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 changeover error, ";
  52 static const char *link_rst_msg = "Resetting link ";
  53 static const char *link_unk_evt = "Unknown link event ";
  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 /*
  80  * Interval between NACKs when packets arrive out of order
  81  */
  82 #define TIPC_NACK_INTV (TIPC_MIN_LINK_WIN * 2)
  83 /*
  84  * Out-of-range value for link session numbers
  85  */
  86 #define WILDCARD_SESSION 0x10000
  87
  88 /* State value stored in 'failover_pkts'
  89  */
  90 #define FIRST_FAILOVER 0xffffu
  91
  92 /* Link FSM states and events:
  93  */
  94 enum {
  95         TIPC_LINK_WORKING,
  96         TIPC_LINK_PROBING,
  97         TIPC_LINK_RESETTING,
  98         TIPC_LINK_ESTABLISHING
  99 };
 100
 101 enum {
 102         PEER_RESET_EVT    = RESET_MSG,
 103         ACTIVATE_EVT      = ACTIVATE_MSG,
 104         TRAFFIC_EVT,      /* Any other valid msg from peer */
 105         SILENCE_EVT       /* Peer was silent during last timer interval*/
 106 };
 107
 108 /* Link FSM state checking routines
 109  */
 110 static int link_working(struct tipc_link *l)
 111 {
 112         return l->state == TIPC_LINK_WORKING;
 113 }
 114
 115 static int link_probing(struct tipc_link *l)
 116 {
 117         return l->state == TIPC_LINK_PROBING;
 118 }
 119
 120 static int link_resetting(struct tipc_link *l)
 121 {
 122         return l->state == TIPC_LINK_RESETTING;
 123 }
 124
 125 static int link_establishing(struct tipc_link *l)
 126 {
 127         return l->state == TIPC_LINK_ESTABLISHING;
 128 }
 129
 130 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
 131                                struct sk_buff_head *xmitq);
 132 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
 133                                       u16 rcvgap, int tolerance, int priority,
 134                                       struct sk_buff_head *xmitq);
 135 static void link_reset_statistics(struct tipc_link *l_ptr);
 136 static void link_print(struct tipc_link *l_ptr, const char *str);
 137 static void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
 138                                            struct sk_buff_head *xmitq);
 139 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 140 static int tipc_link_input(struct tipc_link *l, struct sk_buff *skb);
 141 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb);
 142 static int tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb);
 143
 144 /*
 145  *  Simple link routines
 146  */
 147 static unsigned int align(unsigned int i)
 148 {
 149         return (i + 3) & ~3u;
 150 }
 151
 152 static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
 153 {
 154         struct tipc_node *n = l->owner;
 155
 156         if (node_active_link(n, 0) != l)
 157                 return node_active_link(n, 0);
 158         return node_active_link(n, 1);
 159 }
 160
 161 /*
 162  *  Simple non-static link routines (i.e. referenced outside this file)
 163  */
 164 int tipc_link_is_up(struct tipc_link *l_ptr)
 165 {
 166         if (!l_ptr)
 167                 return 0;
 168         return link_working(l_ptr) || link_probing(l_ptr);
 169 }
 170
 171 int tipc_link_is_active(struct tipc_link *l)
 172 {
 173         struct tipc_node *n = l->owner;
 174
 175         return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
 176 }
 177
 178 /**
 179  * tipc_link_create - create a new link
 180  * @n_ptr: pointer to associated node
 181  * @b_ptr: pointer to associated bearer
 182  * @media_addr: media address to use when sending messages over link
 183  *
 184  * Returns pointer to link.
 185  */
 186 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 187                                    struct tipc_bearer *b_ptr,
 188                                    const struct tipc_media_addr *media_addr,
 189                                    struct sk_buff_head *inputq,
 190                                    struct sk_buff_head *namedq)
 191 {
 192         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 193         struct tipc_link *l_ptr;
 194         struct tipc_msg *msg;
 195         char *if_name;
 196         char addr_string[16];
 197         u32 peer = n_ptr->addr;
 198
 199         if (n_ptr->link_cnt >= MAX_BEARERS) {
 200                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 201                 pr_err("Cannot establish %uth link to %s. Max %u allowed.\n",
 202                        n_ptr->link_cnt, addr_string, MAX_BEARERS);
 203                 return NULL;
 204         }
 205
 206         if (n_ptr->links[b_ptr->identity].link) {
 207                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 208                 pr_err("Attempt to establish second link on <%s> to %s\n",
 209                        b_ptr->name, addr_string);
 210                 return NULL;
 211         }
 212
 213         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 214         if (!l_ptr) {
 215                 pr_warn("Link creation failed, no memory\n");
 216                 return NULL;
 217         }
 218         l_ptr->addr = peer;
 219         if_name = strchr(b_ptr->name, ':') + 1;
 220         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 221                 tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
 222                 tipc_node(tn->own_addr),
 223                 if_name,
 224                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 225                 /* note: peer i/f name is updated by reset/activate message */
 226         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 227         l_ptr->owner = n_ptr;
 228         l_ptr->peer_session = WILDCARD_SESSION;
 229         l_ptr->bearer_id = b_ptr->identity;
 230         l_ptr->tolerance = b_ptr->tolerance;
 231         l_ptr->snd_nxt = 1;
 232         l_ptr->rcv_nxt = 1;
 233         l_ptr->state = TIPC_LINK_RESETTING;
 234
 235         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 236         msg = l_ptr->pmsg;
 237         tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
 238                       l_ptr->addr);
 239         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 240         msg_set_session(msg, (tn->random & 0xffff));
 241         msg_set_bearer_id(msg, b_ptr->identity);
 242         strcpy((char *)msg_data(msg), if_name);
 243         l_ptr->net_plane = b_ptr->net_plane;
 244         l_ptr->advertised_mtu = b_ptr->mtu;
 245         l_ptr->mtu = l_ptr->advertised_mtu;
 246         l_ptr->priority = b_ptr->priority;
 247         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 248         l_ptr->snd_nxt = 1;
 249         __skb_queue_head_init(&l_ptr->transmq);
 250         __skb_queue_head_init(&l_ptr->backlogq);
 251         __skb_queue_head_init(&l_ptr->deferdq);
 252         skb_queue_head_init(&l_ptr->wakeupq);
 253         l_ptr->inputq = inputq;
 254         l_ptr->namedq = namedq;
 255         skb_queue_head_init(l_ptr->inputq);
 256         link_reset_statistics(l_ptr);
 257         tipc_node_attach_link(n_ptr, l_ptr);
 258         return l_ptr;
 259 }
 260
 261 /* tipc_link_build_bcast_sync_msg() - synchronize broadcast link endpoints.
 262  *
 263  * Give a newly added peer node the sequence number where it should
 264  * start receiving and acking broadcast packets.
 265  */
 266 static void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
 267                                            struct sk_buff_head *xmitq)
 268 {
 269         struct sk_buff *skb;
 270         struct sk_buff_head list;
 271         u16 last_sent;
 272
 273         skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
 274                               0, l->addr, link_own_addr(l), 0, 0, 0);
 275         if (!skb)
 276                 return;
 277         last_sent = tipc_bclink_get_last_sent(l->owner->net);
 278         msg_set_last_bcast(buf_msg(skb), last_sent);
 279         __skb_queue_head_init(&list);
 280         __skb_queue_tail(&list, skb);
 281         tipc_link_xmit(l, &list, xmitq);
 282 }
 283
 284 /**
 285  * tipc_link_fsm_evt - link finite state machine
 286  * @l: pointer to link
 287  * @evt: state machine event to be processed
 288  * @xmitq: queue to prepend created protocol message, if any
 289  */
 290 static int tipc_link_fsm_evt(struct tipc_link *l, int evt,
 291                              struct sk_buff_head *xmitq)
 292 {
 293         int mtyp = 0, rc = 0;
 294         struct tipc_link *pl;
 295         enum {
 296                 LINK_RESET     = 1,
 297                 LINK_ACTIVATE  = (1 << 1),
 298                 SND_PROBE      = (1 << 2),
 299                 SND_STATE      = (1 << 3),
 300                 SND_RESET      = (1 << 4),
 301                 SND_ACTIVATE   = (1 << 5),
 302                 SND_BCAST_SYNC = (1 << 6)
 303         } actions = 0;
 304
 305         if (l->exec_mode == TIPC_LINK_BLOCKED)
 306                 return rc;
 307
 308         switch (l->state) {
 309         case TIPC_LINK_WORKING:
 310                 switch (evt) {
 311                 case TRAFFIC_EVT:
 312                 case ACTIVATE_EVT:
 313                         break;
 314                 case SILENCE_EVT:
 315                         l->state = TIPC_LINK_PROBING;
 316                         actions |= SND_PROBE;
 317                         break;
 318                 case PEER_RESET_EVT:
 319                         actions |= LINK_RESET | SND_ACTIVATE;
 320                         break;
 321                 default:
 322                         pr_debug("%s%u WORKING\n", link_unk_evt, evt);
 323                 }
 324                 break;
 325         case TIPC_LINK_PROBING:
 326                 switch (evt) {
 327                 case TRAFFIC_EVT:
 328                 case ACTIVATE_EVT:
 329                         l->state = TIPC_LINK_WORKING;
 330                         break;
 331                 case PEER_RESET_EVT:
 332                         actions |= LINK_RESET | SND_ACTIVATE;
 333                         break;
 334                 case SILENCE_EVT:
 335                         if (l->silent_intv_cnt <= l->abort_limit) {
 336                                 actions |= SND_PROBE;
 337                                 break;
 338                         }
 339                         actions |= LINK_RESET | SND_RESET;
 340                         break;
 341                 default:
 342                         pr_err("%s%u PROBING\n", link_unk_evt, evt);
 343                 }
 344                 break;
 345         case TIPC_LINK_RESETTING:
 346                 switch (evt) {
 347                 case TRAFFIC_EVT:
 348                         break;
 349                 case ACTIVATE_EVT:
 350                         pl = node_active_link(l->owner, 0);
 351                         if (pl && link_probing(pl))
 352                                 break;
 353                         l->state = TIPC_LINK_WORKING;
 354                         actions |= LINK_ACTIVATE;
 355                         if (!l->owner->working_links)
 356                                 actions |= SND_BCAST_SYNC;
 357                         break;
 358                 case PEER_RESET_EVT:
 359                         l->state = TIPC_LINK_ESTABLISHING;
 360                         actions |= SND_ACTIVATE;
 361                         break;
 362                 case SILENCE_EVT:
 363                         actions |= SND_RESET;
 364                         break;
 365                 default:
 366                         pr_err("%s%u in RESETTING\n", link_unk_evt, evt);
 367                 }
 368                 break;
 369         case TIPC_LINK_ESTABLISHING:
 370                 switch (evt) {
 371                 case TRAFFIC_EVT:
 372                 case ACTIVATE_EVT:
 373                         pl = node_active_link(l->owner, 0);
 374                         if (pl && link_probing(pl))
 375                                 break;
 376                         l->state = TIPC_LINK_WORKING;
 377                         actions |= LINK_ACTIVATE;
 378                         if (!l->owner->working_links)
 379                                 actions |= SND_BCAST_SYNC;
 380                         break;
 381                 case PEER_RESET_EVT:
 382                         break;
 383                 case SILENCE_EVT:
 384                         actions |= SND_ACTIVATE;
 385                         break;
 386                 default:
 387                         pr_err("%s%u ESTABLISHING\n", link_unk_evt, evt);
 388                 }
 389                 break;
 390         default:
 391                 pr_err("Unknown link state %u/%u\n", l->state, evt);
 392         }
 393
 394         /* Perform actions as decided by FSM */
 395         if (actions & LINK_RESET) {
 396                 l->exec_mode = TIPC_LINK_BLOCKED;
 397                 rc |= TIPC_LINK_DOWN_EVT;
 398         }
 399         if (actions & LINK_ACTIVATE) {
 400                 l->exec_mode = TIPC_LINK_OPEN;
 401                 rc |= TIPC_LINK_UP_EVT;
 402         }
 403         if (actions & (SND_STATE | SND_PROBE))
 404                 mtyp = STATE_MSG;
 405         if (actions & SND_RESET)
 406                 mtyp = RESET_MSG;
 407         if (actions & SND_ACTIVATE)
 408                 mtyp = ACTIVATE_MSG;
 409         if (actions & (SND_PROBE | SND_STATE | SND_RESET | SND_ACTIVATE))
 410                 tipc_link_build_proto_msg(l, mtyp, actions & SND_PROBE,
 411                                           0, 0, 0, xmitq);
 412         if (actions & SND_BCAST_SYNC)
 413                 tipc_link_build_bcast_sync_msg(l, xmitq);
 414         return rc;
 415 }
 416
 417 /* link_profile_stats - update statistical profiling of traffic
 418  */
 419 static void link_profile_stats(struct tipc_link *l)
 420 {
 421         struct sk_buff *skb;
 422         struct tipc_msg *msg;
 423         int length;
 424
 425         /* Update counters used in statistical profiling of send traffic */
 426         l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 427         l->stats.queue_sz_counts++;
 428
 429         skb = skb_peek(&l->transmq);
 430         if (!skb)
 431                 return;
 432         msg = buf_msg(skb);
 433         length = msg_size(msg);
 434
 435         if (msg_user(msg) == MSG_FRAGMENTER) {
 436                 if (msg_type(msg) != FIRST_FRAGMENT)
 437                         return;
 438                 length = msg_size(msg_get_wrapped(msg));
 439         }
 440         l->stats.msg_lengths_total += length;
 441         l->stats.msg_length_counts++;
 442         if (length <= 64)
 443                 l->stats.msg_length_profile[0]++;
 444         else if (length <= 256)
 445                 l->stats.msg_length_profile[1]++;
 446         else if (length <= 1024)
 447                 l->stats.msg_length_profile[2]++;
 448         else if (length <= 4096)
 449                 l->stats.msg_length_profile[3]++;
 450         else if (length <= 16384)
 451                 l->stats.msg_length_profile[4]++;
 452         else if (length <= 32768)
 453                 l->stats.msg_length_profile[5]++;
 454         else
 455                 l->stats.msg_length_profile[6]++;
 456 }
 457
 458 /* tipc_link_timeout - perform periodic task as instructed from node timeout
 459  */
 460 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 461 {
 462         int rc = 0;
 463
 464         link_profile_stats(l);
 465         if (l->silent_intv_cnt)
 466                 rc = tipc_link_fsm_evt(l, SILENCE_EVT, xmitq);
 467         else if (link_working(l) && tipc_bclink_acks_missing(l->owner))
 468                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
 469         l->silent_intv_cnt++;
 470         return rc;
 471 }
 472
 473 /**
 474  * link_schedule_user - schedule a message sender for wakeup after congestion
 475  * @link: congested link
 476  * @list: message that was attempted sent
 477  * Create pseudo msg to send back to user when congestion abates
 478  * Does not consume buffer list
 479  */
 480 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 481 {
 482         struct tipc_msg *msg = buf_msg(skb_peek(list));
 483         int imp = msg_importance(msg);
 484         u32 oport = msg_origport(msg);
 485         u32 addr = link_own_addr(link);
 486         struct sk_buff *skb;
 487
 488         /* This really cannot happen...  */
 489         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 490                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 491                 return -ENOBUFS;
 492         }
 493         /* Non-blocking sender: */
 494         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 495                 return -ELINKCONG;
 496
 497         /* Create and schedule wakeup pseudo message */
 498         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 499                               addr, addr, oport, 0, 0);
 500         if (!skb)
 501                 return -ENOBUFS;
 502         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 503         TIPC_SKB_CB(skb)->chain_imp = imp;
 504         skb_queue_tail(&link->wakeupq, skb);
 505         link->stats.link_congs++;
 506         return -ELINKCONG;
 507 }
 508
 509 /**
 510  * link_prepare_wakeup - prepare users for wakeup after congestion
 511  * @link: congested link
 512  * Move a number of waiting users, as permitted by available space in
 513  * the send queue, from link wait queue to node wait queue for wakeup
 514  */
 515 void link_prepare_wakeup(struct tipc_link *l)
 516 {
 517         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 518         int imp, lim;
 519         struct sk_buff *skb, *tmp;
 520
 521         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 522                 imp = TIPC_SKB_CB(skb)->chain_imp;
 523                 lim = l->window + l->backlog[imp].limit;
 524                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 525                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 526                         break;
 527                 skb_unlink(skb, &l->wakeupq);
 528                 skb_queue_tail(l->inputq, skb);
 529                 l->owner->inputq = l->inputq;
 530                 l->owner->action_flags |= TIPC_MSG_EVT;
 531         }
 532 }
 533
 534 /**
 535  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 536  * @l_ptr: pointer to link
 537  */
 538 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 539 {
 540         kfree_skb(l_ptr->reasm_buf);
 541         l_ptr->reasm_buf = NULL;
 542 }
 543
 544 void tipc_link_purge_backlog(struct tipc_link *l)
 545 {
 546         __skb_queue_purge(&l->backlogq);
 547         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 548         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 549         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 550         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 551         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 552 }
 553
 554 /**
 555  * tipc_link_purge_queues - purge all pkt queues associated with link
 556  * @l_ptr: pointer to link
 557  */
 558 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 559 {
 560         __skb_queue_purge(&l_ptr->deferdq);
 561         __skb_queue_purge(&l_ptr->transmq);
 562         tipc_link_purge_backlog(l_ptr);
 563         tipc_link_reset_fragments(l_ptr);
 564 }
 565
 566 void tipc_link_reset(struct tipc_link *l_ptr)
 567 {
 568         u32 prev_state = l_ptr->state;
 569         int was_active_link = tipc_link_is_active(l_ptr);
 570         struct tipc_node *owner = l_ptr->owner;
 571         struct tipc_link *pl = tipc_parallel_link(l_ptr);
 572
 573         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 574
 575         /* Link is down, accept any session */
 576         l_ptr->peer_session = WILDCARD_SESSION;
 577
 578         /* Prepare for renewed mtu size negotiation */
 579         l_ptr->mtu = l_ptr->advertised_mtu;
 580
 581         l_ptr->state = TIPC_LINK_RESETTING;
 582
 583         if ((prev_state == TIPC_LINK_RESETTING) ||
 584             (prev_state == TIPC_LINK_ESTABLISHING))
 585                 return;
 586
 587         tipc_node_link_down(l_ptr->owner, l_ptr->bearer_id);
 588         tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 589
 590         if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
 591                 l_ptr->exec_mode = TIPC_LINK_BLOCKED;
 592                 l_ptr->failover_checkpt = l_ptr->rcv_nxt;
 593                 pl->failover_pkts = FIRST_FAILOVER;
 594                 pl->failover_checkpt = l_ptr->rcv_nxt;
 595                 pl->failover_skb = l_ptr->reasm_buf;
 596         } else {
 597                 kfree_skb(l_ptr->reasm_buf);
 598         }
 599         /* Clean up all queues, except inputq: */
 600         __skb_queue_purge(&l_ptr->transmq);
 601         __skb_queue_purge(&l_ptr->deferdq);
 602         if (!owner->inputq)
 603                 owner->inputq = l_ptr->inputq;
 604         skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
 605         if (!skb_queue_empty(owner->inputq))
 606                 owner->action_flags |= TIPC_MSG_EVT;
 607         tipc_link_purge_backlog(l_ptr);
 608         l_ptr->reasm_buf = NULL;
 609         l_ptr->rcv_unacked = 0;
 610         l_ptr->snd_nxt = 1;
 611         l_ptr->rcv_nxt = 1;
 612         l_ptr->silent_intv_cnt = 0;
 613         l_ptr->stats.recv_info = 0;
 614         l_ptr->stale_count = 0;
 615         link_reset_statistics(l_ptr);
 616 }
 617
 618 /**
 619  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 620  * @link: link to use
 621  * @list: chain of buffers containing message
 622  *
 623  * Consumes the buffer chain, except when returning an error code,
 624  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 625  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 626  */
 627 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 628                      struct sk_buff_head *list)
 629 {
 630         struct tipc_msg *msg = buf_msg(skb_peek(list));
 631         unsigned int maxwin = link->window;
 632         unsigned int i, imp = msg_importance(msg);
 633         uint mtu = link->mtu;
 634         u16 ack = mod(link->rcv_nxt - 1);
 635         u16 seqno = link->snd_nxt;
 636         u16 bc_last_in = link->owner->bclink.last_in;
 637         struct tipc_media_addr *addr = &link->media_addr;
 638         struct sk_buff_head *transmq = &link->transmq;
 639         struct sk_buff_head *backlogq = &link->backlogq;
 640         struct sk_buff *skb, *bskb;
 641
 642         /* Match msg importance against this and all higher backlog limits: */
 643         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 644                 if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
 645                         return link_schedule_user(link, list);
 646         }
 647         if (unlikely(msg_size(msg) > mtu))
 648                 return -EMSGSIZE;
 649
 650         /* Prepare each packet for sending, and add to relevant queue: */
 651         while (skb_queue_len(list)) {
 652                 skb = skb_peek(list);
 653                 msg = buf_msg(skb);
 654                 msg_set_seqno(msg, seqno);
 655                 msg_set_ack(msg, ack);
 656                 msg_set_bcast_ack(msg, bc_last_in);
 657
 658                 if (likely(skb_queue_len(transmq) < maxwin)) {
 659                         __skb_dequeue(list);
 660                         __skb_queue_tail(transmq, skb);
 661                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 662                         link->rcv_unacked = 0;
 663                         seqno++;
 664                         continue;
 665                 }
 666                 if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
 667                         kfree_skb(__skb_dequeue(list));
 668                         link->stats.sent_bundled++;
 669                         continue;
 670                 }
 671                 if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
 672                         kfree_skb(__skb_dequeue(list));
 673                         __skb_queue_tail(backlogq, bskb);
 674                         link->backlog[msg_importance(buf_msg(bskb))].len++;
 675                         link->stats.sent_bundled++;
 676                         link->stats.sent_bundles++;
 677                         continue;
 678                 }
 679                 link->backlog[imp].len += skb_queue_len(list);
 680                 skb_queue_splice_tail_init(list, backlogq);
 681         }
 682         link->snd_nxt = seqno;
 683         return 0;
 684 }
 685
 686 /**
 687  * tipc_link_xmit(): enqueue buffer list according to queue situation
 688  * @link: link to use
 689  * @list: chain of buffers containing message
 690  * @xmitq: returned list of packets to be sent by caller
 691  *
 692  * Consumes the buffer chain, except when returning -ELINKCONG,
 693  * since the caller then may want to make more send attempts.
 694  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 695  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 696  */
 697 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 698                    struct sk_buff_head *xmitq)
 699 {
 700         struct tipc_msg *hdr = buf_msg(skb_peek(list));
 701         unsigned int maxwin = l->window;
 702         unsigned int i, imp = msg_importance(hdr);
 703         unsigned int mtu = l->mtu;
 704         u16 ack = l->rcv_nxt - 1;
 705         u16 seqno = l->snd_nxt;
 706         u16 bc_last_in = l->owner->bclink.last_in;
 707         struct sk_buff_head *transmq = &l->transmq;
 708         struct sk_buff_head *backlogq = &l->backlogq;
 709         struct sk_buff *skb, *_skb, *bskb;
 710
 711         /* Match msg importance against this and all higher backlog limits: */
 712         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 713                 if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
 714                         return link_schedule_user(l, list);
 715         }
 716         if (unlikely(msg_size(hdr) > mtu))
 717                 return -EMSGSIZE;
 718
 719         /* Prepare each packet for sending, and add to relevant queue: */
 720         while (skb_queue_len(list)) {
 721                 skb = skb_peek(list);
 722                 hdr = buf_msg(skb);
 723                 msg_set_seqno(hdr, seqno);
 724                 msg_set_ack(hdr, ack);
 725                 msg_set_bcast_ack(hdr, bc_last_in);
 726
 727                 if (likely(skb_queue_len(transmq) < maxwin)) {
 728                         _skb = skb_clone(skb, GFP_ATOMIC);
 729                         if (!_skb)
 730                                 return -ENOBUFS;
 731                         __skb_dequeue(list);
 732                         __skb_queue_tail(transmq, skb);
 733                         __skb_queue_tail(xmitq, _skb);
 734                         l->rcv_unacked = 0;
 735                         seqno++;
 736                         continue;
 737                 }
 738                 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
 739                         kfree_skb(__skb_dequeue(list));
 740                         l->stats.sent_bundled++;
 741                         continue;
 742                 }
 743                 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
 744                         kfree_skb(__skb_dequeue(list));
 745                         __skb_queue_tail(backlogq, bskb);
 746                         l->backlog[msg_importance(buf_msg(bskb))].len++;
 747                         l->stats.sent_bundled++;
 748                         l->stats.sent_bundles++;
 749                         continue;
 750                 }
 751                 l->backlog[imp].len += skb_queue_len(list);
 752                 skb_queue_splice_tail_init(list, backlogq);
 753         }
 754         l->snd_nxt = seqno;
 755         return 0;
 756 }
 757
 758 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
 759 {
 760         skb_queue_head_init(list);
 761         __skb_queue_tail(list, skb);
 762 }
 763
 764 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 765 {
 766         struct sk_buff_head head;
 767
 768         skb2list(skb, &head);
 769         return __tipc_link_xmit(link->owner->net, link, &head);
 770 }
 771
 772 /*
 773  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 774  * Receive the sequence number where we should start receiving and
 775  * acking broadcast packets from a newly added peer node, and open
 776  * up for reception of such packets.
 777  *
 778  * Called with node locked
 779  */
 780 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 781 {
 782         struct tipc_msg *msg = buf_msg(buf);
 783
 784         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 785         n->bclink.recv_permitted = true;
 786         kfree_skb(buf);
 787 }
 788
 789 /*
 790  * tipc_link_push_packets - push unsent packets to bearer
 791  *
 792  * Push out the unsent messages of a link where congestion
 793  * has abated. Node is locked.
 794  *
 795  * Called with node locked
 796  */
 797 void tipc_link_push_packets(struct tipc_link *link)
 798 {
 799         struct sk_buff *skb;
 800         struct tipc_msg *msg;
 801         u16 seqno = link->snd_nxt;
 802         u16 ack = mod(link->rcv_nxt - 1);
 803
 804         while (skb_queue_len(&link->transmq) < link->window) {
 805                 skb = __skb_dequeue(&link->backlogq);
 806                 if (!skb)
 807                         break;
 808                 msg = buf_msg(skb);
 809                 link->backlog[msg_importance(msg)].len--;
 810                 msg_set_ack(msg, ack);
 811                 msg_set_seqno(msg, seqno);
 812                 seqno = mod(seqno + 1);
 813                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 814                 link->rcv_unacked = 0;
 815                 __skb_queue_tail(&link->transmq, skb);
 816                 tipc_bearer_send(link->owner->net, link->bearer_id,
 817                                  skb, &link->media_addr);
 818         }
 819         link->snd_nxt = seqno;
 820 }
 821
 822 void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
 823 {
 824         struct sk_buff *skb, *_skb;
 825         struct tipc_msg *hdr;
 826         u16 seqno = l->snd_nxt;
 827         u16 ack = l->rcv_nxt - 1;
 828
 829         while (skb_queue_len(&l->transmq) < l->window) {
 830                 skb = skb_peek(&l->backlogq);
 831                 if (!skb)
 832                         break;
 833                 _skb = skb_clone(skb, GFP_ATOMIC);
 834                 if (!_skb)
 835                         break;
 836                 __skb_dequeue(&l->backlogq);
 837                 hdr = buf_msg(skb);
 838                 l->backlog[msg_importance(hdr)].len--;
 839                 __skb_queue_tail(&l->transmq, skb);
 840                 __skb_queue_tail(xmitq, _skb);
 841                 msg_set_ack(hdr, ack);
 842                 msg_set_seqno(hdr, seqno);
 843                 msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
 844                 l->rcv_unacked = 0;
 845                 seqno++;
 846         }
 847         l->snd_nxt = seqno;
 848 }
 849
 850 static void link_retransmit_failure(struct tipc_link *l_ptr,
 851                                     struct sk_buff *buf)
 852 {
 853         struct tipc_msg *msg = buf_msg(buf);
 854         struct net *net = l_ptr->owner->net;
 855
 856         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 857
 858         if (l_ptr->addr) {
 859                 /* Handle failure on standard link */
 860                 link_print(l_ptr, "Resetting link ");
 861                 pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
 862                         msg_user(msg), msg_type(msg), msg_size(msg),
 863                         msg_errcode(msg));
 864                 pr_info("sqno %u, prev: %x, src: %x\n",
 865                         msg_seqno(msg), msg_prevnode(msg), msg_orignode(msg));
 866         } else {
 867                 /* Handle failure on broadcast link */
 868                 struct tipc_node *n_ptr;
 869                 char addr_string[16];
 870
 871                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 872                 pr_cont("Outstanding acks: %lu\n",
 873                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 874
 875                 n_ptr = tipc_bclink_retransmit_to(net);
 876
 877                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 878                 pr_info("Broadcast link info for %s\n", addr_string);
 879                 pr_info("Reception permitted: %d,  Acked: %u\n",
 880                         n_ptr->bclink.recv_permitted,
 881                         n_ptr->bclink.acked);
 882                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 883                         n_ptr->bclink.last_in,
 884                         n_ptr->bclink.oos_state,
 885                         n_ptr->bclink.last_sent);
 886
 887                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 888                 l_ptr->stale_count = 0;
 889         }
 890 }
 891
 892 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 893                           u32 retransmits)
 894 {
 895         struct tipc_msg *msg;
 896
 897         if (!skb)
 898                 return;
 899
 900         msg = buf_msg(skb);
 901
 902         /* Detect repeated retransmit failures */
 903         if (l_ptr->last_retransm == msg_seqno(msg)) {
 904                 if (++l_ptr->stale_count > 100) {
 905                         link_retransmit_failure(l_ptr, skb);
 906                         return;
 907                 }
 908         } else {
 909                 l_ptr->last_retransm = msg_seqno(msg);
 910                 l_ptr->stale_count = 1;
 911         }
 912
 913         skb_queue_walk_from(&l_ptr->transmq, skb) {
 914                 if (!retransmits)
 915                         break;
 916                 msg = buf_msg(skb);
 917                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
 918                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 919                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 920                                  &l_ptr->media_addr);
 921                 retransmits--;
 922                 l_ptr->stats.retransmitted++;
 923         }
 924 }
 925
 926 static int tipc_link_retransm(struct tipc_link *l, int retransm,
 927                               struct sk_buff_head *xmitq)
 928 {
 929         struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
 930         struct tipc_msg *hdr;
 931
 932         if (!skb)
 933                 return 0;
 934
 935         /* Detect repeated retransmit failures on same packet */
 936         if (likely(l->last_retransm != buf_seqno(skb))) {
 937                 l->last_retransm = buf_seqno(skb);
 938                 l->stale_count = 1;
 939         } else if (++l->stale_count > 100) {
 940                 link_retransmit_failure(l, skb);
 941                 l->exec_mode = TIPC_LINK_BLOCKED;
 942                 return TIPC_LINK_DOWN_EVT;
 943         }
 944         skb_queue_walk(&l->transmq, skb) {
 945                 if (!retransm)
 946                         return 0;
 947                 hdr = buf_msg(skb);
 948                 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
 949                 if (!_skb)
 950                         return 0;
 951                 hdr = buf_msg(_skb);
 952                 msg_set_ack(hdr, l->rcv_nxt - 1);
 953                 msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
 954                 _skb->priority = TC_PRIO_CONTROL;
 955                 __skb_queue_tail(xmitq, _skb);
 956                 retransm--;
 957                 l->stats.retransmitted++;
 958         }
 959         return 0;
 960 }
 961
 962 /* link_synch(): check if all packets arrived before the synch
 963  *               point have been consumed
 964  * Returns true if the parallel links are synched, otherwise false
 965  */
 966 static bool link_synch(struct tipc_link *l)
 967 {
 968         unsigned int post_synch;
 969         struct tipc_link *pl;
 970
 971         pl  = tipc_parallel_link(l);
 972         if (pl == l)
 973                 goto synched;
 974
 975         /* Was last pre-synch packet added to input queue ? */
 976         if (less_eq(pl->rcv_nxt, l->synch_point))
 977                 return false;
 978
 979         /* Is it still in the input queue ? */
 980         post_synch = mod(pl->rcv_nxt - l->synch_point) - 1;
 981         if (skb_queue_len(pl->inputq) > post_synch)
 982                 return false;
 983 synched:
 984         l->exec_mode = TIPC_LINK_OPEN;
 985         return true;
 986 }
 987
 988 /* tipc_data_input - deliver data and name distr msgs to upper layer
 989  *
 990  * Consumes buffer if message is of right type
 991  * Node lock must be held
 992  */
 993 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
 994 {
 995         struct tipc_node *node = link->owner;
 996         struct tipc_msg *msg = buf_msg(skb);
 997         u32 dport = msg_destport(msg);
 998
 999         switch (msg_user(msg)) {
1000         case TIPC_LOW_IMPORTANCE:
1001         case TIPC_MEDIUM_IMPORTANCE:
1002         case TIPC_HIGH_IMPORTANCE:
1003         case TIPC_CRITICAL_IMPORTANCE:
1004         case CONN_MANAGER:
1005                 if (tipc_skb_queue_tail(link->inputq, skb, dport)) {
1006                         node->inputq = link->inputq;
1007                         node->action_flags |= TIPC_MSG_EVT;
1008                 }
1009                 return true;
1010         case NAME_DISTRIBUTOR:
1011                 node->bclink.recv_permitted = true;
1012                 node->namedq = link->namedq;
1013                 skb_queue_tail(link->namedq, skb);
1014                 if (skb_queue_len(link->namedq) == 1)
1015                         node->action_flags |= TIPC_NAMED_MSG_EVT;
1016                 return true;
1017         case MSG_BUNDLER:
1018         case TUNNEL_PROTOCOL:
1019         case MSG_FRAGMENTER:
1020         case BCAST_PROTOCOL:
1021                 return false;
1022         default:
1023                 pr_warn("Dropping received illegal msg type\n");
1024                 kfree_skb(skb);
1025                 return false;
1026         };
1027 }
1028
1029 /* tipc_link_input - process packet that has passed link protocol check
1030  *
1031  * Consumes buffer
1032  * Node lock must be held
1033  */
1034 static int tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
1035 {
1036         struct tipc_node *node = link->owner;
1037         struct tipc_msg *msg = buf_msg(skb);
1038         struct sk_buff *iskb;
1039         int pos = 0;
1040         int rc = 0;
1041
1042         switch (msg_user(msg)) {
1043         case TUNNEL_PROTOCOL:
1044                 if (msg_dup(msg)) {
1045                         link->exec_mode = TIPC_LINK_TUNNEL;
1046                         link->synch_point = msg_seqno(msg_get_wrapped(msg));
1047                         kfree_skb(skb);
1048                         break;
1049                 }
1050                 rc |= tipc_link_failover_rcv(link, &skb);
1051                 if (!skb)
1052                         break;
1053                 if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
1054                         tipc_data_input(link, skb);
1055                         break;
1056                 }
1057         case MSG_BUNDLER:
1058                 link->stats.recv_bundles++;
1059                 link->stats.recv_bundled += msg_msgcnt(msg);
1060
1061                 while (tipc_msg_extract(skb, &iskb, &pos))
1062                         tipc_data_input(link, iskb);
1063                 break;
1064         case MSG_FRAGMENTER:
1065                 link->stats.recv_fragments++;
1066                 if (tipc_buf_append(&link->reasm_buf, &skb)) {
1067                         link->stats.recv_fragmented++;
1068                         tipc_data_input(link, skb);
1069                 } else if (!link->reasm_buf) {
1070                         link->exec_mode = TIPC_LINK_BLOCKED;
1071                         rc |= TIPC_LINK_DOWN_EVT;
1072                 }
1073                 break;
1074         case BCAST_PROTOCOL:
1075                 tipc_link_sync_rcv(node, skb);
1076                 break;
1077         default:
1078                 break;
1079         };
1080         return rc;
1081 }
1082
1083 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1084 {
1085         bool released = false;
1086         struct sk_buff *skb, *tmp;
1087
1088         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1089                 if (more(buf_seqno(skb), acked))
1090                         break;
1091                 __skb_unlink(skb, &l->transmq);
1092                 kfree_skb(skb);
1093                 released = true;
1094         }
1095         return released;
1096 }
1097
1098 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1099  * @link: the link that should handle the message
1100  * @skb: TIPC packet
1101  * @xmitq: queue to place packets to be sent after this call
1102  */
1103 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1104                   struct sk_buff_head *xmitq)
1105 {
1106         struct sk_buff_head *arrvq = &l->deferdq;
1107         struct sk_buff *tmp;
1108         struct tipc_msg *hdr;
1109         u16 seqno, rcv_nxt;
1110         int rc = 0;
1111
1112         if (unlikely(!__tipc_skb_queue_sorted(arrvq, skb))) {
1113                 if (!(skb_queue_len(arrvq) % TIPC_NACK_INTV))
1114                         tipc_link_build_proto_msg(l, STATE_MSG, 0,
1115                                                   0, 0, 0, xmitq);
1116                 return rc;
1117         }
1118
1119         skb_queue_walk_safe(arrvq, skb, tmp) {
1120                 hdr = buf_msg(skb);
1121
1122                 /* Verify and update link state */
1123                 if (unlikely(msg_user(hdr) == LINK_PROTOCOL)) {
1124                         __skb_dequeue(arrvq);
1125                         rc |= tipc_link_proto_rcv(l, skb, xmitq);
1126                         continue;
1127                 }
1128
1129                 if (unlikely(!link_working(l))) {
1130                         rc |= tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
1131                         if (!link_working(l)) {
1132                                 kfree_skb(__skb_dequeue(arrvq));
1133                                 return rc;
1134                         }
1135                 }
1136
1137                 l->silent_intv_cnt = 0;
1138
1139                 /* Forward queues and wake up waiting users */
1140                 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1141                         tipc_link_advance_backlog(l, xmitq);
1142                         if (unlikely(!skb_queue_empty(&l->wakeupq)))
1143                                 link_prepare_wakeup(l);
1144                 }
1145
1146                 /* Defer reception if there is a gap in the sequence */
1147                 seqno = msg_seqno(hdr);
1148                 rcv_nxt = l->rcv_nxt;
1149                 if (unlikely(less(rcv_nxt, seqno))) {
1150                         l->stats.deferred_recv++;
1151                         return rc;
1152                 }
1153
1154                 __skb_dequeue(arrvq);
1155
1156                 /* Drop if packet already received */
1157                 if (unlikely(more(rcv_nxt, seqno))) {
1158                         l->stats.duplicates++;
1159                         kfree_skb(skb);
1160                         return rc;
1161                 }
1162
1163                 /* Synchronize with parallel link if applicable */
1164                 if (unlikely(l->exec_mode == TIPC_LINK_TUNNEL))
1165                         if (!msg_dup(hdr) && !link_synch(l)) {
1166                                 kfree_skb(skb);
1167                                 return rc;
1168                         }
1169
1170                 /* Packet can be delivered */
1171                 l->rcv_nxt++;
1172                 l->stats.recv_info++;
1173                 if (unlikely(!tipc_data_input(l, skb)))
1174                         rc |= tipc_link_input(l, skb);
1175
1176                 /* Ack at regular intervals */
1177                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
1178                         l->rcv_unacked = 0;
1179                         l->stats.sent_acks++;
1180                         tipc_link_build_proto_msg(l, STATE_MSG,
1181                                                   0, 0, 0, 0, xmitq);
1182                 }
1183         }
1184         return rc;
1185 }
1186
1187 /**
1188  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1189  *
1190  * Returns increase in queue length (i.e. 0 or 1)
1191  */
1192 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1193 {
1194         struct sk_buff *skb1;
1195         u16 seq_no = buf_seqno(skb);
1196
1197         /* Empty queue ? */
1198         if (skb_queue_empty(list)) {
1199                 __skb_queue_tail(list, skb);
1200                 return 1;
1201         }
1202
1203         /* Last ? */
1204         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1205                 __skb_queue_tail(list, skb);
1206                 return 1;
1207         }
1208
1209         /* Locate insertion point in queue, then insert; discard if duplicate */
1210         skb_queue_walk(list, skb1) {
1211                 u16 curr_seqno = buf_seqno(skb1);
1212
1213                 if (seq_no == curr_seqno) {
1214                         kfree_skb(skb);
1215                         return 0;
1216                 }
1217
1218                 if (less(seq_no, curr_seqno))
1219                         break;
1220         }
1221
1222         __skb_queue_before(list, skb1, skb);
1223         return 1;
1224 }
1225
1226 /*
1227  * Send protocol message to the other endpoint.
1228  */
1229 void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg,
1230                           u32 gap, u32 tolerance, u32 priority)
1231 {
1232         struct sk_buff *skb = NULL;
1233         struct sk_buff_head xmitq;
1234
1235         __skb_queue_head_init(&xmitq);
1236         tipc_link_build_proto_msg(l, msg_typ, probe_msg, gap,
1237                                   tolerance, priority, &xmitq);
1238         skb = __skb_dequeue(&xmitq);
1239         if (!skb)
1240                 return;
1241         tipc_bearer_send(l->owner->net, l->bearer_id, skb, &l->media_addr);
1242         l->rcv_unacked = 0;
1243         kfree_skb(skb);
1244 }
1245
1246 /* tipc_link_build_proto_msg: prepare link protocol message for transmission
1247  */
1248 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1249                                       u16 rcvgap, int tolerance, int priority,
1250                                       struct sk_buff_head *xmitq)
1251 {
1252         struct sk_buff *skb = NULL;
1253         struct tipc_msg *hdr = l->pmsg;
1254         u16 snd_nxt = l->snd_nxt;
1255         u16 rcv_nxt = l->rcv_nxt;
1256         u16 rcv_last = rcv_nxt - 1;
1257         int node_up = l->owner->bclink.recv_permitted;
1258
1259         /* Don't send protocol message during reset or link failover */
1260         if (l->exec_mode == TIPC_LINK_BLOCKED)
1261                 return;
1262
1263         msg_set_type(hdr, mtyp);
1264         msg_set_net_plane(hdr, l->net_plane);
1265         msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
1266         msg_set_last_bcast(hdr, tipc_bclink_get_last_sent(l->owner->net));
1267         msg_set_link_tolerance(hdr, tolerance);
1268         msg_set_linkprio(hdr, priority);
1269         msg_set_redundant_link(hdr, node_up);
1270         msg_set_seq_gap(hdr, 0);
1271
1272         /* Compatibility: created msg must not be in sequence with pkt flow */
1273         msg_set_seqno(hdr, snd_nxt + U16_MAX / 2);
1274
1275         if (mtyp == STATE_MSG) {
1276                 if (!tipc_link_is_up(l))
1277                         return;
1278                 msg_set_next_sent(hdr, snd_nxt);
1279
1280                 /* Override rcvgap if there are packets in deferred queue */
1281                 if (!skb_queue_empty(&l->deferdq))
1282                         rcvgap = buf_seqno(skb_peek(&l->deferdq)) - rcv_nxt;
1283                 if (rcvgap) {
1284                         msg_set_seq_gap(hdr, rcvgap);
1285                         l->stats.sent_nacks++;
1286                 }
1287                 msg_set_ack(hdr, rcv_last);
1288                 msg_set_probe(hdr, probe);
1289                 if (probe)
1290                         l->stats.sent_probes++;
1291                 l->stats.sent_states++;
1292         } else {
1293                 /* RESET_MSG or ACTIVATE_MSG */
1294                 msg_set_max_pkt(hdr, l->advertised_mtu);
1295                 msg_set_ack(hdr, l->failover_checkpt - 1);
1296                 msg_set_next_sent(hdr, 1);
1297         }
1298         skb = tipc_buf_acquire(msg_size(hdr));
1299         if (!skb)
1300                 return;
1301         skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
1302         skb->priority = TC_PRIO_CONTROL;
1303         __skb_queue_head(xmitq, skb);
1304 }
1305
1306 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1307  * a different bearer. Owner node is locked.
1308  */
1309 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1310                                   struct tipc_msg *tunnel_hdr,
1311                                   struct tipc_msg *msg,
1312                                   u32 selector)
1313 {
1314         struct tipc_link *tunnel;
1315         struct sk_buff *skb;
1316         u32 length = msg_size(msg);
1317
1318         tunnel = node_active_link(l_ptr->owner, selector & 1);
1319         if (!tipc_link_is_up(tunnel)) {
1320                 pr_warn("%stunnel link no longer available\n", link_co_err);
1321                 return;
1322         }
1323         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1324         skb = tipc_buf_acquire(length + INT_H_SIZE);
1325         if (!skb) {
1326                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1327                 return;
1328         }
1329         skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
1330         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
1331         __tipc_link_xmit_skb(tunnel, skb);
1332 }
1333
1334
1335 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1336  * link is still active. We can do failover. Tunnel the failing link's
1337  * whole send queue via the remaining link. This way, we don't lose
1338  * any packets, and sequence order is preserved for subsequent traffic
1339  * sent over the remaining link. Owner node is locked.
1340  */
1341 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1342 {
1343         int msgcount;
1344         struct tipc_link *tunnel = node_active_link(l_ptr->owner, 0);
1345         struct tipc_msg tunnel_hdr;
1346         struct sk_buff *skb;
1347         int split_bundles;
1348
1349         if (!tunnel)
1350                 return;
1351
1352         tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
1353                       FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
1354
1355         skb_queue_walk(&l_ptr->backlogq, skb) {
1356                 msg_set_seqno(buf_msg(skb), l_ptr->snd_nxt);
1357                 l_ptr->snd_nxt = mod(l_ptr->snd_nxt + 1);
1358         }
1359         skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
1360         tipc_link_purge_backlog(l_ptr);
1361         msgcount = skb_queue_len(&l_ptr->transmq);
1362         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1363         msg_set_msgcnt(&tunnel_hdr, msgcount);
1364
1365         if (skb_queue_empty(&l_ptr->transmq)) {
1366                 skb = tipc_buf_acquire(INT_H_SIZE);
1367                 if (skb) {
1368                         skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
1369                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1370                         __tipc_link_xmit_skb(tunnel, skb);
1371                 } else {
1372                         pr_warn("%sunable to send changeover msg\n",
1373                                 link_co_err);
1374                 }
1375                 return;
1376         }
1377
1378         split_bundles = (node_active_link(l_ptr->owner, 0) !=
1379                          node_active_link(l_ptr->owner, 0));
1380
1381         skb_queue_walk(&l_ptr->transmq, skb) {
1382                 struct tipc_msg *msg = buf_msg(skb);
1383
1384                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1385                         struct tipc_msg *m = msg_get_wrapped(msg);
1386                         unchar *pos = (unchar *)m;
1387
1388                         msgcount = msg_msgcnt(msg);
1389                         while (msgcount--) {
1390                                 msg_set_seqno(m, msg_seqno(msg));
1391                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1392                                                       msg_link_selector(m));
1393                                 pos += align(msg_size(m));
1394                                 m = (struct tipc_msg *)pos;
1395                         }
1396                 } else {
1397                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1398                                               msg_link_selector(msg));
1399                 }
1400         }
1401 }
1402
1403 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1404  * duplicate of the first link's send queue via the new link. This way, we
1405  * are guaranteed that currently queued packets from a socket are delivered
1406  * before future traffic from the same socket, even if this is using the
1407  * new link. The last arriving copy of each duplicate packet is dropped at
1408  * the receiving end by the regular protocol check, so packet cardinality
1409  * and sequence order is preserved per sender/receiver socket pair.
1410  * Owner node is locked.
1411  */
1412 void tipc_link_dup_queue_xmit(struct tipc_link *link,
1413                               struct tipc_link *tnl)
1414 {
1415         struct sk_buff *skb;
1416         struct tipc_msg tnl_hdr;
1417         struct sk_buff_head *queue = &link->transmq;
1418         int mcnt;
1419         u16 seqno;
1420
1421         tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
1422                       SYNCH_MSG, INT_H_SIZE, link->addr);
1423         mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
1424         msg_set_msgcnt(&tnl_hdr, mcnt);
1425         msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
1426
1427 tunnel_queue:
1428         skb_queue_walk(queue, skb) {
1429                 struct sk_buff *outskb;
1430                 struct tipc_msg *msg = buf_msg(skb);
1431                 u32 len = msg_size(msg);
1432
1433                 msg_set_ack(msg, mod(link->rcv_nxt - 1));
1434                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
1435                 msg_set_size(&tnl_hdr, len + INT_H_SIZE);
1436                 outskb = tipc_buf_acquire(len + INT_H_SIZE);
1437                 if (outskb == NULL) {
1438                         pr_warn("%sunable to send duplicate msg\n",
1439                                 link_co_err);
1440                         return;
1441                 }
1442                 skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
1443                 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
1444                                                skb->data, len);
1445                 __tipc_link_xmit_skb(tnl, outskb);
1446                 if (!tipc_link_is_up(link))
1447                         return;
1448         }
1449         if (queue == &link->backlogq)
1450                 return;
1451         seqno = link->snd_nxt;
1452         skb_queue_walk(&link->backlogq, skb) {
1453                 msg_set_seqno(buf_msg(skb), seqno);
1454                 seqno = mod(seqno + 1);
1455         }
1456         queue = &link->backlogq;
1457         goto tunnel_queue;
1458 }
1459
1460 /*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
1461  *  Owner node is locked.
1462  */
1463 static int tipc_link_failover_rcv(struct tipc_link *link,
1464                                   struct sk_buff **skb)
1465 {
1466         struct tipc_msg *msg = buf_msg(*skb);
1467         struct sk_buff *iskb = NULL;
1468         struct tipc_link *pl = NULL;
1469         int bearer_id = msg_bearer_id(msg);
1470         int pos = 0;
1471         int rc = 0;
1472
1473         if (msg_type(msg) != FAILOVER_MSG) {
1474                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1475                 goto exit;
1476         }
1477         if (bearer_id >= MAX_BEARERS)
1478                 goto exit;
1479
1480         if (bearer_id == link->bearer_id)
1481                 goto exit;
1482
1483         pl = link->owner->links[bearer_id].link;
1484
1485         if (link->failover_pkts == FIRST_FAILOVER)
1486                 link->failover_pkts = msg_msgcnt(msg);
1487
1488         /* Should we expect an inner packet? */
1489         if (!link->failover_pkts)
1490                 goto exit;
1491
1492         if (!tipc_msg_extract(*skb, &iskb, &pos)) {
1493                 pr_warn("%sno inner failover pkt\n", link_co_err);
1494                 *skb = NULL;
1495                 goto exit;
1496         }
1497         link->failover_pkts--;
1498         *skb = NULL;
1499
1500         /* Was this packet already delivered? */
1501         if (less(buf_seqno(iskb), link->failover_checkpt)) {
1502                 kfree_skb(iskb);
1503                 iskb = NULL;
1504                 goto exit;
1505         }
1506         if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
1507                 link->stats.recv_fragments++;
1508                 if (!tipc_buf_append(&link->failover_skb, &iskb) &&
1509                     !link->failover_skb) {
1510                         link->exec_mode = TIPC_LINK_BLOCKED;
1511                         rc |= TIPC_LINK_DOWN_EVT;
1512                 }
1513         }
1514 exit:
1515         if (!link->failover_pkts && pl)
1516                 pl->exec_mode = TIPC_LINK_OPEN;
1517         kfree_skb(*skb);
1518         *skb = iskb;
1519         return rc;
1520 }
1521
1522 /* tipc_link_proto_rcv(): receive link level protocol message :
1523  * Note that network plane id propagates through the network, and may
1524  * change at any time. The node with lowest numerical id determines
1525  * network plane
1526  */
1527 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1528                                struct sk_buff_head *xmitq)
1529 {
1530         struct tipc_msg *hdr = buf_msg(skb);
1531         u16 rcvgap = 0;
1532         u16 nacked_gap = msg_seq_gap(hdr);
1533         u16 peers_snd_nxt =  msg_next_sent(hdr);
1534         u16 peers_tol = msg_link_tolerance(hdr);
1535         u16 peers_prio = msg_linkprio(hdr);
1536         char *if_name;
1537         int rc = 0;
1538
1539         if (l->exec_mode == TIPC_LINK_BLOCKED)
1540                 goto exit;
1541
1542         if (link_own_addr(l) > msg_prevnode(hdr))
1543                 l->net_plane = msg_net_plane(hdr);
1544
1545         switch (msg_type(hdr)) {
1546         case RESET_MSG:
1547
1548                 /* Ignore duplicate RESET with old session number */
1549                 if ((less_eq(msg_session(hdr), l->peer_session)) &&
1550                     (l->peer_session != WILDCARD_SESSION))
1551                         break;
1552                 /* fall thru' */
1553         case ACTIVATE_MSG:
1554
1555                 /* Complete own link name with peer's interface name */
1556                 if_name =  strrchr(l->name, ':') + 1;
1557                 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1558                         break;
1559                 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1560                         break;
1561                 strncpy(if_name, msg_data(hdr), TIPC_MAX_IF_NAME);
1562
1563                 /* Update own tolerance if peer indicates a non-zero value */
1564                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1565                         l->tolerance = peers_tol;
1566
1567                 /* Update own priority if peer's priority is higher */
1568                 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1569                         l->priority = peers_prio;
1570
1571                 l->peer_session = msg_session(hdr);
1572                 l->peer_bearer_id = msg_bearer_id(hdr);
1573                 rc = tipc_link_fsm_evt(l, msg_type(hdr), xmitq);
1574                 if (l->mtu > msg_max_pkt(hdr))
1575                         l->mtu = msg_max_pkt(hdr);
1576                 break;
1577         case STATE_MSG:
1578                 /* Update own tolerance if peer indicates a non-zero value */
1579                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1580                         l->tolerance = peers_tol;
1581
1582                 l->silent_intv_cnt = 0;
1583                 l->stats.recv_states++;
1584                 if (msg_probe(hdr))
1585                         l->stats.recv_probes++;
1586                 rc = tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
1587                 if (!tipc_link_is_up(l))
1588                         break;
1589
1590                 /* Has peer sent packets we haven't received yet ? */
1591                 if (more(peers_snd_nxt, l->rcv_nxt))
1592                         rcvgap = peers_snd_nxt - l->rcv_nxt;
1593                 if (rcvgap || (msg_probe(hdr)))
1594                         tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1595                                                   0, 0, xmitq);
1596                 tipc_link_release_pkts(l, msg_ack(hdr));
1597
1598                 /* If NACK, retransmit will now start at right position */
1599                 if (nacked_gap) {
1600                         rc |= tipc_link_retransm(l, nacked_gap, xmitq);
1601                         l->stats.recv_nacks++;
1602                 }
1603                 tipc_link_advance_backlog(l, xmitq);
1604                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1605                         link_prepare_wakeup(l);
1606         }
1607 exit:
1608         kfree_skb(skb);
1609         return rc;
1610 }
1611
1612 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1613 {
1614         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1615
1616         l->window = win;
1617         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1618         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1619         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1620         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1621         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1622 }
1623
1624 /* tipc_link_find_owner - locate owner node of link by link's name
1625  * @net: the applicable net namespace
1626  * @name: pointer to link name string
1627  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1628  *
1629  * Returns pointer to node owning the link, or 0 if no matching link is found.
1630  */
1631 static struct tipc_node *tipc_link_find_owner(struct net *net,
1632                                               const char *link_name,
1633                                               unsigned int *bearer_id)
1634 {
1635         struct tipc_net *tn = net_generic(net, tipc_net_id);
1636         struct tipc_link *l_ptr;
1637         struct tipc_node *n_ptr;
1638         struct tipc_node *found_node = NULL;
1639         int i;
1640
1641         *bearer_id = 0;
1642         rcu_read_lock();
1643         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1644                 tipc_node_lock(n_ptr);
1645                 for (i = 0; i < MAX_BEARERS; i++) {
1646                         l_ptr = n_ptr->links[i].link;
1647                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1648                                 *bearer_id = i;
1649                                 found_node = n_ptr;
1650                                 break;
1651                         }
1652                 }
1653                 tipc_node_unlock(n_ptr);
1654                 if (found_node)
1655                         break;
1656         }
1657         rcu_read_unlock();
1658
1659         return found_node;
1660 }
1661
1662 /**
1663  * link_reset_statistics - reset link statistics
1664  * @l_ptr: pointer to link
1665  */
1666 static void link_reset_statistics(struct tipc_link *l_ptr)
1667 {
1668         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1669         l_ptr->stats.sent_info = l_ptr->snd_nxt;
1670         l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1671 }
1672
1673 static void link_print(struct tipc_link *l, const char *str)
1674 {
1675         struct sk_buff *hskb = skb_peek(&l->transmq);
1676         u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt;
1677         u16 tail = l->snd_nxt - 1;
1678
1679         pr_info("%s Link <%s>:", str, l->name);
1680
1681         if (link_probing(l))
1682                 pr_cont(":P\n");
1683         else if (link_establishing(l))
1684                 pr_cont(":E\n");
1685         else if (link_resetting(l))
1686                 pr_cont(":R\n");
1687         else if (link_working(l))
1688                 pr_cont(":W\n");
1689         else
1690                 pr_cont("\n");
1691
1692         pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1693                 skb_queue_len(&l->transmq), head, tail,
1694                 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1695 }
1696
1697 /* Parse and validate nested (link) properties valid for media, bearer and link
1698  */
1699 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1700 {
1701         int err;
1702
1703         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1704                                tipc_nl_prop_policy);
1705         if (err)
1706                 return err;
1707
1708         if (props[TIPC_NLA_PROP_PRIO]) {
1709                 u32 prio;
1710
1711                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1712                 if (prio > TIPC_MAX_LINK_PRI)
1713                         return -EINVAL;
1714         }
1715
1716         if (props[TIPC_NLA_PROP_TOL]) {
1717                 u32 tol;
1718
1719                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1720                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1721                         return -EINVAL;
1722         }
1723
1724         if (props[TIPC_NLA_PROP_WIN]) {
1725                 u32 win;
1726
1727                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1728                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1729                         return -EINVAL;
1730         }
1731
1732         return 0;
1733 }
1734
1735 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1736 {
1737         int err;
1738         int res = 0;
1739         int bearer_id;
1740         char *name;
1741         struct tipc_link *link;
1742         struct tipc_node *node;
1743         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1744         struct net *net = sock_net(skb->sk);
1745
1746         if (!info->attrs[TIPC_NLA_LINK])
1747                 return -EINVAL;
1748
1749         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1750                                info->attrs[TIPC_NLA_LINK],
1751                                tipc_nl_link_policy);
1752         if (err)
1753                 return err;
1754
1755         if (!attrs[TIPC_NLA_LINK_NAME])
1756                 return -EINVAL;
1757
1758         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1759
1760         if (strcmp(name, tipc_bclink_name) == 0)
1761                 return tipc_nl_bc_link_set(net, attrs);
1762
1763         node = tipc_link_find_owner(net, name, &bearer_id);
1764         if (!node)
1765                 return -EINVAL;
1766
1767         tipc_node_lock(node);
1768
1769         link = node->links[bearer_id].link;
1770         if (!link) {
1771                 res = -EINVAL;
1772                 goto out;
1773         }
1774
1775         if (attrs[TIPC_NLA_LINK_PROP]) {
1776                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1777
1778                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1779                                               props);
1780                 if (err) {
1781                         res = err;
1782                         goto out;
1783                 }
1784
1785                 if (props[TIPC_NLA_PROP_TOL]) {
1786                         u32 tol;
1787
1788                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1789                         link->tolerance = tol;
1790                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1791                 }
1792                 if (props[TIPC_NLA_PROP_PRIO]) {
1793                         u32 prio;
1794
1795                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1796                         link->priority = prio;
1797                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1798                 }
1799                 if (props[TIPC_NLA_PROP_WIN]) {
1800                         u32 win;
1801
1802                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1803                         tipc_link_set_queue_limits(link, win);
1804                 }
1805         }
1806
1807 out:
1808         tipc_node_unlock(node);
1809
1810         return res;
1811 }
1812
1813 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1814 {
1815         int i;
1816         struct nlattr *stats;
1817
1818         struct nla_map {
1819                 u32 key;
1820                 u32 val;
1821         };
1822
1823         struct nla_map map[] = {
1824                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1825                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1826                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1827                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1828                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1829                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1830                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1831                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1832                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1833                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1834                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1835                         s->msg_length_counts : 1},
1836                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1837                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1838                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1839                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1840                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1841                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1842                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1843                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1844                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1845                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1846                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1847                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1848                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1849                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1850                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1851                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1852                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1853                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1854                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1855                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1856                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1857                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1858                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1859         };
1860
1861         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1862         if (!stats)
1863                 return -EMSGSIZE;
1864
1865         for (i = 0; i <  ARRAY_SIZE(map); i++)
1866                 if (nla_put_u32(skb, map[i].key, map[i].val))
1867                         goto msg_full;
1868
1869         nla_nest_end(skb, stats);
1870
1871         return 0;
1872 msg_full:
1873         nla_nest_cancel(skb, stats);
1874
1875         return -EMSGSIZE;
1876 }
1877
1878 /* Caller should hold appropriate locks to protect the link */
1879 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1880                               struct tipc_link *link, int nlflags)
1881 {
1882         int err;
1883         void *hdr;
1884         struct nlattr *attrs;
1885         struct nlattr *prop;
1886         struct tipc_net *tn = net_generic(net, tipc_net_id);
1887
1888         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1889                           nlflags, TIPC_NL_LINK_GET);
1890         if (!hdr)
1891                 return -EMSGSIZE;
1892
1893         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1894         if (!attrs)
1895                 goto msg_full;
1896
1897         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1898                 goto attr_msg_full;
1899         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1900                         tipc_cluster_mask(tn->own_addr)))
1901                 goto attr_msg_full;
1902         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1903                 goto attr_msg_full;
1904         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
1905                 goto attr_msg_full;
1906         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
1907                 goto attr_msg_full;
1908
1909         if (tipc_link_is_up(link))
1910                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1911                         goto attr_msg_full;
1912         if (tipc_link_is_active(link))
1913                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1914                         goto attr_msg_full;
1915
1916         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1917         if (!prop)
1918                 goto attr_msg_full;
1919         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1920                 goto prop_msg_full;
1921         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1922                 goto prop_msg_full;
1923         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1924                         link->window))
1925                 goto prop_msg_full;
1926         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1927                 goto prop_msg_full;
1928         nla_nest_end(msg->skb, prop);
1929
1930         err = __tipc_nl_add_stats(msg->skb, &link->stats);
1931         if (err)
1932                 goto attr_msg_full;
1933
1934         nla_nest_end(msg->skb, attrs);
1935         genlmsg_end(msg->skb, hdr);
1936
1937         return 0;
1938
1939 prop_msg_full:
1940         nla_nest_cancel(msg->skb, prop);
1941 attr_msg_full:
1942         nla_nest_cancel(msg->skb, attrs);
1943 msg_full:
1944         genlmsg_cancel(msg->skb, hdr);
1945
1946         return -EMSGSIZE;
1947 }
1948
1949 /* Caller should hold node lock  */
1950 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
1951                                     struct tipc_node *node, u32 *prev_link)
1952 {
1953         u32 i;
1954         int err;
1955
1956         for (i = *prev_link; i < MAX_BEARERS; i++) {
1957                 *prev_link = i;
1958
1959                 if (!node->links[i].link)
1960                         continue;
1961
1962                 err = __tipc_nl_add_link(net, msg,
1963                                          node->links[i].link, NLM_F_MULTI);
1964                 if (err)
1965                         return err;
1966         }
1967         *prev_link = 0;
1968
1969         return 0;
1970 }
1971
1972 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
1973 {
1974         struct net *net = sock_net(skb->sk);
1975         struct tipc_net *tn = net_generic(net, tipc_net_id);
1976         struct tipc_node *node;
1977         struct tipc_nl_msg msg;
1978         u32 prev_node = cb->args[0];
1979         u32 prev_link = cb->args[1];
1980         int done = cb->args[2];
1981         int err;
1982
1983         if (done)
1984                 return 0;
1985
1986         msg.skb = skb;
1987         msg.portid = NETLINK_CB(cb->skb).portid;
1988         msg.seq = cb->nlh->nlmsg_seq;
1989
1990         rcu_read_lock();
1991         if (prev_node) {
1992                 node = tipc_node_find(net, prev_node);
1993                 if (!node) {
1994                         /* We never set seq or call nl_dump_check_consistent()
1995                          * this means that setting prev_seq here will cause the
1996                          * consistence check to fail in the netlink callback
1997                          * handler. Resulting in the last NLMSG_DONE message
1998                          * having the NLM_F_DUMP_INTR flag set.
1999                          */
2000                         cb->prev_seq = 1;
2001                         goto out;
2002                 }
2003                 tipc_node_put(node);
2004
2005                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2006                                                  list) {
2007                         tipc_node_lock(node);
2008                         err = __tipc_nl_add_node_links(net, &msg, node,
2009                                                        &prev_link);
2010                         tipc_node_unlock(node);
2011                         if (err)
2012                                 goto out;
2013
2014                         prev_node = node->addr;
2015                 }
2016         } else {
2017                 err = tipc_nl_add_bc_link(net, &msg);
2018                 if (err)
2019                         goto out;
2020
2021                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2022                         tipc_node_lock(node);
2023                         err = __tipc_nl_add_node_links(net, &msg, node,
2024                                                        &prev_link);
2025                         tipc_node_unlock(node);
2026                         if (err)
2027                                 goto out;
2028
2029                         prev_node = node->addr;
2030                 }
2031         }
2032         done = 1;
2033 out:
2034         rcu_read_unlock();
2035
2036         cb->args[0] = prev_node;
2037         cb->args[1] = prev_link;
2038         cb->args[2] = done;
2039
2040         return skb->len;
2041 }
2042
2043 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2044 {
2045         struct net *net = genl_info_net(info);
2046         struct tipc_nl_msg msg;
2047         char *name;
2048         int err;
2049
2050         msg.portid = info->snd_portid;
2051         msg.seq = info->snd_seq;
2052
2053         if (!info->attrs[TIPC_NLA_LINK_NAME])
2054                 return -EINVAL;
2055         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2056
2057         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2058         if (!msg.skb)
2059                 return -ENOMEM;
2060
2061         if (strcmp(name, tipc_bclink_name) == 0) {
2062                 err = tipc_nl_add_bc_link(net, &msg);
2063                 if (err) {
2064                         nlmsg_free(msg.skb);
2065                         return err;
2066                 }
2067         } else {
2068                 int bearer_id;
2069                 struct tipc_node *node;
2070                 struct tipc_link *link;
2071
2072                 node = tipc_link_find_owner(net, name, &bearer_id);
2073                 if (!node)
2074                         return -EINVAL;
2075
2076                 tipc_node_lock(node);
2077                 link = node->links[bearer_id].link;
2078                 if (!link) {
2079                         tipc_node_unlock(node);
2080                         nlmsg_free(msg.skb);
2081                         return -EINVAL;
2082                 }
2083
2084                 err = __tipc_nl_add_link(net, &msg, link, 0);
2085                 tipc_node_unlock(node);
2086                 if (err) {
2087                         nlmsg_free(msg.skb);
2088                         return err;
2089                 }
2090         }
2091
2092         return genlmsg_reply(msg.skb, info);
2093 }
2094
2095 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2096 {
2097         int err;
2098         char *link_name;
2099         unsigned int bearer_id;
2100         struct tipc_link *link;
2101         struct tipc_node *node;
2102         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2103         struct net *net = sock_net(skb->sk);
2104
2105         if (!info->attrs[TIPC_NLA_LINK])
2106                 return -EINVAL;
2107
2108         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2109                                info->attrs[TIPC_NLA_LINK],
2110                                tipc_nl_link_policy);
2111         if (err)
2112                 return err;
2113
2114         if (!attrs[TIPC_NLA_LINK_NAME])
2115                 return -EINVAL;
2116
2117         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2118
2119         if (strcmp(link_name, tipc_bclink_name) == 0) {
2120                 err = tipc_bclink_reset_stats(net);
2121                 if (err)
2122                         return err;
2123                 return 0;
2124         }
2125
2126         node = tipc_link_find_owner(net, link_name, &bearer_id);
2127         if (!node)
2128                 return -EINVAL;
2129
2130         tipc_node_lock(node);
2131
2132         link = node->links[bearer_id].link;
2133         if (!link) {
2134                 tipc_node_unlock(node);
2135                 return -EINVAL;
2136         }
2137
2138         link_reset_statistics(link);
2139
2140         tipc_node_unlock(node);
2141
2142         return 0;
2143 }