changed or set differently;
2025		 * 2) Or FAILOVER on the top of a SYNCH message
2026		 *
2027		 * The 2nd case should not happen if peer supports
2028		 * TIPC_TUNNEL_ENHANCED
2029		 */
2030		if (pktlen > tnl->mtu - INT_H_SIZE) {
2031			if (mtyp == FAILOVER_MSG &&
2032			    (tnl->peer_caps & TIPC_TUNNEL_ENHANCED)) {
2033				rc = tipc_msg_fragment(skb, &tnlhdr, tnl->mtu,
2034						       &frags);
2035				if (rc) {
2036					pr_warn("%sunable to frag msg: rc %d\n",
2037						link_co_err, rc);
2038					return;
2039				}
2040				pktcnt += skb_queue_len(&frags) - 1;
2041				pktcnt_need_update = true;
2042				skb_queue_splice_tail_init(&frags, &tnlq);
2043				continue;
2044			}
2045			/* Unluckily, peer doesn't have TIPC_TUNNEL_ENHANCED
2046			 * => Just warn it and return!
2047			 */
2048			pr_warn_ratelimited("%stoo large msg <%d, %d>: %d!\n",
2049					    link_co_err, msg_user(hdr),
2050					    msg_type(hdr), msg_size(hdr));
2051			return;
2052		}
2053
2054		msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
2055		tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
2056		if (!tnlskb) {
2057			pr_warn("%sunable to send packet\n", link_co_err);
2058			return;
2059		}
2060		skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
2061		skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
2062		__skb_queue_tail(&tnlq, tnlskb);
2063	}
2064	if (queue != &l->backlogq) {
2065		queue = &l->backlogq;
2066		goto tnl;
2067	}
2068
2069	if (pktcnt_need_update)
2070		skb_queue_walk(&tnlq, skb) {
2071			hdr = buf_msg(skb);
2072			msg_set_msgcnt(hdr, pktcnt);
2073		}
2074
2075	tipc_link_xmit(tnl, &tnlq, xmitq);
2076
2077	if (mtyp == FAILOVER_MSG) {
2078		struct sk_buff_head *fdefq = &tnl->failover_deferdq;
2079
2080		tnl->drop_point = l->rcv_nxt;
2081		tnl->failover_reasm_skb = l->reasm_buf;
2082		l->reasm_buf = NULL;
2083
2084		/* Failover the link's deferdq */
2085		if (unlikely(!skb_queue_empty(fdefq))) {
2086			pr_warn("Link failover deferdq not empty: %d!\n",
2087				skb_queue_len(fdefq));
2088			__skb_queue_purge(fdefq);
2089		}
2090		skb_queue_splice_init(&l->deferdq, fdefq);
2091	}
2092}
2093
2094/**
2095 * tipc_link_failover_prepare() - prepare tnl for link failover
2096 *
2097 * This is a special version of the precursor - tipc_link_tnl_prepare(),
2098 * see the tipc_node_link_failover() for details
2099 *
2100 * @l: failover link
2101 * @tnl: tunnel link
2102 * @xmitq: queue for messages to be xmited
2103 */
2104void tipc_link_failover_prepare(struct tipc_link *l, struct tipc_link *tnl,
2105				struct sk_buff_head *xmitq)
2106{
2107	struct sk_buff_head *fdefq = &tnl->failover_deferdq;
2108
2109	tipc_link_create_dummy_tnl_msg(tnl, xmitq);
2110
2111	/* This failover link endpoint was never established before,
2112	 * so it has not received anything from peer.
2113	 * Otherwise, it must be a normal failover situation or the
2114	 * node has entered SELF_DOWN_PEER_LEAVING and both peer nodes
2115	 * would have to start over from scratch instead.
2116	 */
2117	tnl->drop_point = 1;
2118	tnl->failover_reasm_skb = NULL;
2119
2120	/* Initiate the link's failover deferdq */
2121	if (unlikely(!skb_queue_empty(fdefq))) {
2122		pr_warn("Link failover deferdq not empty: %d!\n",
2123			skb_queue_len(fdefq));
2124		__skb_queue_purge(fdefq);
2125	}
2126}
2127
2128/* tipc_link_validate_msg(): validate message against current link state
2129 * Returns true if message should be accepted, otherwise false
2130 */
2131bool tipc_link_validate_msg(struct tipc_link *l, struct tipc_msg *hdr)
2132{
2133	u16 curr_session = l->peer_session;
2134	u16 session = msg_session(hdr);
2135	int mtyp = msg_type(hdr);
2136
2137	if (msg_user(hdr) != LINK_PROTOCOL)
2138		return true;
2139
2140	switch (mtyp) {
2141	case RESET_MSG:
2142		if (!l->in_session)
2143			return true;
2144		/* Accept only RESET with new session number */
2145		return more(session, curr_session);
2146	case ACTIVATE_MSG:
2147		if (!l->in_session)
2148			return true;
2149		/* Accept only ACTIVATE with new or current session number */
2150		return !less(session, curr_session);
2151	case STATE_MSG:
2152		/* Accept only STATE with current session number */
2153		if (!l->in_session)
2154			return false;
2155		if (session != curr_session)
2156			return false;
2157		/* Extra sanity check */
2158		if (!tipc_link_is_up(l) && msg_ack(hdr))
2159			return false;
2160		if (!(l->peer_caps & TIPC_LINK_PROTO_SEQNO))
2161			return true;
2162		/* Accept only STATE with new sequence number */
2163		return !less(msg_seqno(hdr), l->rcv_nxt_state);
2164	default:
2165		return false;
2166	}
2167}
2168
2169/* tipc_link_proto_rcv(): receive link level protocol message :
2170 * Note that network plane id propagates through the network, and may
2171 * change at any time. The node with lowest numerical id determines
2172 * network plane
2173 */
2174static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
2175			       struct sk_buff_head *xmitq)
2176{
2177	struct tipc_msg *hdr = buf_msg(skb);
2178	struct tipc_gap_ack_blks *ga = NULL;
2179	bool reply = msg_probe(hdr), retransmitted = false;
2180	u32 dlen = msg_data_sz(hdr), glen = 0, msg_max;
2181	u16 peers_snd_nxt =  msg_next_sent(hdr);
2182	u16 peers_tol = msg_link_tolerance(hdr);
2183	u16 peers_prio = msg_linkprio(hdr);
2184	u16 gap = msg_seq_gap(hdr);
2185	u16 ack = msg_ack(hdr);
2186	u16 rcv_nxt = l->rcv_nxt;
2187	u16 rcvgap = 0;
2188	int mtyp = msg_type(hdr);
2189	int rc = 0, released;
2190	char *if_name;
2191	void *data;
2192
2193	trace_tipc_proto_rcv(skb, false, l->name);
2194
2195	if (dlen > U16_MAX)
2196		goto exit;
2197
2198	if (tipc_link_is_blocked(l) || !xmitq)
2199		goto exit;
2200
2201	if (tipc_own_addr(l->net) > msg_prevnode(hdr))
2202		l->net_plane = msg_net_plane(hdr);
2203
2204	if (skb_linearize(skb))
2205		goto exit;
2206
2207	hdr = buf_msg(skb);
2208	data = msg_data(hdr);
2209
2210	if (!tipc_link_validate_msg(l, hdr)) {
2211		trace_tipc_skb_dump(skb, false, "PROTO invalid (1)!");
2212		trace_tipc_link_dump(l, TIPC_DUMP_NONE, "PROTO invalid (1)!");
2213		goto exit;
2214	}
2215
2216	switch (mtyp) {
2217	case RESET_MSG:
2218	case ACTIVATE_MSG:
2219		msg_max = msg_max_pkt(hdr);
2220		if (msg_max < tipc_bearer_min_mtu(l->net, l->bearer_id))
2221			break;
2222		/* Complete own link name with peer's interface name */
2223		if_name =  strrchr(l->name, ':') + 1;
2224		if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
2225			break;
2226		if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
2227			break;
2228		strscpy(if_name, data, TIPC_MAX_IF_NAME);
2229
2230		/* Update own tolerance if peer indicates a non-zero value */
2231		if (tipc_in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2232			l->tolerance = peers_tol;
2233			l->bc_rcvlink->tolerance = peers_tol;
2234		}
2235		/* Update own priority if peer's priority is higher */
2236		if (tipc_in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
2237			l->priority = peers_prio;
2238
2239		/* If peer is going down we want full re-establish cycle */
2240		if (msg_peer_stopping(hdr)) {
2241			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2242			break;
2243		}
2244
2245		/* If this endpoint was re-created while peer was ESTABLISHING
2246		 * it doesn't know current session number. Force re-synch.
2247		 */
2248		if (mtyp == ACTIVATE_MSG && msg_dest_session_valid(hdr) &&
2249		    l->session != msg_dest_session(hdr)) {
2250			if (less(l->session, msg_dest_session(hdr)))
2251				l->session = msg_dest_session(hdr) + 1;
2252			break;
2253		}
2254
2255		/* ACTIVATE_MSG serves as PEER_RESET if link is already down */
2256		if (mtyp == RESET_MSG || !tipc_link_is_up(l))
2257			rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
2258
2259		/* ACTIVATE_MSG takes up link if it was already locally reset */
2260		if (mtyp == ACTIVATE_MSG && l->state == LINK_ESTABLISHING)
2261			rc = TIPC_LINK_UP_EVT;
2262
2263		l->peer_session = msg_session(hdr);
2264		l->in_session = true;
2265		l->peer_bearer_id = msg_bearer_id(hdr);
2266		if (l->mtu > msg_max)
2267			l->mtu = msg_max;
2268		break;
2269
2270	case STATE_MSG:
2271		/* Validate Gap ACK blocks, drop if invalid */
2272		glen = tipc_get_gap_ack_blks(&ga, l, hdr, true);
2273		if (glen > dlen)
2274			break;
2275
2276		l->rcv_nxt_state = msg_seqno(hdr) + 1;
2277
2278		/* Update own tolerance if peer indicates a non-zero value */
2279		if (tipc_in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL)) {
2280			l->tolerance = peers_tol;
2281			l->bc_rcvlink->tolerance = peers_tol;
2282		}
2283		/* Update own prio if peer indicates a different value */
2284		if ((peers_prio != l->priority) &&
2285		    tipc_in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) {
2286			l->priority = peers_prio;
2287			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
2288		}
2289
2290		l->silent_intv_cnt = 0;
2291		l->stats.recv_states++;
2292		if (msg_probe(hdr))
2293			l->stats.recv_probes++;
2294
2295		if (!tipc_link_is_up(l)) {
2296			if (l->state == LINK_ESTABLISHING)
2297				rc = TIPC_LINK_UP_EVT;
2298			break;
2299		}
2300
2301		tipc_mon_rcv(l->net, data + glen, dlen - glen, l->addr,
2302			     &l->mon_state, l->bearer_id);
2303
2304		/* Send NACK if peer has sent pkts we haven't received yet */
2305		if ((reply || msg_is_keepalive(hdr)) &&
2306		    more(peers_snd_nxt, rcv_nxt) &&
2307		    !tipc_link_is_synching(l) &&
2308		    skb_queue_empty(&l->deferdq))
2309			rcvgap = peers_snd_nxt - l->rcv_nxt;
2310		if (rcvgap || reply)
2311			tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,
2312						  rcvgap, 0, 0, xmitq);
2313
2314		released = tipc_link_advance_transmq(l, l, ack, gap, ga, xmitq,
2315						     &retransmitted, &rc);
2316		if (gap)
2317			l->stats.recv_nacks++;
2318		if (released || retransmitted)
2319			tipc_link_update_cwin(l, released, retransmitted);
2320		if (released)
2321			tipc_link_advance_backlog(l, xmitq);
2322		if (unlikely(!skb_queue_empty(&l->wakeupq)))
2323			link_prepare_wakeup(l);
2324	}
2325exit:
2326	kfree_skb(skb);
2327	return rc;
2328}
2329
2330/* tipc_link_build_bc_proto_msg() - create broadcast protocol message
2331 */
2332static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
2333					 u16 peers_snd_nxt,
2334					 struct sk_buff_head *xmitq)
2335{
2336	struct sk_buff *skb;
2337	struct tipc_msg *hdr;
2338	struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
2339	u16 ack = l->rcv_nxt - 1;
2340	u16 gap_to = peers_snd_nxt - 1;
2341
2342	skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
2343			      0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
2344	if (!skb)
2345		return false;
2346	hdr = buf_msg(skb);
2347	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
2348	msg_set_bcast_ack(hdr, ack);
2349	msg_set_bcgap_after(hdr, ack);
2350	if (dfrd_skb)
2351		gap_to = buf_seqno(dfrd_skb) - 1;
2352	msg_set_bcgap_to(hdr, gap_to);
2353	msg_set_non_seq(hdr, bcast);
2354	__skb_queue_tail(xmitq, skb);
2355	return true;
2356}
2357
2358/* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
2359 *
2360 * Give a newly added peer node the sequence number where it should
2361 * start receiving and acking broadcast packets.
2362 */
2363static void tipc_link_build_bc_init_msg(struct tipc_link *l,
2364					struct sk_buff_head *xmitq)
2365{
2366	struct sk_buff_head list;
2367
2368	__skb_queue_head_init(&list);
2369	if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
2370		return;
2371	msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true);
2372	tipc_link_xmit(l, &list, xmitq);
2373}
2374
2375/* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
2376 */
2377void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
2378{
2379	int mtyp = msg_type(hdr);
2380	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2381
2382	if (tipc_link_is_up(l))
2383		return;
2384
2385	if (msg_user(hdr) == BCAST_PROTOCOL) {
2386		l->rcv_nxt = peers_snd_nxt;
2387		l->state = LINK_ESTABLISHED;
2388		return;
2389	}
2390
2391	if (l->peer_caps & TIPC_BCAST_SYNCH)
2392		return;
2393
2394	if (msg_peer_node_is_up(hdr))
2395		return;
2396
2397	/* Compatibility: accept older, less safe initial synch data */
2398	if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
2399		l->rcv_nxt = peers_snd_nxt;
2400}
2401
2402/* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
2403 */
2404int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
2405			  struct sk_buff_head *xmitq)
2406{
2407	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
2408	int rc = 0;
2409
2410	if (!tipc_link_is_up(l))
2411		return rc;
2412
2413	if (!msg_peer_node_is_up(hdr))
2414		return rc;
2415
2416	/* Open when peer acknowledges our bcast init msg (pkt #1) */
2417	if (msg_ack(hdr))
2418		l->bc_peer_is_up = true;
2419
2420	if (!l->bc_peer_is_up)
2421		return rc;
2422
2423	/* Ignore if peers_snd_nxt goes beyond receive window */
2424	if (more(peers_snd_nxt, l->rcv_nxt + l->window))
2425		return rc;
2426
2427	l->snd_nxt = peers_snd_nxt;
2428	if (link_bc_rcv_gap(l))
2429		rc |= TIPC_LINK_SND_STATE;
2430
2431	/* Return now if sender supports nack via STATE messages */
2432	if (l->peer_caps & TIPC_BCAST_STATE_NACK)
2433		return rc;
2434
2435	/* Otherwise, be backwards compatible */
2436
2437	if (!more(peers_snd_nxt, l->rcv_nxt)) {
2438		l->nack_state = BC_NACK_SND_CONDITIONAL;
2439		return 0;
2440	}
2441
2442	/* Don't NACK if one was recently sent or peeked */
2443	if (l->nack_state == BC_NACK_SND_SUPPRESS) {
2444		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2445		return 0;
2446	}
2447
2448	/* Conditionally delay NACK sending until next synch rcv */
2449	if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
2450		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
2451		if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
2452			return 0;
2453	}
2454
2455	/* Send NACK now but suppress next one */
2456	tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
2457	l->nack_state = BC_NACK_SND_SUPPRESS;
2458	return 0;
2459}
2460
2461int tipc_link_bc_ack_rcv(struct tipc_link *r, u16 acked, u16 gap,
2462			 struct tipc_gap_ack_blks *ga,
2463			 struct sk_buff_head *xmitq,
2464			 struct sk_buff_head *retrq)
2465{
2466	struct tipc_link *l = r->bc_sndlink;
2467	bool unused = false;
2468	int rc = 0;
2469
2470	if (!tipc_link_is_up(r) || !r->bc_peer_is_up)
2471		return 0;
2472
2473	if (gap) {
2474		l->stats.recv_nacks++;
2475		r->stats.recv_nacks++;
2476	}
2477
2478	if (less(acked, r->acked) || (acked == r->acked && !gap && !ga))
2479		return 0;
2480
2481	trace_tipc_link_bc_ack(r, acked, gap, &l->transmq);
2482	tipc_link_advance_transmq(l, r, acked, gap, ga, retrq, &unused, &rc);
2483
2484	tipc_link_advance_backlog(l, xmitq);
2485	if (unlikely(!skb_queue_empty(&l->wakeupq)))
2486		link_prepare_wakeup(l);
2487
2488	return rc;
2489}
2490
2491/* tipc_link_bc_nack_rcv(): receive broadcast nack message
2492 * This function is here for backwards compatibility, since
2493 * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
2494 */
2495int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
2496			  struct sk_buff_head *xmitq)
2497{
2498	struct tipc_msg *hdr = buf_msg(skb);
2499	u32 dnode = msg_destnode(hdr);
2500	int mtyp = msg_type(hdr);
2501	u16 acked = msg_bcast_ack(hdr);
2502	u16 from = acked + 1;
2503	u16 to = msg_bcgap_to(hdr);
2504	u16 peers_snd_nxt = to + 1;
2505	int rc = 0;
2506
2507	kfree_skb(skb);
2508
2509	if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
2510		return 0;
2511
2512	if (mtyp != STATE_MSG)
2513		return 0;
2514
2515	if (dnode == tipc_own_addr(l->net)) {
2516		rc = tipc_link_bc_ack_rcv(l, acked, to - acked, NULL, xmitq,
2517					  xmitq);
2518		l->stats.recv_nacks++;
2519		return rc;
2520	}
2521
2522	/* Msg for other node => suppress own NACK at next sync if applicable */
2523	if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
2524		l->nack_state = BC_NACK_SND_SUPPRESS;
2525
2526	return 0;
2527}
2528
2529void tipc_link_set_queue_limits(struct tipc_link *l, u32 min_win, u32 max_win)
2530{
2531	int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE);
2532
2533	l->min_win = min_win;
2534	l->ssthresh = max_win;
2535	l->max_win = max_win;
2536	l->window = min_win;
2537	l->backlog[TIPC_LOW_IMPORTANCE].limit      = min_win * 2;
2538	l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = min_win * 4;
2539	l->backlog[TIPC_HIGH_IMPORTANCE].limit     = min_win * 6;
2540	l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = min_win * 8;
2541	l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
2542}
2543
2544/**
2545 * tipc_link_reset_stats - reset link statistics
2546 * @l: pointer to link
2547 */
2548void tipc_link_reset_stats(struct tipc_link *l)
2549{
2550	memset(&l->stats, 0, sizeof(l->stats));
2551}
2552
2553static void link_print(struct tipc_link *l, const char *str)
2554{
2555	struct sk_buff *hskb = skb_peek(&l->transmq);
2556	u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
2557	u16 tail = l->snd_nxt - 1;
2558
2559	pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
2560	pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
2561		skb_queue_len(&l->transmq), head, tail,
2562		skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
2563}
2564
2565/* Parse and validate nested (link) properties valid for media, bearer and link
2566 */
2567int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
2568{
2569	int err;
2570
2571	err = nla_parse_nested_deprecated(props, TIPC_NLA_PROP_MAX, prop,
2572					  tipc_nl_prop_policy, NULL);
2573	if (err)
2574		return err;
2575
2576	if (props[TIPC_NLA_PROP_PRIO]) {
2577		u32 prio;
2578
2579		prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2580		if (prio > TIPC_MAX_LINK_PRI)
2581			return -EINVAL;
2582	}
2583
2584	if (props[TIPC_NLA_PROP_TOL]) {
2585		u32 tol;
2586
2587		tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2588		if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
2589			return -EINVAL;
2590	}
2591
2592	if (props[TIPC_NLA_PROP_WIN]) {
2593		u32 max_win;
2594
2595		max_win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2596		if (max_win < TIPC_DEF_LINK_WIN || max_win > TIPC_MAX_LINK_WIN)
2597			return -EINVAL;
2598	}
2599
2600	return 0;
2601}
2602
2603static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
2604{
2605	int i;
2606	struct nlattr *stats;
2607
2608	struct nla_map {
2609		u32 key;
2610		u32 val;
2611	};
2612
2613	struct nla_map map[] = {
2614		{TIPC_NLA_STATS_RX_INFO, 0},
2615		{TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
2616		{TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
2617		{TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
2618		{TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
2619		{TIPC_NLA_STATS_TX_INFO, 0},
2620		{TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
2621		{TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
2622		{TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
2623		{TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
2624		{TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
2625			s->msg_length_counts : 1},
2626		{TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
2627		{TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
2628		{TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
2629		{TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
2630		{TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
2631		{TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
2632		{TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
2633		{TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
2634		{TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
2635		{TIPC_NLA_STATS_RX_STATES, s->recv_states},
2636		{TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
2637		{TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
2638		{TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
2639		{TIPC_NLA_STATS_TX_STATES, s->sent_states},
2640		{TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
2641		{TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
2642		{TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
2643		{TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
2644		{TIPC_NLA_STATS_DUPLICATES, s->duplicates},
2645		{TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
2646		{TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
2647		{TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
2648			(s->accu_queue_sz / s->queue_sz_counts) : 0}
2649	};
2650
2651	stats = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2652	if (!stats)
2653		return -EMSGSIZE;
2654
2655	for (i = 0; i <  ARRAY_SIZE(map); i++)
2656		if (nla_put_u32(skb, map[i].key, map[i].val))
2657			goto msg_full;
2658
2659	nla_nest_end(skb, stats);
2660
2661	return 0;
2662msg_full:
2663	nla_nest_cancel(skb, stats);
2664
2665	return -EMSGSIZE;
2666}
2667
2668/* Caller should hold appropriate locks to protect the link */
2669int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
2670		       struct tipc_link *link, int nlflags)
2671{
2672	u32 self = tipc_own_addr(net);
2673	struct nlattr *attrs;
2674	struct nlattr *prop;
2675	void *hdr;
2676	int err;
2677
2678	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2679			  nlflags, TIPC_NL_LINK_GET);
2680	if (!hdr)
2681		return -EMSGSIZE;
2682
2683	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2684	if (!attrs)
2685		goto msg_full;
2686
2687	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2688		goto attr_msg_full;
2689	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, tipc_cluster_mask(self)))
2690		goto attr_msg_full;
2691	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2692		goto attr_msg_full;
2693	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
2694		goto attr_msg_full;
2695	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
2696		goto attr_msg_full;
2697
2698	if (tipc_link_is_up(link))
2699		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2700			goto attr_msg_full;
2701	if (link->active)
2702		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2703			goto attr_msg_full;
2704
2705	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2706	if (!prop)
2707		goto attr_msg_full;
2708	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2709		goto prop_msg_full;
2710	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2711		goto prop_msg_full;
2712	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2713			link->window))
2714		goto prop_msg_full;
2715	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2716		goto prop_msg_full;
2717	nla_nest_end(msg->skb, prop);
2718
2719	err = __tipc_nl_add_stats(msg->skb, &link->stats);
2720	if (err)
2721		goto attr_msg_full;
2722
2723	nla_nest_end(msg->skb, attrs);
2724	genlmsg_end(msg->skb, hdr);
2725
2726	return 0;
2727
2728prop_msg_full:
2729	nla_nest_cancel(msg->skb, prop);
2730attr_msg_full:
2731	nla_nest_cancel(msg->skb, attrs);
2732msg_full:
2733	genlmsg_cancel(msg->skb, hdr);
2734
2735	return -EMSGSIZE;
2736}
2737
2738static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
2739				      struct tipc_stats *stats)
2740{
2741	int i;
2742	struct nlattr *nest;
2743
2744	struct nla_map {
2745		__u32 key;
2746		__u32 val;
2747	};
2748
2749	struct nla_map map[] = {
2750		{TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
2751		{TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
2752		{TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
2753		{TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
2754		{TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
2755		{TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
2756		{TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
2757		{TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
2758		{TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
2759		{TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
2760		{TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
2761		{TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
2762		{TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
2763		{TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
2764		{TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
2765		{TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
2766		{TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
2767		{TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
2768		{TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
2769			(stats->accu_queue_sz / stats->queue_sz_counts) : 0}
2770	};
2771
2772	nest = nla_nest_start_noflag(skb, TIPC_NLA_LINK_STATS);
2773	if (!nest)
2774		return -EMSGSIZE;
2775
2776	for (i = 0; i <  ARRAY_SIZE(map); i++)
2777		if (nla_put_u32(skb, map[i].key, map[i].val))
2778			goto msg_full;
2779
2780	nla_nest_end(skb, nest);
2781
2782	return 0;
2783msg_full:
2784	nla_nest_cancel(skb, nest);
2785
2786	return -EMSGSIZE;
2787}
2788
2789int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg,
2790			struct tipc_link *bcl)
2791{
2792	int err;
2793	void *hdr;
2794	struct nlattr *attrs;
2795	struct nlattr *prop;
2796	u32 bc_mode = tipc_bcast_get_mode(net);
2797	u32 bc_ratio = tipc_bcast_get_broadcast_ratio(net);
2798
2799	if (!bcl)
2800		return 0;
2801
2802	tipc_bcast_lock(net);
2803
2804	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2805			  NLM_F_MULTI, TIPC_NL_LINK_GET);
2806	if (!hdr) {
2807		tipc_bcast_unlock(net);
2808		return -EMSGSIZE;
2809	}
2810
2811	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK);
2812	if (!attrs)
2813		goto msg_full;
2814
2815	/* The broadcast link is always up */
2816	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2817		goto attr_msg_full;
2818
2819	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
2820		goto attr_msg_full;
2821	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
2822		goto attr_msg_full;
2823	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
2824		goto attr_msg_full;
2825	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
2826		goto attr_msg_full;
2827
2828	prop = nla_nest_start_noflag(msg->skb, TIPC_NLA_LINK_PROP);
2829	if (!prop)
2830		goto attr_msg_full;
2831	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->max_win))
2832		goto prop_msg_full;
2833	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST, bc_mode))
2834		goto prop_msg_full;
2835	if (bc_mode & BCLINK_MODE_SEL)
2836		if (nla_put_u32(msg->skb, TIPC_NLA_PROP_BROADCAST_RATIO,
2837				bc_ratio))
2838			goto prop_msg_full;
2839	nla_nest_end(msg->skb, prop);
2840
2841	err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
2842	if (err)
2843		goto attr_msg_full;
2844
2845	tipc_bcast_unlock(net);
2846	nla_nest_end(msg->skb, attrs);
2847	genlmsg_end(msg->skb, hdr);
2848
2849	return 0;
2850
2851prop_msg_full:
2852	nla_nest_cancel(msg->skb, prop);
2853attr_msg_full:
2854	nla_nest_cancel(msg->skb, attrs);
2855msg_full:
2856	tipc_bcast_unlock(net);
2857	genlmsg_cancel(msg->skb, hdr);
2858
2859	return -EMSGSIZE;
2860}
2861
2862void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
2863			     struct sk_buff_head *xmitq)
2864{
2865	l->tolerance = tol;
2866	if (l->bc_rcvlink)
2867		l->bc_rcvlink->tolerance = tol;
2868	if (tipc_link_is_up(l))
2869		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
2870}
2871
2872void tipc_link_set_prio(struct tipc_link *l, u32 prio,
2873			struct sk_buff_head *xmitq)
2874{
2875	l->priority = prio;
2876	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, prio, xmitq);
2877}
2878
2879void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
2880{
2881	l->abort_limit = limit;
2882}
2883
2884/**
2885 * tipc_link_dump - dump TIPC link data
2886 * @l: tipc link to be dumped
2887 * @dqueues: bitmask to decide if any link queue to be dumped?
2888 *           - TIPC_DUMP_NONE: don't dump link queues
2889 *           - TIPC_DUMP_TRANSMQ: dump link transmq queue
2890 *           - TIPC_DUMP_BACKLOGQ: dump link backlog queue
2891 *           - TIPC_DUMP_DEFERDQ: dump link deferd queue
2892 *           - TIPC_DUMP_INPUTQ: dump link input queue
2893 *           - TIPC_DUMP_WAKEUP: dump link wakeup queue
2894 *           - TIPC_DUMP_ALL: dump all the link queues above
2895 * @buf: returned buffer of dump data in format
2896 */
2897int tipc_link_dump(struct tipc_link *l, u16 dqueues, char *buf)
2898{
2899	int i = 0;
2900	size_t sz = (dqueues) ? LINK_LMAX : LINK_LMIN;
2901	struct sk_buff_head *list;
2902	struct sk_buff *hskb, *tskb;
2903	u32 len;
2904
2905	if (!l) {
2906		i += scnprintf(buf, sz, "link data: (null)\n");
2907		return i;
2908	}
2909
2910	i += scnprintf(buf, sz, "link data: %x", l->addr);
2911	i += scnprintf(buf + i, sz - i, " %x", l->state);
2912	i += scnprintf(buf + i, sz - i, " %u", l->in_session);
2913	i += scnprintf(buf + i, sz - i, " %u", l->session);
2914	i += scnprintf(buf + i, sz - i, " %u", l->peer_session);
2915	i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt);
2916	i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt);
2917	i += scnprintf(buf + i, sz - i, " %u", l->snd_nxt_state);
2918	i += scnprintf(buf + i, sz - i, " %u", l->rcv_nxt_state);
2919	i += scnprintf(buf + i, sz - i, " %x", l->peer_caps);
2920	i += scnprintf(buf + i, sz - i, " %u", l->silent_intv_cnt);
2921	i += scnprintf(buf + i, sz - i, " %u", l->rst_cnt);
2922	i += scnprintf(buf + i, sz - i, " %u", 0);
2923	i += scnprintf(buf + i, sz - i, " %u", 0);
2924	i += scnprintf(buf + i, sz - i, " %u", l->acked);
2925
2926	list = &l->transmq;
2927	len = skb_queue_len(list);
2928	hskb = skb_peek(list);
2929	tskb = skb_peek_tail(list);
2930	i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2931		       (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2932		       (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2933
2934	list = &l->deferdq;
2935	len = skb_queue_len(list);
2936	hskb = skb_peek(list);
2937	tskb = skb_peek_tail(list);
2938	i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2939		       (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2940		       (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2941
2942	list = &l->backlogq;
2943	len = skb_queue_len(list);
2944	hskb = skb_peek(list);
2945	tskb = skb_peek_tail(list);
2946	i += scnprintf(buf + i, sz - i, " | %u %u %u", len,
2947		       (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2948		       (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2949
2950	list = l->inputq;
2951	len = skb_queue_len(list);
2952	hskb = skb_peek(list);
2953	tskb = skb_peek_tail(list);
2954	i += scnprintf(buf + i, sz - i, " | %u %u %u\n", len,
2955		       (hskb) ? msg_seqno(buf_msg(hskb)) : 0,
2956		       (tskb) ? msg_seqno(buf_msg(tskb)) : 0);
2957
2958	if (dqueues & TIPC_DUMP_TRANSMQ) {
2959		i += scnprintf(buf + i, sz - i, "transmq: ");
2960		i += tipc_list_dump(&l->transmq, false, buf + i);
2961	}
2962	if (dqueues & TIPC_DUMP_BACKLOGQ) {
2963		i += scnprintf(buf + i, sz - i,
2964			       "backlogq: <%u %u %u %u %u>, ",
2965			       l->backlog[TIPC_LOW_IMPORTANCE].len,
2966			       l->backlog[TIPC_MEDIUM_IMPORTANCE].len,
2967			       l->backlog[TIPC_HIGH_IMPORTANCE].len,
2968			       l->backlog[TIPC_CRITICAL_IMPORTANCE].len,
2969			       l->backlog[TIPC_SYSTEM_IMPORTANCE].len);
2970		i += tipc_list_dump(&l->backlogq, false, buf + i);
2971	}
2972	if (dqueues & TIPC_DUMP_DEFERDQ) {
2973		i += scnprintf(buf + i, sz - i, "deferdq: ");
2974		i += tipc_list_dump(&l->deferdq, false, buf + i);
2975	}
2976	if (dqueues & TIPC_DUMP_INPUTQ) {
2977		i += scnprintf(buf + i, sz - i, "inputq: ");
2978		i += tipc_list_dump(l->inputq, false, buf + i);
2979	}
2980	if (dqueues & TIPC_DUMP_WAKEUP) {
2981		i += scnprintf(buf + i, sz - i, "wakeup: ");
2982		i += tipc_list_dump(&l->wakeupq, false, buf + i);
2983	}
2984
2985	return i;
2986}