net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, 2012-2015, 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
  48 /*
  49  * Error message prefixes
  50  */
  51 static const char *link_co_err = "Link tunneling error, ";
  52 static const char *link_rst_msg = "Resetting link ";
  53 static const char tipc_bclink_name[] = "broadcast-link";
  54
  55 static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
  56         [TIPC_NLA_LINK_UNSPEC]          = { .type = NLA_UNSPEC },
  57         [TIPC_NLA_LINK_NAME] = {
  58                 .type = NLA_STRING,
  59                 .len = TIPC_MAX_LINK_NAME
  60         },
  61         [TIPC_NLA_LINK_MTU]             = { .type = NLA_U32 },
  62         [TIPC_NLA_LINK_BROADCAST]       = { .type = NLA_FLAG },
  63         [TIPC_NLA_LINK_UP]              = { .type = NLA_FLAG },
  64         [TIPC_NLA_LINK_ACTIVE]          = { .type = NLA_FLAG },
  65         [TIPC_NLA_LINK_PROP]            = { .type = NLA_NESTED },
  66         [TIPC_NLA_LINK_STATS]           = { .type = NLA_NESTED },
  67         [TIPC_NLA_LINK_RX]              = { .type = NLA_U32 },
  68         [TIPC_NLA_LINK_TX]              = { .type = NLA_U32 }
  69 };
  70
  71 /* Properties valid for media, bearar and link */
  72 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
  73         [TIPC_NLA_PROP_UNSPEC]          = { .type = NLA_UNSPEC },
  74         [TIPC_NLA_PROP_PRIO]            = { .type = NLA_U32 },
  75         [TIPC_NLA_PROP_TOL]             = { .type = NLA_U32 },
  76         [TIPC_NLA_PROP_WIN]             = { .type = NLA_U32 }
  77 };
  78
  79 /* Send states for broadcast NACKs
  80  */
  81 enum {
  82         BC_NACK_SND_CONDITIONAL,
  83         BC_NACK_SND_UNCONDITIONAL,
  84         BC_NACK_SND_SUPPRESS,
  85 };
  86
  87 /*
  88  * Interval between NACKs when packets arrive out of order
  89  */
  90 #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
  91 /*
  92  * Out-of-range value for link session numbers
  93  */
  94 #define WILDCARD_SESSION 0x10000
  95
  96 /* Link FSM states:
  97  */
  98 enum {
  99         LINK_ESTABLISHED     = 0xe,
 100         LINK_ESTABLISHING    = 0xe  << 4,
 101         LINK_RESET           = 0x1  << 8,
 102         LINK_RESETTING       = 0x2  << 12,
 103         LINK_PEER_RESET      = 0xd  << 16,
 104         LINK_FAILINGOVER     = 0xf  << 20,
 105         LINK_SYNCHING        = 0xc  << 24
 106 };
 107
 108 /* Link FSM state checking routines
 109  */
 110 static int link_is_up(struct tipc_link *l)
 111 {
 112         return l->state & (LINK_ESTABLISHED | LINK_SYNCHING);
 113 }
 114
 115 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 116                                struct sk_buff_head *xmitq);
 117 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 118                                       u16 rcvgap, int tolerance, int priority,
 119                                       struct sk_buff_head *xmitq);
 120 static void link_reset_statistics(struct tipc_link *l_ptr);
 121 static void link_print(struct tipc_link *l_ptr, const char *str);
 122 static void tipc_link_build_nack_msg(struct tipc_link *l,
 123                                      struct sk_buff_head *xmitq);
 124 static void tipc_link_build_bc_init_msg(struct tipc_link *l,
 125                                         struct sk_buff_head *xmitq);
 126 static bool tipc_link_release_pkts(struct tipc_link *l, u16 to);
 127
 128 /*
 129  *  Simple non-static link routines (i.e. referenced outside this file)
 130  */
 131 bool tipc_link_is_up(struct tipc_link *l)
 132 {
 133         return link_is_up(l);
 134 }
 135
 136 bool tipc_link_peer_is_down(struct tipc_link *l)
 137 {
 138         return l->state == LINK_PEER_RESET;
 139 }
 140
 141 bool tipc_link_is_reset(struct tipc_link *l)
 142 {
 143         return l->state & (LINK_RESET | LINK_FAILINGOVER | LINK_ESTABLISHING);
 144 }
 145
 146 bool tipc_link_is_establishing(struct tipc_link *l)
 147 {
 148         return l->state == LINK_ESTABLISHING;
 149 }
 150
 151 bool tipc_link_is_synching(struct tipc_link *l)
 152 {
 153         return l->state == LINK_SYNCHING;
 154 }
 155
 156 bool tipc_link_is_failingover(struct tipc_link *l)
 157 {
 158         return l->state == LINK_FAILINGOVER;
 159 }
 160
 161 bool tipc_link_is_blocked(struct tipc_link *l)
 162 {
 163         return l->state & (LINK_RESETTING | LINK_PEER_RESET | LINK_FAILINGOVER);
 164 }
 165
 166 bool link_is_bc_sndlink(struct tipc_link *l)
 167 {
 168         return !l->bc_sndlink;
 169 }
 170
 171 bool link_is_bc_rcvlink(struct tipc_link *l)
 172 {
 173         return ((l->bc_rcvlink == l) && !link_is_bc_sndlink(l));
 174 }
 175
 176 int tipc_link_is_active(struct tipc_link *l)
 177 {
 178         struct tipc_node *n = l->owner;
 179
 180         return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
 181 }
 182
 183 void tipc_link_add_bc_peer(struct tipc_link *snd_l,
 184                            struct tipc_link *uc_l,
 185                            struct sk_buff_head *xmitq)
 186 {
 187         struct tipc_link *rcv_l = uc_l->bc_rcvlink;
 188
 189         snd_l->ackers++;
 190         rcv_l->acked = snd_l->snd_nxt - 1;
 191         tipc_link_build_bc_init_msg(uc_l, xmitq);
 192 }
 193
 194 void tipc_link_remove_bc_peer(struct tipc_link *snd_l,
 195                               struct tipc_link *rcv_l,
 196                               struct sk_buff_head *xmitq)
 197 {
 198         u16 ack = snd_l->snd_nxt - 1;
 199
 200         snd_l->ackers--;
 201         tipc_link_bc_ack_rcv(rcv_l, ack, xmitq);
 202         tipc_link_reset(rcv_l);
 203         rcv_l->state = LINK_RESET;
 204         if (!snd_l->ackers) {
 205                 tipc_link_reset(snd_l);
 206                 __skb_queue_purge(xmitq);
 207         }
 208 }
 209
 210 int tipc_link_bc_peers(struct tipc_link *l)
 211 {
 212         return l->ackers;
 213 }
 214
 215 static u32 link_own_addr(struct tipc_link *l)
 216 {
 217         return msg_prevnode(l->pmsg);
 218 }
 219
 220 /**
 221  * tipc_link_create - create a new link
 222  * @n: pointer to associated node
 223  * @if_name: associated interface name
 224  * @bearer_id: id (index) of associated bearer
 225  * @tolerance: link tolerance to be used by link
 226  * @net_plane: network plane (A,B,c..) this link belongs to
 227  * @mtu: mtu to be advertised by link
 228  * @priority: priority to be used by link
 229  * @window: send window to be used by link
 230  * @session: session to be used by link
 231  * @ownnode: identity of own node
 232  * @peer: node id of peer node
 233  * @peer_caps: bitmap describing peer node capabilities
 234  * @maddr: media address to be used
 235  * @bc_sndlink: the namespace global link used for broadcast sending
 236  * @bc_rcvlink: the peer specific link used for broadcast reception
 237  * @inputq: queue to put messages ready for delivery
 238  * @namedq: queue to put binding table update messages ready for delivery
 239  * @link: return value, pointer to put the created link
 240  *
 241  * Returns true if link was created, otherwise false
 242  */
 243 bool tipc_link_create(struct tipc_node *n, char *if_name, int bearer_id,
 244                       int tolerance, char net_plane, u32 mtu, int priority,
 245                       int window, u32 session, u32 ownnode, u32 peer,
 246                       u16 peer_caps,
 247                       struct tipc_media_addr *maddr,
 248                       struct tipc_link *bc_sndlink,
 249                       struct tipc_link *bc_rcvlink,
 250                       struct sk_buff_head *inputq,
 251                       struct sk_buff_head *namedq,
 252                       struct tipc_link **link)
 253 {
 254         struct tipc_link *l;
 255         struct tipc_msg *hdr;
 256
 257         l = kzalloc(sizeof(*l), GFP_ATOMIC);
 258         if (!l)
 259                 return false;
 260         *link = l;
 261         l->pmsg = (struct tipc_msg *)&l->proto_msg;
 262         hdr = l->pmsg;
 263         tipc_msg_init(ownnode, hdr, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, peer);
 264         msg_set_size(hdr, sizeof(l->proto_msg));
 265         msg_set_session(hdr, session);
 266         msg_set_bearer_id(hdr, l->bearer_id);
 267
 268         /* Note: peer i/f name is completed by reset/activate message */
 269         sprintf(l->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 270                 tipc_zone(ownnode), tipc_cluster(ownnode), tipc_node(ownnode),
 271                 if_name, tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 272         strcpy((char *)msg_data(hdr), if_name);
 273
 274         l->addr = peer;
 275         l->peer_caps = peer_caps;
 276         l->media_addr = maddr;
 277         l->owner = n;
 278         l->peer_session = WILDCARD_SESSION;
 279         l->bearer_id = bearer_id;
 280         l->tolerance = tolerance;
 281         l->net_plane = net_plane;
 282         l->advertised_mtu = mtu;
 283         l->mtu = mtu;
 284         l->priority = priority;
 285         tipc_link_set_queue_limits(l, window);
 286         l->ackers = 1;
 287         l->bc_sndlink = bc_sndlink;
 288         l->bc_rcvlink = bc_rcvlink;
 289         l->inputq = inputq;
 290         l->namedq = namedq;
 291         l->state = LINK_RESETTING;
 292         __skb_queue_head_init(&l->transmq);
 293         __skb_queue_head_init(&l->backlogq);
 294         __skb_queue_head_init(&l->deferdq);
 295         skb_queue_head_init(&l->wakeupq);
 296         skb_queue_head_init(l->inputq);
 297         return true;
 298 }
 299
 300 /**
 301  * tipc_link_bc_create - create new link to be used for broadcast
 302  * @n: pointer to associated node
 303  * @mtu: mtu to be used
 304  * @window: send window to be used
 305  * @inputq: queue to put messages ready for delivery
 306  * @namedq: queue to put binding table update messages ready for delivery
 307  * @link: return value, pointer to put the created link
 308  *
 309  * Returns true if link was created, otherwise false
 310  */
 311 bool tipc_link_bc_create(struct tipc_node *n, u32 ownnode, u32 peer,
 312                          int mtu, int window, u16 peer_caps,
 313                          struct sk_buff_head *inputq,
 314                          struct sk_buff_head *namedq,
 315                          struct tipc_link *bc_sndlink,
 316                          struct tipc_link **link)
 317 {
 318         struct tipc_link *l;
 319
 320         if (!tipc_link_create(n, "", MAX_BEARERS, 0, 'Z', mtu, 0, window,
 321                               0, ownnode, peer, peer_caps, NULL, bc_sndlink,
 322                               NULL, inputq, namedq, link))
 323                 return false;
 324
 325         l = *link;
 326         strcpy(l->name, tipc_bclink_name);
 327         tipc_link_reset(l);
 328         l->state = LINK_RESET;
 329         l->ackers = 0;
 330         l->bc_rcvlink = l;
 331
 332         /* Broadcast send link is always up */
 333         if (link_is_bc_sndlink(l))
 334                 l->state = LINK_ESTABLISHED;
 335
 336         return true;
 337 }
 338
 339 /**
 340  * tipc_link_fsm_evt - link finite state machine
 341  * @l: pointer to link
 342  * @evt: state machine event to be processed
 343  */
 344 int tipc_link_fsm_evt(struct tipc_link *l, int evt)
 345 {
 346         int rc = 0;
 347
 348         switch (l->state) {
 349         case LINK_RESETTING:
 350                 switch (evt) {
 351                 case LINK_PEER_RESET_EVT:
 352                         l->state = LINK_PEER_RESET;
 353                         break;
 354                 case LINK_RESET_EVT:
 355                         l->state = LINK_RESET;
 356                         break;
 357                 case LINK_FAILURE_EVT:
 358                 case LINK_FAILOVER_BEGIN_EVT:
 359                 case LINK_ESTABLISH_EVT:
 360                 case LINK_FAILOVER_END_EVT:
 361                 case LINK_SYNCH_BEGIN_EVT:
 362                 case LINK_SYNCH_END_EVT:
 363                 default:
 364                         goto illegal_evt;
 365                 }
 366                 break;
 367         case LINK_RESET:
 368                 switch (evt) {
 369                 case LINK_PEER_RESET_EVT:
 370                         l->state = LINK_ESTABLISHING;
 371                         break;
 372                 case LINK_FAILOVER_BEGIN_EVT:
 373                         l->state = LINK_FAILINGOVER;
 374                 case LINK_FAILURE_EVT:
 375                 case LINK_RESET_EVT:
 376                 case LINK_ESTABLISH_EVT:
 377                 case LINK_FAILOVER_END_EVT:
 378                         break;
 379                 case LINK_SYNCH_BEGIN_EVT:
 380                 case LINK_SYNCH_END_EVT:
 381                 default:
 382                         goto illegal_evt;
 383                 }
 384                 break;
 385         case LINK_PEER_RESET:
 386                 switch (evt) {
 387                 case LINK_RESET_EVT:
 388                         l->state = LINK_ESTABLISHING;
 389                         break;
 390                 case LINK_PEER_RESET_EVT:
 391                 case LINK_ESTABLISH_EVT:
 392                 case LINK_FAILURE_EVT:
 393                         break;
 394                 case LINK_SYNCH_BEGIN_EVT:
 395                 case LINK_SYNCH_END_EVT:
 396                 case LINK_FAILOVER_BEGIN_EVT:
 397                 case LINK_FAILOVER_END_EVT:
 398                 default:
 399                         goto illegal_evt;
 400                 }
 401                 break;
 402         case LINK_FAILINGOVER:
 403                 switch (evt) {
 404                 case LINK_FAILOVER_END_EVT:
 405                         l->state = LINK_RESET;
 406                         break;
 407                 case LINK_PEER_RESET_EVT:
 408                 case LINK_RESET_EVT:
 409                 case LINK_ESTABLISH_EVT:
 410                 case LINK_FAILURE_EVT:
 411                         break;
 412                 case LINK_FAILOVER_BEGIN_EVT:
 413                 case LINK_SYNCH_BEGIN_EVT:
 414                 case LINK_SYNCH_END_EVT:
 415                 default:
 416                         goto illegal_evt;
 417                 }
 418                 break;
 419         case LINK_ESTABLISHING:
 420                 switch (evt) {
 421                 case LINK_ESTABLISH_EVT:
 422                         l->state = LINK_ESTABLISHED;
 423                         break;
 424                 case LINK_FAILOVER_BEGIN_EVT:
 425                         l->state = LINK_FAILINGOVER;
 426                         break;
 427                 case LINK_RESET_EVT:
 428                         l->state = LINK_RESET;
 429                         break;
 430                 case LINK_FAILURE_EVT:
 431                 case LINK_PEER_RESET_EVT:
 432                 case LINK_SYNCH_BEGIN_EVT:
 433                 case LINK_FAILOVER_END_EVT:
 434                         break;
 435                 case LINK_SYNCH_END_EVT:
 436                 default:
 437                         goto illegal_evt;
 438                 }
 439                 break;
 440         case LINK_ESTABLISHED:
 441                 switch (evt) {
 442                 case LINK_PEER_RESET_EVT:
 443                         l->state = LINK_PEER_RESET;
 444                         rc |= TIPC_LINK_DOWN_EVT;
 445                         break;
 446                 case LINK_FAILURE_EVT:
 447                         l->state = LINK_RESETTING;
 448                         rc |= TIPC_LINK_DOWN_EVT;
 449                         break;
 450                 case LINK_RESET_EVT:
 451                         l->state = LINK_RESET;
 452                         break;
 453                 case LINK_ESTABLISH_EVT:
 454                 case LINK_SYNCH_END_EVT:
 455                         break;
 456                 case LINK_SYNCH_BEGIN_EVT:
 457                         l->state = LINK_SYNCHING;
 458                         break;
 459                 case LINK_FAILOVER_BEGIN_EVT:
 460                 case LINK_FAILOVER_END_EVT:
 461                 default:
 462                         goto illegal_evt;
 463                 }
 464                 break;
 465         case LINK_SYNCHING:
 466                 switch (evt) {
 467                 case LINK_PEER_RESET_EVT:
 468                         l->state = LINK_PEER_RESET;
 469                         rc |= TIPC_LINK_DOWN_EVT;
 470                         break;
 471                 case LINK_FAILURE_EVT:
 472                         l->state = LINK_RESETTING;
 473                         rc |= TIPC_LINK_DOWN_EVT;
 474                         break;
 475                 case LINK_RESET_EVT:
 476                         l->state = LINK_RESET;
 477                         break;
 478                 case LINK_ESTABLISH_EVT:
 479                 case LINK_SYNCH_BEGIN_EVT:
 480                         break;
 481                 case LINK_SYNCH_END_EVT:
 482                         l->state = LINK_ESTABLISHED;
 483                         break;
 484                 case LINK_FAILOVER_BEGIN_EVT:
 485                 case LINK_FAILOVER_END_EVT:
 486                 default:
 487                         goto illegal_evt;
 488                 }
 489                 break;
 490         default:
 491                 pr_err("Unknown FSM state %x in %s\n", l->state, l->name);
 492         }
 493         return rc;
 494 illegal_evt:
 495         pr_err("Illegal FSM event %x in state %x on link %s\n",
 496                evt, l->state, l->name);
 497         return rc;
 498 }
 499
 500 /* link_profile_stats - update statistical profiling of traffic
 501  */
 502 static void link_profile_stats(struct tipc_link *l)
 503 {
 504         struct sk_buff *skb;
 505         struct tipc_msg *msg;
 506         int length;
 507
 508         /* Update counters used in statistical profiling of send traffic */
 509         l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 510         l->stats.queue_sz_counts++;
 511
 512         skb = skb_peek(&l->transmq);
 513         if (!skb)
 514                 return;
 515         msg = buf_msg(skb);
 516         length = msg_size(msg);
 517
 518         if (msg_user(msg) == MSG_FRAGMENTER) {
 519                 if (msg_type(msg) != FIRST_FRAGMENT)
 520                         return;
 521                 length = msg_size(msg_get_wrapped(msg));
 522         }
 523         l->stats.msg_lengths_total += length;
 524         l->stats.msg_length_counts++;
 525         if (length <= 64)
 526                 l->stats.msg_length_profile[0]++;
 527         else if (length <= 256)
 528                 l->stats.msg_length_profile[1]++;
 529         else if (length <= 1024)
 530                 l->stats.msg_length_profile[2]++;
 531         else if (length <= 4096)
 532                 l->stats.msg_length_profile[3]++;
 533         else if (length <= 16384)
 534                 l->stats.msg_length_profile[4]++;
 535         else if (length <= 32768)
 536                 l->stats.msg_length_profile[5]++;
 537         else
 538                 l->stats.msg_length_profile[6]++;
 539 }
 540
 541 /* tipc_link_timeout - perform periodic task as instructed from node timeout
 542  */
 543 /* tipc_link_timeout - perform periodic task as instructed from node timeout
 544  */
 545 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 546 {
 547         int rc = 0;
 548         int mtyp = STATE_MSG;
 549         bool xmit = false;
 550         bool prb = false;
 551         u16 bc_snt = l->bc_sndlink->snd_nxt - 1;
 552         u16 bc_acked = l->bc_rcvlink->acked;
 553         bool bc_up = link_is_up(l->bc_rcvlink);
 554
 555         link_profile_stats(l);
 556
 557         switch (l->state) {
 558         case LINK_ESTABLISHED:
 559         case LINK_SYNCHING:
 560                 if (!l->silent_intv_cnt) {
 561                         if (bc_up && (bc_acked != bc_snt))
 562                                 xmit = true;
 563                 } else if (l->silent_intv_cnt <= l->abort_limit) {
 564                         xmit = true;
 565                         prb = true;
 566                 } else {
 567                         rc |= tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 568                 }
 569                 l->silent_intv_cnt++;
 570                 break;
 571         case LINK_RESET:
 572                 xmit = true;
 573                 mtyp = RESET_MSG;
 574                 break;
 575         case LINK_ESTABLISHING:
 576                 xmit = true;
 577                 mtyp = ACTIVATE_MSG;
 578                 break;
 579         case LINK_PEER_RESET:
 580         case LINK_RESETTING:
 581         case LINK_FAILINGOVER:
 582                 break;
 583         default:
 584                 break;
 585         }
 586
 587         if (xmit)
 588                 tipc_link_build_proto_msg(l, mtyp, prb, 0, 0, 0, xmitq);
 589
 590         return rc;
 591 }
 592
 593 /**
 594  * link_schedule_user - schedule a message sender for wakeup after congestion
 595  * @link: congested link
 596  * @list: message that was attempted sent
 597  * Create pseudo msg to send back to user when congestion abates
 598  * Does not consume buffer list
 599  */
 600 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 601 {
 602         struct tipc_msg *msg = buf_msg(skb_peek(list));
 603         int imp = msg_importance(msg);
 604         u32 oport = msg_origport(msg);
 605         u32 addr = link_own_addr(link);
 606         struct sk_buff *skb;
 607
 608         /* This really cannot happen...  */
 609         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 610                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 611                 return -ENOBUFS;
 612         }
 613         /* Non-blocking sender: */
 614         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 615                 return -ELINKCONG;
 616
 617         /* Create and schedule wakeup pseudo message */
 618         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 619                               addr, addr, oport, 0, 0);
 620         if (!skb)
 621                 return -ENOBUFS;
 622         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 623         TIPC_SKB_CB(skb)->chain_imp = imp;
 624         skb_queue_tail(&link->wakeupq, skb);
 625         link->stats.link_congs++;
 626         return -ELINKCONG;
 627 }
 628
 629 /**
 630  * link_prepare_wakeup - prepare users for wakeup after congestion
 631  * @link: congested link
 632  * Move a number of waiting users, as permitted by available space in
 633  * the send queue, from link wait queue to node wait queue for wakeup
 634  */
 635 void link_prepare_wakeup(struct tipc_link *l)
 636 {
 637         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 638         int imp, lim;
 639         struct sk_buff *skb, *tmp;
 640
 641         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 642                 imp = TIPC_SKB_CB(skb)->chain_imp;
 643                 lim = l->window + l->backlog[imp].limit;
 644                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 645                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 646                         break;
 647                 skb_unlink(skb, &l->wakeupq);
 648                 skb_queue_tail(l->inputq, skb);
 649         }
 650 }
 651
 652 /**
 653  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 654  * @l_ptr: pointer to link
 655  */
 656 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 657 {
 658         kfree_skb(l_ptr->reasm_buf);
 659         l_ptr->reasm_buf = NULL;
 660 }
 661
 662 void tipc_link_purge_backlog(struct tipc_link *l)
 663 {
 664         __skb_queue_purge(&l->backlogq);
 665         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 666         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 667         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 668         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 669         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 670 }
 671
 672 /**
 673  * tipc_link_purge_queues - purge all pkt queues associated with link
 674  * @l_ptr: pointer to link
 675  */
 676 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 677 {
 678         __skb_queue_purge(&l_ptr->deferdq);
 679         __skb_queue_purge(&l_ptr->transmq);
 680         tipc_link_purge_backlog(l_ptr);
 681         tipc_link_reset_fragments(l_ptr);
 682 }
 683
 684 void tipc_link_reset(struct tipc_link *l)
 685 {
 686         /* Link is down, accept any session */
 687         l->peer_session = WILDCARD_SESSION;
 688
 689         /* If peer is up, it only accepts an incremented session number */
 690         msg_set_session(l->pmsg, msg_session(l->pmsg) + 1);
 691
 692         /* Prepare for renewed mtu size negotiation */
 693         l->mtu = l->advertised_mtu;
 694
 695         /* Clean up all queues: */
 696         __skb_queue_purge(&l->transmq);
 697         __skb_queue_purge(&l->deferdq);
 698         skb_queue_splice_init(&l->wakeupq, l->inputq);
 699
 700         tipc_link_purge_backlog(l);
 701         kfree_skb(l->reasm_buf);
 702         kfree_skb(l->failover_reasm_skb);
 703         l->reasm_buf = NULL;
 704         l->failover_reasm_skb = NULL;
 705         l->rcv_unacked = 0;
 706         l->snd_nxt = 1;
 707         l->rcv_nxt = 1;
 708         l->acked = 0;
 709         l->silent_intv_cnt = 0;
 710         l->stats.recv_info = 0;
 711         l->stale_count = 0;
 712         l->bc_peer_is_up = false;
 713         link_reset_statistics(l);
 714 }
 715
 716 /**
 717  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 718  * @link: link to use
 719  * @list: chain of buffers containing message
 720  *
 721  * Consumes the buffer chain, except when returning an error code,
 722  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 723  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 724  */
 725 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 726                      struct sk_buff_head *list)
 727 {
 728         struct tipc_msg *msg = buf_msg(skb_peek(list));
 729         unsigned int maxwin = link->window;
 730         unsigned int i, imp = msg_importance(msg);
 731         uint mtu = link->mtu;
 732         u16 ack = mod(link->rcv_nxt - 1);
 733         u16 seqno = link->snd_nxt;
 734         u16 bc_ack = link->bc_rcvlink->rcv_nxt - 1;
 735         struct tipc_media_addr *addr = link->media_addr;
 736         struct sk_buff_head *transmq = &link->transmq;
 737         struct sk_buff_head *backlogq = &link->backlogq;
 738         struct sk_buff *skb, *bskb;
 739
 740         /* Match msg importance against this and all higher backlog limits: */
 741         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 742                 if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
 743                         return link_schedule_user(link, list);
 744         }
 745         if (unlikely(msg_size(msg) > mtu))
 746                 return -EMSGSIZE;
 747
 748         /* Prepare each packet for sending, and add to relevant queue: */
 749         while (skb_queue_len(list)) {
 750                 skb = skb_peek(list);
 751                 msg = buf_msg(skb);
 752                 msg_set_seqno(msg, seqno);
 753                 msg_set_ack(msg, ack);
 754                 msg_set_bcast_ack(msg, bc_ack);
 755
 756                 if (likely(skb_queue_len(transmq) < maxwin)) {
 757                         __skb_dequeue(list);
 758                         __skb_queue_tail(transmq, skb);
 759                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 760                         link->rcv_unacked = 0;
 761                         seqno++;
 762                         continue;
 763                 }
 764                 if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
 765                         kfree_skb(__skb_dequeue(list));
 766                         link->stats.sent_bundled++;
 767                         continue;
 768                 }
 769                 if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
 770                         kfree_skb(__skb_dequeue(list));
 771                         __skb_queue_tail(backlogq, bskb);
 772                         link->backlog[msg_importance(buf_msg(bskb))].len++;
 773                         link->stats.sent_bundled++;
 774                         link->stats.sent_bundles++;
 775                         continue;
 776                 }
 777                 link->backlog[imp].len += skb_queue_len(list);
 778                 skb_queue_splice_tail_init(list, backlogq);
 779         }
 780         link->snd_nxt = seqno;
 781         return 0;
 782 }
 783
 784 /**
 785  * tipc_link_xmit(): enqueue buffer list according to queue situation
 786  * @link: link to use
 787  * @list: chain of buffers containing message
 788  * @xmitq: returned list of packets to be sent by caller
 789  *
 790  * Consumes the buffer chain, except when returning -ELINKCONG,
 791  * since the caller then may want to make more send attempts.
 792  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 793  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 794  */
 795 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 796                    struct sk_buff_head *xmitq)
 797 {
 798         struct tipc_msg *hdr = buf_msg(skb_peek(list));
 799         unsigned int maxwin = l->window;
 800         unsigned int i, imp = msg_importance(hdr);
 801         unsigned int mtu = l->mtu;
 802         u16 ack = l->rcv_nxt - 1;
 803         u16 seqno = l->snd_nxt;
 804         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 805         struct sk_buff_head *transmq = &l->transmq;
 806         struct sk_buff_head *backlogq = &l->backlogq;
 807         struct sk_buff *skb, *_skb, *bskb;
 808
 809         /* Match msg importance against this and all higher backlog limits: */
 810         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 811                 if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
 812                         return link_schedule_user(l, list);
 813         }
 814         if (unlikely(msg_size(hdr) > mtu))
 815                 return -EMSGSIZE;
 816
 817         /* Prepare each packet for sending, and add to relevant queue: */
 818         while (skb_queue_len(list)) {
 819                 skb = skb_peek(list);
 820                 hdr = buf_msg(skb);
 821                 msg_set_seqno(hdr, seqno);
 822                 msg_set_ack(hdr, ack);
 823                 msg_set_bcast_ack(hdr, bc_ack);
 824
 825                 if (likely(skb_queue_len(transmq) < maxwin)) {
 826                         _skb = skb_clone(skb, GFP_ATOMIC);
 827                         if (!_skb)
 828                                 return -ENOBUFS;
 829                         __skb_dequeue(list);
 830                         __skb_queue_tail(transmq, skb);
 831                         __skb_queue_tail(xmitq, _skb);
 832                         TIPC_SKB_CB(skb)->ackers = l->ackers;
 833                         l->rcv_unacked = 0;
 834                         seqno++;
 835                         continue;
 836                 }
 837                 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
 838                         kfree_skb(__skb_dequeue(list));
 839                         l->stats.sent_bundled++;
 840                         continue;
 841                 }
 842                 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
 843                         kfree_skb(__skb_dequeue(list));
 844                         __skb_queue_tail(backlogq, bskb);
 845                         l->backlog[msg_importance(buf_msg(bskb))].len++;
 846                         l->stats.sent_bundled++;
 847                         l->stats.sent_bundles++;
 848                         continue;
 849                 }
 850                 l->backlog[imp].len += skb_queue_len(list);
 851                 skb_queue_splice_tail_init(list, backlogq);
 852         }
 853         l->snd_nxt = seqno;
 854         return 0;
 855 }
 856
 857 /*
 858  * tipc_link_push_packets - push unsent packets to bearer
 859  *
 860  * Push out the unsent messages of a link where congestion
 861  * has abated. Node is locked.
 862  *
 863  * Called with node locked
 864  */
 865 void tipc_link_push_packets(struct tipc_link *link)
 866 {
 867         struct sk_buff *skb;
 868         struct tipc_msg *msg;
 869         u16 seqno = link->snd_nxt;
 870         u16 ack = mod(link->rcv_nxt - 1);
 871
 872         while (skb_queue_len(&link->transmq) < link->window) {
 873                 skb = __skb_dequeue(&link->backlogq);
 874                 if (!skb)
 875                         break;
 876                 TIPC_SKB_CB(skb)->ackers = link->ackers;
 877                 msg = buf_msg(skb);
 878                 link->backlog[msg_importance(msg)].len--;
 879                 msg_set_ack(msg, ack);
 880                 msg_set_seqno(msg, seqno);
 881                 seqno = mod(seqno + 1);
 882                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 883                 link->rcv_unacked = 0;
 884                 __skb_queue_tail(&link->transmq, skb);
 885                 tipc_bearer_send(link->owner->net, link->bearer_id,
 886                                  skb, link->media_addr);
 887         }
 888         link->snd_nxt = seqno;
 889 }
 890
 891 void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
 892 {
 893         struct sk_buff *skb, *_skb;
 894         struct tipc_msg *hdr;
 895         u16 seqno = l->snd_nxt;
 896         u16 ack = l->rcv_nxt - 1;
 897         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 898
 899         while (skb_queue_len(&l->transmq) < l->window) {
 900                 skb = skb_peek(&l->backlogq);
 901                 if (!skb)
 902                         break;
 903                 _skb = skb_clone(skb, GFP_ATOMIC);
 904                 if (!_skb)
 905                         break;
 906                 __skb_dequeue(&l->backlogq);
 907                 hdr = buf_msg(skb);
 908                 l->backlog[msg_importance(hdr)].len--;
 909                 __skb_queue_tail(&l->transmq, skb);
 910                 __skb_queue_tail(xmitq, _skb);
 911                 TIPC_SKB_CB(skb)->ackers = l->ackers;
 912                 msg_set_seqno(hdr, seqno);
 913                 msg_set_ack(hdr, ack);
 914                 msg_set_bcast_ack(hdr, bc_ack);
 915                 l->rcv_unacked = 0;
 916                 seqno++;
 917         }
 918         l->snd_nxt = seqno;
 919 }
 920
 921 static void link_retransmit_failure(struct tipc_link *l, struct sk_buff *skb)
 922 {
 923         struct tipc_msg *hdr = buf_msg(skb);
 924
 925         pr_warn("Retransmission failure on link <%s>\n", l->name);
 926         link_print(l, "Resetting link ");
 927         pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
 928                 msg_user(hdr), msg_type(hdr), msg_size(hdr), msg_errcode(hdr));
 929         pr_info("sqno %u, prev: %x, src: %x\n",
 930                 msg_seqno(hdr), msg_prevnode(hdr), msg_orignode(hdr));
 931 }
 932
 933 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 934                           u32 retransmits)
 935 {
 936         struct tipc_msg *msg;
 937
 938         if (!skb)
 939                 return;
 940
 941         msg = buf_msg(skb);
 942
 943         /* Detect repeated retransmit failures */
 944         if (l_ptr->last_retransm == msg_seqno(msg)) {
 945                 if (++l_ptr->stale_count > 100) {
 946                         link_retransmit_failure(l_ptr, skb);
 947                         return;
 948                 }
 949         } else {
 950                 l_ptr->last_retransm = msg_seqno(msg);
 951                 l_ptr->stale_count = 1;
 952         }
 953
 954         skb_queue_walk_from(&l_ptr->transmq, skb) {
 955                 if (!retransmits)
 956                         break;
 957                 msg = buf_msg(skb);
 958                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
 959                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 960                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 961                                  l_ptr->media_addr);
 962                 retransmits--;
 963                 l_ptr->stats.retransmitted++;
 964         }
 965 }
 966
 967 int tipc_link_retrans(struct tipc_link *l, u16 from, u16 to,
 968                       struct sk_buff_head *xmitq)
 969 {
 970         struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
 971         struct tipc_msg *hdr;
 972         u16 ack = l->rcv_nxt - 1;
 973         u16 bc_ack = l->bc_rcvlink->rcv_nxt - 1;
 974
 975         if (!skb)
 976                 return 0;
 977
 978         /* Detect repeated retransmit failures on same packet */
 979         if (likely(l->last_retransm != buf_seqno(skb))) {
 980                 l->last_retransm = buf_seqno(skb);
 981                 l->stale_count = 1;
 982         } else if (++l->stale_count > 100) {
 983                 link_retransmit_failure(l, skb);
 984                 return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
 985         }
 986
 987         /* Move forward to where retransmission should start */
 988         skb_queue_walk(&l->transmq, skb) {
 989                 if (!less(buf_seqno(skb), from))
 990                         break;
 991         }
 992
 993         skb_queue_walk_from(&l->transmq, skb) {
 994                 if (more(buf_seqno(skb), to))
 995                         break;
 996                 hdr = buf_msg(skb);
 997                 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
 998                 if (!_skb)
 999                         return 0;
1000                 hdr = buf_msg(_skb);
1001                 msg_set_ack(hdr, ack);
1002                 msg_set_bcast_ack(hdr, bc_ack);
1003                 _skb->priority = TC_PRIO_CONTROL;
1004                 __skb_queue_tail(xmitq, _skb);
1005                 l->stats.retransmitted++;
1006         }
1007         return 0;
1008 }
1009
1010 /* tipc_data_input - deliver data and name distr msgs to upper layer
1011  *
1012  * Consumes buffer if message is of right type
1013  * Node lock must be held
1014  */
1015 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb,
1016                             struct sk_buff_head *inputq)
1017 {
1018         switch (msg_user(buf_msg(skb))) {
1019         case TIPC_LOW_IMPORTANCE:
1020         case TIPC_MEDIUM_IMPORTANCE:
1021         case TIPC_HIGH_IMPORTANCE:
1022         case TIPC_CRITICAL_IMPORTANCE:
1023         case CONN_MANAGER:
1024                 skb_queue_tail(inputq, skb);
1025                 return true;
1026         case NAME_DISTRIBUTOR:
1027                 l->bc_rcvlink->state = LINK_ESTABLISHED;
1028                 skb_queue_tail(l->namedq, skb);
1029                 return true;
1030         case MSG_BUNDLER:
1031         case TUNNEL_PROTOCOL:
1032         case MSG_FRAGMENTER:
1033         case BCAST_PROTOCOL:
1034                 return false;
1035         default:
1036                 pr_warn("Dropping received illegal msg type\n");
1037                 kfree_skb(skb);
1038                 return false;
1039         };
1040 }
1041
1042 /* tipc_link_input - process packet that has passed link protocol check
1043  *
1044  * Consumes buffer
1045  */
1046 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb,
1047                            struct sk_buff_head *inputq)
1048 {
1049         struct tipc_msg *hdr = buf_msg(skb);
1050         struct sk_buff **reasm_skb = &l->reasm_buf;
1051         struct sk_buff *iskb;
1052         struct sk_buff_head tmpq;
1053         int usr = msg_user(hdr);
1054         int rc = 0;
1055         int pos = 0;
1056         int ipos = 0;
1057
1058         if (unlikely(usr == TUNNEL_PROTOCOL)) {
1059                 if (msg_type(hdr) == SYNCH_MSG) {
1060                         __skb_queue_purge(&l->deferdq);
1061                         goto drop;
1062                 }
1063                 if (!tipc_msg_extract(skb, &iskb, &ipos))
1064                         return rc;
1065                 kfree_skb(skb);
1066                 skb = iskb;
1067                 hdr = buf_msg(skb);
1068                 if (less(msg_seqno(hdr), l->drop_point))
1069                         goto drop;
1070                 if (tipc_data_input(l, skb, inputq))
1071                         return rc;
1072                 usr = msg_user(hdr);
1073                 reasm_skb = &l->failover_reasm_skb;
1074         }
1075
1076         if (usr == MSG_BUNDLER) {
1077                 skb_queue_head_init(&tmpq);
1078                 l->stats.recv_bundles++;
1079                 l->stats.recv_bundled += msg_msgcnt(hdr);
1080                 while (tipc_msg_extract(skb, &iskb, &pos))
1081                         tipc_data_input(l, iskb, &tmpq);
1082                 tipc_skb_queue_splice_tail(&tmpq, inputq);
1083                 return 0;
1084         } else if (usr == MSG_FRAGMENTER) {
1085                 l->stats.recv_fragments++;
1086                 if (tipc_buf_append(reasm_skb, &skb)) {
1087                         l->stats.recv_fragmented++;
1088                         tipc_data_input(l, skb, inputq);
1089                 } else if (!*reasm_skb && !link_is_bc_rcvlink(l)) {
1090                         pr_warn_ratelimited("Unable to build fragment list\n");
1091                         return tipc_link_fsm_evt(l, LINK_FAILURE_EVT);
1092                 }
1093                 return 0;
1094         } else if (usr == BCAST_PROTOCOL) {
1095                 tipc_bcast_lock(l->owner->net);
1096                 tipc_link_bc_init_rcv(l->bc_rcvlink, hdr);
1097                 tipc_bcast_unlock(l->owner->net);
1098         }
1099 drop:
1100         kfree_skb(skb);
1101         return 0;
1102 }
1103
1104 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1105 {
1106         bool released = false;
1107         struct sk_buff *skb, *tmp;
1108
1109         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1110                 if (more(buf_seqno(skb), acked))
1111                         break;
1112                 __skb_unlink(skb, &l->transmq);
1113                 kfree_skb(skb);
1114                 released = true;
1115         }
1116         return released;
1117 }
1118
1119 /* tipc_link_build_ack_msg: prepare link acknowledge message for transmission
1120  *
1121  * Note that sending of broadcast ack is coordinated among nodes, to reduce
1122  * risk of ack storms towards the sender
1123  */
1124 int tipc_link_build_ack_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1125 {
1126         if (!l)
1127                 return 0;
1128
1129         /* Broadcast ACK must be sent via a unicast link => defer to caller */
1130         if (link_is_bc_rcvlink(l)) {
1131                 if (((l->rcv_nxt ^ link_own_addr(l)) & 0xf) != 0xf)
1132                         return 0;
1133                 l->rcv_unacked = 0;
1134                 return TIPC_LINK_SND_BC_ACK;
1135         }
1136
1137         /* Unicast ACK */
1138         l->rcv_unacked = 0;
1139         l->stats.sent_acks++;
1140         tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1141         return 0;
1142 }
1143
1144 /* tipc_link_build_reset_msg: prepare link RESET or ACTIVATE message
1145  */
1146 void tipc_link_build_reset_msg(struct tipc_link *l, struct sk_buff_head *xmitq)
1147 {
1148         int mtyp = RESET_MSG;
1149
1150         if (l->state == LINK_ESTABLISHING)
1151                 mtyp = ACTIVATE_MSG;
1152
1153         tipc_link_build_proto_msg(l, mtyp, 0, 0, 0, 0, xmitq);
1154 }
1155
1156 /* tipc_link_build_nack_msg: prepare link nack message for transmission
1157  */
1158 static void tipc_link_build_nack_msg(struct tipc_link *l,
1159                                      struct sk_buff_head *xmitq)
1160 {
1161         u32 def_cnt = ++l->stats.deferred_recv;
1162
1163         if (link_is_bc_rcvlink(l))
1164                 return;
1165
1166         if ((skb_queue_len(&l->deferdq) == 1) || !(def_cnt % TIPC_NACK_INTV))
1167                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
1168 }
1169
1170 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1171  * @l: the link that should handle the message
1172  * @skb: TIPC packet
1173  * @xmitq: queue to place packets to be sent after this call
1174  */
1175 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1176                   struct sk_buff_head *xmitq)
1177 {
1178         struct sk_buff_head *defq = &l->deferdq;
1179         struct tipc_msg *hdr;
1180         u16 seqno, rcv_nxt, win_lim;
1181         int rc = 0;
1182
1183         do {
1184                 hdr = buf_msg(skb);
1185                 seqno = msg_seqno(hdr);
1186                 rcv_nxt = l->rcv_nxt;
1187                 win_lim = rcv_nxt + TIPC_MAX_LINK_WIN;
1188
1189                 /* Verify and update link state */
1190                 if (unlikely(msg_user(hdr) == LINK_PROTOCOL))
1191                         return tipc_link_proto_rcv(l, skb, xmitq);
1192
1193                 if (unlikely(!link_is_up(l))) {
1194                         if (l->state == LINK_ESTABLISHING)
1195                                 rc = TIPC_LINK_UP_EVT;
1196                         goto drop;
1197                 }
1198
1199                 /* Don't send probe at next timeout expiration */
1200                 l->silent_intv_cnt = 0;
1201
1202                 /* Drop if outside receive window */
1203                 if (unlikely(less(seqno, rcv_nxt) || more(seqno, win_lim))) {
1204                         l->stats.duplicates++;
1205                         goto drop;
1206                 }
1207
1208                 /* Forward queues and wake up waiting users */
1209                 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1210                         tipc_link_advance_backlog(l, xmitq);
1211                         if (unlikely(!skb_queue_empty(&l->wakeupq)))
1212                                 link_prepare_wakeup(l);
1213                 }
1214
1215                 /* Defer delivery if sequence gap */
1216                 if (unlikely(seqno != rcv_nxt)) {
1217                         __tipc_skb_queue_sorted(defq, seqno, skb);
1218                         tipc_link_build_nack_msg(l, xmitq);
1219                         break;
1220                 }
1221
1222                 /* Deliver packet */
1223                 l->rcv_nxt++;
1224                 l->stats.recv_info++;
1225                 if (!tipc_data_input(l, skb, l->inputq))
1226                         rc |= tipc_link_input(l, skb, l->inputq);
1227                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN))
1228                         rc |= tipc_link_build_ack_msg(l, xmitq);
1229                 if (unlikely(rc & ~TIPC_LINK_SND_BC_ACK))
1230                         break;
1231         } while ((skb = __skb_dequeue(defq)));
1232
1233         return rc;
1234 drop:
1235         kfree_skb(skb);
1236         return rc;
1237 }
1238
1239 /**
1240  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1241  *
1242  * Returns increase in queue length (i.e. 0 or 1)
1243  */
1244 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1245 {
1246         struct sk_buff *skb1;
1247         u16 seq_no = buf_seqno(skb);
1248
1249         /* Empty queue ? */
1250         if (skb_queue_empty(list)) {
1251                 __skb_queue_tail(list, skb);
1252                 return 1;
1253         }
1254
1255         /* Last ? */
1256         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1257                 __skb_queue_tail(list, skb);
1258                 return 1;
1259         }
1260
1261         /* Locate insertion point in queue, then insert; discard if duplicate */
1262         skb_queue_walk(list, skb1) {
1263                 u16 curr_seqno = buf_seqno(skb1);
1264
1265                 if (seq_no == curr_seqno) {
1266                         kfree_skb(skb);
1267                         return 0;
1268                 }
1269
1270                 if (less(seq_no, curr_seqno))
1271                         break;
1272         }
1273
1274         __skb_queue_before(list, skb1, skb);
1275         return 1;
1276 }
1277
1278 /*
1279  * Send protocol message to the other endpoint.
1280  */
1281 void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg,
1282                           u32 gap, u32 tolerance, u32 priority)
1283 {
1284         struct sk_buff *skb = NULL;
1285         struct sk_buff_head xmitq;
1286
1287         __skb_queue_head_init(&xmitq);
1288         tipc_link_build_proto_msg(l, msg_typ, probe_msg, gap,
1289                                   tolerance, priority, &xmitq);
1290         skb = __skb_dequeue(&xmitq);
1291         if (!skb)
1292                 return;
1293         tipc_bearer_send(l->owner->net, l->bearer_id, skb, l->media_addr);
1294         l->rcv_unacked = 0;
1295         kfree_skb(skb);
1296 }
1297
1298 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1299                                       u16 rcvgap, int tolerance, int priority,
1300                                       struct sk_buff_head *xmitq)
1301 {
1302         struct sk_buff *skb = NULL;
1303         struct tipc_msg *hdr = l->pmsg;
1304         bool node_up = link_is_up(l->bc_rcvlink);
1305
1306         /* Don't send protocol message during reset or link failover */
1307         if (tipc_link_is_blocked(l))
1308                 return;
1309
1310         msg_set_type(hdr, mtyp);
1311         msg_set_net_plane(hdr, l->net_plane);
1312         msg_set_next_sent(hdr, l->snd_nxt);
1313         msg_set_ack(hdr, l->rcv_nxt - 1);
1314         msg_set_bcast_ack(hdr, l->bc_rcvlink->rcv_nxt - 1);
1315         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1316         msg_set_link_tolerance(hdr, tolerance);
1317         msg_set_linkprio(hdr, priority);
1318         msg_set_redundant_link(hdr, node_up);
1319         msg_set_seq_gap(hdr, 0);
1320
1321         /* Compatibility: created msg must not be in sequence with pkt flow */
1322         msg_set_seqno(hdr, l->snd_nxt + U16_MAX / 2);
1323
1324         if (mtyp == STATE_MSG) {
1325                 if (!tipc_link_is_up(l))
1326                         return;
1327
1328                 /* Override rcvgap if there are packets in deferred queue */
1329                 if (!skb_queue_empty(&l->deferdq))
1330                         rcvgap = buf_seqno(skb_peek(&l->deferdq)) - l->rcv_nxt;
1331                 if (rcvgap) {
1332                         msg_set_seq_gap(hdr, rcvgap);
1333                         l->stats.sent_nacks++;
1334                 }
1335                 msg_set_probe(hdr, probe);
1336                 if (probe)
1337                         l->stats.sent_probes++;
1338                 l->stats.sent_states++;
1339                 l->rcv_unacked = 0;
1340         } else {
1341                 /* RESET_MSG or ACTIVATE_MSG */
1342                 msg_set_max_pkt(hdr, l->advertised_mtu);
1343                 msg_set_ack(hdr, l->rcv_nxt - 1);
1344                 msg_set_next_sent(hdr, 1);
1345         }
1346         skb = tipc_buf_acquire(msg_size(hdr));
1347         if (!skb)
1348                 return;
1349         skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
1350         skb->priority = TC_PRIO_CONTROL;
1351         __skb_queue_tail(xmitq, skb);
1352 }
1353
1354 /* tipc_link_tnl_prepare(): prepare and return a list of tunnel packets
1355  * with contents of the link's transmit and backlog queues.
1356  */
1357 void tipc_link_tnl_prepare(struct tipc_link *l, struct tipc_link *tnl,
1358                            int mtyp, struct sk_buff_head *xmitq)
1359 {
1360         struct sk_buff *skb, *tnlskb;
1361         struct tipc_msg *hdr, tnlhdr;
1362         struct sk_buff_head *queue = &l->transmq;
1363         struct sk_buff_head tmpxq, tnlq;
1364         u16 pktlen, pktcnt, seqno = l->snd_nxt;
1365
1366         if (!tnl)
1367                 return;
1368
1369         skb_queue_head_init(&tnlq);
1370         skb_queue_head_init(&tmpxq);
1371
1372         /* At least one packet required for safe algorithm => add dummy */
1373         skb = tipc_msg_create(TIPC_LOW_IMPORTANCE, TIPC_DIRECT_MSG,
1374                               BASIC_H_SIZE, 0, l->addr, link_own_addr(l),
1375                               0, 0, TIPC_ERR_NO_PORT);
1376         if (!skb) {
1377                 pr_warn("%sunable to create tunnel packet\n", link_co_err);
1378                 return;
1379         }
1380         skb_queue_tail(&tnlq, skb);
1381         tipc_link_xmit(l, &tnlq, &tmpxq);
1382         __skb_queue_purge(&tmpxq);
1383
1384         /* Initialize reusable tunnel packet header */
1385         tipc_msg_init(link_own_addr(l), &tnlhdr, TUNNEL_PROTOCOL,
1386                       mtyp, INT_H_SIZE, l->addr);
1387         pktcnt = skb_queue_len(&l->transmq) + skb_queue_len(&l->backlogq);
1388         msg_set_msgcnt(&tnlhdr, pktcnt);
1389         msg_set_bearer_id(&tnlhdr, l->peer_bearer_id);
1390 tnl:
1391         /* Wrap each packet into a tunnel packet */
1392         skb_queue_walk(queue, skb) {
1393                 hdr = buf_msg(skb);
1394                 if (queue == &l->backlogq)
1395                         msg_set_seqno(hdr, seqno++);
1396                 pktlen = msg_size(hdr);
1397                 msg_set_size(&tnlhdr, pktlen + INT_H_SIZE);
1398                 tnlskb = tipc_buf_acquire(pktlen + INT_H_SIZE);
1399                 if (!tnlskb) {
1400                         pr_warn("%sunable to send packet\n", link_co_err);
1401                         return;
1402                 }
1403                 skb_copy_to_linear_data(tnlskb, &tnlhdr, INT_H_SIZE);
1404                 skb_copy_to_linear_data_offset(tnlskb, INT_H_SIZE, hdr, pktlen);
1405                 __skb_queue_tail(&tnlq, tnlskb);
1406         }
1407         if (queue != &l->backlogq) {
1408                 queue = &l->backlogq;
1409                 goto tnl;
1410         }
1411
1412         tipc_link_xmit(tnl, &tnlq, xmitq);
1413
1414         if (mtyp == FAILOVER_MSG) {
1415                 tnl->drop_point = l->rcv_nxt;
1416                 tnl->failover_reasm_skb = l->reasm_buf;
1417                 l->reasm_buf = NULL;
1418         }
1419 }
1420
1421 /* tipc_link_proto_rcv(): receive link level protocol message :
1422  * Note that network plane id propagates through the network, and may
1423  * change at any time. The node with lowest numerical id determines
1424  * network plane
1425  */
1426 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1427                                struct sk_buff_head *xmitq)
1428 {
1429         struct tipc_msg *hdr = buf_msg(skb);
1430         u16 rcvgap = 0;
1431         u16 ack = msg_ack(hdr);
1432         u16 gap = msg_seq_gap(hdr);
1433         u16 peers_snd_nxt =  msg_next_sent(hdr);
1434         u16 peers_tol = msg_link_tolerance(hdr);
1435         u16 peers_prio = msg_linkprio(hdr);
1436         u16 rcv_nxt = l->rcv_nxt;
1437         int mtyp = msg_type(hdr);
1438         char *if_name;
1439         int rc = 0;
1440
1441         if (tipc_link_is_blocked(l) || !xmitq)
1442                 goto exit;
1443
1444         if (link_own_addr(l) > msg_prevnode(hdr))
1445                 l->net_plane = msg_net_plane(hdr);
1446
1447         switch (mtyp) {
1448         case RESET_MSG:
1449
1450                 /* Ignore duplicate RESET with old session number */
1451                 if ((less_eq(msg_session(hdr), l->peer_session)) &&
1452                     (l->peer_session != WILDCARD_SESSION))
1453                         break;
1454                 /* fall thru' */
1455
1456         case ACTIVATE_MSG:
1457
1458                 /* Complete own link name with peer's interface name */
1459                 if_name =  strrchr(l->name, ':') + 1;
1460                 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1461                         break;
1462                 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1463                         break;
1464                 strncpy(if_name, msg_data(hdr), TIPC_MAX_IF_NAME);
1465
1466                 /* Update own tolerance if peer indicates a non-zero value */
1467                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1468                         l->tolerance = peers_tol;
1469
1470                 /* Update own priority if peer's priority is higher */
1471                 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1472                         l->priority = peers_prio;
1473
1474                 /* ACTIVATE_MSG serves as PEER_RESET if link is already down */
1475                 if ((mtyp == RESET_MSG) || !link_is_up(l))
1476                         rc = tipc_link_fsm_evt(l, LINK_PEER_RESET_EVT);
1477
1478                 /* ACTIVATE_MSG takes up link if it was already locally reset */
1479                 if ((mtyp == ACTIVATE_MSG) && (l->state == LINK_ESTABLISHING))
1480                         rc = TIPC_LINK_UP_EVT;
1481
1482                 l->peer_session = msg_session(hdr);
1483                 l->peer_bearer_id = msg_bearer_id(hdr);
1484                 if (l->mtu > msg_max_pkt(hdr))
1485                         l->mtu = msg_max_pkt(hdr);
1486                 break;
1487
1488         case STATE_MSG:
1489
1490                 /* Update own tolerance if peer indicates a non-zero value */
1491                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1492                         l->tolerance = peers_tol;
1493
1494                 l->silent_intv_cnt = 0;
1495                 l->stats.recv_states++;
1496                 if (msg_probe(hdr))
1497                         l->stats.recv_probes++;
1498
1499                 if (!link_is_up(l)) {
1500                         if (l->state == LINK_ESTABLISHING)
1501                                 rc = TIPC_LINK_UP_EVT;
1502                         break;
1503                 }
1504
1505                 /* Send NACK if peer has sent pkts we haven't received yet */
1506                 if (more(peers_snd_nxt, rcv_nxt) && !tipc_link_is_synching(l))
1507                         rcvgap = peers_snd_nxt - l->rcv_nxt;
1508                 if (rcvgap || (msg_probe(hdr)))
1509                         tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1510                                                   0, 0, xmitq);
1511                 tipc_link_release_pkts(l, ack);
1512
1513                 /* If NACK, retransmit will now start at right position */
1514                 if (gap) {
1515                         rc = tipc_link_retrans(l, ack + 1, ack + gap, xmitq);
1516                         l->stats.recv_nacks++;
1517                 }
1518
1519                 tipc_link_advance_backlog(l, xmitq);
1520                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1521                         link_prepare_wakeup(l);
1522         }
1523 exit:
1524         kfree_skb(skb);
1525         return rc;
1526 }
1527
1528 /* tipc_link_build_bc_proto_msg() - create broadcast protocol message
1529  */
1530 static bool tipc_link_build_bc_proto_msg(struct tipc_link *l, bool bcast,
1531                                          u16 peers_snd_nxt,
1532                                          struct sk_buff_head *xmitq)
1533 {
1534         struct sk_buff *skb;
1535         struct tipc_msg *hdr;
1536         struct sk_buff *dfrd_skb = skb_peek(&l->deferdq);
1537         u16 ack = l->rcv_nxt - 1;
1538         u16 gap_to = peers_snd_nxt - 1;
1539
1540         skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
1541                               0, l->addr, link_own_addr(l), 0, 0, 0);
1542         if (!skb)
1543                 return false;
1544         hdr = buf_msg(skb);
1545         msg_set_last_bcast(hdr, l->bc_sndlink->snd_nxt - 1);
1546         msg_set_bcast_ack(hdr, ack);
1547         msg_set_bcgap_after(hdr, ack);
1548         if (dfrd_skb)
1549                 gap_to = buf_seqno(dfrd_skb) - 1;
1550         msg_set_bcgap_to(hdr, gap_to);
1551         msg_set_non_seq(hdr, bcast);
1552         __skb_queue_tail(xmitq, skb);
1553         return true;
1554 }
1555
1556 /* tipc_link_build_bc_init_msg() - synchronize broadcast link endpoints.
1557  *
1558  * Give a newly added peer node the sequence number where it should
1559  * start receiving and acking broadcast packets.
1560  */
1561 void tipc_link_build_bc_init_msg(struct tipc_link *l,
1562                                  struct sk_buff_head *xmitq)
1563 {
1564         struct sk_buff_head list;
1565
1566         __skb_queue_head_init(&list);
1567         if (!tipc_link_build_bc_proto_msg(l->bc_rcvlink, false, 0, &list))
1568                 return;
1569         tipc_link_xmit(l, &list, xmitq);
1570 }
1571
1572 /* tipc_link_bc_init_rcv - receive initial broadcast synch data from peer
1573  */
1574 void tipc_link_bc_init_rcv(struct tipc_link *l, struct tipc_msg *hdr)
1575 {
1576         int mtyp = msg_type(hdr);
1577         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1578
1579         if (link_is_up(l))
1580                 return;
1581
1582         if (msg_user(hdr) == BCAST_PROTOCOL) {
1583                 l->rcv_nxt = peers_snd_nxt;
1584                 l->state = LINK_ESTABLISHED;
1585                 return;
1586         }
1587
1588         if (l->peer_caps & TIPC_BCAST_SYNCH)
1589                 return;
1590
1591         if (msg_peer_node_is_up(hdr))
1592                 return;
1593
1594         /* Compatibility: accept older, less safe initial synch data */
1595         if ((mtyp == RESET_MSG) || (mtyp == ACTIVATE_MSG))
1596                 l->rcv_nxt = peers_snd_nxt;
1597 }
1598
1599 /* tipc_link_bc_sync_rcv - update rcv link according to peer's send state
1600  */
1601 void tipc_link_bc_sync_rcv(struct tipc_link *l, struct tipc_msg *hdr,
1602                            struct sk_buff_head *xmitq)
1603 {
1604         u16 peers_snd_nxt = msg_bc_snd_nxt(hdr);
1605
1606         if (!link_is_up(l))
1607                 return;
1608
1609         if (!msg_peer_node_is_up(hdr))
1610                 return;
1611
1612         l->bc_peer_is_up = true;
1613
1614         /* Ignore if peers_snd_nxt goes beyond receive window */
1615         if (more(peers_snd_nxt, l->rcv_nxt + l->window))
1616                 return;
1617
1618         if (!more(peers_snd_nxt, l->rcv_nxt)) {
1619                 l->nack_state = BC_NACK_SND_CONDITIONAL;
1620                 return;
1621         }
1622
1623         /* Don't NACK if one was recently sent or peeked */
1624         if (l->nack_state == BC_NACK_SND_SUPPRESS) {
1625                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1626                 return;
1627         }
1628
1629         /* Conditionally delay NACK sending until next synch rcv */
1630         if (l->nack_state == BC_NACK_SND_CONDITIONAL) {
1631                 l->nack_state = BC_NACK_SND_UNCONDITIONAL;
1632                 if ((peers_snd_nxt - l->rcv_nxt) < TIPC_MIN_LINK_WIN)
1633                         return;
1634         }
1635
1636         /* Send NACK now but suppress next one */
1637         tipc_link_build_bc_proto_msg(l, true, peers_snd_nxt, xmitq);
1638         l->nack_state = BC_NACK_SND_SUPPRESS;
1639 }
1640
1641 void tipc_link_bc_ack_rcv(struct tipc_link *l, u16 acked,
1642                           struct sk_buff_head *xmitq)
1643 {
1644         struct sk_buff *skb, *tmp;
1645         struct tipc_link *snd_l = l->bc_sndlink;
1646
1647         if (!link_is_up(l) || !l->bc_peer_is_up)
1648                 return;
1649
1650         if (!more(acked, l->acked))
1651                 return;
1652
1653         /* Skip over packets peer has already acked */
1654         skb_queue_walk(&snd_l->transmq, skb) {
1655                 if (more(buf_seqno(skb), l->acked))
1656                         break;
1657         }
1658
1659         /* Update/release the packets peer is acking now */
1660         skb_queue_walk_from_safe(&snd_l->transmq, skb, tmp) {
1661                 if (more(buf_seqno(skb), acked))
1662                         break;
1663                 if (!--TIPC_SKB_CB(skb)->ackers) {
1664                         __skb_unlink(skb, &snd_l->transmq);
1665                         kfree_skb(skb);
1666                 }
1667         }
1668         l->acked = acked;
1669         tipc_link_advance_backlog(snd_l, xmitq);
1670         if (unlikely(!skb_queue_empty(&snd_l->wakeupq)))
1671                 link_prepare_wakeup(snd_l);
1672 }
1673
1674 /* tipc_link_bc_nack_rcv(): receive broadcast nack message
1675  */
1676 int tipc_link_bc_nack_rcv(struct tipc_link *l, struct sk_buff *skb,
1677                           struct sk_buff_head *xmitq)
1678 {
1679         struct tipc_msg *hdr = buf_msg(skb);
1680         u32 dnode = msg_destnode(hdr);
1681         int mtyp = msg_type(hdr);
1682         u16 acked = msg_bcast_ack(hdr);
1683         u16 from = acked + 1;
1684         u16 to = msg_bcgap_to(hdr);
1685         u16 peers_snd_nxt = to + 1;
1686         int rc = 0;
1687
1688         kfree_skb(skb);
1689
1690         if (!tipc_link_is_up(l) || !l->bc_peer_is_up)
1691                 return 0;
1692
1693         if (mtyp != STATE_MSG)
1694                 return 0;
1695
1696         if (dnode == link_own_addr(l)) {
1697                 tipc_link_bc_ack_rcv(l, acked, xmitq);
1698                 rc = tipc_link_retrans(l->bc_sndlink, from, to, xmitq);
1699                 l->stats.recv_nacks++;
1700                 return rc;
1701         }
1702
1703         /* Msg for other node => suppress own NACK at next sync if applicable */
1704         if (more(peers_snd_nxt, l->rcv_nxt) && !less(l->rcv_nxt, from))
1705                 l->nack_state = BC_NACK_SND_SUPPRESS;
1706
1707         return 0;
1708 }
1709
1710 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1711 {
1712         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1713
1714         l->window = win;
1715         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1716         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1717         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1718         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1719         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1720 }
1721
1722 /* tipc_link_find_owner - locate owner node of link by link's name
1723  * @net: the applicable net namespace
1724  * @name: pointer to link name string
1725  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1726  *
1727  * Returns pointer to node owning the link, or 0 if no matching link is found.
1728  */
1729 static struct tipc_node *tipc_link_find_owner(struct net *net,
1730                                               const char *link_name,
1731                                               unsigned int *bearer_id)
1732 {
1733         struct tipc_net *tn = net_generic(net, tipc_net_id);
1734         struct tipc_link *l_ptr;
1735         struct tipc_node *n_ptr;
1736         struct tipc_node *found_node = NULL;
1737         int i;
1738
1739         *bearer_id = 0;
1740         rcu_read_lock();
1741         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1742                 tipc_node_lock(n_ptr);
1743                 for (i = 0; i < MAX_BEARERS; i++) {
1744                         l_ptr = n_ptr->links[i].link;
1745                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1746                                 *bearer_id = i;
1747                                 found_node = n_ptr;
1748                                 break;
1749                         }
1750                 }
1751                 tipc_node_unlock(n_ptr);
1752                 if (found_node)
1753                         break;
1754         }
1755         rcu_read_unlock();
1756
1757         return found_node;
1758 }
1759
1760 /**
1761  * link_reset_statistics - reset link statistics
1762  * @l_ptr: pointer to link
1763  */
1764 static void link_reset_statistics(struct tipc_link *l_ptr)
1765 {
1766         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1767         l_ptr->stats.sent_info = l_ptr->snd_nxt;
1768         l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1769 }
1770
1771 static void link_print(struct tipc_link *l, const char *str)
1772 {
1773         struct sk_buff *hskb = skb_peek(&l->transmq);
1774         u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt - 1;
1775         u16 tail = l->snd_nxt - 1;
1776
1777         pr_info("%s Link <%s> state %x\n", str, l->name, l->state);
1778         pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1779                 skb_queue_len(&l->transmq), head, tail,
1780                 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1781 }
1782
1783 /* Parse and validate nested (link) properties valid for media, bearer and link
1784  */
1785 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1786 {
1787         int err;
1788
1789         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1790                                tipc_nl_prop_policy);
1791         if (err)
1792                 return err;
1793
1794         if (props[TIPC_NLA_PROP_PRIO]) {
1795                 u32 prio;
1796
1797                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1798                 if (prio > TIPC_MAX_LINK_PRI)
1799                         return -EINVAL;
1800         }
1801
1802         if (props[TIPC_NLA_PROP_TOL]) {
1803                 u32 tol;
1804
1805                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1806                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1807                         return -EINVAL;
1808         }
1809
1810         if (props[TIPC_NLA_PROP_WIN]) {
1811                 u32 win;
1812
1813                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1814                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1815                         return -EINVAL;
1816         }
1817
1818         return 0;
1819 }
1820
1821 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1822 {
1823         int err;
1824         int res = 0;
1825         int bearer_id;
1826         char *name;
1827         struct tipc_link *link;
1828         struct tipc_node *node;
1829         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1830         struct net *net = sock_net(skb->sk);
1831
1832         if (!info->attrs[TIPC_NLA_LINK])
1833                 return -EINVAL;
1834
1835         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1836                                info->attrs[TIPC_NLA_LINK],
1837                                tipc_nl_link_policy);
1838         if (err)
1839                 return err;
1840
1841         if (!attrs[TIPC_NLA_LINK_NAME])
1842                 return -EINVAL;
1843
1844         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1845
1846         if (strcmp(name, tipc_bclink_name) == 0)
1847                 return tipc_nl_bc_link_set(net, attrs);
1848
1849         node = tipc_link_find_owner(net, name, &bearer_id);
1850         if (!node)
1851                 return -EINVAL;
1852
1853         tipc_node_lock(node);
1854
1855         link = node->links[bearer_id].link;
1856         if (!link) {
1857                 res = -EINVAL;
1858                 goto out;
1859         }
1860
1861         if (attrs[TIPC_NLA_LINK_PROP]) {
1862                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1863
1864                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1865                                               props);
1866                 if (err) {
1867                         res = err;
1868                         goto out;
1869                 }
1870
1871                 if (props[TIPC_NLA_PROP_TOL]) {
1872                         u32 tol;
1873
1874                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1875                         link->tolerance = tol;
1876                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1877                 }
1878                 if (props[TIPC_NLA_PROP_PRIO]) {
1879                         u32 prio;
1880
1881                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1882                         link->priority = prio;
1883                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1884                 }
1885                 if (props[TIPC_NLA_PROP_WIN]) {
1886                         u32 win;
1887
1888                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1889                         tipc_link_set_queue_limits(link, win);
1890                 }
1891         }
1892
1893 out:
1894         tipc_node_unlock(node);
1895
1896         return res;
1897 }
1898
1899 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1900 {
1901         int i;
1902         struct nlattr *stats;
1903
1904         struct nla_map {
1905                 u32 key;
1906                 u32 val;
1907         };
1908
1909         struct nla_map map[] = {
1910                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1911                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1912                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1913                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1914                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1915                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1916                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1917                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1918                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1919                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1920                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1921                         s->msg_length_counts : 1},
1922                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1923                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1924                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1925                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1926                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1927                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1928                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1929                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1930                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1931                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1932                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1933                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1934                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1935                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1936                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1937                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1938                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1939                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1940                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1941                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1942                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1943                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1944                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1945         };
1946
1947         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1948         if (!stats)
1949                 return -EMSGSIZE;
1950
1951         for (i = 0; i <  ARRAY_SIZE(map); i++)
1952                 if (nla_put_u32(skb, map[i].key, map[i].val))
1953                         goto msg_full;
1954
1955         nla_nest_end(skb, stats);
1956
1957         return 0;
1958 msg_full:
1959         nla_nest_cancel(skb, stats);
1960
1961         return -EMSGSIZE;
1962 }
1963
1964 /* Caller should hold appropriate locks to protect the link */
1965 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1966                               struct tipc_link *link, int nlflags)
1967 {
1968         int err;
1969         void *hdr;
1970         struct nlattr *attrs;
1971         struct nlattr *prop;
1972         struct tipc_net *tn = net_generic(net, tipc_net_id);
1973
1974         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1975                           nlflags, TIPC_NL_LINK_GET);
1976         if (!hdr)
1977                 return -EMSGSIZE;
1978
1979         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1980         if (!attrs)
1981                 goto msg_full;
1982
1983         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1984                 goto attr_msg_full;
1985         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1986                         tipc_cluster_mask(tn->own_addr)))
1987                 goto attr_msg_full;
1988         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1989                 goto attr_msg_full;
1990         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
1991                 goto attr_msg_full;
1992         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
1993                 goto attr_msg_full;
1994
1995         if (tipc_link_is_up(link))
1996                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1997                         goto attr_msg_full;
1998         if (tipc_link_is_active(link))
1999                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2000                         goto attr_msg_full;
2001
2002         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2003         if (!prop)
2004                 goto attr_msg_full;
2005         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2006                 goto prop_msg_full;
2007         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2008                 goto prop_msg_full;
2009         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2010                         link->window))
2011                 goto prop_msg_full;
2012         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2013                 goto prop_msg_full;
2014         nla_nest_end(msg->skb, prop);
2015
2016         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2017         if (err)
2018                 goto attr_msg_full;
2019
2020         nla_nest_end(msg->skb, attrs);
2021         genlmsg_end(msg->skb, hdr);
2022
2023         return 0;
2024
2025 prop_msg_full:
2026         nla_nest_cancel(msg->skb, prop);
2027 attr_msg_full:
2028         nla_nest_cancel(msg->skb, attrs);
2029 msg_full:
2030         genlmsg_cancel(msg->skb, hdr);
2031
2032         return -EMSGSIZE;
2033 }
2034
2035 /* Caller should hold node lock  */
2036 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2037                                     struct tipc_node *node, u32 *prev_link)
2038 {
2039         u32 i;
2040         int err;
2041
2042         for (i = *prev_link; i < MAX_BEARERS; i++) {
2043                 *prev_link = i;
2044
2045                 if (!node->links[i].link)
2046                         continue;
2047
2048                 err = __tipc_nl_add_link(net, msg,
2049                                          node->links[i].link, NLM_F_MULTI);
2050                 if (err)
2051                         return err;
2052         }
2053         *prev_link = 0;
2054
2055         return 0;
2056 }
2057
2058 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2059 {
2060         struct net *net = sock_net(skb->sk);
2061         struct tipc_net *tn = net_generic(net, tipc_net_id);
2062         struct tipc_node *node;
2063         struct tipc_nl_msg msg;
2064         u32 prev_node = cb->args[0];
2065         u32 prev_link = cb->args[1];
2066         int done = cb->args[2];
2067         int err;
2068
2069         if (done)
2070                 return 0;
2071
2072         msg.skb = skb;
2073         msg.portid = NETLINK_CB(cb->skb).portid;
2074         msg.seq = cb->nlh->nlmsg_seq;
2075
2076         rcu_read_lock();
2077         if (prev_node) {
2078                 node = tipc_node_find(net, prev_node);
2079                 if (!node) {
2080                         /* We never set seq or call nl_dump_check_consistent()
2081                          * this means that setting prev_seq here will cause the
2082                          * consistence check to fail in the netlink callback
2083                          * handler. Resulting in the last NLMSG_DONE message
2084                          * having the NLM_F_DUMP_INTR flag set.
2085                          */
2086                         cb->prev_seq = 1;
2087                         goto out;
2088                 }
2089                 tipc_node_put(node);
2090
2091                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2092                                                  list) {
2093                         tipc_node_lock(node);
2094                         err = __tipc_nl_add_node_links(net, &msg, node,
2095                                                        &prev_link);
2096                         tipc_node_unlock(node);
2097                         if (err)
2098                                 goto out;
2099
2100                         prev_node = node->addr;
2101                 }
2102         } else {
2103                 err = tipc_nl_add_bc_link(net, &msg);
2104                 if (err)
2105                         goto out;
2106
2107                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2108                         tipc_node_lock(node);
2109                         err = __tipc_nl_add_node_links(net, &msg, node,
2110                                                        &prev_link);
2111                         tipc_node_unlock(node);
2112                         if (err)
2113                                 goto out;
2114
2115                         prev_node = node->addr;
2116                 }
2117         }
2118         done = 1;
2119 out:
2120         rcu_read_unlock();
2121
2122         cb->args[0] = prev_node;
2123         cb->args[1] = prev_link;
2124         cb->args[2] = done;
2125
2126         return skb->len;
2127 }
2128
2129 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2130 {
2131         struct net *net = genl_info_net(info);
2132         struct tipc_nl_msg msg;
2133         char *name;
2134         int err;
2135
2136         msg.portid = info->snd_portid;
2137         msg.seq = info->snd_seq;
2138
2139         if (!info->attrs[TIPC_NLA_LINK_NAME])
2140                 return -EINVAL;
2141         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2142
2143         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2144         if (!msg.skb)
2145                 return -ENOMEM;
2146
2147         if (strcmp(name, tipc_bclink_name) == 0) {
2148                 err = tipc_nl_add_bc_link(net, &msg);
2149                 if (err) {
2150                         nlmsg_free(msg.skb);
2151                         return err;
2152                 }
2153         } else {
2154                 int bearer_id;
2155                 struct tipc_node *node;
2156                 struct tipc_link *link;
2157
2158                 node = tipc_link_find_owner(net, name, &bearer_id);
2159                 if (!node)
2160                         return -EINVAL;
2161
2162                 tipc_node_lock(node);
2163                 link = node->links[bearer_id].link;
2164                 if (!link) {
2165                         tipc_node_unlock(node);
2166                         nlmsg_free(msg.skb);
2167                         return -EINVAL;
2168                 }
2169
2170                 err = __tipc_nl_add_link(net, &msg, link, 0);
2171                 tipc_node_unlock(node);
2172                 if (err) {
2173                         nlmsg_free(msg.skb);
2174                         return err;
2175                 }
2176         }
2177
2178         return genlmsg_reply(msg.skb, info);
2179 }
2180
2181 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2182 {
2183         int err;
2184         char *link_name;
2185         unsigned int bearer_id;
2186         struct tipc_link *link;
2187         struct tipc_node *node;
2188         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2189         struct net *net = sock_net(skb->sk);
2190
2191         if (!info->attrs[TIPC_NLA_LINK])
2192                 return -EINVAL;
2193
2194         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2195                                info->attrs[TIPC_NLA_LINK],
2196                                tipc_nl_link_policy);
2197         if (err)
2198                 return err;
2199
2200         if (!attrs[TIPC_NLA_LINK_NAME])
2201                 return -EINVAL;
2202
2203         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2204
2205         if (strcmp(link_name, tipc_bclink_name) == 0) {
2206                 err = tipc_bclink_reset_stats(net);
2207                 if (err)
2208                         return err;
2209                 return 0;
2210         }
2211
2212         node = tipc_link_find_owner(net, link_name, &bearer_id);
2213         if (!node)
2214                 return -EINVAL;
2215
2216         tipc_node_lock(node);
2217
2218         link = node->links[bearer_id].link;
2219         if (!link) {
2220                 tipc_node_unlock(node);
2221                 return -EINVAL;
2222         }
2223
2224         link_reset_statistics(link);
2225
2226         tipc_node_unlock(node);
2227
2228         return 0;
2229 }