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
  47#include <linux/pkt_sched.h>
  48
  49struct tipc_stats {
  50	u32 sent_pkts;
  51	u32 recv_pkts;
  52	u32 sent_states;
  53	u32 recv_states;
  54	u32 sent_probes;
  55	u32 recv_probes;
  56	u32 sent_nacks;
  57	u32 recv_nacks;
  58	u32 sent_acks;
  59	u32 sent_bundled;
  60	u32 sent_bundles;
  61	u32 recv_bundled;
  62	u32 recv_bundles;
  63	u32 retransmitted;
  64	u32 sent_fragmented;
  65	u32 sent_fragments;
  66	u32 recv_fragmented;
  67	u32 recv_fragments;
  68	u32 link_congs;		/* # port sends blocked by congestion */
  69	u32 deferred_recv;
  70	u32 duplicates;
  71	u32 max_queue_sz;	/* send queue size high water mark */
  72	u32 accu_queue_sz;	/* used for send queue size profiling */
  73	u32 queue_sz_counts;	/* used for send queue size profiling */
  74	u32 msg_length_counts;	/* used for message length profiling */
  75	u32 msg_lengths_total;	/* used for message length profiling */
  76	u32 msg_length_profile[7]; /* used for msg. length profiling */
  77};
  78
  79/**
  80 * struct tipc_link - TIPC link data structure
  81 * @addr: network address of link's peer node
  82 * @name: link name character string
  83 * @media_addr: media address to use when sending messages over link
  84 * @timer: link timer
  85 * @net: pointer to namespace struct
  86 * @refcnt: reference counter for permanent references (owner node & timer)
  87 * @peer_session: link session # being used by peer end of link
  88 * @peer_bearer_id: bearer id used by link's peer endpoint
  89 * @bearer_id: local bearer id used by link
  90 * @tolerance: minimum link continuity loss needed to reset link [in ms]
  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 * @mon_state: cookie with information needed by link monitor
 100 * @backlog_limit: backlog queue congestion thresholds (indexed by importance)
 101 * @exp_msg_count: # of tunnelled messages expected during link changeover
 102 * @reset_rcv_checkpt: seq # of last acknowledged message at time of link reset
 103 * @mtu: current maximum packet size for this link
 104 * @advertised_mtu: advertised own mtu when link is being established
 105 * @transmitq: queue for sent, non-acked messages
 106 * @backlogq: queue for messages waiting to be sent
 107 * @snt_nxt: next sequence number to use for outbound messages
 108 * @last_retransmitted: sequence number of most recently retransmitted message
 109 * @stale_count: # of identical retransmit requests made by peer
 110 * @ackers: # of peers that needs to ack each packet before it can be released
 111 * @acked: # last packet acked by a certain peer. Used for broadcast.
 112 * @rcv_nxt: next sequence number to expect for inbound messages
 113 * @deferred_queue: deferred queue saved OOS b'cast message received from node
 114 * @unacked_window: # of inbound messages rx'd without ack'ing back to peer
 115 * @inputq: buffer queue for messages to be delivered upwards
 116 * @namedq: buffer queue for name table messages to be delivered upwards
 117 * @next_out: ptr to first unsent outbound message in queue
 118 * @wakeupq: linked list of wakeup msgs waiting for link congestion to abate
 119 * @long_msg_seq_no: next identifier to use for outbound fragmented messages
 120 * @reasm_buf: head of partially reassembled inbound message fragments
 121 * @bc_rcvr: marks that this is a broadcast receiver link
 122 * @stats: collects statistics regarding link activity
 123 */
 124struct tipc_link {
 125	u32 addr;
 126	char name[TIPC_MAX_LINK_NAME];
 127	struct net *net;
 128
 129	/* Management and link supervision data */
 130	u32 peer_session;
 131	u32 session;
 
 
 132	u32 peer_bearer_id;
 133	u32 bearer_id;
 134	u32 tolerance;
 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	struct tipc_mon_state mon_state;
 144	u16 rst_cnt;
 145
 146	/* Failover/synch */
 147	u16 drop_point;
 148	struct sk_buff *failover_reasm_skb;
 
 149
 150	/* Max packet negotiation */
 151	u16 mtu;
 152	u16 advertised_mtu;
 153
 154	/* Sending */
 155	struct sk_buff_head transmq;
 156	struct sk_buff_head backlogq;
 157	struct {
 158		u16 len;
 159		u16 limit;
 
 160	} backlog[5];
 161	u16 snd_nxt;
 162	u16 last_retransm;
 163	u16 window;
 164	u32 stale_count;
 165
 166	/* Reception */
 167	u16 rcv_nxt;
 168	u32 rcv_unacked;
 169	struct sk_buff_head deferdq;
 170	struct sk_buff_head *inputq;
 171	struct sk_buff_head *namedq;
 172
 173	/* Congestion handling */
 174	struct sk_buff_head wakeupq;
 
 
 
 
 
 
 175
 176	/* Fragmentation/reassembly */
 177	struct sk_buff *reasm_buf;
 
 178
 179	/* Broadcast */
 180	u16 ackers;
 181	u16 acked;
 
 
 182	struct tipc_link *bc_rcvlink;
 183	struct tipc_link *bc_sndlink;
 184	unsigned long prev_retr;
 185	u16 prev_from;
 186	u16 prev_to;
 187	u8 nack_state;
 188	bool bc_peer_is_up;
 189
 190	/* Statistics */
 191	struct tipc_stats stats;
 192};
 193
 194/*
 195 * Error message prefixes
 196 */
 197static const char *link_co_err = "Link tunneling error, ";
 198static const char *link_rst_msg = "Resetting link ";
 199
 200/* Send states for broadcast NACKs
 201 */
 202enum {
 203	BC_NACK_SND_CONDITIONAL,
 204	BC_NACK_SND_UNCONDITIONAL,
 205	BC_NACK_SND_SUPPRESS,
 206};
 207
 208#define TIPC_BC_RETR_LIMIT 10   /* [ms] */
 
 209
 210/*
 211 * Interval between NACKs when packets arrive out of order
 212 */
 213#define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
 214
 215/* Wildcard value for link session numbers. When it is known that
 216 * peer endpoint is down, any session number must be accepted.
 217 */
 218#define ANY_SESSION 0x10000
 219
 220/* Link FSM states:
 221 */
 222enum {
 223	LINK_ESTABLISHED     = 0xe,
 224	LINK_ESTABLISHING    = 0xe  << 4,
 225	LINK_RESET           = 0x1  << 8,
 226	LINK_RESETTING       = 0x2  << 12,
 227	LINK_PEER_RESET      = 0xd  << 16,
 228	LINK_FAILINGOVER     = 0xf  << 20,
 229	LINK_SYNCHING        = 0xc  << 24
 230};
 231
 232/* Link FSM state checking routines
 233 */
 234static int link_is_up(struct tipc_link *l)
 235{
 236	return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
 237}
 238
 239static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 240			       struct sk_buff_head *xmitq);
 241static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 242				      bool probe_reply, u16 rcvgap,
 243				      int tolerance, int priority,
 244				      struct sk_buff_head *xmitq);
 245static void link_print(struct tipc_link *l, const char *str);
 246static int tipc_link_build_nack_msg(struct tipc_link *l,
 247				    struct sk_buff_head *xmitq);
 248static void tipc_link_build_bc_init_msg(struct tipc_link *l,
 249					struct sk_buff_head *xmitq);
 250static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
 251
 
 
 
 
 
 
 
 
 252/*
 253 *  Simple non-static link routines (i.e. referenced outside this file)
 254 */
 255bool tipc_link_is_up(struct tipc_link *l)
 256{
 257	return link_is_up(l);
 258}
 259
 260bool tipc_link_peer_is_down(struct tipc_link *l)
 261{
 262	return l->state == LINK_PEER_RESET;
 263}
 264
 265bool tipc_link_is_reset(struct tipc_link *l)
 266{
 267	return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
 268}
 269
 270bool tipc_link_is_establishing(struct tipc_link *l)
 271{
 272	return l->state == LINK_ESTABLISHING;
 273}
 274
 275bool tipc_link_is_synching(struct tipc_link *l)
 276{
 277	return l->state == LINK_SYNCHING;
 278}
 279
 280bool tipc_link_is_failingover(struct tipc_link *l)
 281{
 282	return l->state == LINK_FAILINGOVER;
 283}
 284
 285bool tipc_link_is_blocked(struct tipc_link *l)
 286{
 287	return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
 288}
 289
 290static bool link_is_bc_sndlink(struct tipc_link *l)
 291{
 292	return !l->bc_sndlink;
 293}
 294
 295static bool link_is_bc_rcvlink(struct tipc_link *l)
 296{
 297	return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
 298}
 299
 300int tipc_link_is_active(struct tipc_link *l)
 301{
 302	return l->active;
 303}
 304
 305void tipc_link_set_active(struct tipc_link *l, bool active)
 306{
 307	l->active = active;
 308}
 309
 310u32 tipc_link_id(struct tipc_link *l)
 311{
 312	return l->peer_bearer_id << 16 | l->bearer_id;
 313}
 314
 315int tipc_link_window(struct tipc_link *l)
 
 
 
 
 
 316{
 317	return l->window;
 318}
 319
 320int tipc_link_prio(struct tipc_link *l)
 321{
 322	return l->priority;
 323}
 324
 325unsigned long tipc_link_tolerance(struct tipc_link *l)
 326{
 327	return l->tolerance;
 328}
 329
 330struct sk_buff_head *tipc_link_inputq(struct tipc_link *l)
 331{
 332	return l->inputq;
 333}
 334
 335char tipc_link_plane(struct tipc_link *l)
 336{
 337	return l->net_plane;
 338}
 339
 
 
 
 
 
 340void tipc_link_add_bc_peer(struct tipc_link *snd_l,
 341			   struct tipc_link *uc_l,
 342			   struct sk_buff_head *xmitq)
 343{
 344	struct tipc_link *rcv_l = uc_l->bc_rcvlink;
 345
 346	snd_l->ackers++;
 347	rcv_l->acked = snd_l->snd_nxt - 1;
 348	snd_l->state = LINK_ESTABLISHED;
 349	tipc_link_build_bc_init_msg(uc_l, xmitq);
 350}
 351
 352void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
 353			      struct tipc_link *rcv_l,
 354			      struct sk_buff_head *xmitq)
 355{
 356	u16 ack = snd_l->snd_nxt - 1;
 357
 358	snd_l->ackers--;
 359	rcv_l->bc_peer_is_up = true;
 360	rcv_l->state = LINK_ESTABLISHED;
 361	tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
 
 362	tipc_link_reset(rcv_l);
 363	rcv_l->state = LINK_RESET;
 364	if (!snd_l->ackers) {
 
 365		tipc_link_reset(snd_l);
 366		snd_l->state = LINK_RESET;
 367		__skb_queue_purge(xmitq);
 368	}
 369}
 370
 371int tipc_link_bc_peers(struct tipc_link *l)
 372{
 373	return l->ackers;
 374}
 375
 376u16 link_bc_rcv_gap(struct tipc_link *l)
 377{
 378	struct sk_buff *skb = skb_peek(&l->deferdq);
 379	u16 gap = 0;
 380
 381	if (more(l->snd_nxt, l->rcv_nxt))
 382		gap = l->snd_nxt - l->rcv_nxt;
 383	if (skb)
 384		gap = buf_seqno(skb) - l->rcv_nxt;
 385	return gap;
 386}
 387
 388void tipc_link_set_mtu(struct tipc_link *l, int mtu)
 389{
 390	l->mtu = mtu;
 391}
 392
 393int tipc_link_mtu(struct tipc_link *l)
 394{
 395	return l->mtu;
 396}
 397
 
 
 
 
 
 
 
 
 
 398u16 tipc_link_rcv_nxt(struct tipc_link *l)
 399{
 400	return l->rcv_nxt;
 401}
 402
 403u16 tipc_link_acked(struct tipc_link *l)
 404{
 405	return l->acked;
 406}
 407
 408char *tipc_link_name(struct tipc_link *l)
 409{
 410	return l->name;
 411}
 412
 
 
 
 
 
 413/**
 414 * tipc_link_create - create a new link
 415 * @n: pointer to associated node
 416 * @if_name: associated interface name
 417 * @bearer_id: id (index) of associated bearer
 418 * @tolerance: link tolerance to be used by link
 419 * @net_plane: network plane (A,B,c..) this link belongs to
 420 * @mtu: mtu to be advertised by link
 421 * @priority: priority to be used by link
 422 * @window: send window to be used by link
 
 423 * @session: session to be used by link
 424 * @ownnode: identity of own node
 425 * @peer: node id of peer node
 426 * @peer_caps: bitmap describing peer node capabilities
 427 * @bc_sndlink: the namespace global link used for broadcast sending
 428 * @bc_rcvlink: the peer specific link used for broadcast reception
 429 * @inputq: queue to put messages ready for delivery
 430 * @namedq: queue to put binding table update messages ready for delivery
 431 * @link: return value, pointer to put the created link
 432 *
 433 * Returns true if link was created, otherwise false
 434 */
 435bool tipc_link_create(struct net *net, char *if_name, int bearer_id,
 436		      int tolerance, char net_plane, u32 mtu, int priority,
 437		      int window, u32 session, u32 self,
 438		      u32 peer, u8 *peer_id, u16 peer_caps,
 439		      struct tipc_link *bc_sndlink,
 440		      struct tipc_link *bc_rcvlink,
 441		      struct sk_buff_head *inputq,
 442		      struct sk_buff_head *namedq,
 443		      struct tipc_link **link)
 444{
 445	char peer_str[NODE_ID_STR_LEN] = {0,};
 446	char self_str[NODE_ID_STR_LEN] = {0,};
 447	struct tipc_link *l;
 448
 449	l = kzalloc(sizeof(*l), GFP_ATOMIC);
 450	if (!l)
 451		return false;
 452	*link = l;
 453	l->session = session;
 454
 455	/* Set link name for unicast links only */
 456	if (peer_id) {
 457		tipc_nodeid2string(self_str, tipc_own_id(net));
 458		if (strlen(self_str) > 16)
 459			sprintf(self_str, "%x", self);
 460		tipc_nodeid2string(peer_str, peer_id);
 461		if (strlen(peer_str) > 16)
 462			sprintf(peer_str, "%x", peer);
 463	}
 464	/* Peer i/f name will be completed by reset/activate message */
 465	snprintf(l->name, sizeof(l->name), "%s:%s-%s:unknown",
 466		 self_str, if_name, peer_str);
 467
 468	strcpy(l->if_name, if_name);
 469	l->addr = peer;
 470	l->peer_caps = peer_caps;
 471	l->net = net;
 472	l->peer_session = ANY_SESSION;
 473	l->bearer_id = bearer_id;
 474	l->tolerance = tolerance;
 
 
 475	l->net_plane = net_plane;
 476	l->advertised_mtu = mtu;
 477	l->mtu = mtu;
 478	l->priority = priority;
 479	tipc_link_set_queue_limits(l, window);
 480	l->ackers = 1;
 481	l->bc_sndlink = bc_sndlink;
 482	l->bc_rcvlink = bc_rcvlink;
 483	l->inputq = inputq;
 484	l->namedq = namedq;
 485	l->state = LINK_RESETTING;
 486	__skb_queue_head_init(&l->transmq);
 487	__skb_queue_head_init(&l->backlogq);
 488	__skb_queue_head_init(&l->deferdq);
 
 489	skb_queue_head_init(&l->wakeupq);
 490	skb_queue_head_init(l->inputq);
 491	return true;
 492}
 493
 494/**
 495 * tipc_link_bc_create - create new link to be used for broadcast
 496 * @n: pointer to associated node
 497 * @mtu: mtu to be used initially if no peers
 498 * @window: send window to be used
 
 499 * @inputq: queue to put messages ready for delivery
 500 * @namedq: queue to put binding table update messages ready for delivery
 501 * @link: return value, pointer to put the created link
 502 *
 503 * Returns true if link was created, otherwise false
 504 */
 505bool tipc_link_bc_create(struct net *net, u32 ownnode, u32 peer,
 506			 int mtu, int window, u16 peer_caps,
 507			 struct sk_buff_head *inputq,
 508			 struct sk_buff_head *namedq,
 509			 struct tipc_link *bc_sndlink,
 510			 struct tipc_link **link)
 511{
 512	struct tipc_link *l;
 513
 514	if (!tipc_link_create(net, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
 515			      0, ownnode, peer, NULL, peer_caps, bc_sndlink,
 516			      NULL, inputq, namedq, link))
 517		return false;
 518
 519	l = *link;
 520	strcpy(l->name, tipc_bclink_name);
 
 
 
 
 
 
 
 
 
 
 
 
 521	tipc_link_reset(l);
 522	l->state = LINK_RESET;
 523	l->ackers = 0;
 524	l->bc_rcvlink = l;
 525
 526	/* Broadcast send link is always up */
 527	if (link_is_bc_sndlink(l))
 528		l->state = LINK_ESTABLISHED;
 529
 530	/* Disable replicast if even a single peer doesn't support it */
 531	if (link_is_bc_rcvlink(l) && !(peer_caps & TIPC_BCAST_RCAST))
 532		tipc_bcast_disable_rcast(net);
 533
 534	return true;
 535}
 536
 537/**
 538 * tipc_link_fsm_evt - link finite state machine
 539 * @l: pointer to link
 540 * @evt: state machine event to be processed
 541 */
 542int tipc_link_fsm_evt(struct tipc_link *l, int evt)
 543{
 544	int rc = 0;
 
 545
 546	switch (l->state) {
 547	case LINK_RESETTING:
 548		switch (evt) {
 549		case LINK_PEER_RESET_EVT:
 550			l->state = LINK_PEER_RESET;
 551			break;
 552		case LINK_RESET_EVT:
 553			l->state = LINK_RESET;
 554			break;
 555		case LINK_FAILURE_EVT:
 556		case LINK_FAILOVER_BEGIN_EVT:
 557		case LINK_ESTABLISH_EVT:
 558		case LINK_FAILOVER_END_EVT:
 559		case LINK_SYNCH_BEGIN_EVT:
 560		case LINK_SYNCH_END_EVT:
 561		default:
 562			goto illegal_evt;
 563		}
 564		break;
 565	case LINK_RESET:
 566		switch (evt) {
 567		case LINK_PEER_RESET_EVT:
 568			l->state = LINK_ESTABLISHING;
 569			break;
 570		case LINK_FAILOVER_BEGIN_EVT:
 571			l->state = LINK_FAILINGOVER;
 572		case LINK_FAILURE_EVT:
 573		case LINK_RESET_EVT:
 574		case LINK_ESTABLISH_EVT:
 575		case LINK_FAILOVER_END_EVT:
 576			break;
 577		case LINK_SYNCH_BEGIN_EVT:
 578		case LINK_SYNCH_END_EVT:
 579		default:
 580			goto illegal_evt;
 581		}
 582		break;
 583	case LINK_PEER_RESET:
 584		switch (evt) {
 585		case LINK_RESET_EVT:
 586			l->state = LINK_ESTABLISHING;
 587			break;
 588		case LINK_PEER_RESET_EVT:
 589		case LINK_ESTABLISH_EVT:
 590		case LINK_FAILURE_EVT:
 591			break;
 592		case LINK_SYNCH_BEGIN_EVT:
 593		case LINK_SYNCH_END_EVT:
 594		case LINK_FAILOVER_BEGIN_EVT:
 595		case LINK_FAILOVER_END_EVT:
 596		default:
 597			goto illegal_evt;
 598		}
 599		break;
 600	case LINK_FAILINGOVER:
 601		switch (evt) {
 602		case LINK_FAILOVER_END_EVT:
 603			l->state = LINK_RESET;
 604			break;
 605		case LINK_PEER_RESET_EVT:
 606		case LINK_RESET_EVT:
 607		case LINK_ESTABLISH_EVT:
 608		case LINK_FAILURE_EVT:
 609			break;
 610		case LINK_FAILOVER_BEGIN_EVT:
 611		case LINK_SYNCH_BEGIN_EVT:
 612		case LINK_SYNCH_END_EVT:
 613		default:
 614			goto illegal_evt;
 615		}
 616		break;
 617	case LINK_ESTABLISHING:
 618		switch (evt) {
 619		case LINK_ESTABLISH_EVT:
 620			l->state = LINK_ESTABLISHED;
 621			break;
 622		case LINK_FAILOVER_BEGIN_EVT:
 623			l->state = LINK_FAILINGOVER;
 624			break;
 625		case LINK_RESET_EVT:
 626			l->state = LINK_RESET;
 627			break;
 628		case LINK_FAILURE_EVT:
 629		case LINK_PEER_RESET_EVT:
 630		case LINK_SYNCH_BEGIN_EVT:
 631		case LINK_FAILOVER_END_EVT:
 632			break;
 633		case LINK_SYNCH_END_EVT:
 634		default:
 635			goto illegal_evt;
 636		}
 637		break;
 638	case LINK_ESTABLISHED:
 639		switch (evt) {
 640		case LINK_PEER_RESET_EVT:
 641			l->state = LINK_PEER_RESET;
 642			rc |= TIPC_LINK_DOWN_EVT;
 643			break;
 644		case LINK_FAILURE_EVT:
 645			l->state = LINK_RESETTING;
 646			rc |= TIPC_LINK_DOWN_EVT;
 647			break;
 648		case LINK_RESET_EVT:
 649			l->state = LINK_RESET;
 650			break;
 651		case LINK_ESTABLISH_EVT:
 652		case LINK_SYNCH_END_EVT:
 653			break;
 654		case LINK_SYNCH_BEGIN_EVT:
 655			l->state = LINK_SYNCHING;
 656			break;
 657		case LINK_FAILOVER_BEGIN_EVT:
 658		case LINK_FAILOVER_END_EVT:
 659		default:
 660			goto illegal_evt;
 661		}
 662		break;
 663	case LINK_SYNCHING:
 664		switch (evt) {
 665		case LINK_PEER_RESET_EVT:
 666			l->state = LINK_PEER_RESET;
 667			rc |= TIPC_LINK_DOWN_EVT;
 668			break;
 669		case LINK_FAILURE_EVT:
 670			l->state = LINK_RESETTING;
 671			rc |= TIPC_LINK_DOWN_EVT;
 672			break;
 673		case LINK_RESET_EVT:
 674			l->state = LINK_RESET;
 675			break;
 676		case LINK_ESTABLISH_EVT:
 677		case LINK_SYNCH_BEGIN_EVT:
 678			break;
 679		case LINK_SYNCH_END_EVT:
 680			l->state = LINK_ESTABLISHED;
 681			break;
 682		case LINK_FAILOVER_BEGIN_EVT:
 683		case LINK_FAILOVER_END_EVT:
 684		default:
 685			goto illegal_evt;
 686		}
 687		break;
 688	default:
 689		pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
 690	}
 
 691	return rc;
 692illegal_evt:
 693	pr_err("Illegal FSM event %x in state %x on link %s\n",
 694	       evt, l->state, l->name);
 
 695	return rc;
 696}
 697
 698/* link_profile_stats - update statistical profiling of traffic
 699 */
 700static void link_profile_stats(struct tipc_link *l)
 701{
 702	struct sk_buff *skb;
 703	struct tipc_msg *msg;
 704	int length;
 705
 706	/* Update counters used in statistical profiling of send traffic */
 707	l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 708	l->stats.queue_sz_counts++;
 709
 710	skb = skb_peek(&l->transmq);
 711	if (!skb)
 712		return;
 713	msg = buf_msg(skb);
 714	length = msg_size(msg);
 715
 716	if (msg_user(msg) == MSG_FRAGMENTER) {
 717		if (msg_type(msg) != FIRST_FRAGMENT)
 718			return;
 719		length = msg_size(msg_get_wrapped(msg));
 720	}
 721	l->stats.msg_lengths_total += length;
 722	l->stats.msg_length_counts++;
 723	if (length <= 64)
 724		l->stats.msg_length_profile[0]++;
 725	else if (length <= 256)
 726		l->stats.msg_length_profile[1]++;
 727	else if (length <= 1024)
 728		l->stats.msg_length_profile[2]++;
 729	else if (length <= 4096)
 730		l->stats.msg_length_profile[3]++;
 731	else if (length <= 16384)
 732		l->stats.msg_length_profile[4]++;
 733	else if (length <= 32768)
 734		l->stats.msg_length_profile[5]++;
 735	else
 736		l->stats.msg_length_profile[6]++;
 737}
 738
 
 
 
 
 
 
 
 
 
 
 
 
 739/* tipc_link_timeout - perform periodic task as instructed from node timeout
 740 */
 741int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 742{
 743	int mtyp = 0;
 744	int rc = 0;
 745	bool state = false;
 746	bool probe = false;
 747	bool setup = false;
 748	u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
 749	u16 bc_acked = l->bc_rcvlink->acked;
 750	struct tipc_mon_state *mstate = &l->mon_state;
 751
 
 
 752	switch (l->state) {
 753	case LINK_ESTABLISHED:
 754	case LINK_SYNCHING:
 755		mtyp = STATE_MSG;
 756		link_profile_stats(l);
 757		tipc_mon_get_state(l->net, l->addr, mstate, l->bearer_id);
 758		if (mstate->reset || (l->silent_intv_cnt > l->abort_limit))
 759			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 760		state = bc_acked != bc_snt;
 761		state |= l->bc_rcvlink->rcv_unacked;
 762		state |= l->rcv_unacked;
 763		state |= !skb_queue_empty(&l->transmq);
 764		state |= !skb_queue_empty(&l->deferdq);
 765		probe = mstate->probing;
 766		probe |= l->silent_intv_cnt;
 767		if (probe || mstate->monitoring)
 768			l->silent_intv_cnt++;
 
 
 
 
 
 
 769		break;
 770	case LINK_RESET:
 771		setup = l->rst_cnt++ <= 4;
 772		setup |= !(l->rst_cnt % 16);
 773		mtyp = RESET_MSG;
 774		break;
 775	case LINK_ESTABLISHING:
 776		setup = true;
 777		mtyp = ACTIVATE_MSG;
 778		break;
 779	case LINK_PEER_RESET:
 780	case LINK_RESETTING:
 781	case LINK_FAILINGOVER:
 782		break;
 783	default:
 784		break;
 785	}
 786
 787	if (state || probe || setup)
 788		tipc_link_build_proto_msg(l, mtyp, probe, 0, 0, 0, 0, xmitq);
 789
 790	return rc;
 791}
 792
 793/**
 794 * link_schedule_user - schedule a message sender for wakeup after congestion
 795 * @l: congested link
 796 * @hdr: header of message that is being sent
 797 * Create pseudo msg to send back to user when congestion abates
 798 */
 799static int link_schedule_user(struct tipc_link *l, struct tipc_msg *hdr)
 800{
 801	u32 dnode = tipc_own_addr(l->net);
 802	u32 dport = msg_origport(hdr);
 803	struct sk_buff *skb;
 804
 805	/* Create and schedule wakeup pseudo message */
 806	skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 807			      dnode, l->addr, dport, 0, 0);
 808	if (!skb)
 809		return -ENOBUFS;
 810	msg_set_dest_droppable(buf_msg(skb), true);
 811	TIPC_SKB_CB(skb)->chain_imp = msg_importance(hdr);
 812	skb_queue_tail(&l->wakeupq, skb);
 813	l->stats.link_congs++;
 
 814	return -ELINKCONG;
 815}
 816
 817/**
 818 * link_prepare_wakeup - prepare users for wakeup after congestion
 819 * @l: congested link
 820 * Wake up a number of waiting users, as permitted by available space
 821 * in the send queue
 822 */
 823void link_prepare_wakeup(struct tipc_link *l)
 824{
 
 
 825	struct sk_buff *skb, *tmp;
 826	int imp, i = 0;
 
 
 827
 828	skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 
 
 
 
 
 829		imp = TIPC_SKB_CB(skb)->chain_imp;
 830		if (l->backlog[imp].len < l->backlog[imp].limit) {
 831			skb_unlink(skb, &l->wakeupq);
 832			skb_queue_tail(l->inputq, skb);
 833		} else if (i++ > 10) {
 834			break;
 835		}
 836	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 837}
 838
 839void tipc_link_reset(struct tipc_link *l)
 840{
 841	l->peer_session = ANY_SESSION;
 
 
 
 
 
 
 
 842	l->session++;
 843	l->mtu = l->advertised_mtu;
 
 
 
 
 
 
 
 
 
 844	__skb_queue_purge(&l->transmq);
 845	__skb_queue_purge(&l->deferdq);
 846	skb_queue_splice_init(&l->wakeupq, l->inputq);
 847	__skb_queue_purge(&l->backlogq);
 848	l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 849	l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 850	l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 851	l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 852	l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 853	kfree_skb(l->reasm_buf);
 
 854	kfree_skb(l->failover_reasm_skb);
 855	l->reasm_buf = NULL;
 
 856	l->failover_reasm_skb = NULL;
 857	l->rcv_unacked = 0;
 858	l->snd_nxt = 1;
 859	l->rcv_nxt = 1;
 
 
 860	l->acked = 0;
 
 
 
 861	l->silent_intv_cnt = 0;
 862	l->rst_cnt = 0;
 863	l->stale_count = 0;
 864	l->bc_peer_is_up = false;
 865	memset(&l->mon_state, 0, sizeof(l->mon_state));
 866	tipc_link_reset_stats(l);
 867}
 868
 869/**
 870 * tipc_link_xmit(): enqueue buffer list according to queue situation
 871 * @link: link to use
 872 * @list: chain of buffers containing message
 873 * @xmitq: returned list of packets to be sent by caller
 874 *
 875 * Consumes the buffer chain.
 876 * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 877 * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 878 */
 879int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 880		   struct sk_buff_head *xmitq)
 881{
 882	struct tipc_msg *hdr = buf_msg(skb_peek(list));
 883	unsigned int maxwin = l->window;
 884	int imp = msg_importance(hdr);
 885	unsigned int mtu = l->mtu;
 
 886	u16 ack = l->rcv_nxt - 1;
 887	u16 seqno = l->snd_nxt;
 888	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 889	struct sk_buff_head *transmq = &l->transmq;
 890	struct sk_buff_head *backlogq = &l->backlogq;
 891	struct sk_buff *skb, *_skb, *bskb;
 892	int pkt_cnt = skb_queue_len(list);
 
 
 
 
 
 893	int rc = 0;
 894
 895	if (unlikely(msg_size(hdr) > mtu)) {
 896		skb_queue_purge(list);
 
 
 
 897		return -EMSGSIZE;
 898	}
 899
 900	/* Allow oversubscription of one data msg per source at congestion */
 901	if (unlikely(l->backlog[imp].len >= l->backlog[imp].limit)) {
 902		if (imp == TIPC_SYSTEM_IMPORTANCE) {
 903			pr_warn("%s<%s>, link overflow", link_rst_msg, l->name);
 904			return -ENOBUFS;
 905		}
 906		rc = link_schedule_user(l, hdr);
 907	}
 908
 909	if (pkt_cnt > 1) {
 910		l->stats.sent_fragmented++;
 911		l->stats.sent_fragments += pkt_cnt;
 912	}
 913
 914	/* Prepare each packet for sending, and add to relevant queue: */
 915	while (skb_queue_len(list)) {
 916		skb = skb_peek(list);
 917		hdr = buf_msg(skb);
 918		msg_set_seqno(hdr, seqno);
 919		msg_set_ack(hdr, ack);
 920		msg_set_bcast_ack(hdr, bc_ack);
 921
 922		if (likely(skb_queue_len(transmq) < maxwin)) {
 923			_skb = skb_clone(skb, GFP_ATOMIC);
 924			if (!_skb) {
 925				skb_queue_purge(list);
 
 926				return -ENOBUFS;
 927			}
 928			__skb_dequeue(list);
 929			__skb_queue_tail(transmq, skb);
 
 930			__skb_queue_tail(xmitq, _skb);
 931			TIPC_SKB_CB(skb)->ackers = l->ackers;
 932			l->rcv_unacked = 0;
 933			l->stats.sent_pkts++;
 934			seqno++;
 935			continue;
 936		}
 937		if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
 938			kfree_skb(__skb_dequeue(list));
 939			l->stats.sent_bundled++;
 940			continue;
 941		}
 942		if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
 943			kfree_skb(__skb_dequeue(list));
 944			__skb_queue_tail(backlogq, bskb);
 945			l->backlog[msg_importance(buf_msg(bskb))].len++;
 946			l->stats.sent_bundled++;
 947			l->stats.sent_bundles++;
 
 
 
 948			continue;
 949		}
 950		l->backlog[imp].len += skb_queue_len(list);
 
 
 951		skb_queue_splice_tail_init(list, backlogq);
 952	}
 953	l->snd_nxt = seqno;
 954	return rc;
 955}
 956
 957void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
 
 958{
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 959	struct sk_buff *skb, *_skb;
 960	struct tipc_msg *hdr;
 961	u16 seqno = l->snd_nxt;
 962	u16 ack = l->rcv_nxt - 1;
 963	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 
 
 
 964
 965	while (skb_queue_len(&l->transmq) < l->window) {
 966		skb = skb_peek(&l->backlogq);
 967		if (!skb)
 968			break;
 969		_skb = skb_clone(skb, GFP_ATOMIC);
 970		if (!_skb)
 971			break;
 972		__skb_dequeue(&l->backlogq);
 973		hdr = buf_msg(skb);
 974		l->backlog[msg_importance(hdr)].len--;
 
 
 
 975		__skb_queue_tail(&l->transmq, skb);
 
 
 976		__skb_queue_tail(xmitq, _skb);
 977		TIPC_SKB_CB(skb)->ackers = l->ackers;
 978		msg_set_seqno(hdr, seqno);
 979		msg_set_ack(hdr, ack);
 980		msg_set_bcast_ack(hdr, bc_ack);
 981		l->rcv_unacked = 0;
 982		l->stats.sent_pkts++;
 983		seqno++;
 984	}
 985	l->snd_nxt = seqno;
 986}
 987
 988static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)
 
 
 
 
 
 
 
 
 
 
 989{
 990	struct tipc_msg *hdr = buf_msg(skb);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 991
 992	pr_warn("Retransmission failure on link <%s>\n", l->name);
 993	link_print(l, "State of link ");
 994	pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
 995		msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
 996	pr_info("sqno %u, prev: %x, src: %x\n",
 997		msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));
 998}
 999
1000int tipc_link_retrans(struct tipc_link *l, struct tipc_link *nacker,
1001		      u16 from, u16 to, struct sk_buff_head *xmitq)
1002{
1003	struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
1004	struct tipc_msg *hdr;
1005	u16 ack = l->rcv_nxt - 1;
1006	u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
1007
1008	if (!skb)
1009		return 0;
1010
1011	/* Detect repeated retransmit failures on same packet */
1012	if (nacker->last_retransm != buf_seqno(skb)) {
1013		nacker->last_retransm = buf_seqno(skb);
1014		nacker->stale_count = 1;
1015	} else if (++nacker->stale_count > 100) {
1016		link_retransmit_failure(l, skb);
1017		nacker->stale_count = 0;
1018		if (link_is_bc_sndlink(l))
1019			return TIPC_LINK_DOWN_EVT;
1020		return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1021	}
1022
1023	/* Move forward to where retransmission should start */
1024	skb_queue_walk(&l->transmq, skb) {
1025		if (!less(buf_seqno(skb), from))
1026			break;
1027	}
1028
1029	skb_queue_walk_from(&l->transmq, skb) {
1030		if (more(buf_seqno(skb), to))
1031			break;
1032		hdr = buf_msg(skb);
1033		_skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
1034		if (!_skb)
1035			return 0;
1036		hdr = buf_msg(_skb);
1037		msg_set_ack(hdr, ack);
1038		msg_set_bcast_ack(hdr, bc_ack);
1039		_skb->priority = TC_PRIO_CONTROL;
1040		__skb_queue_tail(xmitq, _skb);
1041		l->stats.retransmitted++;
1042	}
1043	return 0;
1044}
1045
1046/* tipc_data_input - deliver data and name distr msgs to upper layer
1047 *
1048 * Consumes buffer if message is of right type
1049 * Node lock must be held
1050 */
1051static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1052			    struct sk_buff_head *inputq)
1053{
1054	struct sk_buff_head *mc_inputq = l->bc_rcvlink->inputq;
1055	struct tipc_msg *hdr = buf_msg(skb);
1056
1057	switch (msg_user(hdr)) {
1058	case TIPC_LOW_IMPORTANCE:
1059	case TIPC_MEDIUM_IMPORTANCE:
1060	case TIPC_HIGH_IMPORTANCE:
1061	case TIPC_CRITICAL_IMPORTANCE:
1062		if (unlikely(msg_in_group(hdr) || msg_mcast(hdr))) {
1063			skb_queue_tail(mc_inputq, skb);
1064			return true;
1065		}
 
1066	case CONN_MANAGER:
1067		skb_queue_tail(inputq, skb);
1068		return true;
1069	case GROUP_PROTOCOL:
1070		skb_queue_tail(mc_inputq, skb);
1071		return true;
1072	case NAME_DISTRIBUTOR:
1073		l->bc_rcvlink->state = LINK_ESTABLISHED;
1074		skb_queue_tail(l->namedq, skb);
1075		return true;
1076	case MSG_BUNDLER:
1077	case TUNNEL_PROTOCOL:
1078	case MSG_FRAGMENTER:
1079	case BCAST_PROTOCOL:
1080		return false;
1081	default:
1082		pr_warn("Dropping received illegal msg type\n");
1083		kfree_skb(skb);
1084		return false;
1085	};
1086}
1087
1088/* tipc_link_input - process packet that has passed link protocol check
1089 *
1090 * Consumes buffer
1091 */
1092static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1093			   struct sk_buff_head *inputq)
 
1094{
1095	struct tipc_msg *hdr = buf_msg(skb);
1096	struct sk_buff **reasm_skb = &l->reasm_buf;
1097	struct sk_buff *iskb;
1098	struct sk_buff_head tmpq;
1099	int usr = msg_user(hdr);
1100	int rc = 0;
1101	int pos = 0;
1102	int ipos = 0;
1103
1104	if (unlikely(usr == TUNNEL_PROTOCOL)) {
1105		if (msg_type(hdr) == SYNCH_MSG) {
1106			__skb_queue_purge(&l->deferdq);
1107			goto drop;
1108		}
1109		if (!tipc_msg_extract(skb, &iskb, &ipos))
1110			return rc;
1111		kfree_skb(skb);
1112		skb = iskb;
1113		hdr = buf_msg(skb);
1114		if (less(msg_seqno(hdr), l->drop_point))
1115			goto drop;
1116		if (tipc_data_input(l, skb, inputq))
1117			return rc;
1118		usr = msg_user(hdr);
1119		reasm_skb = &l->failover_reasm_skb;
1120	}
1121
1122	if (usr == MSG_BUNDLER) {
1123		skb_queue_head_init(&tmpq);
1124		l->stats.recv_bundles++;
1125		l->stats.recv_bundled += msg_msgcnt(hdr);
1126		while (tipc_msg_extract(skb, &iskb, &pos))
1127			tipc_data_input(l, iskb, &tmpq);
1128		tipc_skb_queue_splice_tail(&tmpq, inputq);
1129		return 0;
1130	} else if (usr == MSG_FRAGMENTER) {
1131		l->stats.recv_fragments++;
1132		if (tipc_buf_append(reasm_skb, &skb)) {
1133			l->stats.recv_fragmented++;
1134			tipc_data_input(l, skb, inputq);
1135		} else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1136			pr_warn_ratelimited("Unable to build fragment list\n");
1137			return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1138		}
1139		return 0;
1140	} else if (usr == BCAST_PROTOCOL) {
1141		tipc_bcast_lock(l->net);
1142		tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1143		tipc_bcast_unlock(l->net);
1144	}
1145drop:
1146	kfree_skb(skb);
1147	return 0;
1148}
1149
1150static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
 
 
 
 
 
 
 
 
1151{
1152	bool released = false;
1153	struct sk_buff *skb, *tmp;
 
 
 
 
 
 
1154
1155	skb_queue_walk_safe(&l->transmq, skb, tmp) {
1156		if (more(buf_seqno(skb), acked))
1157			break;
1158		__skb_unlink(skb, &l->transmq);
1159		kfree_skb(skb);
1160		released = true;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1161	}
1162	return released;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1163}
1164
1165/* tipc_link_build_state_msg: prepare link state message for transmission
1166 *
1167 * Note that sending of broadcast ack is coordinated among nodes, to reduce
1168 * risk of ack storms towards the sender
1169 */
1170int tipc_link_build_state_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1171{
1172	if (!l)
1173		return 0;
1174
1175	/* Broadcast ACK must be sent via a unicast link => defer to caller */
1176	if (link_is_bc_rcvlink(l)) {
1177		if (((l->rcv_nxt ^ tipc_own_addr(l->net)) & 0xf) != 0xf)
1178			return 0;
1179		l->rcv_unacked = 0;
1180
1181		/* Use snd_nxt to store peer's snd_nxt in broadcast rcv link */
1182		l->snd_nxt = l->rcv_nxt;
1183		return TIPC_LINK_SND_STATE;
1184	}
1185
1186	/* Unicast ACK */
1187	l->rcv_unacked = 0;
1188	l->stats.sent_acks++;
1189	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
1190	return 0;
1191}
1192
1193/* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1194 */
1195void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1196{
1197	int mtyp = RESET_MSG;
1198	struct sk_buff *skb;
1199
1200	if (l->state == LINK_ESTABLISHING)
1201		mtyp = ACTIVATE_MSG;
1202
1203	tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, 0, xmitq);
1204
1205	/* Inform peer that this endpoint is going down if applicable */
1206	skb = skb_peek_tail(xmitq);
1207	if (skb && (l->state == LINK_RESET))
1208		msg_set_peer_stopping(buf_msg(skb), 1);
1209}
1210
1211/* tipc_link_build_nack_msg: prepare link nack message for transmission
1212 * Note that sending of broadcast NACK is coordinated among nodes, to
1213 * reduce the risk of NACK storms towards the sender
1214 */
1215static int tipc_link_build_nack_msg(struct tipc_link *l,
1216				    struct sk_buff_head *xmitq)
1217{
1218	u32 def_cnt = ++l->stats.deferred_recv;
 
 
1219	int match1, match2;
1220
1221	if (link_is_bc_rcvlink(l)) {
1222		match1 = def_cnt & 0xf;
1223		match2 = tipc_own_addr(l->net) & 0xf;
1224		if (match1 == match2)
1225			return TIPC_LINK_SND_STATE;
1226		return 0;
1227	}
1228
1229	if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
1230		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, 0, xmitq);
 
 
 
 
1231	return 0;
1232}
1233
1234/* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1235 * @l: the link that should handle the message
1236 * @skb: TIPC packet
1237 * @xmitq: queue to place packets to be sent after this call
1238 */
1239int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1240		  struct sk_buff_head *xmitq)
1241{
1242	struct sk_buff_head *defq = &l->deferdq;
1243	struct tipc_msg *hdr;
1244	u16 seqno, rcv_nxt, win_lim;
 
1245	int rc = 0;
1246
 
 
 
 
 
 
 
1247	do {
1248		hdr = buf_msg(skb);
1249		seqno = msg_seqno(hdr);
1250		rcv_nxt = l->rcv_nxt;
1251		win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1252
1253		/* Verify and update link state */
1254		if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1255			return tipc_link_proto_rcv(l, skb, xmitq);
1256
1257		if (unlikely(!link_is_up(l))) {
1258			if (l->state == LINK_ESTABLISHING)
1259				rc = TIPC_LINK_UP_EVT;
1260			goto drop;
 
1261		}
1262
1263		/* Don't send probe at next timeout expiration */
1264		l->silent_intv_cnt = 0;
1265
1266		/* Drop if outside receive window */
1267		if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1268			l->stats.duplicates++;
1269			goto drop;
1270		}
1271
1272		/* Forward queues and wake up waiting users */
1273		if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1274			tipc_link_advance_backlog(l, xmitq);
1275			if (unlikely(!skb_queue_empty(&l->wakeupq)))
1276				link_prepare_wakeup(l);
1277		}
 
 
1278
1279		/* Defer delivery if sequence gap */
1280		if (unlikely(seqno != rcv_nxt)) {
1281			__tipc_skb_queue_sorted(defq, seqno, skb);
 
1282			rc |= tipc_link_build_nack_msg(l, xmitq);
1283			break;
1284		}
1285
1286		/* Deliver packet */
1287		l->rcv_nxt++;
1288		l->stats.recv_pkts++;
1289		if (!tipc_data_input(l, skb, l->inputq))
1290			rc |= tipc_link_input(l, skb, l->inputq);
 
 
 
1291		if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1292			rc |= tipc_link_build_state_msg(l, xmitq);
1293		if (unlikely(rc & ~TIPC_LINK_SND_STATE))
1294			break;
1295	} while ((skb = __skb_dequeue(defq)));
1296
1297	return rc;
1298drop:
1299	kfree_skb(skb);
 
 
 
 
1300	return rc;
1301}
1302
1303static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1304				      bool probe_reply, u16 rcvgap,
1305				      int tolerance, int priority,
1306				      struct sk_buff_head *xmitq)
1307{
 
 
1308	struct tipc_link *bcl = l->bc_rcvlink;
1309	struct sk_buff *skb;
1310	struct tipc_msg *hdr;
1311	struct sk_buff_head *dfq = &l->deferdq;
1312	bool node_up = link_is_up(bcl);
1313	struct tipc_mon_state *mstate = &l->mon_state;
1314	int dlen = 0;
1315	void *data;
1316
1317	/* Don't send protocol message during reset or link failover */
1318	if (tipc_link_is_blocked(l))
1319		return;
1320
1321	if (!tipc_link_is_up(l) && (mtyp == STATE_MSG))
1322		return;
1323
1324	if (!skb_queue_empty(dfq))
1325		rcvgap = buf_seqno(skb_peek(dfq)) - l->rcv_nxt;
1326
1327	skb = tipc_msg_create(LINK_PROTOCOL, mtyp, INT_H_SIZE,
1328			      tipc_max_domain_size, l->addr,
1329			      tipc_own_addr(l->net), 0, 0, 0);
1330	if (!skb)
1331		return;
1332
1333	hdr = buf_msg(skb);
1334	data = msg_data(hdr);
1335	msg_set_session(hdr, l->session);
1336	msg_set_bearer_id(hdr, l->bearer_id);
1337	msg_set_net_plane(hdr, l->net_plane);
1338	msg_set_next_sent(hdr, l->snd_nxt);
1339	msg_set_ack(hdr, l->rcv_nxt - 1);
1340	msg_set_bcast_ack(hdr, bcl->rcv_nxt - 1);
1341	msg_set_bc_ack_invalid(hdr, !node_up);
1342	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1343	msg_set_link_tolerance(hdr, tolerance);
1344	msg_set_linkprio(hdr, priority);
1345	msg_set_redundant_link(hdr, node_up);
1346	msg_set_seq_gap(hdr, 0);
1347	msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1348
1349	if (mtyp == STATE_MSG) {
 
 
1350		msg_set_seq_gap(hdr, rcvgap);
1351		msg_set_bc_gap(hdr, link_bc_rcv_gap(bcl));
 
1352		msg_set_probe(hdr, probe);
1353		msg_set_is_keepalive(hdr, probe || probe_reply);
1354		tipc_mon_prep(l->net, data, &dlen, mstate, l->bearer_id);
1355		msg_set_size(hdr, INT_H_SIZE + dlen);
1356		skb_trim(skb, INT_H_SIZE + dlen);
 
 
1357		l->stats.sent_states++;
1358		l->rcv_unacked = 0;
1359	} else {
1360		/* RESET_MSG or ACTIVATE_MSG */
 
 
 
 
1361		msg_set_max_pkt(hdr, l->advertised_mtu);
1362		strcpy(data, l->if_name);
1363		msg_set_size(hdr, INT_H_SIZE + TIPC_MAX_IF_NAME);
1364		skb_trim(skb, INT_H_SIZE + TIPC_MAX_IF_NAME);
1365	}
1366	if (probe)
1367		l->stats.sent_probes++;
1368	if (rcvgap)
1369		l->stats.sent_nacks++;
 
 
1370	skb->priority = TC_PRIO_CONTROL;
1371	__skb_queue_tail(xmitq, skb);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1372}
1373
1374/* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1375 * with contents of the link's transmit and backlog queues.
1376 */
1377void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1378			   int mtyp, struct sk_buff_head *xmitq)
1379{
 
1380	struct sk_buff *skb, *tnlskb;
1381	struct tipc_msg *hdr, tnlhdr;
1382	struct sk_buff_head *queue = &l->transmq;
1383	struct sk_buff_head tmpxq, tnlq;
1384	u16 pktlen, pktcnt, seqno = l->snd_nxt;
 
 
 
1385
1386	if (!tnl)
1387		return;
1388
1389	skb_queue_head_init(&tnlq);
1390	skb_queue_head_init(&tmpxq);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1391
 
 
1392	/* At least one packet required for safe algorithm => add dummy */
1393	skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1394			      BASIC_H_SIZE, 0, l->addr, tipc_own_addr(l->net),
1395			      0, 0, TIPC_ERR_NO_PORT);
1396	if (!skb) {
1397		pr_warn("%sunable to create tunnel packet\n", link_co_err);
1398		return;
1399	}
1400	skb_queue_tail(&tnlq, skb);
1401	tipc_link_xmit(l, &tnlq, &tmpxq);
1402	__skb_queue_purge(&tmpxq);
1403
1404	/* Initialize reusable tunnel packet header */
1405	tipc_msg_init(tipc_own_addr(l->net), &tnlhdr, TUNNEL_PROTOCOL,
1406		      mtyp, INT_H_SIZE, l->addr);
1407	pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
 
 
 
 
1408	msg_set_msgcnt(&tnlhdr, pktcnt);
1409	msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1410tnl:
1411	/* Wrap each packet into a tunnel packet */
1412	skb_queue_walk(queue, skb) {
1413		hdr = buf_msg(skb);
1414		if (queue == &l->backlogq)
1415			msg_set_seqno(hdr, seqno++);
1416		pktlen = msg_size(hdr);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1417		msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1418		tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE, GFP_ATOMIC);
1419		if (!tnlskb) {
1420			pr_warn("%sunable to send packet\n", link_co_err);
1421			return;
1422		}
1423		skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1424		skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1425		__skb_queue_tail(&tnlq, tnlskb);
1426	}
1427	if (queue != &l->backlogq) {
1428		queue = &l->backlogq;
1429		goto tnl;
1430	}
1431
 
 
 
 
 
 
1432	tipc_link_xmit(tnl, &tnlq, xmitq);
1433
1434	if (mtyp == FAILOVER_MSG) {
1435		tnl->drop_point = l->rcv_nxt;
1436		tnl->failover_reasm_skb = l->reasm_buf;
1437		l->reasm_buf = NULL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1438	}
1439}
1440
1441/* tipc_link_proto_rcv(): receive link level protocol message :
1442 * Note that network plane id propagates through the network, and may
1443 * change at any time. The node with lowest numerical id determines
1444 * network plane
1445 */
1446static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1447			       struct sk_buff_head *xmitq)
1448{
1449	struct tipc_msg *hdr = buf_msg(skb);
1450	u16 rcvgap = 0;
1451	u16 ack = msg_ack(hdr);
1452	u16 gap = msg_seq_gap(hdr);
1453	u16 peers_snd_nxt =  msg_next_sent(hdr);
1454	u16 peers_tol = msg_link_tolerance(hdr);
1455	u16 peers_prio = msg_linkprio(hdr);
 
 
1456	u16 rcv_nxt = l->rcv_nxt;
1457	u16 dlen = msg_data_sz(hdr);
1458	int mtyp = msg_type(hdr);
1459	bool reply = msg_probe(hdr);
1460	void *data;
1461	char *if_name;
1462	int rc = 0;
1463
 
1464	if (tipc_link_is_blocked(l) || !xmitq)
1465		goto exit;
1466
1467	if (tipc_own_addr(l->net) > msg_prevnode(hdr))
1468		l->net_plane = msg_net_plane(hdr);
1469
1470	skb_linearize(skb);
1471	hdr = buf_msg(skb);
1472	data = msg_data(hdr);
1473
 
 
 
 
 
 
1474	switch (mtyp) {
1475	case RESET_MSG:
1476
1477		/* Ignore duplicate RESET with old session number */
1478		if ((less_eq(msg_session(hdr), l->peer_session)) &&
1479		    (l->peer_session != ANY_SESSION))
1480			break;
1481		/* fall thru' */
1482
1483	case ACTIVATE_MSG:
1484
1485		/* Complete own link name with peer's interface name */
1486		if_name =  strrchr(l->name, ':') + 1;
1487		if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1488			break;
1489		if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1490			break;
1491		strncpy(if_name, data, TIPC_MAX_IF_NAME);
1492
1493		/* Update own tolerance if peer indicates a non-zero value */
1494		if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1495			l->tolerance = peers_tol;
1496
 
1497		/* Update own priority if peer's priority is higher */
1498		if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1499			l->priority = peers_prio;
1500
1501		/* ACTIVATE_MSG serves as PEER_RESET if link is already down */
1502		if (msg_peer_stopping(hdr))
1503			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1504		else if ((mtyp == RESET_MSG) || !link_is_up(l))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1505			rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
1506
1507		/* ACTIVATE_MSG takes up link if it was already locally reset */
1508		if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
1509			rc = TIPC_LINK_UP_EVT;
1510
1511		l->peer_session = msg_session(hdr);
 
1512		l->peer_bearer_id = msg_bearer_id(hdr);
1513		if (l->mtu > msg_max_pkt(hdr))
1514			l->mtu = msg_max_pkt(hdr);
1515		break;
1516
1517	case STATE_MSG:
 
1518
1519		/* Update own tolerance if peer indicates a non-zero value */
1520		if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1521			l->tolerance = peers_tol;
1522
 
1523		/* Update own prio if peer indicates a different value */
1524		if ((peers_prio != l->priority) &&
1525		    in_range(peers_prio, 1, TIPC_MAX_LINK_PRI)) {
1526			l->priority = peers_prio;
1527			rc = tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1528		}
1529
1530		l->silent_intv_cnt = 0;
1531		l->stats.recv_states++;
1532		if (msg_probe(hdr))
1533			l->stats.recv_probes++;
1534
1535		if (!link_is_up(l)) {
1536			if (l->state == LINK_ESTABLISHING)
1537				rc = TIPC_LINK_UP_EVT;
1538			break;
1539		}
1540		tipc_mon_rcv(l->net, data, dlen, l->addr,
 
 
 
 
1541			     &l->mon_state, l->bearer_id);
1542
1543		/* Send NACK if peer has sent pkts we haven't received yet */
1544		if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
 
 
 
1545			rcvgap = peers_snd_nxt - l->rcv_nxt;
1546		if (rcvgap || reply)
1547			tipc_link_build_proto_msg(l, STATE_MSG, 0, reply,
1548						  rcvgap, 0, 0, xmitq);
1549		tipc_link_release_pkts(l, ack);
1550
1551		/* If NACK, retransmit will now start at right position */
1552		if (gap) {
1553			rc = tipc_link_retrans(l, l, ack + 1, ack + gap, xmitq);
1554			l->stats.recv_nacks++;
1555		}
1556
1557		tipc_link_advance_backlog(l, xmitq);
 
1558		if (unlikely(!skb_queue_empty(&l->wakeupq)))
1559			link_prepare_wakeup(l);
1560	}
1561exit:
1562	kfree_skb(skb);
1563	return rc;
1564}
1565
1566/* tipc_link_build_bc_proto_msg() - create broadcast protocol message
1567 */
1568static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
1569					 u16 peers_snd_nxt,
1570					 struct sk_buff_head *xmitq)
1571{
1572	struct sk_buff *skb;
1573	struct tipc_msg *hdr;
1574	struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
1575	u16 ack = l->rcv_nxt - 1;
1576	u16 gap_to = peers_snd_nxt - 1;
1577
1578	skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
1579			      0, l->addr, tipc_own_addr(l->net), 0, 0, 0);
1580	if (!skb)
1581		return false;
1582	hdr = buf_msg(skb);
1583	msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1584	msg_set_bcast_ack(hdr, ack);
1585	msg_set_bcgap_after(hdr, ack);
1586	if (dfrd_skb)
1587		gap_to = buf_seqno(dfrd_skb) - 1;
1588	msg_set_bcgap_to(hdr, gap_to);
1589	msg_set_non_seq(hdr, bcast);
1590	__skb_queue_tail(xmitq, skb);
1591	return true;
1592}
1593
1594/* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
1595 *
1596 * Give a newly added peer node the sequence number where it should
1597 * start receiving and acking broadcast packets.
1598 */
1599static void tipc_link_build_bc_init_msg(struct tipc_link *l,
1600					struct sk_buff_head *xmitq)
1601{
1602	struct sk_buff_head list;
1603
1604	__skb_queue_head_init(&list);
1605	if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
1606		return;
1607	msg_set_bc_ack_invalid(buf_msg(skb_peek(&list)), true);
1608	tipc_link_xmit(l, &list, xmitq);
1609}
1610
1611/* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
1612 */
1613void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
1614{
1615	int mtyp = msg_type(hdr);
1616	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1617
1618	if (link_is_up(l))
1619		return;
1620
1621	if (msg_user(hdr) == BCAST_PROTOCOL) {
1622		l->rcv_nxt = peers_snd_nxt;
1623		l->state = LINK_ESTABLISHED;
1624		return;
1625	}
1626
1627	if (l->peer_caps & TIPC_BCAST_SYNCH)
1628		return;
1629
1630	if (msg_peer_node_is_up(hdr))
1631		return;
1632
1633	/* Compatibility: accept older, less safe initial synch data */
1634	if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
1635		l->rcv_nxt = peers_snd_nxt;
1636}
1637
1638/* link_bc_retr eval()- check if the indicated range can be retransmitted now
1639 * - Adjust permitted range if there is overlap with previous retransmission
1640 */
1641static bool link_bc_retr_eval(struct tipc_link *l, u16 *from, u16 *to)
1642{
1643	unsigned long elapsed = jiffies_to_msecs(jiffies - l->prev_retr);
1644
1645	if (less(*to, *from))
1646		return false;
1647
1648	/* New retransmission request */
1649	if ((elapsed > TIPC_BC_RETR_LIMIT) ||
1650	    less(*to, l->prev_from) || more(*from, l->prev_to)) {
1651		l->prev_from = *from;
1652		l->prev_to = *to;
1653		l->prev_retr = jiffies;
1654		return true;
1655	}
1656
1657	/* Inside range of previous retransmit */
1658	if (!less(*from, l->prev_from) && !more(*to, l->prev_to))
1659		return false;
1660
1661	/* Fully or partially outside previous range => exclude overlap */
1662	if (less(*from, l->prev_from)) {
1663		*to = l->prev_from - 1;
1664		l->prev_from = *from;
1665	}
1666	if (more(*to, l->prev_to)) {
1667		*from = l->prev_to + 1;
1668		l->prev_to = *to;
1669	}
1670	l->prev_retr = jiffies;
1671	return true;
1672}
1673
1674/* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
1675 */
1676int tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
1677			  struct sk_buff_head *xmitq)
1678{
1679	struct tipc_link *snd_l = l->bc_sndlink;
1680	u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1681	u16 from = msg_bcast_ack(hdr) + 1;
1682	u16 to = from + msg_bc_gap(hdr) - 1;
1683	int rc = 0;
1684
1685	if (!link_is_up(l))
1686		return rc;
1687
1688	if (!msg_peer_node_is_up(hdr))
1689		return rc;
1690
1691	/* Open when peer ackowledges our bcast init msg (pkt #1) */
1692	if (msg_ack(hdr))
1693		l->bc_peer_is_up = true;
1694
1695	if (!l->bc_peer_is_up)
1696		return rc;
1697
1698	l->stats.recv_nacks++;
1699
1700	/* Ignore if peers_snd_nxt goes beyond receive window */
1701	if (more(peers_snd_nxt, l->rcv_nxt + l->window))
1702		return rc;
1703
1704	if (link_bc_retr_eval(snd_l, &from, &to))
1705		rc = tipc_link_retrans(snd_l, l, from, to, xmitq);
1706
1707	l->snd_nxt = peers_snd_nxt;
1708	if (link_bc_rcv_gap(l))
1709		rc |= TIPC_LINK_SND_STATE;
1710
1711	/* Return now if sender supports nack via STATE messages */
1712	if (l->peer_caps & TIPC_BCAST_STATE_NACK)
1713		return rc;
1714
1715	/* Otherwise, be backwards compatible */
1716
1717	if (!more(peers_snd_nxt, l->rcv_nxt)) {
1718		l->nack_state = BC_NACK_SND_CONDITIONAL;
1719		return 0;
1720	}
1721
1722	/* Don't NACK if one was recently sent or peeked */
1723	if (l->nack_state == BC_NACK_SND_SUPPRESS) {
1724		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1725		return 0;
1726	}
1727
1728	/* Conditionally delay NACK sending until next synch rcv */
1729	if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
1730		l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1731		if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
1732			return 0;
1733	}
1734
1735	/* Send NACK now but suppress next one */
1736	tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
1737	l->nack_state = BC_NACK_SND_SUPPRESS;
1738	return 0;
1739}
1740
1741void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
1742			  struct sk_buff_head *xmitq)
 
 
1743{
1744	struct sk_buff *skb, *tmp;
1745	struct tipc_link *snd_l = l->bc_sndlink;
1746
1747	if (!link_is_up(l) || !l->bc_peer_is_up)
1748		return;
1749
1750	if (!more(acked, l->acked))
1751		return;
1752
1753	/* Skip over packets peer has already acked */
1754	skb_queue_walk(&snd_l->transmq, skb) {
1755		if (more(buf_seqno(skb), l->acked))
1756			break;
1757	}
1758
1759	/* Update/release the packets peer is acking now */
1760	skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
1761		if (more(buf_seqno(skb), acked))
1762			break;
1763		if (!--TIPC_SKB_CB(skb)->ackers) {
1764			__skb_unlink(skb, &snd_l->transmq);
1765			kfree_skb(skb);
1766		}
1767	}
1768	l->acked = acked;
1769	tipc_link_advance_backlog(snd_l, xmitq);
1770	if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
1771		link_prepare_wakeup(snd_l);
1772}
1773
1774/* tipc_link_bc_nack_rcv(): receive broadcast nack message
1775 * This function is here for backwards compatibility, since
1776 * no BCAST_PROTOCOL/STATE messages occur from TIPC v2.5.
1777 */
1778int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
1779			  struct sk_buff_head *xmitq)
1780{
1781	struct tipc_msg *hdr = buf_msg(skb);
1782	u32 dnode = msg_destnode(hdr);
1783	int mtyp = msg_type(hdr);
1784	u16 acked = msg_bcast_ack(hdr);
1785	u16 from = acked + 1;
1786	u16 to = msg_bcgap_to(hdr);
1787	u16 peers_snd_nxt = to + 1;
1788	int rc = 0;
1789
1790	kfree_skb(skb);
1791
1792	if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
1793		return 0;
1794
1795	if (mtyp != STATE_MSG)
1796		return 0;
1797
1798	if (dnode == tipc_own_addr(l->net)) {
1799		tipc_link_bc_ack_rcv(l, acked, xmitq);
1800		rc = tipc_link_retrans(l->bc_sndlink, l, from, to, xmitq);
1801		l->stats.recv_nacks++;
1802		return rc;
1803	}
1804
1805	/* Msg for other node => suppress own NACK at next sync if applicable */
1806	if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
1807		l->nack_state = BC_NACK_SND_SUPPRESS;
1808
1809	return 0;
1810}
1811
1812void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1813{
1814	int max_bulk = TIPC_MAX_PUBL / (l->mtu / ITEM_SIZE);
1815
1816	l->window = win;
1817	l->backlog[TIPC_LOW_IMPORTANCE].limit      = max_t(u16, 50, win);
1818	l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = max_t(u16, 100, win * 2);
1819	l->backlog[TIPC_HIGH_IMPORTANCE].limit     = max_t(u16, 150, win * 3);
1820	l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = max_t(u16, 200, win * 4);
 
 
 
1821	l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1822}
1823
1824/**
1825 * link_reset_stats - reset link statistics
1826 * @l: pointer to link
1827 */
1828void tipc_link_reset_stats(struct tipc_link *l)
1829{
1830	memset(&l->stats, 0, sizeof(l->stats));
1831}
1832
1833static void link_print(struct tipc_link *l, const char *str)
1834{
1835	struct sk_buff *hskb = skb_peek(&l->transmq);
1836	u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
1837	u16 tail = l->snd_nxt - 1;
1838
1839	pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
1840	pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1841		skb_queue_len(&l->transmq), head, tail,
1842		skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1843}
1844
1845/* Parse and validate nested (link) properties valid for media, bearer and link
1846 */
1847int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1848{
1849	int err;
1850
1851	err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1852			       tipc_nl_prop_policy, NULL);
1853	if (err)
1854		return err;
1855
1856	if (props[TIPC_NLA_PROP_PRIO]) {
1857		u32 prio;
1858
1859		prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1860		if (prio > TIPC_MAX_LINK_PRI)
1861			return -EINVAL;
1862	}
1863
1864	if (props[TIPC_NLA_PROP_TOL]) {
1865		u32 tol;
1866
1867		tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1868		if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1869			return -EINVAL;
1870	}
1871
1872	if (props[TIPC_NLA_PROP_WIN]) {
1873		u32 win;
1874
1875		win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1876		if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1877			return -EINVAL;
1878	}
1879
1880	return 0;
1881}
1882
1883static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1884{
1885	int i;
1886	struct nlattr *stats;
1887
1888	struct nla_map {
1889		u32 key;
1890		u32 val;
1891	};
1892
1893	struct nla_map map[] = {
1894		{TIPC_NLA_STATS_RX_INFO, 0},
1895		{TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1896		{TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1897		{TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1898		{TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1899		{TIPC_NLA_STATS_TX_INFO, 0},
1900		{TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1901		{TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1902		{TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1903		{TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1904		{TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1905			s->msg_length_counts : 1},
1906		{TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1907		{TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1908		{TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1909		{TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1910		{TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1911		{TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1912		{TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1913		{TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1914		{TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1915		{TIPC_NLA_STATS_RX_STATES, s->recv_states},
1916		{TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1917		{TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1918		{TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1919		{TIPC_NLA_STATS_TX_STATES, s->sent_states},
1920		{TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1921		{TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1922		{TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1923		{TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1924		{TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1925		{TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1926		{TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1927		{TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1928			(s->accu_queue_sz / s->queue_sz_counts) : 0}
1929	};
1930
1931	stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1932	if (!stats)
1933		return -EMSGSIZE;
1934
1935	for (i = 0; i <  ARRAY_SIZE(map); i++)
1936		if (nla_put_u32(skb, map[i].key, map[i].val))
1937			goto msg_full;
1938
1939	nla_nest_end(skb, stats);
1940
1941	return 0;
1942msg_full:
1943	nla_nest_cancel(skb, stats);
1944
1945	return -EMSGSIZE;
1946}
1947
1948/* Caller should hold appropriate locks to protect the link */
1949int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1950		       struct tipc_link *link, int nlflags)
1951{
1952	u32 self = tipc_own_addr(net);
1953	struct nlattr *attrs;
1954	struct nlattr *prop;
1955	void *hdr;
1956	int err;
1957
1958	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1959			  nlflags, TIPC_NL_LINK_GET);
1960	if (!hdr)
1961		return -EMSGSIZE;
1962
1963	attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1964	if (!attrs)
1965		goto msg_full;
1966
1967	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1968		goto attr_msg_full;
1969	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST, tipc_cluster_mask(self)))
1970		goto attr_msg_full;
1971	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1972		goto attr_msg_full;
1973	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->stats.recv_pkts))
1974		goto attr_msg_full;
1975	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->stats.sent_pkts))
1976		goto attr_msg_full;
1977
1978	if (tipc_link_is_up(link))
1979		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1980			goto attr_msg_full;
1981	if (link->active)
1982		if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1983			goto attr_msg_full;
1984
1985	prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1986	if (!prop)
1987		goto attr_msg_full;
1988	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1989		goto prop_msg_full;
1990	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1991		goto prop_msg_full;
1992	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1993			link->window))
1994		goto prop_msg_full;
1995	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1996		goto prop_msg_full;
1997	nla_nest_end(msg->skb, prop);
1998
1999	err = __tipc_nl_add_stats(msg->skb, &link->stats);
2000	if (err)
2001		goto attr_msg_full;
2002
2003	nla_nest_end(msg->skb, attrs);
2004	genlmsg_end(msg->skb, hdr);
2005
2006	return 0;
2007
2008prop_msg_full:
2009	nla_nest_cancel(msg->skb, prop);
2010attr_msg_full:
2011	nla_nest_cancel(msg->skb, attrs);
2012msg_full:
2013	genlmsg_cancel(msg->skb, hdr);
2014
2015	return -EMSGSIZE;
2016}
2017
2018static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
2019				      struct tipc_stats *stats)
2020{
2021	int i;
2022	struct nlattr *nest;
2023
2024	struct nla_map {
2025		__u32 key;
2026		__u32 val;
2027	};
2028
2029	struct nla_map map[] = {
2030		{TIPC_NLA_STATS_RX_INFO, stats->recv_pkts},
2031		{TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
2032		{TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
2033		{TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
2034		{TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
2035		{TIPC_NLA_STATS_TX_INFO, stats->sent_pkts},
2036		{TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
2037		{TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
2038		{TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
2039		{TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
2040		{TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
2041		{TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
2042		{TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
2043		{TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
2044		{TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
2045		{TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
2046		{TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
2047		{TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
2048		{TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
2049			(stats->accu_queue_sz / stats->queue_sz_counts) : 0}
2050	};
2051
2052	nest = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
2053	if (!nest)
2054		return -EMSGSIZE;
2055
2056	for (i = 0; i <  ARRAY_SIZE(map); i++)
2057		if (nla_put_u32(skb, map[i].key, map[i].val))
2058			goto msg_full;
2059
2060	nla_nest_end(skb, nest);
2061
2062	return 0;
2063msg_full:
2064	nla_nest_cancel(skb, nest);
2065
2066	return -EMSGSIZE;
2067}
2068
2069int tipc_nl_add_bc_link(struct net *net, struct tipc_nl_msg *msg)
 
2070{
2071	int err;
2072	void *hdr;
2073	struct nlattr *attrs;
2074	struct nlattr *prop;
2075	struct tipc_net *tn = net_generic(net, tipc_net_id);
2076	struct tipc_link *bcl = tn->bcl;
2077
2078	if (!bcl)
2079		return 0;
2080
2081	tipc_bcast_lock(net);
2082
2083	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2084			  NLM_F_MULTI, TIPC_NL_LINK_GET);
2085	if (!hdr) {
2086		tipc_bcast_unlock(net);
2087		return -EMSGSIZE;
2088	}
2089
2090	attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
2091	if (!attrs)
2092		goto msg_full;
2093
2094	/* The broadcast link is always up */
2095	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2096		goto attr_msg_full;
2097
2098	if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
2099		goto attr_msg_full;
2100	if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
2101		goto attr_msg_full;
2102	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, 0))
2103		goto attr_msg_full;
2104	if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, 0))
2105		goto attr_msg_full;
2106
2107	prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2108	if (!prop)
2109		goto attr_msg_full;
2110	if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->window))
2111		goto prop_msg_full;
 
 
 
 
 
 
2112	nla_nest_end(msg->skb, prop);
2113
2114	err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
2115	if (err)
2116		goto attr_msg_full;
2117
2118	tipc_bcast_unlock(net);
2119	nla_nest_end(msg->skb, attrs);
2120	genlmsg_end(msg->skb, hdr);
2121
2122	return 0;
2123
2124prop_msg_full:
2125	nla_nest_cancel(msg->skb, prop);
2126attr_msg_full:
2127	nla_nest_cancel(msg->skb, attrs);
2128msg_full:
2129	tipc_bcast_unlock(net);
2130	genlmsg_cancel(msg->skb, hdr);
2131
2132	return -EMSGSIZE;
2133}
2134
2135void tipc_link_set_tolerance(struct tipc_link *l, u32 tol,
2136			     struct sk_buff_head *xmitq)
2137{
2138	l->tolerance = tol;
 
 
2139	if (link_is_up(l))
2140		tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, tol, 0, xmitq);
2141}
2142
2143void tipc_link_set_prio(struct tipc_link *l, u32 prio,
2144			struct sk_buff_head *xmitq)
2145{
2146	l->priority = prio;
2147	tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, prio, xmitq);
2148}
2149
2150void tipc_link_set_abort_limit(struct tipc_link *l, u32 limit)
2151{
2152	l->abort_limit = limit;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2153}