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
  46#include <linux/pkt_sched.h>
  47
  48struct tipc_stats {
  49	u32 sent_info;		/* used in counting # sent packets */
  50	u32 recv_info;		/* used in counting # recv'd packets */
  51	u32 sent_states;
  52	u32 recv_states;
  53	u32 sent_probes;
  54	u32 recv_probes;
  55	u32 sent_nacks;
  56	u32 recv_nacks;
  57	u32 sent_acks;
  58	u32 sent_bundled;
  59	u32 sent_bundles;
  60	u32 recv_bundled;
  61	u32 recv_bundles;
  62	u32 retransmitted;
  63	u32 sent_fragmented;
  64	u32 sent_fragments;
  65	u32 recv_fragmented;
  66	u32 recv_fragments;
  67	u32 link_congs;		/* # port sends blocked by congestion */
  68	u32 deferred_recv;
  69	u32 duplicates;
  70	u32 max_queue_sz;	/* send queue size high water mark */
  71	u32 accu_queue_sz;	/* used for send queue size profiling */
  72	u32 queue_sz_counts;	/* used for send queue size profiling */
  73	u32 msg_length_counts;	/* used for message length profiling */
  74	u32 msg_lengths_total;	/* used for message length profiling */
  75	u32 msg_length_profile[7]; /* used for msg. length profiling */
  76};
  77
  78/**
  79 * struct tipc_link - TIPC link data structure
  80 * @addr: network address of link's peer node
  81 * @name: link name character string
  82 * @media_addr: media address to use when sending messages over link
  83 * @timer: link timer
  84 * @net: pointer to namespace struct
  85 * @refcnt: reference counter for permanent references (owner node & timer)
  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 * @keepalive_intv: link keepalive timer interval
  91 * @abort_limit: # of unacknowledged continuity probes needed to reset link
  92 * @state: current state of link FSM
  93 * @peer_caps: bitmap describing capabilities of peer node
  94 * @silent_intv_cnt: # of timer intervals without any reception from peer
  95 * @proto_msg: template for control messages generated by link
  96 * @pmsg: convenience pointer to "proto_msg" field
  97 * @priority: current link priority
  98 * @net_plane: current link network plane ('A' through 'H')
 
  99 * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
 100 * @exp_msg_count: # of tunnelled messages expected during link changeover
 101 * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
 102 * @mtu: current maximum packet size for this link
 103 * @advertised_mtu: advertised own mtu when link is being established
 104 * @transmitq: queue for sent, non-acked messages
 105 * @backlogq: queue for messages waiting to be sent
 106 * @snt_nxt: next sequence number to use for outbound messages
 107 * @last_retransmitted: sequence number of most recently retransmitted message
 108 * @stale_count: # of identical retransmit requests made by peer
 109 * @ackers: # of peers that needs to ack each packet before it can be released
 110 * @acked: # last packet acked by a certain peer. Used for broadcast.
 111 * @rcv_nxt: next sequence number to expect for inbound messages
 112 * @deferred_queue: deferred queue saved OOS b'cast message received from node
 113 * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
 114 * @inputq: buffer queue for messages to be delivered upwards
 115 * @namedq: buffer queue for name table messages to be delivered upwards
 116 * @next_out: ptr to first unsent outbound message in queue
 117 * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
 118 * @long_msg_seq_no: next identifier to use for outbound fragmented messages
 119 * @reasm_buf: head of partially reassembled inbound message fragments
 120 * @bc_rcvr: marks that this is a broadcast receiver link
 121 * @stats: collects statistics regarding link activity
 122 */
 123struct tipc_link {
 124	u32 addr;
 125	char name[TIPC_MAX_LINK_NAME];
 126	struct net *net;
 127
 128	/* Management and link supervision data */
 129	u32 peer_session;
 130	u32 session;
 131	u32 peer_bearer_id;
 132	u32 bearer_id;
 133	u32 tolerance;
 134	unsigned long keepalive_intv;
 135	u32 abort_limit;
 136	u32 state;
 137	u16 peer_caps;
 138	bool active;
 139	u32 silent_intv_cnt;
 140	char if_name[TIPC_MAX_IF_NAME];
 141	u32 priority;
 142	char net_plane;
 
 
 143
 144	/* Failover/synch */
 145	u16 drop_point;
 146	struct sk_buff *failover_reasm_skb;
 147
 148	/* Max packet negotiation */
 149	u16 mtu;
 150	u16 advertised_mtu;
 151
 152	/* Sending */
 153	struct sk_buff_head transmq;
 154	struct sk_buff_head backlogq;
 155	struct {
 156		u16 len;
 157		u16 limit;
 158	} backlog[5];
 159	u16 snd_nxt;
 160	u16 last_retransm;
 161	u16 window;
 162	u32 stale_count;
 163
 164	/* Reception */
 165	u16 rcv_nxt;
 166	u32 rcv_unacked;
 167	struct sk_buff_head deferdq;
 168	struct sk_buff_head *inputq;
 169	struct sk_buff_head *namedq;
 170
 171	/* Congestion handling */
 172	struct sk_buff_head wakeupq;
 173
 174	/* Fragmentation/reassembly */
 175	struct sk_buff *reasm_buf;
 176
 177	/* Broadcast */
 178	u16 ackers;
 179	u16 acked;
 180	struct tipc_link *bc_rcvlink;
 181	struct tipc_link *bc_sndlink;
 182	int nack_state;
 
 
 
 183	bool bc_peer_is_up;
 184
 185	/* Statistics */
 186	struct tipc_stats stats;
 187};
 188
 189/*
 190 * Error message prefixes
 191 */
 192static const char *link_co_err = "Link tunneling error, ";
 193static const char *link_rst_msg = "Resetting link ";
 194
 195/* Send states for broadcast NACKs
 196 */
 197enum {
 198	BC_NACK_SND_CONDITIONAL,
 199	BC_NACK_SND_UNCONDITIONAL,
 200	BC_NACK_SND_SUPPRESS,
 201};
 202
 
 
 203/*
 204 * Interval between NACKs when packets arrive out of order
 205 */
 206#define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
 207
 208/* Wildcard value for link session numbers. When it is known that
 209 * peer endpoint is down, any session number must be accepted.
 210 */
 211#define ANY_SESSION 0x10000
 212
 213/* Link FSM states:
 214 */
 215enum {
 216	LINK_ESTABLISHED     = 0xe,
 217	LINK_ESTABLISHING    = 0xe  << 4,
 218	LINK_RESET           = 0x1  << 8,
 219	LINK_RESETTING       = 0x2  << 12,
 220	LINK_PEER_RESET      = 0xd  << 16,
 221	LINK_FAILINGOVER     = 0xf  << 20,
 222	LINK_SYNCHING        = 0xc  << 24
 223};
 224
 225/* Link FSM state checking routines
 226 */
 227static int link_is_up(struct tipc_link *l)
 228{
 229	return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
 230}
 231
 232static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 233			       struct sk_buff_head *xmitq);
 234static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 235				      u16 rcvgap, int tolerance, int priority,
 236				      struct sk_buff_head *xmitq);
 237static void link_print(struct tipc_link *l, const char *str);
 238static void tipc_link_build_nack_msg(struct tipc_link *l,
 239				     struct sk_buff_head *xmitq);
 240static void tipc_link_build_bc_init_msg(struct tipc_link *l,
 241					struct sk_buff_head *xmitq);
 242static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
 243
 244/*
 245 *  Simple non-static link routines (i.e. referenced outside this file)
 246 */
 247bool tipc_link_is_up(struct tipc_link *l)
 248{
 249	return link_is_up(l);
 250}
 251
 252bool tipc_link_peer_is_down(struct tipc_link *l)
 253{
 254	return l->state == LINK_PEER_RESET;
 255}
 256
 257bool tipc_link_is_reset(struct tipc_link *l)
 258{
 259	return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
 260}
 261
 262bool tipc_link_is_establishing(struct tipc_link *l)
 263{
 264	return l->state == LINK_ESTABLISHING;
 265}
 266
 267bool tipc_link_is_synching(struct tipc_link *l)
 268{
 269	return l->state == LINK_SYNCHING;
 270}
 271
 272bool tipc_link_is_failingover(struct tipc_link *l)
 273{
 274	return l->state == LINK_FAILINGOVER;
 275}
 276
 277bool tipc_link_is_blocked(struct tipc_link *l)
 278{
 279	return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
 280}
 281
 282static bool link_is_bc_sndlink(struct tipc_link *l)
 283{
 284	return !l->bc_sndlink;
 285}
 286
 287static bool link_is_bc_rcvlink(struct tipc_link *l)
 288{
 289	return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
 290}
 291
 292int tipc_link_is_active(struct tipc_link *l)
 293{
 294	return l->active;
 295}
 296
 297void tipc_link_set_active(struct tipc_link *l, bool active)
 298{
 299	l->active = active;
 300}
 301
 302u32 tipc_link_id(struct tipc_link *l)
 303{
 304	return l->peer_bearer_id << 16 | l->bearer_id;
 305}
 306
 307int tipc_link_window(struct tipc_link *l)
 308{
 309	return l->window;
 310}
 311
 312int tipc_link_prio(struct tipc_link *l)
 313{
 314	return l->priority;
 315}
 316
 317unsigned long tipc_link_tolerance(struct tipc_link *l)
 318{
 319	return l->tolerance;
 320}
 321
 322struct sk_buff_head *tipc_link_inputq(struct tipc_link *l)
 323{
 324	return l->inputq;
 325}
 326
 327char tipc_link_plane(struct tipc_link *l)
 328{
 329	return l->net_plane;
 330}
 331
 332void tipc_link_add_bc_peer(struct tipc_link *snd_l,
 333			   struct tipc_link *uc_l,
 334			   struct sk_buff_head *xmitq)
 335{
 336	struct tipc_link *rcv_l = uc_l->bc_rcvlink;
 337
 338	snd_l->ackers++;
 339	rcv_l->acked = snd_l->snd_nxt - 1;
 340	snd_l->state = LINK_ESTABLISHED;
 341	tipc_link_build_bc_init_msg(uc_l, xmitq);
 342}
 343
 344void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
 345			      struct tipc_link *rcv_l,
 346			      struct sk_buff_head *xmitq)
 347{
 348	u16 ack = snd_l->snd_nxt - 1;
 349
 350	snd_l->ackers--;
 
 
 351	tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
 352	tipc_link_reset(rcv_l);
 353	rcv_l->state = LINK_RESET;
 354	if (!snd_l->ackers) {
 355		tipc_link_reset(snd_l);
 356		snd_l->state = LINK_RESET;
 357		__skb_queue_purge(xmitq);
 358	}
 359}
 360
 361int tipc_link_bc_peers(struct tipc_link *l)
 362{
 363	return l->ackers;
 364}
 365
 
 
 
 
 
 
 
 
 
 
 
 
 366void tipc_link_set_mtu(struct tipc_link *l, int mtu)
 367{
 368	l->mtu = mtu;
 369}
 370
 371int tipc_link_mtu(struct tipc_link *l)
 372{
 373	return l->mtu;
 374}
 375
 376u16 tipc_link_rcv_nxt(struct tipc_link *l)
 377{
 378	return l->rcv_nxt;
 379}
 380
 381u16 tipc_link_acked(struct tipc_link *l)
 382{
 383	return l->acked;
 384}
 385
 386char *tipc_link_name(struct tipc_link *l)
 387{
 388	return l->name;
 389}
 390
 391/**
 392 * tipc_link_create - create a new link
 393 * @n: pointer to associated node
 394 * @if_name: associated interface name
 395 * @bearer_id: id (index) of associated bearer
 396 * @tolerance: link tolerance to be used by link
 397 * @net_plane: network plane (A,B,c..) this link belongs to
 398 * @mtu: mtu to be advertised by link
 399 * @priority: priority to be used by link
 400 * @window: send window to be used by link
 401 * @session: session to be used by link
 402 * @ownnode: identity of own node
 403 * @peer: node id of peer node
 404 * @peer_caps: bitmap describing peer node capabilities
 405 * @bc_sndlink: the namespace global link used for broadcast sending
 406 * @bc_rcvlink: the peer specific link used for broadcast reception
 407 * @inputq: queue to put messages ready for delivery
 408 * @namedq: queue to put binding table update messages ready for delivery
 409 * @link: return value, pointer to put the created link
 410 *
 411 * Returns true if link was created, otherwise false
 412 */
 413bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
 414		      int tolerance, char net_plane, u32 mtu, int priority,
 415		      int window, u32 session, u32 ownnode, u32 peer,
 416		      u16 peer_caps,
 417		      struct tipc_link *bc_sndlink,
 418		      struct tipc_link *bc_rcvlink,
 419		      struct sk_buff_head *inputq,
 420		      struct sk_buff_head *namedq,
 421		      struct tipc_link **link)
 422{
 423	struct tipc_link *l;
 424
 425	l = kzalloc(sizeof(*l), GFP_ATOMIC);
 426	if (!l)
 427		return false;
 428	*link = l;
 429	l->session = session;
 430
 431	/* Note: peer i/f name is completed by reset/activate message */
 432	sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 433		tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
 434		if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 435	strcpy(l->if_name, if_name);
 436	l->addr = peer;
 437	l->peer_caps = peer_caps;
 438	l->net = net;
 439	l->peer_session = ANY_SESSION;
 440	l->bearer_id = bearer_id;
 441	l->tolerance = tolerance;
 442	l->net_plane = net_plane;
 443	l->advertised_mtu = mtu;
 444	l->mtu = mtu;
 445	l->priority = priority;
 446	tipc_link_set_queue_limits(l, window);
 447	l->ackers = 1;
 448	l->bc_sndlink = bc_sndlink;
 449	l->bc_rcvlink = bc_rcvlink;
 450	l->inputq = inputq;
 451	l->namedq = namedq;
 452	l->state = LINK_RESETTING;
 453	__skb_queue_head_init(&l->transmq);
 454	__skb_queue_head_init(&l->backlogq);
 455	__skb_queue_head_init(&l->deferdq);
 456	skb_queue_head_init(&l->wakeupq);
 457	skb_queue_head_init(l->inputq);
 458	return true;
 459}
 460
 461/**
 462 * tipc_link_bc_create - create new link to be used for broadcast
 463 * @n: pointer to associated node
 464 * @mtu: mtu to be used
 465 * @window: send window to be used
 466 * @inputq: queue to put messages ready for delivery
 467 * @namedq: queue to put binding table update messages ready for delivery
 468 * @link: return value, pointer to put the created link
 469 *
 470 * Returns true if link was created, otherwise false
 471 */
 472bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
 473			 int mtu, int window, u16 peer_caps,
 474			 struct sk_buff_head *inputq,
 475			 struct sk_buff_head *namedq,
 476			 struct tipc_link *bc_sndlink,
 477			 struct tipc_link **link)
 478{
 479	struct tipc_link *l;
 480
 481	if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
 482			      0, ownnode, peer, peer_caps, bc_sndlink,
 483			      NULL, inputq, namedq, link))
 484		return false;
 485
 486	l = *link;
 487	strcpy(l->name, tipc_bclink_name);
 488	tipc_link_reset(l);
 489	l->state = LINK_RESET;
 490	l->ackers = 0;
 491	l->bc_rcvlink = l;
 492
 493	/* Broadcast send link is always up */
 494	if (link_is_bc_sndlink(l))
 495		l->state = LINK_ESTABLISHED;
 496
 497	return true;
 498}
 499
 500/**
 501 * tipc_link_fsm_evt - link finite state machine
 502 * @l: pointer to link
 503 * @evt: state machine event to be processed
 504 */
 505int tipc_link_fsm_evt(struct tipc_link *l, int evt)
 506{
 507	int rc = 0;
 508
 509	switch (l->state) {
 510	case LINK_RESETTING:
 511		switch (evt) {
 512		case LINK_PEER_RESET_EVT:
 513			l->state = LINK_PEER_RESET;
 514			break;
 515		case LINK_RESET_EVT:
 516			l->state = LINK_RESET;
 517			break;
 518		case LINK_FAILURE_EVT:
 519		case LINK_FAILOVER_BEGIN_EVT:
 520		case LINK_ESTABLISH_EVT:
 521		case LINK_FAILOVER_END_EVT:
 522		case LINK_SYNCH_BEGIN_EVT:
 523		case LINK_SYNCH_END_EVT:
 524		default:
 525			goto illegal_evt;
 526		}
 527		break;
 528	case LINK_RESET:
 529		switch (evt) {
 530		case LINK_PEER_RESET_EVT:
 531			l->state = LINK_ESTABLISHING;
 532			break;
 533		case LINK_FAILOVER_BEGIN_EVT:
 534			l->state = LINK_FAILINGOVER;
 535		case LINK_FAILURE_EVT:
 536		case LINK_RESET_EVT:
 537		case LINK_ESTABLISH_EVT:
 538		case LINK_FAILOVER_END_EVT:
 539			break;
 540		case LINK_SYNCH_BEGIN_EVT:
 541		case LINK_SYNCH_END_EVT:
 542		default:
 543			goto illegal_evt;
 544		}
 545		break;
 546	case LINK_PEER_RESET:
 547		switch (evt) {
 548		case LINK_RESET_EVT:
 549			l->state = LINK_ESTABLISHING;
 550			break;
 551		case LINK_PEER_RESET_EVT:
 552		case LINK_ESTABLISH_EVT:
 553		case LINK_FAILURE_EVT:
 554			break;
 555		case LINK_SYNCH_BEGIN_EVT:
 556		case LINK_SYNCH_END_EVT:
 557		case LINK_FAILOVER_BEGIN_EVT:
 558		case LINK_FAILOVER_END_EVT:
 559		default:
 560			goto illegal_evt;
 561		}
 562		break;
 563	case LINK_FAILINGOVER:
 564		switch (evt) {
 565		case LINK_FAILOVER_END_EVT:
 566			l->state = LINK_RESET;
 567			break;
 568		case LINK_PEER_RESET_EVT:
 569		case LINK_RESET_EVT:
 570		case LINK_ESTABLISH_EVT:
 571		case LINK_FAILURE_EVT:
 572			break;
 573		case LINK_FAILOVER_BEGIN_EVT:
 574		case LINK_SYNCH_BEGIN_EVT:
 575		case LINK_SYNCH_END_EVT:
 576		default:
 577			goto illegal_evt;
 578		}
 579		break;
 580	case LINK_ESTABLISHING:
 581		switch (evt) {
 582		case LINK_ESTABLISH_EVT:
 583			l->state = LINK_ESTABLISHED;
 584			break;
 585		case LINK_FAILOVER_BEGIN_EVT:
 586			l->state = LINK_FAILINGOVER;
 587			break;
 588		case LINK_RESET_EVT:
 589			l->state = LINK_RESET;
 590			break;
 591		case LINK_FAILURE_EVT:
 592		case LINK_PEER_RESET_EVT:
 593		case LINK_SYNCH_BEGIN_EVT:
 594		case LINK_FAILOVER_END_EVT:
 595			break;
 596		case LINK_SYNCH_END_EVT:
 597		default:
 598			goto illegal_evt;
 599		}
 600		break;
 601	case LINK_ESTABLISHED:
 602		switch (evt) {
 603		case LINK_PEER_RESET_EVT:
 604			l->state = LINK_PEER_RESET;
 605			rc |= TIPC_LINK_DOWN_EVT;
 606			break;
 607		case LINK_FAILURE_EVT:
 608			l->state = LINK_RESETTING;
 609			rc |= TIPC_LINK_DOWN_EVT;
 610			break;
 611		case LINK_RESET_EVT:
 612			l->state = LINK_RESET;
 613			break;
 614		case LINK_ESTABLISH_EVT:
 615		case LINK_SYNCH_END_EVT:
 616			break;
 617		case LINK_SYNCH_BEGIN_EVT:
 618			l->state = LINK_SYNCHING;
 619			break;
 620		case LINK_FAILOVER_BEGIN_EVT:
 621		case LINK_FAILOVER_END_EVT:
 622		default:
 623			goto illegal_evt;
 624		}
 625		break;
 626	case LINK_SYNCHING:
 627		switch (evt) {
 628		case LINK_PEER_RESET_EVT:
 629			l->state = LINK_PEER_RESET;
 630			rc |= TIPC_LINK_DOWN_EVT;
 631			break;
 632		case LINK_FAILURE_EVT:
 633			l->state = LINK_RESETTING;
 634			rc |= TIPC_LINK_DOWN_EVT;
 635			break;
 636		case LINK_RESET_EVT:
 637			l->state = LINK_RESET;
 638			break;
 639		case LINK_ESTABLISH_EVT:
 640		case LINK_SYNCH_BEGIN_EVT:
 641			break;
 642		case LINK_SYNCH_END_EVT:
 643			l->state = LINK_ESTABLISHED;
 644			break;
 645		case LINK_FAILOVER_BEGIN_EVT:
 646		case LINK_FAILOVER_END_EVT:
 647		default:
 648			goto illegal_evt;
 649		}
 650		break;
 651	default:
 652		pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
 653	}
 654	return rc;
 655illegal_evt:
 656	pr_err("Illegal FSM event %x in state %x on link %s\n",
 657	       evt, l->state, l->name);
 658	return rc;
 659}
 660
 661/* link_profile_stats - update statistical profiling of traffic
 662 */
 663static void link_profile_stats(struct tipc_link *l)
 664{
 665	struct sk_buff *skb;
 666	struct tipc_msg *msg;
 667	int length;
 668
 669	/* Update counters used in statistical profiling of send traffic */
 670	l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 671	l->stats.queue_sz_counts++;
 672
 673	skb = skb_peek(&l->transmq);
 674	if (!skb)
 675		return;
 676	msg = buf_msg(skb);
 677	length = msg_size(msg);
 678
 679	if (msg_user(msg) == MSG_FRAGMENTER) {
 680		if (msg_type(msg) != FIRST_FRAGMENT)
 681			return;
 682		length = msg_size(msg_get_wrapped(msg));
 683	}
 684	l->stats.msg_lengths_total += length;
 685	l->stats.msg_length_counts++;
 686	if (length <= 64)
 687		l->stats.msg_length_profile[0]++;
 688	else if (length <= 256)
 689		l->stats.msg_length_profile[1]++;
 690	else if (length <= 1024)
 691		l->stats.msg_length_profile[2]++;
 692	else if (length <= 4096)
 693		l->stats.msg_length_profile[3]++;
 694	else if (length <= 16384)
 695		l->stats.msg_length_profile[4]++;
 696	else if (length <= 32768)
 697		l->stats.msg_length_profile[5]++;
 698	else
 699		l->stats.msg_length_profile[6]++;
 700}
 701
 702/* tipc_link_timeout - perform periodic task as instructed from node timeout
 703 */
 704/* tipc_link_timeout - perform periodic task as instructed from node timeout
 705 */
 706int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 707{
 
 708	int rc = 0;
 709	int mtyp = STATE_MSG;
 710	bool xmit = false;
 711	bool prb = false;
 712	u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
 713	u16 bc_acked = l->bc_rcvlink->acked;
 714	bool bc_up = link_is_up(l->bc_rcvlink);
 715
 716	link_profile_stats(l);
 717
 718	switch (l->state) {
 719	case LINK_ESTABLISHED:
 720	case LINK_SYNCHING:
 721		if (!l->silent_intv_cnt) {
 722			if (bc_up && (bc_acked != bc_snt))
 723				xmit = true;
 724		} else if (l->silent_intv_cnt <= l->abort_limit) {
 725			xmit = true;
 726			prb = true;
 727		} else {
 728			rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 729		}
 730		l->silent_intv_cnt++;
 
 
 
 
 731		break;
 732	case LINK_RESET:
 733		xmit = true;
 
 734		mtyp = RESET_MSG;
 735		break;
 736	case LINK_ESTABLISHING:
 737		xmit = true;
 738		mtyp = ACTIVATE_MSG;
 739		break;
 740	case LINK_PEER_RESET:
 741	case LINK_RESETTING:
 742	case LINK_FAILINGOVER:
 743		break;
 744	default:
 745		break;
 746	}
 747
 748	if (xmit)
 749		tipc_link_build_proto_msg(l, mtyp, prb, 0, 0, 0, xmitq);
 750
 751	return rc;
 752}
 753
 754/**
 755 * link_schedule_user - schedule a message sender for wakeup after congestion
 756 * @link: congested link
 757 * @list: message that was attempted sent
 758 * Create pseudo msg to send back to user when congestion abates
 759 * Does not consume buffer list
 760 */
 761static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 762{
 763	struct tipc_msg *msg = buf_msg(skb_peek(list));
 764	int imp = msg_importance(msg);
 765	u32 oport = msg_origport(msg);
 766	u32 addr = tipc_own_addr(link->net);
 767	struct sk_buff *skb;
 768
 769	/* This really cannot happen...  */
 770	if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 771		pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 772		return -ENOBUFS;
 773	}
 774	/* Non-blocking sender: */
 775	if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 776		return -ELINKCONG;
 777
 778	/* Create and schedule wakeup pseudo message */
 779	skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 780			      addr, addr, oport, 0, 0);
 781	if (!skb)
 782		return -ENOBUFS;
 783	TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 784	TIPC_SKB_CB(skb)->chain_imp = imp;
 785	skb_queue_tail(&link->wakeupq, skb);
 786	link->stats.link_congs++;
 787	return -ELINKCONG;
 788}
 789
 790/**
 791 * link_prepare_wakeup - prepare users for wakeup after congestion
 792 * @link: congested link
 793 * Move a number of waiting users, as permitted by available space in
 794 * the send queue, from link wait queue to node wait queue for wakeup
 795 */
 796void link_prepare_wakeup(struct tipc_link *l)
 797{
 798	int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 799	int imp, lim;
 800	struct sk_buff *skb, *tmp;
 801
 802	skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 803		imp = TIPC_SKB_CB(skb)->chain_imp;
 804		lim = l->window + l->backlog[imp].limit;
 805		pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 806		if ((pnd[imp] + l->backlog[imp].len) >= lim)
 807			break;
 808		skb_unlink(skb, &l->wakeupq);
 809		skb_queue_tail(l->inputq, skb);
 810	}
 811}
 812
 813void tipc_link_reset(struct tipc_link *l)
 814{
 815	l->peer_session = ANY_SESSION;
 816	l->session++;
 817	l->mtu = l->advertised_mtu;
 818	__skb_queue_purge(&l->transmq);
 819	__skb_queue_purge(&l->deferdq);
 820	skb_queue_splice_init(&l->wakeupq, l->inputq);
 821	__skb_queue_purge(&l->backlogq);
 822	l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 823	l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 824	l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 825	l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 826	l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 827	kfree_skb(l->reasm_buf);
 828	kfree_skb(l->failover_reasm_skb);
 829	l->reasm_buf = NULL;
 830	l->failover_reasm_skb = NULL;
 831	l->rcv_unacked = 0;
 832	l->snd_nxt = 1;
 833	l->rcv_nxt = 1;
 834	l->acked = 0;
 835	l->silent_intv_cnt = 0;
 836	l->stats.recv_info = 0;
 837	l->stale_count = 0;
 838	l->bc_peer_is_up = false;
 
 839	tipc_link_reset_stats(l);
 840}
 841
 842/**
 843 * tipc_link_xmit(): enqueue buffer list according to queue situation
 844 * @link: link to use
 845 * @list: chain of buffers containing message
 846 * @xmitq: returned list of packets to be sent by caller
 847 *
 848 * Consumes the buffer chain, except when returning -ELINKCONG,
 849 * since the caller then may want to make more send attempts.
 850 * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 851 * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 852 */
 853int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 854		   struct sk_buff_head *xmitq)
 855{
 856	struct tipc_msg *hdr = buf_msg(skb_peek(list));
 857	unsigned int maxwin = l->window;
 858	unsigned int i, imp = msg_importance(hdr);
 859	unsigned int mtu = l->mtu;
 860	u16 ack = l->rcv_nxt - 1;
 861	u16 seqno = l->snd_nxt;
 862	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 863	struct sk_buff_head *transmq = &l->transmq;
 864	struct sk_buff_head *backlogq = &l->backlogq;
 865	struct sk_buff *skb, *_skb, *bskb;
 
 866
 867	/* Match msg importance against this and all higher backlog limits: */
 868	for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 869		if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
 870			return link_schedule_user(l, list);
 
 
 871	}
 872	if (unlikely(msg_size(hdr) > mtu)) {
 873		skb_queue_purge(list);
 874		return -EMSGSIZE;
 875	}
 876
 
 
 
 
 
 877	/* Prepare each packet for sending, and add to relevant queue: */
 878	while (skb_queue_len(list)) {
 879		skb = skb_peek(list);
 880		hdr = buf_msg(skb);
 881		msg_set_seqno(hdr, seqno);
 882		msg_set_ack(hdr, ack);
 883		msg_set_bcast_ack(hdr, bc_ack);
 884
 885		if (likely(skb_queue_len(transmq) < maxwin)) {
 886			_skb = skb_clone(skb, GFP_ATOMIC);
 887			if (!_skb) {
 888				skb_queue_purge(list);
 889				return -ENOBUFS;
 890			}
 891			__skb_dequeue(list);
 892			__skb_queue_tail(transmq, skb);
 893			__skb_queue_tail(xmitq, _skb);
 894			TIPC_SKB_CB(skb)->ackers = l->ackers;
 895			l->rcv_unacked = 0;
 
 896			seqno++;
 897			continue;
 898		}
 899		if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
 900			kfree_skb(__skb_dequeue(list));
 901			l->stats.sent_bundled++;
 902			continue;
 903		}
 904		if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
 905			kfree_skb(__skb_dequeue(list));
 906			__skb_queue_tail(backlogq, bskb);
 907			l->backlog[msg_importance(buf_msg(bskb))].len++;
 908			l->stats.sent_bundled++;
 909			l->stats.sent_bundles++;
 910			continue;
 911		}
 912		l->backlog[imp].len += skb_queue_len(list);
 913		skb_queue_splice_tail_init(list, backlogq);
 914	}
 915	l->snd_nxt = seqno;
 916	return 0;
 917}
 918
 919void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
 920{
 921	struct sk_buff *skb, *_skb;
 922	struct tipc_msg *hdr;
 923	u16 seqno = l->snd_nxt;
 924	u16 ack = l->rcv_nxt - 1;
 925	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 926
 927	while (skb_queue_len(&l->transmq) < l->window) {
 928		skb = skb_peek(&l->backlogq);
 929		if (!skb)
 930			break;
 931		_skb = skb_clone(skb, GFP_ATOMIC);
 932		if (!_skb)
 933			break;
 934		__skb_dequeue(&l->backlogq);
 935		hdr = buf_msg(skb);
 936		l->backlog[msg_importance(hdr)].len--;
 937		__skb_queue_tail(&l->transmq, skb);
 938		__skb_queue_tail(xmitq, _skb);
 939		TIPC_SKB_CB(skb)->ackers = l->ackers;
 940		msg_set_seqno(hdr, seqno);
 941		msg_set_ack(hdr, ack);
 942		msg_set_bcast_ack(hdr, bc_ack);
 943		l->rcv_unacked = 0;
 
 944		seqno++;
 945	}
 946	l->snd_nxt = seqno;
 947}
 948
 949static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)
 950{
 951	struct tipc_msg *hdr = buf_msg(skb);
 952
 953	pr_warn("Retransmission failure on link <%s>\n", l->name);
 954	link_print(l, "Resetting link ");
 955	pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
 956		msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
 957	pr_info("sqno %u, prev: %x, src: %x\n",
 958		msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));
 959}
 960
 961int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
 962		      struct sk_buff_head *xmitq)
 963{
 964	struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
 965	struct tipc_msg *hdr;
 966	u16 ack = l->rcv_nxt - 1;
 967	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 968
 969	if (!skb)
 970		return 0;
 971
 972	/* Detect repeated retransmit failures on same packet */
 973	if (likely(l->last_retransm != buf_seqno(skb))) {
 974		l->last_retransm = buf_seqno(skb);
 975		l->stale_count = 1;
 976	} else if (++l->stale_count > 100) {
 977		link_retransmit_failure(l, skb);
 978		return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 979	}
 980
 981	/* Move forward to where retransmission should start */
 982	skb_queue_walk(&l->transmq, skb) {
 983		if (!less(buf_seqno(skb), from))
 984			break;
 985	}
 986
 987	skb_queue_walk_from(&l->transmq, skb) {
 988		if (more(buf_seqno(skb), to))
 989			break;
 990		hdr = buf_msg(skb);
 991		_skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
 992		if (!_skb)
 993			return 0;
 994		hdr = buf_msg(_skb);
 995		msg_set_ack(hdr, ack);
 996		msg_set_bcast_ack(hdr, bc_ack);
 997		_skb->priority = TC_PRIO_CONTROL;
 998		__skb_queue_tail(xmitq, _skb);
 999		l->stats.retransmitted++;
1000	}
1001	return 0;
1002}
1003
1004/* tipc_data_input - deliver data and name distr msgs to upper layer
1005 *
1006 * Consumes buffer if message is of right type
1007 * Node lock must be held
1008 */
1009static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1010			    struct sk_buff_head *inputq)
1011{
1012	switch (msg_user(buf_msg(skb))) {
1013	case TIPC_LOW_IMPORTANCE:
1014	case TIPC_MEDIUM_IMPORTANCE:
1015	case TIPC_HIGH_IMPORTANCE:
1016	case TIPC_CRITICAL_IMPORTANCE:
1017	case CONN_MANAGER:
1018		skb_queue_tail(inputq, skb);
1019		return true;
1020	case NAME_DISTRIBUTOR:
1021		l->bc_rcvlink->state = LINK_ESTABLISHED;
1022		skb_queue_tail(l->namedq, skb);
1023		return true;
1024	case MSG_BUNDLER:
1025	case TUNNEL_PROTOCOL:
1026	case MSG_FRAGMENTER:
1027	case BCAST_PROTOCOL:
1028		return false;
1029	default:
1030		pr_warn("Dropping received illegal msg type\n");
1031		kfree_skb(skb);
1032		return false;
1033	};
1034}
1035
1036/* tipc_link_input - process packet that has passed link protocol check
1037 *
1038 * Consumes buffer
1039 */
1040static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1041			   struct sk_buff_head *inputq)
1042{
1043	struct tipc_msg *hdr = buf_msg(skb);
1044	struct sk_buff **reasm_skb = &l->reasm_buf;
1045	struct sk_buff *iskb;
1046	struct sk_buff_head tmpq;
1047	int usr = msg_user(hdr);
1048	int rc = 0;
1049	int pos = 0;
1050	int ipos = 0;
1051
1052	if (unlikely(usr == TUNNEL_PROTOCOL)) {
1053		if (msg_type(hdr) == SYNCH_MSG) {
1054			__skb_queue_purge(&l->deferdq);
1055			goto drop;
1056		}
1057		if (!tipc_msg_extract(skb, &iskb, &ipos))
1058			return rc;
1059		kfree_skb(skb);
1060		skb = iskb;
1061		hdr = buf_msg(skb);
1062		if (less(msg_seqno(hdr), l->drop_point))
1063			goto drop;
1064		if (tipc_data_input(l, skb, inputq))
1065			return rc;
1066		usr = msg_user(hdr);
1067		reasm_skb = &l->failover_reasm_skb;
1068	}
1069
1070	if (usr == MSG_BUNDLER) {
1071		skb_queue_head_init(&tmpq);
1072		l->stats.recv_bundles++;
1073		l->stats.recv_bundled += msg_msgcnt(hdr);
1074		while (tipc_msg_extract(skb, &iskb, &pos))
1075			tipc_data_input(l, iskb, &tmpq);
1076		tipc_skb_queue_splice_tail(&tmpq, inputq);
1077		return 0;
1078	} else if (usr == MSG_FRAGMENTER) {
1079		l->stats.recv_fragments++;
1080		if (tipc_buf_append(reasm_skb, &skb)) {
1081			l->stats.recv_fragmented++;
1082			tipc_data_input(l, skb, inputq);
1083		} else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1084			pr_warn_ratelimited("Unable to build fragment list\n");
1085			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1086		}
1087		return 0;
1088	} else if (usr == BCAST_PROTOCOL) {
1089		tipc_bcast_lock(l->net);
1090		tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1091		tipc_bcast_unlock(l->net);
1092	}
1093drop:
1094	kfree_skb(skb);
1095	return 0;
1096}
1097
1098static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1099{
1100	bool released = false;
1101	struct sk_buff *skb, *tmp;
1102
1103	skb_queue_walk_safe(&l->transmq, skb, tmp) {
1104		if (more(buf_seqno(skb), acked))
1105			break;
1106		__skb_unlink(skb, &l->transmq);
1107		kfree_skb(skb);
1108		released = true;
1109	}
1110	return released;
1111}
1112
1113/* tipc_link_build_ack_msg: prepare link acknowledge message for transmission
1114 *
1115 * Note that sending of broadcast ack is coordinated among nodes, to reduce
1116 * risk of ack storms towards the sender
1117 */
1118int tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1119{
1120	if (!l)
1121		return 0;
1122
1123	/* Broadcast ACK must be sent via a unicast link => defer to caller */
1124	if (link_is_bc_rcvlink(l)) {
1125		if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1126			return 0;
1127		l->rcv_unacked = 0;
1128		return TIPC_LINK_SND_BC_ACK;
 
 
 
1129	}
1130
1131	/* Unicast ACK */
1132	l->rcv_unacked = 0;
1133	l->stats.sent_acks++;
1134	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1135	return 0;
1136}
1137
1138/* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1139 */
1140void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1141{
1142	int mtyp = RESET_MSG;
 
1143
1144	if (l->state == LINK_ESTABLISHING)
1145		mtyp = ACTIVATE_MSG;
1146
1147	tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
 
 
 
 
 
1148}
1149
1150/* tipc_link_build_nack_msg: prepare link nack message for transmission
 
 
1151 */
1152static void tipc_link_build_nack_msg(struct tipc_link *l,
1153				     struct sk_buff_head *xmitq)
1154{
1155	u32 def_cnt = ++l->stats.deferred_recv;
 
1156
1157	if (link_is_bc_rcvlink(l))
1158		return;
 
 
 
 
 
1159
1160	if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
1161		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
 
1162}
1163
1164/* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1165 * @l: the link that should handle the message
1166 * @skb: TIPC packet
1167 * @xmitq: queue to place packets to be sent after this call
1168 */
1169int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1170		  struct sk_buff_head *xmitq)
1171{
1172	struct sk_buff_head *defq = &l->deferdq;
1173	struct tipc_msg *hdr;
1174	u16 seqno, rcv_nxt, win_lim;
1175	int rc = 0;
1176
1177	do {
1178		hdr = buf_msg(skb);
1179		seqno = msg_seqno(hdr);
1180		rcv_nxt = l->rcv_nxt;
1181		win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1182
1183		/* Verify and update link state */
1184		if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1185			return tipc_link_proto_rcv(l, skb, xmitq);
1186
1187		if (unlikely(!link_is_up(l))) {
1188			if (l->state == LINK_ESTABLISHING)
1189				rc = TIPC_LINK_UP_EVT;
1190			goto drop;
1191		}
1192
1193		/* Don't send probe at next timeout expiration */
1194		l->silent_intv_cnt = 0;
1195
1196		/* Drop if outside receive window */
1197		if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1198			l->stats.duplicates++;
1199			goto drop;
1200		}
1201
1202		/* Forward queues and wake up waiting users */
1203		if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1204			tipc_link_advance_backlog(l, xmitq);
1205			if (unlikely(!skb_queue_empty(&l->wakeupq)))
1206				link_prepare_wakeup(l);
1207		}
1208
1209		/* Defer delivery if sequence gap */
1210		if (unlikely(seqno != rcv_nxt)) {
1211			__tipc_skb_queue_sorted(defq, seqno, skb);
1212			tipc_link_build_nack_msg(l, xmitq);
1213			break;
1214		}
1215
1216		/* Deliver packet */
1217		l->rcv_nxt++;
1218		l->stats.recv_info++;
1219		if (!tipc_data_input(l, skb, l->inputq))
1220			rc |= tipc_link_input(l, skb, l->inputq);
1221		if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1222			rc |= tipc_link_build_ack_msg(l, xmitq);
1223		if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
1224			break;
1225	} while ((skb = __skb_dequeue(defq)));
1226
1227	return rc;
1228drop:
1229	kfree_skb(skb);
1230	return rc;
1231}
1232
1233static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1234				      u16 rcvgap, int tolerance, int priority,
1235				      struct sk_buff_head *xmitq)
1236{
 
1237	struct sk_buff *skb;
1238	struct tipc_msg *hdr;
1239	struct sk_buff_head *dfq = &l->deferdq;
1240	bool node_up = link_is_up(l->bc_rcvlink);
 
 
 
1241
1242	/* Don't send protocol message during reset or link failover */
1243	if (tipc_link_is_blocked(l))
1244		return;
1245
1246	if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1247		return;
1248
1249	if (!skb_queue_empty(dfq))
1250		rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1251
1252	skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1253			      TIPC_MAX_IF_NAME, l->addr,
1254			      tipc_own_addr(l->net), 0, 0, 0);
1255	if (!skb)
1256		return;
1257
1258	hdr = buf_msg(skb);
 
1259	msg_set_session(hdr, l->session);
1260	msg_set_bearer_id(hdr, l->bearer_id);
1261	msg_set_net_plane(hdr, l->net_plane);
1262	msg_set_next_sent(hdr, l->snd_nxt);
1263	msg_set_ack(hdr, l->rcv_nxt - 1);
1264	msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1);
 
1265	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1266	msg_set_link_tolerance(hdr, tolerance);
1267	msg_set_linkprio(hdr, priority);
1268	msg_set_redundant_link(hdr, node_up);
1269	msg_set_seq_gap(hdr, 0);
1270	msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1271
1272	if (mtyp == STATE_MSG) {
1273		msg_set_seq_gap(hdr, rcvgap);
1274		msg_set_size(hdr, INT_H_SIZE);
1275		msg_set_probe(hdr, probe);
 
 
 
1276		l->stats.sent_states++;
1277		l->rcv_unacked = 0;
1278	} else {
1279		/* RESET_MSG or ACTIVATE_MSG */
1280		msg_set_max_pkt(hdr, l->advertised_mtu);
1281		strcpy(msg_data(hdr), l->if_name);
 
 
1282	}
1283	if (probe)
1284		l->stats.sent_probes++;
1285	if (rcvgap)
1286		l->stats.sent_nacks++;
1287	skb->priority = TC_PRIO_CONTROL;
1288	__skb_queue_tail(xmitq, skb);
1289}
1290
1291/* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1292 * with contents of the link's transmit and backlog queues.
1293 */
1294void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1295			   int mtyp, struct sk_buff_head *xmitq)
1296{
1297	struct sk_buff *skb, *tnlskb;
1298	struct tipc_msg *hdr, tnlhdr;
1299	struct sk_buff_head *queue = &l->transmq;
1300	struct sk_buff_head tmpxq, tnlq;
1301	u16 pktlen, pktcnt, seqno = l->snd_nxt;
1302
1303	if (!tnl)
1304		return;
1305
1306	skb_queue_head_init(&tnlq);
1307	skb_queue_head_init(&tmpxq);
1308
1309	/* At least one packet required for safe algorithm => add dummy */
1310	skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1311			      BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
1312			      0, 0, TIPC_ERR_NO_PORT);
1313	if (!skb) {
1314		pr_warn("%sunable to create tunnel packet\n", link_co_err);
1315		return;
1316	}
1317	skb_queue_tail(&tnlq, skb);
1318	tipc_link_xmit(l, &tnlq, &tmpxq);
1319	__skb_queue_purge(&tmpxq);
1320
1321	/* Initialize reusable tunnel packet header */
1322	tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
1323		      mtyp, INT_H_SIZE, l->addr);
1324	pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
1325	msg_set_msgcnt(&tnlhdr, pktcnt);
1326	msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1327tnl:
1328	/* Wrap each packet into a tunnel packet */
1329	skb_queue_walk(queue, skb) {
1330		hdr = buf_msg(skb);
1331		if (queue == &l->backlogq)
1332			msg_set_seqno(hdr, seqno++);
1333		pktlen = msg_size(hdr);
1334		msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1335		tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE);
1336		if (!tnlskb) {
1337			pr_warn("%sunable to send packet\n", link_co_err);
1338			return;
1339		}
1340		skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1341		skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1342		__skb_queue_tail(&tnlq, tnlskb);
1343	}
1344	if (queue != &l->backlogq) {
1345		queue = &l->backlogq;
1346		goto tnl;
1347	}
1348
1349	tipc_link_xmit(tnl, &tnlq, xmitq);
1350
1351	if (mtyp == FAILOVER_MSG) {
1352		tnl->drop_point = l->rcv_nxt;
1353		tnl->failover_reasm_skb = l->reasm_buf;
1354		l->reasm_buf = NULL;
1355	}
1356}
1357
1358/* tipc_link_proto_rcv(): receive link level protocol message :
1359 * Note that network plane id propagates through the network, and may
1360 * change at any time. The node with lowest numerical id determines
1361 * network plane
1362 */
1363static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1364			       struct sk_buff_head *xmitq)
1365{
1366	struct tipc_msg *hdr = buf_msg(skb);
1367	u16 rcvgap = 0;
1368	u16 ack = msg_ack(hdr);
1369	u16 gap = msg_seq_gap(hdr);
1370	u16 peers_snd_nxt =  msg_next_sent(hdr);
1371	u16 peers_tol = msg_link_tolerance(hdr);
1372	u16 peers_prio = msg_linkprio(hdr);
1373	u16 rcv_nxt = l->rcv_nxt;
 
1374	int mtyp = msg_type(hdr);
 
1375	char *if_name;
1376	int rc = 0;
1377
1378	if (tipc_link_is_blocked(l) || !xmitq)
1379		goto exit;
1380
1381	if (tipc_own_addr(l->net) > msg_prevnode(hdr))
1382		l->net_plane = msg_net_plane(hdr);
1383
 
 
 
 
1384	switch (mtyp) {
1385	case RESET_MSG:
1386
1387		/* Ignore duplicate RESET with old session number */
1388		if ((less_eq(msg_session(hdr), l->peer_session)) &&
1389		    (l->peer_session != ANY_SESSION))
1390			break;
1391		/* fall thru' */
1392
1393	case ACTIVATE_MSG:
1394		skb_linearize(skb);
1395		hdr = buf_msg(skb);
1396
1397		/* Complete own link name with peer's interface name */
1398		if_name =  strrchr(l->name, ':') + 1;
1399		if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1400			break;
1401		if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1402			break;
1403		strncpy(if_name, msg_data(hdr),	TIPC_MAX_IF_NAME);
1404
1405		/* Update own tolerance if peer indicates a non-zero value */
1406		if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1407			l->tolerance = peers_tol;
1408
1409		/* Update own priority if peer's priority is higher */
1410		if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1411			l->priority = peers_prio;
1412
1413		/* ACTIVATE_MSG serves as PEER_RESET if link is already down */
1414		if ((mtyp == RESET_MSG) || !link_is_up(l))
 
 
1415			rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
1416
1417		/* ACTIVATE_MSG takes up link if it was already locally reset */
1418		if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
1419			rc = TIPC_LINK_UP_EVT;
1420
1421		l->peer_session = msg_session(hdr);
1422		l->peer_bearer_id = msg_bearer_id(hdr);
1423		if (l->mtu > msg_max_pkt(hdr))
1424			l->mtu = msg_max_pkt(hdr);
1425		break;
1426
1427	case STATE_MSG:
1428
1429		/* Update own tolerance if peer indicates a non-zero value */
1430		if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1431			l->tolerance = peers_tol;
1432
1433		if (peers_prio && in_range(peers_prio, TIPC_MIN_LINK_PRI,
1434					   TIPC_MAX_LINK_PRI)) {
 
1435			l->priority = peers_prio;
1436			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1437		}
1438
1439		l->silent_intv_cnt = 0;
1440		l->stats.recv_states++;
1441		if (msg_probe(hdr))
1442			l->stats.recv_probes++;
1443
1444		if (!link_is_up(l)) {
1445			if (l->state == LINK_ESTABLISHING)
1446				rc = TIPC_LINK_UP_EVT;
1447			break;
1448		}
 
 
1449
1450		/* Send NACK if peer has sent pkts we haven't received yet */
1451		if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
1452			rcvgap = peers_snd_nxt - l->rcv_nxt;
1453		if (rcvgap || (msg_probe(hdr)))
1454			tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1455						  0, 0, xmitq);
1456		tipc_link_release_pkts(l, ack);
1457
1458		/* If NACK, retransmit will now start at right position */
1459		if (gap) {
1460			rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq);
1461			l->stats.recv_nacks++;
1462		}
1463
1464		tipc_link_advance_backlog(l, xmitq);
1465		if (unlikely(!skb_queue_empty(&l->wakeupq)))
1466			link_prepare_wakeup(l);
1467	}
1468exit:
1469	kfree_skb(skb);
1470	return rc;
1471}
1472
1473/* tipc_link_build_bc_proto_msg() - create broadcast protocol message
1474 */
1475static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
1476					 u16 peers_snd_nxt,
1477					 struct sk_buff_head *xmitq)
1478{
1479	struct sk_buff *skb;
1480	struct tipc_msg *hdr;
1481	struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
1482	u16 ack = l->rcv_nxt - 1;
1483	u16 gap_to = peers_snd_nxt - 1;
1484
1485	skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
1486			      0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
1487	if (!skb)
1488		return false;
1489	hdr = buf_msg(skb);
1490	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1491	msg_set_bcast_ack(hdr, ack);
1492	msg_set_bcgap_after(hdr, ack);
1493	if (dfrd_skb)
1494		gap_to = buf_seqno(dfrd_skb) - 1;
1495	msg_set_bcgap_to(hdr, gap_to);
1496	msg_set_non_seq(hdr, bcast);
1497	__skb_queue_tail(xmitq, skb);
1498	return true;
1499}
1500
1501/* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
1502 *
1503 * Give a newly added peer node the sequence number where it should
1504 * start receiving and acking broadcast packets.
1505 */
1506static void tipc_link_build_bc_init_msg(struct tipc_link *l,
1507					struct sk_buff_head *xmitq)
1508{
1509	struct sk_buff_head list;
1510
1511	__skb_queue_head_init(&list);
1512	if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
1513		return;
 
1514	tipc_link_xmit(l, &list, xmitq);
1515}
1516
1517/* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
1518 */
1519void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
1520{
1521	int mtyp = msg_type(hdr);
1522	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1523
1524	if (link_is_up(l))
1525		return;
1526
1527	if (msg_user(hdr) == BCAST_PROTOCOL) {
1528		l->rcv_nxt = peers_snd_nxt;
1529		l->state = LINK_ESTABLISHED;
1530		return;
1531	}
1532
1533	if (l->peer_caps & TIPC_BCAST_SYNCH)
1534		return;
1535
1536	if (msg_peer_node_is_up(hdr))
1537		return;
1538
1539	/* Compatibility: accept older, less safe initial synch data */
1540	if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
1541		l->rcv_nxt = peers_snd_nxt;
1542}
1543
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1544/* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
1545 */
1546void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
1547			   struct sk_buff_head *xmitq)
1548{
 
1549	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
 
 
 
1550
1551	if (!link_is_up(l))
1552		return;
1553
1554	if (!msg_peer_node_is_up(hdr))
1555		return;
 
 
 
 
 
 
 
1556
1557	l->bc_peer_is_up = true;
1558
1559	/* Ignore if peers_snd_nxt goes beyond receive window */
1560	if (more(peers_snd_nxt, l->rcv_nxt + l->window))
1561		return;
 
 
 
 
 
 
 
 
 
 
 
 
 
1562
1563	if (!more(peers_snd_nxt, l->rcv_nxt)) {
1564		l->nack_state = BC_NACK_SND_CONDITIONAL;
1565		return;
1566	}
1567
1568	/* Don't NACK if one was recently sent or peeked */
1569	if (l->nack_state == BC_NACK_SND_SUPPRESS) {
1570		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1571		return;
1572	}
1573
1574	/* Conditionally delay NACK sending until next synch rcv */
1575	if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
1576		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1577		if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
1578			return;
1579	}
1580
1581	/* Send NACK now but suppress next one */
1582	tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
1583	l->nack_state = BC_NACK_SND_SUPPRESS;
 
1584}
1585
1586void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
1587			  struct sk_buff_head *xmitq)
1588{
1589	struct sk_buff *skb, *tmp;
1590	struct tipc_link *snd_l = l->bc_sndlink;
1591
1592	if (!link_is_up(l) || !l->bc_peer_is_up)
1593		return;
1594
1595	if (!more(acked, l->acked))
1596		return;
1597
1598	/* Skip over packets peer has already acked */
1599	skb_queue_walk(&snd_l->transmq, skb) {
1600		if (more(buf_seqno(skb), l->acked))
1601			break;
1602	}
1603
1604	/* Update/release the packets peer is acking now */
1605	skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
1606		if (more(buf_seqno(skb), acked))
1607			break;
1608		if (!--TIPC_SKB_CB(skb)->ackers) {
1609			__skb_unlink(skb, &snd_l->transmq);
1610			kfree_skb(skb);
1611		}
1612	}
1613	l->acked = acked;
1614	tipc_link_advance_backlog(snd_l, xmitq);
1615	if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
1616		link_prepare_wakeup(snd_l);
1617}
1618
1619/* tipc_link_bc_nack_rcv(): receive broadcast nack message
 
 
1620 */
1621int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
1622			  struct sk_buff_head *xmitq)
1623{
1624	struct tipc_msg *hdr = buf_msg(skb);
1625	u32 dnode = msg_destnode(hdr);
1626	int mtyp = msg_type(hdr);
1627	u16 acked = msg_bcast_ack(hdr);
1628	u16 from = acked + 1;
1629	u16 to = msg_bcgap_to(hdr);
1630	u16 peers_snd_nxt = to + 1;
1631	int rc = 0;
1632
1633	kfree_skb(skb);
1634
1635	if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
1636		return 0;
1637
1638	if (mtyp != STATE_MSG)
1639		return 0;
1640
1641	if (dnode == tipc_own_addr(l->net)) {
1642		tipc_link_bc_ack_rcv(l, acked, xmitq);
1643		rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
1644		l->stats.recv_nacks++;
1645		return rc;
1646	}
1647
1648	/* Msg for other node => suppress own NACK at next sync if applicable */
1649	if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
1650		l->nack_state = BC_NACK_SND_SUPPRESS;
1651
1652	return 0;
1653}
1654
1655void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1656{
1657	int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1658
1659	l->window = win;
1660	l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1661	l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1662	l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1663	l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1664	l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1665}
1666
1667/**
1668 * link_reset_stats - reset link statistics
1669 * @l: pointer to link
1670 */
1671void tipc_link_reset_stats(struct tipc_link *l)
1672{
1673	memset(&l->stats, 0, sizeof(l->stats));
1674	if (!link_is_bc_sndlink(l)) {
1675		l->stats.sent_info = l->snd_nxt;
1676		l->stats.recv_info = l->rcv_nxt;
1677	}
1678}
1679
1680static void link_print(struct tipc_link *l, const char *str)
1681{
1682	struct sk_buff *hskb = skb_peek(&l->transmq);
1683	u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
1684	u16 tail = l->snd_nxt - 1;
1685
1686	pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
1687	pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1688		skb_queue_len(&l->transmq), head, tail,
1689		skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1690}
1691
1692/* Parse and validate nested (link) properties valid for media, bearer and link
1693 */
1694int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1695{
1696	int err;
1697
1698	err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1699			       tipc_nl_prop_policy);
1700	if (err)
1701		return err;
1702
1703	if (props[TIPC_NLA_PROP_PRIO]) {
1704		u32 prio;
1705
1706		prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1707		if (prio > TIPC_MAX_LINK_PRI)
1708			return -EINVAL;
1709	}
1710
1711	if (props[TIPC_NLA_PROP_TOL]) {
1712		u32 tol;
1713
1714		tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1715		if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1716			return -EINVAL;
1717	}
1718
1719	if (props[TIPC_NLA_PROP_WIN]) {
1720		u32 win;
1721
1722		win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1723		if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1724			return -EINVAL;
1725	}
1726
1727	return 0;
1728}
1729
1730static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1731{
1732	int i;
1733	struct nlattr *stats;
1734
1735	struct nla_map {
1736		u32 key;
1737		u32 val;
1738	};
1739
1740	struct nla_map map[] = {
1741		{TIPC_NLA_STATS_RX_INFO, s->recv_info},
1742		{TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1743		{TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1744		{TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1745		{TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1746		{TIPC_NLA_STATS_TX_INFO, s->sent_info},
1747		{TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1748		{TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1749		{TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1750		{TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1751		{TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1752			s->msg_length_counts : 1},
1753		{TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1754		{TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1755		{TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1756		{TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1757		{TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1758		{TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1759		{TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1760		{TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1761		{TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1762		{TIPC_NLA_STATS_RX_STATES, s->recv_states},
1763		{TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1764		{TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1765		{TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1766		{TIPC_NLA_STATS_TX_STATES, s->sent_states},
1767		{TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1768		{TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1769		{TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1770		{TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1771		{TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1772		{TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1773		{TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1774		{TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1775			(s->accu_queue_sz / s->queue_sz_counts) : 0}
1776	};
1777
1778	stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1779	if (!stats)
1780		return -EMSGSIZE;
1781
1782	for (i = 0; i <  ARRAY_SIZE(map); i++)
1783		if (nla_put_u32(skb, map[i].key, map[i].val))
1784			goto msg_full;
1785
1786	nla_nest_end(skb, stats);
1787
1788	return 0;
1789msg_full:
1790	nla_nest_cancel(skb, stats);
1791
1792	return -EMSGSIZE;
1793}
1794
1795/* Caller should hold appropriate locks to protect the link */
1796int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1797		       struct tipc_link *link, int nlflags)
1798{
1799	int err;
1800	void *hdr;
1801	struct nlattr *attrs;
1802	struct nlattr *prop;
1803	struct tipc_net *tn = net_generic(net, tipc_net_id);
1804
1805	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1806			  nlflags, TIPC_NL_LINK_GET);
1807	if (!hdr)
1808		return -EMSGSIZE;
1809
1810	attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1811	if (!attrs)
1812		goto msg_full;
1813
1814	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1815		goto attr_msg_full;
1816	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1817			tipc_cluster_mask(tn->own_addr)))
1818		goto attr_msg_full;
1819	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1820		goto attr_msg_full;
1821	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
1822		goto attr_msg_full;
1823	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
1824		goto attr_msg_full;
1825
1826	if (tipc_link_is_up(link))
1827		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1828			goto attr_msg_full;
1829	if (link->active)
1830		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1831			goto attr_msg_full;
1832
1833	prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1834	if (!prop)
1835		goto attr_msg_full;
1836	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1837		goto prop_msg_full;
1838	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1839		goto prop_msg_full;
1840	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1841			link->window))
1842		goto prop_msg_full;
1843	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1844		goto prop_msg_full;
1845	nla_nest_end(msg->skb, prop);
1846
1847	err = __tipc_nl_add_stats(msg->skb, &link->stats);
1848	if (err)
1849		goto attr_msg_full;
1850
1851	nla_nest_end(msg->skb, attrs);
1852	genlmsg_end(msg->skb, hdr);
1853
1854	return 0;
1855
1856prop_msg_full:
1857	nla_nest_cancel(msg->skb, prop);
1858attr_msg_full:
1859	nla_nest_cancel(msg->skb, attrs);
1860msg_full:
1861	genlmsg_cancel(msg->skb, hdr);
1862
1863	return -EMSGSIZE;
1864}
1865
1866static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
1867				      struct tipc_stats *stats)
1868{
1869	int i;
1870	struct nlattr *nest;
1871
1872	struct nla_map {
1873		__u32 key;
1874		__u32 val;
1875	};
1876
1877	struct nla_map map[] = {
1878		{TIPC_NLA_STATS_RX_INFO, stats->recv_info},
1879		{TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
1880		{TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
1881		{TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
1882		{TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
1883		{TIPC_NLA_STATS_TX_INFO, stats->sent_info},
1884		{TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
1885		{TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
1886		{TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
1887		{TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
1888		{TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
1889		{TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
1890		{TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
1891		{TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
1892		{TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
1893		{TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
1894		{TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
1895		{TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
1896		{TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
1897			(stats->accu_queue_sz / stats->queue_sz_counts) : 0}
1898	};
1899
1900	nest = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1901	if (!nest)
1902		return -EMSGSIZE;
1903
1904	for (i = 0; i <  ARRAY_SIZE(map); i++)
1905		if (nla_put_u32(skb, map[i].key, map[i].val))
1906			goto msg_full;
1907
1908	nla_nest_end(skb, nest);
1909
1910	return 0;
1911msg_full:
1912	nla_nest_cancel(skb, nest);
1913
1914	return -EMSGSIZE;
1915}
1916
1917int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
1918{
1919	int err;
1920	void *hdr;
1921	struct nlattr *attrs;
1922	struct nlattr *prop;
1923	struct tipc_net *tn = net_generic(net, tipc_net_id);
1924	struct tipc_link *bcl = tn->bcl;
1925
1926	if (!bcl)
1927		return 0;
1928
1929	tipc_bcast_lock(net);
1930
1931	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1932			  NLM_F_MULTI, TIPC_NL_LINK_GET);
1933	if (!hdr) {
1934		tipc_bcast_unlock(net);
1935		return -EMSGSIZE;
1936	}
1937
1938	attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1939	if (!attrs)
1940		goto msg_full;
1941
1942	/* The broadcast link is always up */
1943	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1944		goto attr_msg_full;
1945
1946	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
1947		goto attr_msg_full;
1948	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
1949		goto attr_msg_full;
1950	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, bcl->rcv_nxt))
1951		goto attr_msg_full;
1952	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, bcl->snd_nxt))
1953		goto attr_msg_full;
1954
1955	prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1956	if (!prop)
1957		goto attr_msg_full;
1958	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->window))
1959		goto prop_msg_full;
1960	nla_nest_end(msg->skb, prop);
1961
1962	err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
1963	if (err)
1964		goto attr_msg_full;
1965
1966	tipc_bcast_unlock(net);
1967	nla_nest_end(msg->skb, attrs);
1968	genlmsg_end(msg->skb, hdr);
1969
1970	return 0;
1971
1972prop_msg_full:
1973	nla_nest_cancel(msg->skb, prop);
1974attr_msg_full:
1975	nla_nest_cancel(msg->skb, attrs);
1976msg_full:
1977	tipc_bcast_unlock(net);
1978	genlmsg_cancel(msg->skb, hdr);
1979
1980	return -EMSGSIZE;
1981}
1982
1983void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
1984			     struct sk_buff_head *xmitq)
1985{
1986	l->tolerance = tol;
1987	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, tol, 0, xmitq);
1988}
1989
1990void tipc_link_set_prio(struct tipc_link *l, u32 prio,
1991			struct sk_buff_head *xmitq)
1992{
1993	l->priority = prio;
1994	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, prio, xmitq);
1995}
1996
1997void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
1998{
1999	l->abort_limit = limit;
2000}