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 void 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 bool 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 /**
 262  * tipc_link_delete - Delete a link
 263  * @l: link to be deleted
 264  */
 265 void tipc_link_delete(struct tipc_link *l)
 266 {
 267         tipc_link_reset(l);
 268         tipc_link_reset_fragments(l);
 269         tipc_node_detach_link(l->owner, l);
 270 }
 271
 272 void tipc_link_delete_list(struct net *net, unsigned int bearer_id)
 273 {
 274         struct tipc_net *tn = net_generic(net, tipc_net_id);
 275         struct tipc_link *link;
 276         struct tipc_node *node;
 277
 278         rcu_read_lock();
 279         list_for_each_entry_rcu(node, &tn->node_list, list) {
 280                 tipc_node_lock(node);
 281                 link = node->links[bearer_id].link;
 282                 if (link)
 283                         tipc_link_delete(link);
 284                 tipc_node_unlock(node);
 285         }
 286         rcu_read_unlock();
 287 }
 288
 289 /* tipc_link_build_bcast_sync_msg() - synchronize broadcast link endpoints.
 290  *
 291  * Give a newly added peer node the sequence number where it should
 292  * start receiving and acking broadcast packets.
 293  */
 294 static void tipc_link_build_bcast_sync_msg(struct tipc_link *l,
 295                                            struct sk_buff_head *xmitq)
 296 {
 297         struct sk_buff *skb;
 298         struct sk_buff_head list;
 299         u16 last_sent;
 300
 301         skb = tipc_msg_create(BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE,
 302                               0, l->addr, link_own_addr(l), 0, 0, 0);
 303         if (!skb)
 304                 return;
 305         last_sent = tipc_bclink_get_last_sent(l->owner->net);
 306         msg_set_last_bcast(buf_msg(skb), last_sent);
 307         __skb_queue_head_init(&list);
 308         __skb_queue_tail(&list, skb);
 309         tipc_link_xmit(l, &list, xmitq);
 310 }
 311
 312 /**
 313  * tipc_link_fsm_evt - link finite state machine
 314  * @l: pointer to link
 315  * @evt: state machine event to be processed
 316  * @xmitq: queue to prepend created protocol message, if any
 317  */
 318 static int tipc_link_fsm_evt(struct tipc_link *l, int evt,
 319                              struct sk_buff_head *xmitq)
 320 {
 321         int mtyp = 0, rc = 0;
 322         struct tipc_link *pl;
 323         enum {
 324                 LINK_RESET     = 1,
 325                 LINK_ACTIVATE  = (1 << 1),
 326                 SND_PROBE      = (1 << 2),
 327                 SND_STATE      = (1 << 3),
 328                 SND_RESET      = (1 << 4),
 329                 SND_ACTIVATE   = (1 << 5),
 330                 SND_BCAST_SYNC = (1 << 6)
 331         } actions = 0;
 332
 333         if (l->exec_mode == TIPC_LINK_BLOCKED)
 334                 return rc;
 335
 336         switch (l->state) {
 337         case TIPC_LINK_WORKING:
 338                 switch (evt) {
 339                 case TRAFFIC_EVT:
 340                 case ACTIVATE_EVT:
 341                         break;
 342                 case SILENCE_EVT:
 343                         l->state = TIPC_LINK_PROBING;
 344                         actions |= SND_PROBE;
 345                         break;
 346                 case PEER_RESET_EVT:
 347                         actions |= LINK_RESET | SND_ACTIVATE;
 348                         break;
 349                 default:
 350                         pr_debug("%s%u WORKING\n", link_unk_evt, evt);
 351                 }
 352                 break;
 353         case TIPC_LINK_PROBING:
 354                 switch (evt) {
 355                 case TRAFFIC_EVT:
 356                 case ACTIVATE_EVT:
 357                         l->state = TIPC_LINK_WORKING;
 358                         break;
 359                 case PEER_RESET_EVT:
 360                         actions |= LINK_RESET | SND_ACTIVATE;
 361                         break;
 362                 case SILENCE_EVT:
 363                         if (l->silent_intv_cnt <= l->abort_limit) {
 364                                 actions |= SND_PROBE;
 365                                 break;
 366                         }
 367                         actions |= LINK_RESET | SND_RESET;
 368                         break;
 369                 default:
 370                         pr_err("%s%u PROBING\n", link_unk_evt, evt);
 371                 }
 372                 break;
 373         case TIPC_LINK_RESETTING:
 374                 switch (evt) {
 375                 case TRAFFIC_EVT:
 376                         break;
 377                 case ACTIVATE_EVT:
 378                         pl = node_active_link(l->owner, 0);
 379                         if (pl && link_probing(pl))
 380                                 break;
 381                         l->state = TIPC_LINK_WORKING;
 382                         actions |= LINK_ACTIVATE;
 383                         if (!l->owner->working_links)
 384                                 actions |= SND_BCAST_SYNC;
 385                         break;
 386                 case PEER_RESET_EVT:
 387                         l->state = TIPC_LINK_ESTABLISHING;
 388                         actions |= SND_ACTIVATE;
 389                         break;
 390                 case SILENCE_EVT:
 391                         actions |= SND_RESET;
 392                         break;
 393                 default:
 394                         pr_err("%s%u in RESETTING\n", link_unk_evt, evt);
 395                 }
 396                 break;
 397         case TIPC_LINK_ESTABLISHING:
 398                 switch (evt) {
 399                 case TRAFFIC_EVT:
 400                 case ACTIVATE_EVT:
 401                         pl = node_active_link(l->owner, 0);
 402                         if (pl && link_probing(pl))
 403                                 break;
 404                         l->state = TIPC_LINK_WORKING;
 405                         actions |= LINK_ACTIVATE;
 406                         if (!l->owner->working_links)
 407                                 actions |= SND_BCAST_SYNC;
 408                         break;
 409                 case PEER_RESET_EVT:
 410                         break;
 411                 case SILENCE_EVT:
 412                         actions |= SND_ACTIVATE;
 413                         break;
 414                 default:
 415                         pr_err("%s%u ESTABLISHING\n", link_unk_evt, evt);
 416                 }
 417                 break;
 418         default:
 419                 pr_err("Unknown link state %u/%u\n", l->state, evt);
 420         }
 421
 422         /* Perform actions as decided by FSM */
 423         if (actions & LINK_RESET) {
 424                 l->exec_mode = TIPC_LINK_BLOCKED;
 425                 rc |= TIPC_LINK_DOWN_EVT;
 426         }
 427         if (actions & LINK_ACTIVATE) {
 428                 l->exec_mode = TIPC_LINK_OPEN;
 429                 rc |= TIPC_LINK_UP_EVT;
 430         }
 431         if (actions & (SND_STATE | SND_PROBE))
 432                 mtyp = STATE_MSG;
 433         if (actions & SND_RESET)
 434                 mtyp = RESET_MSG;
 435         if (actions & SND_ACTIVATE)
 436                 mtyp = ACTIVATE_MSG;
 437         if (actions & (SND_PROBE | SND_STATE | SND_RESET | SND_ACTIVATE))
 438                 tipc_link_build_proto_msg(l, mtyp, actions & SND_PROBE,
 439                                           0, 0, 0, xmitq);
 440         if (actions & SND_BCAST_SYNC)
 441                 tipc_link_build_bcast_sync_msg(l, xmitq);
 442         return rc;
 443 }
 444
 445 /* link_profile_stats - update statistical profiling of traffic
 446  */
 447 static void link_profile_stats(struct tipc_link *l)
 448 {
 449         struct sk_buff *skb;
 450         struct tipc_msg *msg;
 451         int length;
 452
 453         /* Update counters used in statistical profiling of send traffic */
 454         l->stats.accu_queue_sz += skb_queue_len(&l->transmq);
 455         l->stats.queue_sz_counts++;
 456
 457         skb = skb_peek(&l->transmq);
 458         if (!skb)
 459                 return;
 460         msg = buf_msg(skb);
 461         length = msg_size(msg);
 462
 463         if (msg_user(msg) == MSG_FRAGMENTER) {
 464                 if (msg_type(msg) != FIRST_FRAGMENT)
 465                         return;
 466                 length = msg_size(msg_get_wrapped(msg));
 467         }
 468         l->stats.msg_lengths_total += length;
 469         l->stats.msg_length_counts++;
 470         if (length <= 64)
 471                 l->stats.msg_length_profile[0]++;
 472         else if (length <= 256)
 473                 l->stats.msg_length_profile[1]++;
 474         else if (length <= 1024)
 475                 l->stats.msg_length_profile[2]++;
 476         else if (length <= 4096)
 477                 l->stats.msg_length_profile[3]++;
 478         else if (length <= 16384)
 479                 l->stats.msg_length_profile[4]++;
 480         else if (length <= 32768)
 481                 l->stats.msg_length_profile[5]++;
 482         else
 483                 l->stats.msg_length_profile[6]++;
 484 }
 485
 486 /* tipc_link_timeout - perform periodic task as instructed from node timeout
 487  */
 488 int tipc_link_timeout(struct tipc_link *l, struct sk_buff_head *xmitq)
 489 {
 490         int rc = 0;
 491
 492         link_profile_stats(l);
 493         if (l->silent_intv_cnt)
 494                 rc = tipc_link_fsm_evt(l, SILENCE_EVT, xmitq);
 495         else if (link_working(l) && tipc_bclink_acks_missing(l->owner))
 496                 tipc_link_build_proto_msg(l, STATE_MSG, 0, 0, 0, 0, xmitq);
 497         l->silent_intv_cnt++;
 498         return rc;
 499 }
 500
 501 /**
 502  * link_schedule_user - schedule a message sender for wakeup after congestion
 503  * @link: congested link
 504  * @list: message that was attempted sent
 505  * Create pseudo msg to send back to user when congestion abates
 506  * Does not consume buffer list
 507  */
 508 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 509 {
 510         struct tipc_msg *msg = buf_msg(skb_peek(list));
 511         int imp = msg_importance(msg);
 512         u32 oport = msg_origport(msg);
 513         u32 addr = link_own_addr(link);
 514         struct sk_buff *skb;
 515
 516         /* This really cannot happen...  */
 517         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 518                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 519                 return -ENOBUFS;
 520         }
 521         /* Non-blocking sender: */
 522         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 523                 return -ELINKCONG;
 524
 525         /* Create and schedule wakeup pseudo message */
 526         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 527                               addr, addr, oport, 0, 0);
 528         if (!skb)
 529                 return -ENOBUFS;
 530         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 531         TIPC_SKB_CB(skb)->chain_imp = imp;
 532         skb_queue_tail(&link->wakeupq, skb);
 533         link->stats.link_congs++;
 534         return -ELINKCONG;
 535 }
 536
 537 /**
 538  * link_prepare_wakeup - prepare users for wakeup after congestion
 539  * @link: congested link
 540  * Move a number of waiting users, as permitted by available space in
 541  * the send queue, from link wait queue to node wait queue for wakeup
 542  */
 543 void link_prepare_wakeup(struct tipc_link *l)
 544 {
 545         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 546         int imp, lim;
 547         struct sk_buff *skb, *tmp;
 548
 549         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 550                 imp = TIPC_SKB_CB(skb)->chain_imp;
 551                 lim = l->window + l->backlog[imp].limit;
 552                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 553                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 554                         break;
 555                 skb_unlink(skb, &l->wakeupq);
 556                 skb_queue_tail(l->inputq, skb);
 557                 l->owner->inputq = l->inputq;
 558                 l->owner->action_flags |= TIPC_MSG_EVT;
 559         }
 560 }
 561
 562 /**
 563  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 564  * @l_ptr: pointer to link
 565  */
 566 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 567 {
 568         kfree_skb(l_ptr->reasm_buf);
 569         l_ptr->reasm_buf = NULL;
 570 }
 571
 572 void tipc_link_purge_backlog(struct tipc_link *l)
 573 {
 574         __skb_queue_purge(&l->backlogq);
 575         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 576         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 577         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 578         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 579         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 580 }
 581
 582 /**
 583  * tipc_link_purge_queues - purge all pkt queues associated with link
 584  * @l_ptr: pointer to link
 585  */
 586 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 587 {
 588         __skb_queue_purge(&l_ptr->deferdq);
 589         __skb_queue_purge(&l_ptr->transmq);
 590         tipc_link_purge_backlog(l_ptr);
 591         tipc_link_reset_fragments(l_ptr);
 592 }
 593
 594 void tipc_link_reset(struct tipc_link *l_ptr)
 595 {
 596         u32 prev_state = l_ptr->state;
 597         int was_active_link = tipc_link_is_active(l_ptr);
 598         struct tipc_node *owner = l_ptr->owner;
 599         struct tipc_link *pl = tipc_parallel_link(l_ptr);
 600
 601         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 602
 603         /* Link is down, accept any session */
 604         l_ptr->peer_session = WILDCARD_SESSION;
 605
 606         /* Prepare for renewed mtu size negotiation */
 607         l_ptr->mtu = l_ptr->advertised_mtu;
 608
 609         l_ptr->state = TIPC_LINK_RESETTING;
 610
 611         if ((prev_state == TIPC_LINK_RESETTING) ||
 612             (prev_state == TIPC_LINK_ESTABLISHING))
 613                 return;
 614
 615         tipc_node_link_down(l_ptr->owner, l_ptr->bearer_id);
 616         tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 617
 618         if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
 619                 l_ptr->exec_mode = TIPC_LINK_BLOCKED;
 620                 l_ptr->failover_checkpt = l_ptr->rcv_nxt;
 621                 pl->failover_pkts = FIRST_FAILOVER;
 622                 pl->failover_checkpt = l_ptr->rcv_nxt;
 623                 pl->failover_skb = l_ptr->reasm_buf;
 624         } else {
 625                 kfree_skb(l_ptr->reasm_buf);
 626         }
 627         /* Clean up all queues, except inputq: */
 628         __skb_queue_purge(&l_ptr->transmq);
 629         __skb_queue_purge(&l_ptr->deferdq);
 630         if (!owner->inputq)
 631                 owner->inputq = l_ptr->inputq;
 632         skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
 633         if (!skb_queue_empty(owner->inputq))
 634                 owner->action_flags |= TIPC_MSG_EVT;
 635         tipc_link_purge_backlog(l_ptr);
 636         l_ptr->reasm_buf = NULL;
 637         l_ptr->rcv_unacked = 0;
 638         l_ptr->snd_nxt = 1;
 639         l_ptr->rcv_nxt = 1;
 640         l_ptr->silent_intv_cnt = 0;
 641         l_ptr->stats.recv_info = 0;
 642         l_ptr->stale_count = 0;
 643         link_reset_statistics(l_ptr);
 644 }
 645
 646 /**
 647  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 648  * @link: link to use
 649  * @list: chain of buffers containing message
 650  *
 651  * Consumes the buffer chain, except when returning an error code,
 652  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 653  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 654  */
 655 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 656                      struct sk_buff_head *list)
 657 {
 658         struct tipc_msg *msg = buf_msg(skb_peek(list));
 659         unsigned int maxwin = link->window;
 660         unsigned int i, imp = msg_importance(msg);
 661         uint mtu = link->mtu;
 662         u16 ack = mod(link->rcv_nxt - 1);
 663         u16 seqno = link->snd_nxt;
 664         u16 bc_last_in = link->owner->bclink.last_in;
 665         struct tipc_media_addr *addr = &link->media_addr;
 666         struct sk_buff_head *transmq = &link->transmq;
 667         struct sk_buff_head *backlogq = &link->backlogq;
 668         struct sk_buff *skb, *bskb;
 669
 670         /* Match msg importance against this and all higher backlog limits: */
 671         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 672                 if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
 673                         return link_schedule_user(link, list);
 674         }
 675         if (unlikely(msg_size(msg) > mtu))
 676                 return -EMSGSIZE;
 677
 678         /* Prepare each packet for sending, and add to relevant queue: */
 679         while (skb_queue_len(list)) {
 680                 skb = skb_peek(list);
 681                 msg = buf_msg(skb);
 682                 msg_set_seqno(msg, seqno);
 683                 msg_set_ack(msg, ack);
 684                 msg_set_bcast_ack(msg, bc_last_in);
 685
 686                 if (likely(skb_queue_len(transmq) < maxwin)) {
 687                         __skb_dequeue(list);
 688                         __skb_queue_tail(transmq, skb);
 689                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 690                         link->rcv_unacked = 0;
 691                         seqno++;
 692                         continue;
 693                 }
 694                 if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
 695                         kfree_skb(__skb_dequeue(list));
 696                         link->stats.sent_bundled++;
 697                         continue;
 698                 }
 699                 if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
 700                         kfree_skb(__skb_dequeue(list));
 701                         __skb_queue_tail(backlogq, bskb);
 702                         link->backlog[msg_importance(buf_msg(bskb))].len++;
 703                         link->stats.sent_bundled++;
 704                         link->stats.sent_bundles++;
 705                         continue;
 706                 }
 707                 link->backlog[imp].len += skb_queue_len(list);
 708                 skb_queue_splice_tail_init(list, backlogq);
 709         }
 710         link->snd_nxt = seqno;
 711         return 0;
 712 }
 713
 714 /**
 715  * tipc_link_xmit(): enqueue buffer list according to queue situation
 716  * @link: link to use
 717  * @list: chain of buffers containing message
 718  * @xmitq: returned list of packets to be sent by caller
 719  *
 720  * Consumes the buffer chain, except when returning -ELINKCONG,
 721  * since the caller then may want to make more send attempts.
 722  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 723  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 724  */
 725 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 726                    struct sk_buff_head *xmitq)
 727 {
 728         struct tipc_msg *hdr = buf_msg(skb_peek(list));
 729         unsigned int maxwin = l->window;
 730         unsigned int i, imp = msg_importance(hdr);
 731         unsigned int mtu = l->mtu;
 732         u16 ack = l->rcv_nxt - 1;
 733         u16 seqno = l->snd_nxt;
 734         u16 bc_last_in = l->owner->bclink.last_in;
 735         struct sk_buff_head *transmq = &l->transmq;
 736         struct sk_buff_head *backlogq = &l->backlogq;
 737         struct sk_buff *skb, *_skb, *bskb;
 738
 739         /* Match msg importance against this and all higher backlog limits: */
 740         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 741                 if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
 742                         return link_schedule_user(l, list);
 743         }
 744         if (unlikely(msg_size(hdr) > mtu))
 745                 return -EMSGSIZE;
 746
 747         /* Prepare each packet for sending, and add to relevant queue: */
 748         while (skb_queue_len(list)) {
 749                 skb = skb_peek(list);
 750                 hdr = buf_msg(skb);
 751                 msg_set_seqno(hdr, seqno);
 752                 msg_set_ack(hdr, ack);
 753                 msg_set_bcast_ack(hdr, bc_last_in);
 754
 755                 if (likely(skb_queue_len(transmq) < maxwin)) {
 756                         _skb = skb_clone(skb, GFP_ATOMIC);
 757                         if (!_skb)
 758                                 return -ENOBUFS;
 759                         __skb_dequeue(list);
 760                         __skb_queue_tail(transmq, skb);
 761                         __skb_queue_tail(xmitq, _skb);
 762                         l->rcv_unacked = 0;
 763                         seqno++;
 764                         continue;
 765                 }
 766                 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
 767                         kfree_skb(__skb_dequeue(list));
 768                         l->stats.sent_bundled++;
 769                         continue;
 770                 }
 771                 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
 772                         kfree_skb(__skb_dequeue(list));
 773                         __skb_queue_tail(backlogq, bskb);
 774                         l->backlog[msg_importance(buf_msg(bskb))].len++;
 775                         l->stats.sent_bundled++;
 776                         l->stats.sent_bundles++;
 777                         continue;
 778                 }
 779                 l->backlog[imp].len += skb_queue_len(list);
 780                 skb_queue_splice_tail_init(list, backlogq);
 781         }
 782         l->snd_nxt = seqno;
 783         return 0;
 784 }
 785
 786 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
 787 {
 788         skb_queue_head_init(list);
 789         __skb_queue_tail(list, skb);
 790 }
 791
 792 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 793 {
 794         struct sk_buff_head head;
 795
 796         skb2list(skb, &head);
 797         return __tipc_link_xmit(link->owner->net, link, &head);
 798 }
 799
 800 /*
 801  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 802  * Receive the sequence number where we should start receiving and
 803  * acking broadcast packets from a newly added peer node, and open
 804  * up for reception of such packets.
 805  *
 806  * Called with node locked
 807  */
 808 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 809 {
 810         struct tipc_msg *msg = buf_msg(buf);
 811
 812         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 813         n->bclink.recv_permitted = true;
 814         kfree_skb(buf);
 815 }
 816
 817 /*
 818  * tipc_link_push_packets - push unsent packets to bearer
 819  *
 820  * Push out the unsent messages of a link where congestion
 821  * has abated. Node is locked.
 822  *
 823  * Called with node locked
 824  */
 825 void tipc_link_push_packets(struct tipc_link *link)
 826 {
 827         struct sk_buff *skb;
 828         struct tipc_msg *msg;
 829         u16 seqno = link->snd_nxt;
 830         u16 ack = mod(link->rcv_nxt - 1);
 831
 832         while (skb_queue_len(&link->transmq) < link->window) {
 833                 skb = __skb_dequeue(&link->backlogq);
 834                 if (!skb)
 835                         break;
 836                 msg = buf_msg(skb);
 837                 link->backlog[msg_importance(msg)].len--;
 838                 msg_set_ack(msg, ack);
 839                 msg_set_seqno(msg, seqno);
 840                 seqno = mod(seqno + 1);
 841                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 842                 link->rcv_unacked = 0;
 843                 __skb_queue_tail(&link->transmq, skb);
 844                 tipc_bearer_send(link->owner->net, link->bearer_id,
 845                                  skb, &link->media_addr);
 846         }
 847         link->snd_nxt = seqno;
 848 }
 849
 850 void tipc_link_advance_backlog(struct tipc_link *l, struct sk_buff_head *xmitq)
 851 {
 852         struct sk_buff *skb, *_skb;
 853         struct tipc_msg *hdr;
 854         u16 seqno = l->snd_nxt;
 855         u16 ack = l->rcv_nxt - 1;
 856
 857         while (skb_queue_len(&l->transmq) < l->window) {
 858                 skb = skb_peek(&l->backlogq);
 859                 if (!skb)
 860                         break;
 861                 _skb = skb_clone(skb, GFP_ATOMIC);
 862                 if (!_skb)
 863                         break;
 864                 __skb_dequeue(&l->backlogq);
 865                 hdr = buf_msg(skb);
 866                 l->backlog[msg_importance(hdr)].len--;
 867                 __skb_queue_tail(&l->transmq, skb);
 868                 __skb_queue_tail(xmitq, _skb);
 869                 msg_set_ack(hdr, ack);
 870                 msg_set_seqno(hdr, seqno);
 871                 msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
 872                 l->rcv_unacked = 0;
 873                 seqno++;
 874         }
 875         l->snd_nxt = seqno;
 876 }
 877
 878 void tipc_link_reset_all(struct tipc_node *node)
 879 {
 880         char addr_string[16];
 881         u32 i;
 882
 883         tipc_node_lock(node);
 884
 885         pr_warn("Resetting all links to %s\n",
 886                 tipc_addr_string_fill(addr_string, node->addr));
 887
 888         for (i = 0; i < MAX_BEARERS; i++) {
 889                 if (node->links[i].link) {
 890                         link_print(node->links[i].link, "Resetting link\n");
 891                         tipc_link_reset(node->links[i].link);
 892                 }
 893         }
 894
 895         tipc_node_unlock(node);
 896 }
 897
 898 static void link_retransmit_failure(struct tipc_link *l_ptr,
 899                                     struct sk_buff *buf)
 900 {
 901         struct tipc_msg *msg = buf_msg(buf);
 902         struct net *net = l_ptr->owner->net;
 903
 904         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 905
 906         if (l_ptr->addr) {
 907                 /* Handle failure on standard link */
 908                 link_print(l_ptr, "Resetting link ");
 909                 pr_info("Failed msg: usr %u, typ %u, len %u, err %u\n",
 910                         msg_user(msg), msg_type(msg), msg_size(msg),
 911                         msg_errcode(msg));
 912                 pr_info("sqno %u, prev: %x, src: %x\n",
 913                         msg_seqno(msg), msg_prevnode(msg), msg_orignode(msg));
 914                 tipc_link_reset(l_ptr);
 915         } else {
 916                 /* Handle failure on broadcast link */
 917                 struct tipc_node *n_ptr;
 918                 char addr_string[16];
 919
 920                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 921                 pr_cont("Outstanding acks: %lu\n",
 922                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 923
 924                 n_ptr = tipc_bclink_retransmit_to(net);
 925
 926                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 927                 pr_info("Broadcast link info for %s\n", addr_string);
 928                 pr_info("Reception permitted: %d,  Acked: %u\n",
 929                         n_ptr->bclink.recv_permitted,
 930                         n_ptr->bclink.acked);
 931                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 932                         n_ptr->bclink.last_in,
 933                         n_ptr->bclink.oos_state,
 934                         n_ptr->bclink.last_sent);
 935
 936                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 937                 l_ptr->stale_count = 0;
 938         }
 939 }
 940
 941 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 942                           u32 retransmits)
 943 {
 944         struct tipc_msg *msg;
 945
 946         if (!skb)
 947                 return;
 948
 949         msg = buf_msg(skb);
 950
 951         /* Detect repeated retransmit failures */
 952         if (l_ptr->last_retransm == msg_seqno(msg)) {
 953                 if (++l_ptr->stale_count > 100) {
 954                         link_retransmit_failure(l_ptr, skb);
 955                         return;
 956                 }
 957         } else {
 958                 l_ptr->last_retransm = msg_seqno(msg);
 959                 l_ptr->stale_count = 1;
 960         }
 961
 962         skb_queue_walk_from(&l_ptr->transmq, skb) {
 963                 if (!retransmits)
 964                         break;
 965                 msg = buf_msg(skb);
 966                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
 967                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 968                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 969                                  &l_ptr->media_addr);
 970                 retransmits--;
 971                 l_ptr->stats.retransmitted++;
 972         }
 973 }
 974
 975 static int tipc_link_retransm(struct tipc_link *l, int retransm,
 976                               struct sk_buff_head *xmitq)
 977 {
 978         struct sk_buff *_skb, *skb = skb_peek(&l->transmq);
 979         struct tipc_msg *hdr;
 980
 981         if (!skb)
 982                 return 0;
 983
 984         /* Detect repeated retransmit failures on same packet */
 985         if (likely(l->last_retransm != buf_seqno(skb))) {
 986                 l->last_retransm = buf_seqno(skb);
 987                 l->stale_count = 1;
 988         } else if (++l->stale_count > 100) {
 989                 link_retransmit_failure(l, skb);
 990                 return TIPC_LINK_DOWN_EVT;
 991         }
 992         skb_queue_walk(&l->transmq, skb) {
 993                 if (!retransm)
 994                         return 0;
 995                 hdr = buf_msg(skb);
 996                 _skb = __pskb_copy(skb, MIN_H_SIZE, GFP_ATOMIC);
 997                 if (!_skb)
 998                         return 0;
 999                 hdr = buf_msg(_skb);
1000                 msg_set_ack(hdr, l->rcv_nxt - 1);
1001                 msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
1002                 _skb->priority = TC_PRIO_CONTROL;
1003                 __skb_queue_tail(xmitq, _skb);
1004                 retransm--;
1005                 l->stats.retransmitted++;
1006         }
1007         return 0;
1008 }
1009
1010 /* link_synch(): check if all packets arrived before the synch
1011  *               point have been consumed
1012  * Returns true if the parallel links are synched, otherwise false
1013  */
1014 static bool link_synch(struct tipc_link *l)
1015 {
1016         unsigned int post_synch;
1017         struct tipc_link *pl;
1018
1019         pl  = tipc_parallel_link(l);
1020         if (pl == l)
1021                 goto synched;
1022
1023         /* Was last pre-synch packet added to input queue ? */
1024         if (less_eq(pl->rcv_nxt, l->synch_point))
1025                 return false;
1026
1027         /* Is it still in the input queue ? */
1028         post_synch = mod(pl->rcv_nxt - l->synch_point) - 1;
1029         if (skb_queue_len(pl->inputq) > post_synch)
1030                 return false;
1031 synched:
1032         l->exec_mode = TIPC_LINK_OPEN;
1033         return true;
1034 }
1035
1036 /* tipc_data_input - deliver data and name distr msgs to upper layer
1037  *
1038  * Consumes buffer if message is of right type
1039  * Node lock must be held
1040  */
1041 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
1042 {
1043         struct tipc_node *node = link->owner;
1044         struct tipc_msg *msg = buf_msg(skb);
1045         u32 dport = msg_destport(msg);
1046
1047         switch (msg_user(msg)) {
1048         case TIPC_LOW_IMPORTANCE:
1049         case TIPC_MEDIUM_IMPORTANCE:
1050         case TIPC_HIGH_IMPORTANCE:
1051         case TIPC_CRITICAL_IMPORTANCE:
1052         case CONN_MANAGER:
1053                 if (tipc_skb_queue_tail(link->inputq, skb, dport)) {
1054                         node->inputq = link->inputq;
1055                         node->action_flags |= TIPC_MSG_EVT;
1056                 }
1057                 return true;
1058         case NAME_DISTRIBUTOR:
1059                 node->bclink.recv_permitted = true;
1060                 node->namedq = link->namedq;
1061                 skb_queue_tail(link->namedq, skb);
1062                 if (skb_queue_len(link->namedq) == 1)
1063                         node->action_flags |= TIPC_NAMED_MSG_EVT;
1064                 return true;
1065         case MSG_BUNDLER:
1066         case TUNNEL_PROTOCOL:
1067         case MSG_FRAGMENTER:
1068         case BCAST_PROTOCOL:
1069                 return false;
1070         default:
1071                 pr_warn("Dropping received illegal msg type\n");
1072                 kfree_skb(skb);
1073                 return false;
1074         };
1075 }
1076
1077 /* tipc_link_input - process packet that has passed link protocol check
1078  *
1079  * Consumes buffer
1080  * Node lock must be held
1081  */
1082 static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
1083 {
1084         struct tipc_node *node = link->owner;
1085         struct tipc_msg *msg = buf_msg(skb);
1086         struct sk_buff *iskb;
1087         int pos = 0;
1088
1089         switch (msg_user(msg)) {
1090         case TUNNEL_PROTOCOL:
1091                 if (msg_dup(msg)) {
1092                         link->exec_mode = TIPC_LINK_TUNNEL;
1093                         link->synch_point = msg_seqno(msg_get_wrapped(msg));
1094                         kfree_skb(skb);
1095                         break;
1096                 }
1097                 if (!tipc_link_failover_rcv(link, &skb))
1098                         break;
1099                 if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
1100                         tipc_data_input(link, skb);
1101                         break;
1102                 }
1103         case MSG_BUNDLER:
1104                 link->stats.recv_bundles++;
1105                 link->stats.recv_bundled += msg_msgcnt(msg);
1106
1107                 while (tipc_msg_extract(skb, &iskb, &pos))
1108                         tipc_data_input(link, iskb);
1109                 break;
1110         case MSG_FRAGMENTER:
1111                 link->stats.recv_fragments++;
1112                 if (tipc_buf_append(&link->reasm_buf, &skb)) {
1113                         link->stats.recv_fragmented++;
1114                         tipc_data_input(link, skb);
1115                 } else if (!link->reasm_buf) {
1116                         tipc_link_reset(link);
1117                 }
1118                 break;
1119         case BCAST_PROTOCOL:
1120                 tipc_link_sync_rcv(node, skb);
1121                 break;
1122         default:
1123                 break;
1124         };
1125 }
1126
1127 static bool tipc_link_release_pkts(struct tipc_link *l, u16 acked)
1128 {
1129         bool released = false;
1130         struct sk_buff *skb, *tmp;
1131
1132         skb_queue_walk_safe(&l->transmq, skb, tmp) {
1133                 if (more(buf_seqno(skb), acked))
1134                         break;
1135                 __skb_unlink(skb, &l->transmq);
1136                 kfree_skb(skb);
1137                 released = true;
1138         }
1139         return released;
1140 }
1141
1142 /* tipc_link_rcv - process TIPC packets/messages arriving from off-node
1143  * @link: the link that should handle the message
1144  * @skb: TIPC packet
1145  * @xmitq: queue to place packets to be sent after this call
1146  */
1147 int tipc_link_rcv(struct tipc_link *l, struct sk_buff *skb,
1148                   struct sk_buff_head *xmitq)
1149 {
1150         struct sk_buff_head *arrvq = &l->deferdq;
1151         struct sk_buff *tmp;
1152         struct tipc_msg *hdr;
1153         u16 seqno, rcv_nxt;
1154         int rc = 0;
1155
1156         if (unlikely(!__tipc_skb_queue_sorted(arrvq, skb))) {
1157                 if (!(skb_queue_len(arrvq) % TIPC_NACK_INTV))
1158                         tipc_link_build_proto_msg(l, STATE_MSG, 0,
1159                                                   0, 0, 0, xmitq);
1160                 return rc;
1161         }
1162
1163         skb_queue_walk_safe(arrvq, skb, tmp) {
1164                 hdr = buf_msg(skb);
1165
1166                 /* Verify and update link state */
1167                 if (unlikely(msg_user(hdr) == LINK_PROTOCOL)) {
1168                         __skb_dequeue(arrvq);
1169                         rc |= tipc_link_proto_rcv(l, skb, xmitq);
1170                         continue;
1171                 }
1172
1173                 if (unlikely(!link_working(l))) {
1174                         rc |= tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
1175                         if (!link_working(l)) {
1176                                 kfree_skb(__skb_dequeue(arrvq));
1177                                 return rc;
1178                         }
1179                 }
1180
1181                 l->silent_intv_cnt = 0;
1182
1183                 /* Forward queues and wake up waiting users */
1184                 if (likely(tipc_link_release_pkts(l, msg_ack(hdr)))) {
1185                         tipc_link_advance_backlog(l, xmitq);
1186                         if (unlikely(!skb_queue_empty(&l->wakeupq)))
1187                                 link_prepare_wakeup(l);
1188                 }
1189
1190                 /* Defer reception if there is a gap in the sequence */
1191                 seqno = msg_seqno(hdr);
1192                 rcv_nxt = l->rcv_nxt;
1193                 if (unlikely(less(rcv_nxt, seqno))) {
1194                         l->stats.deferred_recv++;
1195                         return rc;
1196                 }
1197
1198                 __skb_dequeue(arrvq);
1199
1200                 /* Drop if packet already received */
1201                 if (unlikely(more(rcv_nxt, seqno))) {
1202                         l->stats.duplicates++;
1203                         kfree_skb(skb);
1204                         return rc;
1205                 }
1206
1207                 /* Synchronize with parallel link if applicable */
1208                 if (unlikely(l->exec_mode == TIPC_LINK_TUNNEL))
1209                         if (!msg_dup(hdr) && !link_synch(l)) {
1210                                 kfree_skb(skb);
1211                                 return rc;
1212                         }
1213
1214                 /* Packet can be delivered */
1215                 l->rcv_nxt++;
1216                 l->stats.recv_info++;
1217                 if (unlikely(!tipc_data_input(l, skb)))
1218                         tipc_link_input(l, skb);
1219
1220                 /* Ack at regular intervals */
1221                 if (unlikely(++l->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
1222                         l->rcv_unacked = 0;
1223                         l->stats.sent_acks++;
1224                         tipc_link_build_proto_msg(l, STATE_MSG,
1225                                                   0, 0, 0, 0, xmitq);
1226                 }
1227         }
1228         return rc;
1229 }
1230
1231 /**
1232  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1233  *
1234  * Returns increase in queue length (i.e. 0 or 1)
1235  */
1236 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1237 {
1238         struct sk_buff *skb1;
1239         u16 seq_no = buf_seqno(skb);
1240
1241         /* Empty queue ? */
1242         if (skb_queue_empty(list)) {
1243                 __skb_queue_tail(list, skb);
1244                 return 1;
1245         }
1246
1247         /* Last ? */
1248         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1249                 __skb_queue_tail(list, skb);
1250                 return 1;
1251         }
1252
1253         /* Locate insertion point in queue, then insert; discard if duplicate */
1254         skb_queue_walk(list, skb1) {
1255                 u16 curr_seqno = buf_seqno(skb1);
1256
1257                 if (seq_no == curr_seqno) {
1258                         kfree_skb(skb);
1259                         return 0;
1260                 }
1261
1262                 if (less(seq_no, curr_seqno))
1263                         break;
1264         }
1265
1266         __skb_queue_before(list, skb1, skb);
1267         return 1;
1268 }
1269
1270 /*
1271  * Send protocol message to the other endpoint.
1272  */
1273 void tipc_link_proto_xmit(struct tipc_link *l, u32 msg_typ, int probe_msg,
1274                           u32 gap, u32 tolerance, u32 priority)
1275 {
1276         struct sk_buff *skb = NULL;
1277         struct sk_buff_head xmitq;
1278
1279         __skb_queue_head_init(&xmitq);
1280         tipc_link_build_proto_msg(l, msg_typ, probe_msg, gap,
1281                                   tolerance, priority, &xmitq);
1282         skb = __skb_dequeue(&xmitq);
1283         if (!skb)
1284                 return;
1285         tipc_bearer_send(l->owner->net, l->bearer_id, skb, &l->media_addr);
1286         l->rcv_unacked = 0;
1287         kfree_skb(skb);
1288 }
1289
1290 /* tipc_link_build_proto_msg: prepare link protocol message for transmission
1291  */
1292 static void tipc_link_build_proto_msg(struct tipc_link *l, int mtyp, bool probe,
1293                                       u16 rcvgap, int tolerance, int priority,
1294                                       struct sk_buff_head *xmitq)
1295 {
1296         struct sk_buff *skb = NULL;
1297         struct tipc_msg *hdr = l->pmsg;
1298         u16 snd_nxt = l->snd_nxt;
1299         u16 rcv_nxt = l->rcv_nxt;
1300         u16 rcv_last = rcv_nxt - 1;
1301         int node_up = l->owner->bclink.recv_permitted;
1302
1303         /* Don't send protocol message during reset or link failover */
1304         if (l->exec_mode == TIPC_LINK_BLOCKED)
1305                 return;
1306
1307         msg_set_type(hdr, mtyp);
1308         msg_set_net_plane(hdr, l->net_plane);
1309         msg_set_bcast_ack(hdr, l->owner->bclink.last_in);
1310         msg_set_last_bcast(hdr, tipc_bclink_get_last_sent(l->owner->net));
1311         msg_set_link_tolerance(hdr, tolerance);
1312         msg_set_linkprio(hdr, priority);
1313         msg_set_redundant_link(hdr, node_up);
1314         msg_set_seq_gap(hdr, 0);
1315
1316         /* Compatibility: created msg must not be in sequence with pkt flow */
1317         msg_set_seqno(hdr, snd_nxt + U16_MAX / 2);
1318
1319         if (mtyp == STATE_MSG) {
1320                 if (!tipc_link_is_up(l))
1321                         return;
1322                 msg_set_next_sent(hdr, snd_nxt);
1323
1324                 /* Override rcvgap if there are packets in deferred queue */
1325                 if (!skb_queue_empty(&l->deferdq))
1326                         rcvgap = buf_seqno(skb_peek(&l->deferdq)) - rcv_nxt;
1327                 if (rcvgap) {
1328                         msg_set_seq_gap(hdr, rcvgap);
1329                         l->stats.sent_nacks++;
1330                 }
1331                 msg_set_ack(hdr, rcv_last);
1332                 msg_set_probe(hdr, probe);
1333                 if (probe)
1334                         l->stats.sent_probes++;
1335                 l->stats.sent_states++;
1336         } else {
1337                 /* RESET_MSG or ACTIVATE_MSG */
1338                 msg_set_max_pkt(hdr, l->advertised_mtu);
1339                 msg_set_ack(hdr, l->failover_checkpt - 1);
1340                 msg_set_next_sent(hdr, 1);
1341         }
1342         skb = tipc_buf_acquire(msg_size(hdr));
1343         if (!skb)
1344                 return;
1345         skb_copy_to_linear_data(skb, hdr, msg_size(hdr));
1346         skb->priority = TC_PRIO_CONTROL;
1347         __skb_queue_head(xmitq, skb);
1348 }
1349
1350 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1351  * a different bearer. Owner node is locked.
1352  */
1353 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1354                                   struct tipc_msg *tunnel_hdr,
1355                                   struct tipc_msg *msg,
1356                                   u32 selector)
1357 {
1358         struct tipc_link *tunnel;
1359         struct sk_buff *skb;
1360         u32 length = msg_size(msg);
1361
1362         tunnel = node_active_link(l_ptr->owner, selector & 1);
1363         if (!tipc_link_is_up(tunnel)) {
1364                 pr_warn("%stunnel link no longer available\n", link_co_err);
1365                 return;
1366         }
1367         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1368         skb = tipc_buf_acquire(length + INT_H_SIZE);
1369         if (!skb) {
1370                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1371                 return;
1372         }
1373         skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
1374         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
1375         __tipc_link_xmit_skb(tunnel, skb);
1376 }
1377
1378
1379 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1380  * link is still active. We can do failover. Tunnel the failing link's
1381  * whole send queue via the remaining link. This way, we don't lose
1382  * any packets, and sequence order is preserved for subsequent traffic
1383  * sent over the remaining link. Owner node is locked.
1384  */
1385 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1386 {
1387         int msgcount;
1388         struct tipc_link *tunnel = node_active_link(l_ptr->owner, 0);
1389         struct tipc_msg tunnel_hdr;
1390         struct sk_buff *skb;
1391         int split_bundles;
1392
1393         if (!tunnel)
1394                 return;
1395
1396         tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
1397                       FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
1398
1399         skb_queue_walk(&l_ptr->backlogq, skb) {
1400                 msg_set_seqno(buf_msg(skb), l_ptr->snd_nxt);
1401                 l_ptr->snd_nxt = mod(l_ptr->snd_nxt + 1);
1402         }
1403         skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
1404         tipc_link_purge_backlog(l_ptr);
1405         msgcount = skb_queue_len(&l_ptr->transmq);
1406         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1407         msg_set_msgcnt(&tunnel_hdr, msgcount);
1408
1409         if (skb_queue_empty(&l_ptr->transmq)) {
1410                 skb = tipc_buf_acquire(INT_H_SIZE);
1411                 if (skb) {
1412                         skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
1413                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1414                         __tipc_link_xmit_skb(tunnel, skb);
1415                 } else {
1416                         pr_warn("%sunable to send changeover msg\n",
1417                                 link_co_err);
1418                 }
1419                 return;
1420         }
1421
1422         split_bundles = (node_active_link(l_ptr->owner, 0) !=
1423                          node_active_link(l_ptr->owner, 0));
1424
1425         skb_queue_walk(&l_ptr->transmq, skb) {
1426                 struct tipc_msg *msg = buf_msg(skb);
1427
1428                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1429                         struct tipc_msg *m = msg_get_wrapped(msg);
1430                         unchar *pos = (unchar *)m;
1431
1432                         msgcount = msg_msgcnt(msg);
1433                         while (msgcount--) {
1434                                 msg_set_seqno(m, msg_seqno(msg));
1435                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1436                                                       msg_link_selector(m));
1437                                 pos += align(msg_size(m));
1438                                 m = (struct tipc_msg *)pos;
1439                         }
1440                 } else {
1441                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1442                                               msg_link_selector(msg));
1443                 }
1444         }
1445 }
1446
1447 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1448  * duplicate of the first link's send queue via the new link. This way, we
1449  * are guaranteed that currently queued packets from a socket are delivered
1450  * before future traffic from the same socket, even if this is using the
1451  * new link. The last arriving copy of each duplicate packet is dropped at
1452  * the receiving end by the regular protocol check, so packet cardinality
1453  * and sequence order is preserved per sender/receiver socket pair.
1454  * Owner node is locked.
1455  */
1456 void tipc_link_dup_queue_xmit(struct tipc_link *link,
1457                               struct tipc_link *tnl)
1458 {
1459         struct sk_buff *skb;
1460         struct tipc_msg tnl_hdr;
1461         struct sk_buff_head *queue = &link->transmq;
1462         int mcnt;
1463         u16 seqno;
1464
1465         tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
1466                       SYNCH_MSG, INT_H_SIZE, link->addr);
1467         mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
1468         msg_set_msgcnt(&tnl_hdr, mcnt);
1469         msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
1470
1471 tunnel_queue:
1472         skb_queue_walk(queue, skb) {
1473                 struct sk_buff *outskb;
1474                 struct tipc_msg *msg = buf_msg(skb);
1475                 u32 len = msg_size(msg);
1476
1477                 msg_set_ack(msg, mod(link->rcv_nxt - 1));
1478                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
1479                 msg_set_size(&tnl_hdr, len + INT_H_SIZE);
1480                 outskb = tipc_buf_acquire(len + INT_H_SIZE);
1481                 if (outskb == NULL) {
1482                         pr_warn("%sunable to send duplicate msg\n",
1483                                 link_co_err);
1484                         return;
1485                 }
1486                 skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
1487                 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
1488                                                skb->data, len);
1489                 __tipc_link_xmit_skb(tnl, outskb);
1490                 if (!tipc_link_is_up(link))
1491                         return;
1492         }
1493         if (queue == &link->backlogq)
1494                 return;
1495         seqno = link->snd_nxt;
1496         skb_queue_walk(&link->backlogq, skb) {
1497                 msg_set_seqno(buf_msg(skb), seqno);
1498                 seqno = mod(seqno + 1);
1499         }
1500         queue = &link->backlogq;
1501         goto tunnel_queue;
1502 }
1503
1504 /*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
1505  *  Owner node is locked.
1506  */
1507 static bool tipc_link_failover_rcv(struct tipc_link *link,
1508                                    struct sk_buff **skb)
1509 {
1510         struct tipc_msg *msg = buf_msg(*skb);
1511         struct sk_buff *iskb = NULL;
1512         struct tipc_link *pl = NULL;
1513         int bearer_id = msg_bearer_id(msg);
1514         int pos = 0;
1515
1516         if (msg_type(msg) != FAILOVER_MSG) {
1517                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1518                 goto exit;
1519         }
1520         if (bearer_id >= MAX_BEARERS)
1521                 goto exit;
1522
1523         if (bearer_id == link->bearer_id)
1524                 goto exit;
1525
1526         pl = link->owner->links[bearer_id].link;
1527         if (pl && tipc_link_is_up(pl))
1528                 tipc_link_reset(pl);
1529
1530         if (link->failover_pkts == FIRST_FAILOVER)
1531                 link->failover_pkts = msg_msgcnt(msg);
1532
1533         /* Should we expect an inner packet? */
1534         if (!link->failover_pkts)
1535                 goto exit;
1536
1537         if (!tipc_msg_extract(*skb, &iskb, &pos)) {
1538                 pr_warn("%sno inner failover pkt\n", link_co_err);
1539                 *skb = NULL;
1540                 goto exit;
1541         }
1542         link->failover_pkts--;
1543         *skb = NULL;
1544
1545         /* Was this packet already delivered? */
1546         if (less(buf_seqno(iskb), link->failover_checkpt)) {
1547                 kfree_skb(iskb);
1548                 iskb = NULL;
1549                 goto exit;
1550         }
1551         if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
1552                 link->stats.recv_fragments++;
1553                 tipc_buf_append(&link->failover_skb, &iskb);
1554         }
1555 exit:
1556         if (!link->failover_pkts && pl)
1557                 pl->exec_mode = TIPC_LINK_OPEN;
1558         kfree_skb(*skb);
1559         *skb = iskb;
1560         return *skb;
1561 }
1562
1563 /* tipc_link_proto_rcv(): receive link level protocol message :
1564  * Note that network plane id propagates through the network, and may
1565  * change at any time. The node with lowest numerical id determines
1566  * network plane
1567  */
1568 static int tipc_link_proto_rcv(struct tipc_link *l, struct sk_buff *skb,
1569                                struct sk_buff_head *xmitq)
1570 {
1571         struct tipc_msg *hdr = buf_msg(skb);
1572         u16 rcvgap = 0;
1573         u16 nacked_gap = msg_seq_gap(hdr);
1574         u16 peers_snd_nxt =  msg_next_sent(hdr);
1575         u16 peers_tol = msg_link_tolerance(hdr);
1576         u16 peers_prio = msg_linkprio(hdr);
1577         char *if_name;
1578         int rc = 0;
1579
1580         if (l->exec_mode == TIPC_LINK_BLOCKED)
1581                 goto exit;
1582
1583         if (link_own_addr(l) > msg_prevnode(hdr))
1584                 l->net_plane = msg_net_plane(hdr);
1585
1586         switch (msg_type(hdr)) {
1587         case RESET_MSG:
1588
1589                 /* Ignore duplicate RESET with old session number */
1590                 if ((less_eq(msg_session(hdr), l->peer_session)) &&
1591                     (l->peer_session != WILDCARD_SESSION))
1592                         break;
1593                 /* fall thru' */
1594         case ACTIVATE_MSG:
1595
1596                 /* Complete own link name with peer's interface name */
1597                 if_name =  strrchr(l->name, ':') + 1;
1598                 if (sizeof(l->name) - (if_name - l->name) <= TIPC_MAX_IF_NAME)
1599                         break;
1600                 if (msg_data_sz(hdr) < TIPC_MAX_IF_NAME)
1601                         break;
1602                 strncpy(if_name, msg_data(hdr), TIPC_MAX_IF_NAME);
1603
1604                 /* Update own tolerance if peer indicates a non-zero value */
1605                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1606                         l->tolerance = peers_tol;
1607
1608                 /* Update own priority if peer's priority is higher */
1609                 if (in_range(peers_prio, l->priority + 1, TIPC_MAX_LINK_PRI))
1610                         l->priority = peers_prio;
1611
1612                 l->peer_session = msg_session(hdr);
1613                 l->peer_bearer_id = msg_bearer_id(hdr);
1614                 rc = tipc_link_fsm_evt(l, msg_type(hdr), xmitq);
1615                 if (l->mtu > msg_max_pkt(hdr))
1616                         l->mtu = msg_max_pkt(hdr);
1617                 break;
1618         case STATE_MSG:
1619                 /* Update own tolerance if peer indicates a non-zero value */
1620                 if (in_range(peers_tol, TIPC_MIN_LINK_TOL, TIPC_MAX_LINK_TOL))
1621                         l->tolerance = peers_tol;
1622
1623                 l->silent_intv_cnt = 0;
1624                 l->stats.recv_states++;
1625                 if (msg_probe(hdr))
1626                         l->stats.recv_probes++;
1627                 rc = tipc_link_fsm_evt(l, TRAFFIC_EVT, xmitq);
1628                 if (!tipc_link_is_up(l))
1629                         break;
1630
1631                 /* Has peer sent packets we haven't received yet ? */
1632                 if (more(peers_snd_nxt, l->rcv_nxt))
1633                         rcvgap = peers_snd_nxt - l->rcv_nxt;
1634                 if (rcvgap || (msg_probe(hdr)))
1635                         tipc_link_build_proto_msg(l, STATE_MSG, 0, rcvgap,
1636                                                   0, 0, xmitq);
1637                 tipc_link_release_pkts(l, msg_ack(hdr));
1638
1639                 /* If NACK, retransmit will now start at right position */
1640                 if (nacked_gap) {
1641                         rc |= tipc_link_retransm(l, nacked_gap, xmitq);
1642                         l->stats.recv_nacks++;
1643                 }
1644                 tipc_link_advance_backlog(l, xmitq);
1645                 if (unlikely(!skb_queue_empty(&l->wakeupq)))
1646                         link_prepare_wakeup(l);
1647         }
1648 exit:
1649         kfree_skb(skb);
1650         return rc;
1651 }
1652
1653 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1654 {
1655         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1656
1657         l->window = win;
1658         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1659         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1660         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1661         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1662         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1663 }
1664
1665 /* tipc_link_find_owner - locate owner node of link by link's name
1666  * @net: the applicable net namespace
1667  * @name: pointer to link name string
1668  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1669  *
1670  * Returns pointer to node owning the link, or 0 if no matching link is found.
1671  */
1672 static struct tipc_node *tipc_link_find_owner(struct net *net,
1673                                               const char *link_name,
1674                                               unsigned int *bearer_id)
1675 {
1676         struct tipc_net *tn = net_generic(net, tipc_net_id);
1677         struct tipc_link *l_ptr;
1678         struct tipc_node *n_ptr;
1679         struct tipc_node *found_node = NULL;
1680         int i;
1681
1682         *bearer_id = 0;
1683         rcu_read_lock();
1684         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1685                 tipc_node_lock(n_ptr);
1686                 for (i = 0; i < MAX_BEARERS; i++) {
1687                         l_ptr = n_ptr->links[i].link;
1688                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1689                                 *bearer_id = i;
1690                                 found_node = n_ptr;
1691                                 break;
1692                         }
1693                 }
1694                 tipc_node_unlock(n_ptr);
1695                 if (found_node)
1696                         break;
1697         }
1698         rcu_read_unlock();
1699
1700         return found_node;
1701 }
1702
1703 /**
1704  * link_reset_statistics - reset link statistics
1705  * @l_ptr: pointer to link
1706  */
1707 static void link_reset_statistics(struct tipc_link *l_ptr)
1708 {
1709         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1710         l_ptr->stats.sent_info = l_ptr->snd_nxt;
1711         l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1712 }
1713
1714 static void link_print(struct tipc_link *l, const char *str)
1715 {
1716         struct sk_buff *hskb = skb_peek(&l->transmq);
1717         u16 head = hskb ? msg_seqno(buf_msg(hskb)) : l->snd_nxt;
1718         u16 tail = l->snd_nxt - 1;
1719
1720         pr_info("%s Link <%s>:", str, l->name);
1721
1722         if (link_probing(l))
1723                 pr_cont(":P\n");
1724         else if (link_establishing(l))
1725                 pr_cont(":E\n");
1726         else if (link_resetting(l))
1727                 pr_cont(":R\n");
1728         else if (link_working(l))
1729                 pr_cont(":W\n");
1730         else
1731                 pr_cont("\n");
1732
1733         pr_info("XMTQ: %u [%u-%u], BKLGQ: %u, SNDNX: %u, RCVNX: %u\n",
1734                 skb_queue_len(&l->transmq), head, tail,
1735                 skb_queue_len(&l->backlogq), l->snd_nxt, l->rcv_nxt);
1736 }
1737
1738 /* Parse and validate nested (link) properties valid for media, bearer and link
1739  */
1740 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1741 {
1742         int err;
1743
1744         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1745                                tipc_nl_prop_policy);
1746         if (err)
1747                 return err;
1748
1749         if (props[TIPC_NLA_PROP_PRIO]) {
1750                 u32 prio;
1751
1752                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1753                 if (prio > TIPC_MAX_LINK_PRI)
1754                         return -EINVAL;
1755         }
1756
1757         if (props[TIPC_NLA_PROP_TOL]) {
1758                 u32 tol;
1759
1760                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1761                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1762                         return -EINVAL;
1763         }
1764
1765         if (props[TIPC_NLA_PROP_WIN]) {
1766                 u32 win;
1767
1768                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1769                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1770                         return -EINVAL;
1771         }
1772
1773         return 0;
1774 }
1775
1776 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1777 {
1778         int err;
1779         int res = 0;
1780         int bearer_id;
1781         char *name;
1782         struct tipc_link *link;
1783         struct tipc_node *node;
1784         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1785         struct net *net = sock_net(skb->sk);
1786
1787         if (!info->attrs[TIPC_NLA_LINK])
1788                 return -EINVAL;
1789
1790         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1791                                info->attrs[TIPC_NLA_LINK],
1792                                tipc_nl_link_policy);
1793         if (err)
1794                 return err;
1795
1796         if (!attrs[TIPC_NLA_LINK_NAME])
1797                 return -EINVAL;
1798
1799         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1800
1801         if (strcmp(name, tipc_bclink_name) == 0)
1802                 return tipc_nl_bc_link_set(net, attrs);
1803
1804         node = tipc_link_find_owner(net, name, &bearer_id);
1805         if (!node)
1806                 return -EINVAL;
1807
1808         tipc_node_lock(node);
1809
1810         link = node->links[bearer_id].link;
1811         if (!link) {
1812                 res = -EINVAL;
1813                 goto out;
1814         }
1815
1816         if (attrs[TIPC_NLA_LINK_PROP]) {
1817                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1818
1819                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1820                                               props);
1821                 if (err) {
1822                         res = err;
1823                         goto out;
1824                 }
1825
1826                 if (props[TIPC_NLA_PROP_TOL]) {
1827                         u32 tol;
1828
1829                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1830                         link->tolerance = tol;
1831                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1832                 }
1833                 if (props[TIPC_NLA_PROP_PRIO]) {
1834                         u32 prio;
1835
1836                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1837                         link->priority = prio;
1838                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1839                 }
1840                 if (props[TIPC_NLA_PROP_WIN]) {
1841                         u32 win;
1842
1843                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1844                         tipc_link_set_queue_limits(link, win);
1845                 }
1846         }
1847
1848 out:
1849         tipc_node_unlock(node);
1850
1851         return res;
1852 }
1853
1854 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1855 {
1856         int i;
1857         struct nlattr *stats;
1858
1859         struct nla_map {
1860                 u32 key;
1861                 u32 val;
1862         };
1863
1864         struct nla_map map[] = {
1865                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1866                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1867                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1868                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1869                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1870                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1871                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1872                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1873                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1874                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1875                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1876                         s->msg_length_counts : 1},
1877                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1878                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1879                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1880                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1881                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1882                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1883                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1884                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1885                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1886                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1887                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1888                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1889                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1890                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1891                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1892                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1893                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1894                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1895                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1896                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1897                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1898                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1899                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1900         };
1901
1902         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1903         if (!stats)
1904                 return -EMSGSIZE;
1905
1906         for (i = 0; i <  ARRAY_SIZE(map); i++)
1907                 if (nla_put_u32(skb, map[i].key, map[i].val))
1908                         goto msg_full;
1909
1910         nla_nest_end(skb, stats);
1911
1912         return 0;
1913 msg_full:
1914         nla_nest_cancel(skb, stats);
1915
1916         return -EMSGSIZE;
1917 }
1918
1919 /* Caller should hold appropriate locks to protect the link */
1920 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1921                               struct tipc_link *link, int nlflags)
1922 {
1923         int err;
1924         void *hdr;
1925         struct nlattr *attrs;
1926         struct nlattr *prop;
1927         struct tipc_net *tn = net_generic(net, tipc_net_id);
1928
1929         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1930                           nlflags, TIPC_NL_LINK_GET);
1931         if (!hdr)
1932                 return -EMSGSIZE;
1933
1934         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1935         if (!attrs)
1936                 goto msg_full;
1937
1938         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1939                 goto attr_msg_full;
1940         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
1941                         tipc_cluster_mask(tn->own_addr)))
1942                 goto attr_msg_full;
1943         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
1944                 goto attr_msg_full;
1945         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
1946                 goto attr_msg_full;
1947         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
1948                 goto attr_msg_full;
1949
1950         if (tipc_link_is_up(link))
1951                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
1952                         goto attr_msg_full;
1953         if (tipc_link_is_active(link))
1954                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
1955                         goto attr_msg_full;
1956
1957         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
1958         if (!prop)
1959                 goto attr_msg_full;
1960         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1961                 goto prop_msg_full;
1962         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
1963                 goto prop_msg_full;
1964         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
1965                         link->window))
1966                 goto prop_msg_full;
1967         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
1968                 goto prop_msg_full;
1969         nla_nest_end(msg->skb, prop);
1970
1971         err = __tipc_nl_add_stats(msg->skb, &link->stats);
1972         if (err)
1973                 goto attr_msg_full;
1974
1975         nla_nest_end(msg->skb, attrs);
1976         genlmsg_end(msg->skb, hdr);
1977
1978         return 0;
1979
1980 prop_msg_full:
1981         nla_nest_cancel(msg->skb, prop);
1982 attr_msg_full:
1983         nla_nest_cancel(msg->skb, attrs);
1984 msg_full:
1985         genlmsg_cancel(msg->skb, hdr);
1986
1987         return -EMSGSIZE;
1988 }
1989
1990 /* Caller should hold node lock  */
1991 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
1992                                     struct tipc_node *node, u32 *prev_link)
1993 {
1994         u32 i;
1995         int err;
1996
1997         for (i = *prev_link; i < MAX_BEARERS; i++) {
1998                 *prev_link = i;
1999
2000                 if (!node->links[i].link)
2001                         continue;
2002
2003                 err = __tipc_nl_add_link(net, msg,
2004                                          node->links[i].link, NLM_F_MULTI);
2005                 if (err)
2006                         return err;
2007         }
2008         *prev_link = 0;
2009
2010         return 0;
2011 }
2012
2013 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2014 {
2015         struct net *net = sock_net(skb->sk);
2016         struct tipc_net *tn = net_generic(net, tipc_net_id);
2017         struct tipc_node *node;
2018         struct tipc_nl_msg msg;
2019         u32 prev_node = cb->args[0];
2020         u32 prev_link = cb->args[1];
2021         int done = cb->args[2];
2022         int err;
2023
2024         if (done)
2025                 return 0;
2026
2027         msg.skb = skb;
2028         msg.portid = NETLINK_CB(cb->skb).portid;
2029         msg.seq = cb->nlh->nlmsg_seq;
2030
2031         rcu_read_lock();
2032         if (prev_node) {
2033                 node = tipc_node_find(net, prev_node);
2034                 if (!node) {
2035                         /* We never set seq or call nl_dump_check_consistent()
2036                          * this means that setting prev_seq here will cause the
2037                          * consistence check to fail in the netlink callback
2038                          * handler. Resulting in the last NLMSG_DONE message
2039                          * having the NLM_F_DUMP_INTR flag set.
2040                          */
2041                         cb->prev_seq = 1;
2042                         goto out;
2043                 }
2044                 tipc_node_put(node);
2045
2046                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2047                                                  list) {
2048                         tipc_node_lock(node);
2049                         err = __tipc_nl_add_node_links(net, &msg, node,
2050                                                        &prev_link);
2051                         tipc_node_unlock(node);
2052                         if (err)
2053                                 goto out;
2054
2055                         prev_node = node->addr;
2056                 }
2057         } else {
2058                 err = tipc_nl_add_bc_link(net, &msg);
2059                 if (err)
2060                         goto out;
2061
2062                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2063                         tipc_node_lock(node);
2064                         err = __tipc_nl_add_node_links(net, &msg, node,
2065                                                        &prev_link);
2066                         tipc_node_unlock(node);
2067                         if (err)
2068                                 goto out;
2069
2070                         prev_node = node->addr;
2071                 }
2072         }
2073         done = 1;
2074 out:
2075         rcu_read_unlock();
2076
2077         cb->args[0] = prev_node;
2078         cb->args[1] = prev_link;
2079         cb->args[2] = done;
2080
2081         return skb->len;
2082 }
2083
2084 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2085 {
2086         struct net *net = genl_info_net(info);
2087         struct tipc_nl_msg msg;
2088         char *name;
2089         int err;
2090
2091         msg.portid = info->snd_portid;
2092         msg.seq = info->snd_seq;
2093
2094         if (!info->attrs[TIPC_NLA_LINK_NAME])
2095                 return -EINVAL;
2096         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2097
2098         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2099         if (!msg.skb)
2100                 return -ENOMEM;
2101
2102         if (strcmp(name, tipc_bclink_name) == 0) {
2103                 err = tipc_nl_add_bc_link(net, &msg);
2104                 if (err) {
2105                         nlmsg_free(msg.skb);
2106                         return err;
2107                 }
2108         } else {
2109                 int bearer_id;
2110                 struct tipc_node *node;
2111                 struct tipc_link *link;
2112
2113                 node = tipc_link_find_owner(net, name, &bearer_id);
2114                 if (!node)
2115                         return -EINVAL;
2116
2117                 tipc_node_lock(node);
2118                 link = node->links[bearer_id].link;
2119                 if (!link) {
2120                         tipc_node_unlock(node);
2121                         nlmsg_free(msg.skb);
2122                         return -EINVAL;
2123                 }
2124
2125                 err = __tipc_nl_add_link(net, &msg, link, 0);
2126                 tipc_node_unlock(node);
2127                 if (err) {
2128                         nlmsg_free(msg.skb);
2129                         return err;
2130                 }
2131         }
2132
2133         return genlmsg_reply(msg.skb, info);
2134 }
2135
2136 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2137 {
2138         int err;
2139         char *link_name;
2140         unsigned int bearer_id;
2141         struct tipc_link *link;
2142         struct tipc_node *node;
2143         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2144         struct net *net = sock_net(skb->sk);
2145
2146         if (!info->attrs[TIPC_NLA_LINK])
2147                 return -EINVAL;
2148
2149         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2150                                info->attrs[TIPC_NLA_LINK],
2151                                tipc_nl_link_policy);
2152         if (err)
2153                 return err;
2154
2155         if (!attrs[TIPC_NLA_LINK_NAME])
2156                 return -EINVAL;
2157
2158         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2159
2160         if (strcmp(link_name, tipc_bclink_name) == 0) {
2161                 err = tipc_bclink_reset_stats(net);
2162                 if (err)
2163                         return err;
2164                 return 0;
2165         }
2166
2167         node = tipc_link_find_owner(net, link_name, &bearer_id);
2168         if (!node)
2169                 return -EINVAL;
2170
2171         tipc_node_lock(node);
2172
2173         link = node->links[bearer_id].link;
2174         if (!link) {
2175                 tipc_node_unlock(node);
2176                 return -EINVAL;
2177         }
2178
2179         link_reset_statistics(link);
2180
2181         tipc_node_unlock(node);
2182
2183         return 0;
2184 }