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