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  * Out-of-range value for link session numbers
  81  */
  82 #define INVALID_SESSION 0x10000
  83
  84 /*
  85  * Link state events:
  86  */
  87 #define  STARTING_EVT    856384768      /* link processing trigger */
  88 #define  TRAFFIC_MSG_EVT 560815u        /* rx'd ??? */
  89 #define  SILENCE_EVT     560817u        /* timer dicovered silence from peer */
  90
  91 /*
  92  * State value stored in 'failover_pkts'
  93  */
  94 #define FIRST_FAILOVER 0xffffu
  95
  96 static void link_handle_out_of_seq_msg(struct tipc_link *link,
  97                                        struct sk_buff *skb);
  98 static void tipc_link_proto_rcv(struct tipc_link *link,
  99                                 struct sk_buff *skb);
 100 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol);
 101 static void link_state_event(struct tipc_link *l_ptr, u32 event);
 102 static void link_reset_statistics(struct tipc_link *l_ptr);
 103 static void link_print(struct tipc_link *l_ptr, const char *str);
 104 static void tipc_link_sync_xmit(struct tipc_link *l);
 105 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 106 static void tipc_link_input(struct tipc_link *l, struct sk_buff *skb);
 107 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb);
 108 static bool tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb);
 109 static void link_set_timer(struct tipc_link *link, unsigned long time);
 110 /*
 111  *  Simple link routines
 112  */
 113 static unsigned int align(unsigned int i)
 114 {
 115         return (i + 3) & ~3u;
 116 }
 117
 118 static void tipc_link_release(struct kref *kref)
 119 {
 120         kfree(container_of(kref, struct tipc_link, ref));
 121 }
 122
 123 static void tipc_link_get(struct tipc_link *l_ptr)
 124 {
 125         kref_get(&l_ptr->ref);
 126 }
 127
 128 static void tipc_link_put(struct tipc_link *l_ptr)
 129 {
 130         kref_put(&l_ptr->ref, tipc_link_release);
 131 }
 132
 133 static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
 134 {
 135         if (l->owner->active_links[0] != l)
 136                 return l->owner->active_links[0];
 137         return l->owner->active_links[1];
 138 }
 139
 140 /*
 141  *  Simple non-static link routines (i.e. referenced outside this file)
 142  */
 143 int tipc_link_is_up(struct tipc_link *l_ptr)
 144 {
 145         if (!l_ptr)
 146                 return 0;
 147         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 148 }
 149
 150 int tipc_link_is_active(struct tipc_link *l_ptr)
 151 {
 152         return  (l_ptr->owner->active_links[0] == l_ptr) ||
 153                 (l_ptr->owner->active_links[1] == l_ptr);
 154 }
 155
 156 /**
 157  * link_timeout - handle expiration of link timer
 158  * @l_ptr: pointer to link
 159  */
 160 static void link_timeout(unsigned long data)
 161 {
 162         struct tipc_link *l_ptr = (struct tipc_link *)data;
 163         struct sk_buff *skb;
 164
 165         tipc_node_lock(l_ptr->owner);
 166
 167         /* update counters used in statistical profiling of send traffic */
 168         l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->transmq);
 169         l_ptr->stats.queue_sz_counts++;
 170
 171         skb = skb_peek(&l_ptr->transmq);
 172         if (skb) {
 173                 struct tipc_msg *msg = buf_msg(skb);
 174                 u32 length = msg_size(msg);
 175
 176                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 177                     (msg_type(msg) == FIRST_FRAGMENT)) {
 178                         length = msg_size(msg_get_wrapped(msg));
 179                 }
 180                 if (length) {
 181                         l_ptr->stats.msg_lengths_total += length;
 182                         l_ptr->stats.msg_length_counts++;
 183                         if (length <= 64)
 184                                 l_ptr->stats.msg_length_profile[0]++;
 185                         else if (length <= 256)
 186                                 l_ptr->stats.msg_length_profile[1]++;
 187                         else if (length <= 1024)
 188                                 l_ptr->stats.msg_length_profile[2]++;
 189                         else if (length <= 4096)
 190                                 l_ptr->stats.msg_length_profile[3]++;
 191                         else if (length <= 16384)
 192                                 l_ptr->stats.msg_length_profile[4]++;
 193                         else if (length <= 32768)
 194                                 l_ptr->stats.msg_length_profile[5]++;
 195                         else
 196                                 l_ptr->stats.msg_length_profile[6]++;
 197                 }
 198         }
 199
 200         /* do all other link processing performed on a periodic basis */
 201         if (l_ptr->silent_intv_cnt || tipc_bclink_acks_missing(l_ptr->owner))
 202                 link_state_event(l_ptr, SILENCE_EVT);
 203         l_ptr->silent_intv_cnt++;
 204         if (skb_queue_len(&l_ptr->backlogq))
 205                 tipc_link_push_packets(l_ptr);
 206         link_set_timer(l_ptr, l_ptr->keepalive_intv);
 207         tipc_node_unlock(l_ptr->owner);
 208         tipc_link_put(l_ptr);
 209 }
 210
 211 static void link_set_timer(struct tipc_link *link, unsigned long time)
 212 {
 213         if (!mod_timer(&link->timer, jiffies + time))
 214                 tipc_link_get(link);
 215 }
 216
 217 /**
 218  * tipc_link_create - create a new link
 219  * @n_ptr: pointer to associated node
 220  * @b_ptr: pointer to associated bearer
 221  * @media_addr: media address to use when sending messages over link
 222  *
 223  * Returns pointer to link.
 224  */
 225 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 226                                    struct tipc_bearer *b_ptr,
 227                                    const struct tipc_media_addr *media_addr)
 228 {
 229         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 230         struct tipc_link *l_ptr;
 231         struct tipc_msg *msg;
 232         char *if_name;
 233         char addr_string[16];
 234         u32 peer = n_ptr->addr;
 235
 236         if (n_ptr->link_cnt >= MAX_BEARERS) {
 237                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 238                 pr_err("Cannot establish %uth link to %s. Max %u allowed.\n",
 239                        n_ptr->link_cnt, addr_string, MAX_BEARERS);
 240                 return NULL;
 241         }
 242
 243         if (n_ptr->links[b_ptr->identity]) {
 244                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 245                 pr_err("Attempt to establish second link on <%s> to %s\n",
 246                        b_ptr->name, addr_string);
 247                 return NULL;
 248         }
 249
 250         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 251         if (!l_ptr) {
 252                 pr_warn("Link creation failed, no memory\n");
 253                 return NULL;
 254         }
 255         kref_init(&l_ptr->ref);
 256         l_ptr->addr = peer;
 257         if_name = strchr(b_ptr->name, ':') + 1;
 258         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 259                 tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
 260                 tipc_node(tn->own_addr),
 261                 if_name,
 262                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 263                 /* note: peer i/f name is updated by reset/activate message */
 264         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 265         l_ptr->owner = n_ptr;
 266         l_ptr->peer_session = INVALID_SESSION;
 267         l_ptr->bearer_id = b_ptr->identity;
 268         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 269         l_ptr->state = RESET_UNKNOWN;
 270
 271         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 272         msg = l_ptr->pmsg;
 273         tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
 274                       l_ptr->addr);
 275         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 276         msg_set_session(msg, (tn->random & 0xffff));
 277         msg_set_bearer_id(msg, b_ptr->identity);
 278         strcpy((char *)msg_data(msg), if_name);
 279         l_ptr->net_plane = b_ptr->net_plane;
 280         l_ptr->advertised_mtu = b_ptr->mtu;
 281         l_ptr->mtu = l_ptr->advertised_mtu;
 282         l_ptr->priority = b_ptr->priority;
 283         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 284         l_ptr->snd_nxt = 1;
 285         __skb_queue_head_init(&l_ptr->transmq);
 286         __skb_queue_head_init(&l_ptr->backlogq);
 287         __skb_queue_head_init(&l_ptr->deferdq);
 288         skb_queue_head_init(&l_ptr->wakeupq);
 289         skb_queue_head_init(&l_ptr->inputq);
 290         skb_queue_head_init(&l_ptr->namedq);
 291         link_reset_statistics(l_ptr);
 292         tipc_node_attach_link(n_ptr, l_ptr);
 293         setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr);
 294         link_state_event(l_ptr, STARTING_EVT);
 295
 296         return l_ptr;
 297 }
 298
 299 /**
 300  * tipc_link_delete - Delete a link
 301  * @l: link to be deleted
 302  */
 303 void tipc_link_delete(struct tipc_link *l)
 304 {
 305         tipc_link_reset(l);
 306         if (del_timer(&l->timer))
 307                 tipc_link_put(l);
 308         l->flags |= LINK_STOPPED;
 309         /* Delete link now, or when timer is finished: */
 310         tipc_link_reset_fragments(l);
 311         tipc_node_detach_link(l->owner, l);
 312         tipc_link_put(l);
 313 }
 314
 315 void tipc_link_delete_list(struct net *net, unsigned int bearer_id)
 316 {
 317         struct tipc_net *tn = net_generic(net, tipc_net_id);
 318         struct tipc_link *link;
 319         struct tipc_node *node;
 320
 321         rcu_read_lock();
 322         list_for_each_entry_rcu(node, &tn->node_list, list) {
 323                 tipc_node_lock(node);
 324                 link = node->links[bearer_id];
 325                 if (link)
 326                         tipc_link_delete(link);
 327                 tipc_node_unlock(node);
 328         }
 329         rcu_read_unlock();
 330 }
 331
 332 /**
 333  * link_schedule_user - schedule a message sender for wakeup after congestion
 334  * @link: congested link
 335  * @list: message that was attempted sent
 336  * Create pseudo msg to send back to user when congestion abates
 337  * Only consumes message if there is an error
 338  */
 339 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 340 {
 341         struct tipc_msg *msg = buf_msg(skb_peek(list));
 342         int imp = msg_importance(msg);
 343         u32 oport = msg_origport(msg);
 344         u32 addr = link_own_addr(link);
 345         struct sk_buff *skb;
 346
 347         /* This really cannot happen...  */
 348         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 349                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 350                 tipc_link_reset(link);
 351                 goto err;
 352         }
 353         /* Non-blocking sender: */
 354         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 355                 return -ELINKCONG;
 356
 357         /* Create and schedule wakeup pseudo message */
 358         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 359                               addr, addr, oport, 0, 0);
 360         if (!skb)
 361                 goto err;
 362         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 363         TIPC_SKB_CB(skb)->chain_imp = imp;
 364         skb_queue_tail(&link->wakeupq, skb);
 365         link->stats.link_congs++;
 366         return -ELINKCONG;
 367 err:
 368         __skb_queue_purge(list);
 369         return -ENOBUFS;
 370 }
 371
 372 /**
 373  * link_prepare_wakeup - prepare users for wakeup after congestion
 374  * @link: congested link
 375  * Move a number of waiting users, as permitted by available space in
 376  * the send queue, from link wait queue to node wait queue for wakeup
 377  */
 378 void link_prepare_wakeup(struct tipc_link *l)
 379 {
 380         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 381         int imp, lim;
 382         struct sk_buff *skb, *tmp;
 383
 384         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 385                 imp = TIPC_SKB_CB(skb)->chain_imp;
 386                 lim = l->window + l->backlog[imp].limit;
 387                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 388                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 389                         break;
 390                 skb_unlink(skb, &l->wakeupq);
 391                 skb_queue_tail(&l->inputq, skb);
 392                 l->owner->inputq = &l->inputq;
 393                 l->owner->action_flags |= TIPC_MSG_EVT;
 394         }
 395 }
 396
 397 /**
 398  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 399  * @l_ptr: pointer to link
 400  */
 401 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 402 {
 403         kfree_skb(l_ptr->reasm_buf);
 404         l_ptr->reasm_buf = NULL;
 405 }
 406
 407 static void tipc_link_purge_backlog(struct tipc_link *l)
 408 {
 409         __skb_queue_purge(&l->backlogq);
 410         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 411         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 412         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 413         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 414         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 415 }
 416
 417 /**
 418  * tipc_link_purge_queues - purge all pkt queues associated with link
 419  * @l_ptr: pointer to link
 420  */
 421 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 422 {
 423         __skb_queue_purge(&l_ptr->deferdq);
 424         __skb_queue_purge(&l_ptr->transmq);
 425         tipc_link_purge_backlog(l_ptr);
 426         tipc_link_reset_fragments(l_ptr);
 427 }
 428
 429 void tipc_link_reset(struct tipc_link *l_ptr)
 430 {
 431         u32 prev_state = l_ptr->state;
 432         int was_active_link = tipc_link_is_active(l_ptr);
 433         struct tipc_node *owner = l_ptr->owner;
 434         struct tipc_link *pl = tipc_parallel_link(l_ptr);
 435
 436         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 437
 438         /* Link is down, accept any session */
 439         l_ptr->peer_session = INVALID_SESSION;
 440
 441         /* Prepare for renewed mtu size negotiation */
 442         l_ptr->mtu = l_ptr->advertised_mtu;
 443
 444         l_ptr->state = RESET_UNKNOWN;
 445
 446         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 447                 return;
 448
 449         tipc_node_link_down(l_ptr->owner, l_ptr);
 450         tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 451
 452         if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
 453                 l_ptr->flags |= LINK_FAILINGOVER;
 454                 l_ptr->failover_checkpt = l_ptr->rcv_nxt;
 455                 pl->failover_pkts = FIRST_FAILOVER;
 456                 pl->failover_checkpt = l_ptr->rcv_nxt;
 457                 pl->failover_skb = l_ptr->reasm_buf;
 458         } else {
 459                 kfree_skb(l_ptr->reasm_buf);
 460         }
 461         /* Clean up all queues, except inputq: */
 462         __skb_queue_purge(&l_ptr->transmq);
 463         __skb_queue_purge(&l_ptr->deferdq);
 464         if (!owner->inputq)
 465                 owner->inputq = &l_ptr->inputq;
 466         skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
 467         if (!skb_queue_empty(owner->inputq))
 468                 owner->action_flags |= TIPC_MSG_EVT;
 469         tipc_link_purge_backlog(l_ptr);
 470         l_ptr->reasm_buf = NULL;
 471         l_ptr->rcv_unacked = 0;
 472         l_ptr->snd_nxt = 1;
 473         l_ptr->silent_intv_cnt = 0;
 474         l_ptr->stale_count = 0;
 475         link_reset_statistics(l_ptr);
 476 }
 477
 478 static void link_activate(struct tipc_link *link)
 479 {
 480         struct tipc_node *node = link->owner;
 481
 482         link->rcv_nxt = 1;
 483         link->stats.recv_info = 1;
 484         link->silent_intv_cnt = 0;
 485         tipc_node_link_up(node, link);
 486         tipc_bearer_add_dest(node->net, link->bearer_id, link->addr);
 487 }
 488
 489 /**
 490  * link_state_event - link finite state machine
 491  * @l_ptr: pointer to link
 492  * @event: state machine event to process
 493  */
 494 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 495 {
 496         struct tipc_link *other;
 497         unsigned long timer_intv = l_ptr->keepalive_intv;
 498
 499         if (l_ptr->flags & LINK_STOPPED)
 500                 return;
 501
 502         if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 503                 return;         /* Not yet. */
 504
 505         if (l_ptr->flags & LINK_FAILINGOVER)
 506                 return;
 507
 508         switch (l_ptr->state) {
 509         case WORKING_WORKING:
 510                 switch (event) {
 511                 case TRAFFIC_MSG_EVT:
 512                 case ACTIVATE_MSG:
 513                         l_ptr->silent_intv_cnt = 0;
 514                         break;
 515                 case SILENCE_EVT:
 516                         if (!l_ptr->silent_intv_cnt) {
 517                                 if (tipc_bclink_acks_missing(l_ptr->owner))
 518                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 519                                                              0, 0, 0, 0);
 520                                 break;
 521                         }
 522                         l_ptr->state = WORKING_UNKNOWN;
 523                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 524                         break;
 525                 case RESET_MSG:
 526                         pr_debug("%s<%s>, requested by peer\n",
 527                                  link_rst_msg, l_ptr->name);
 528                         tipc_link_reset(l_ptr);
 529                         l_ptr->state = RESET_RESET;
 530                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 531                                              0, 0, 0, 0);
 532                         break;
 533                 default:
 534                         pr_debug("%s%u in WW state\n", link_unk_evt, event);
 535                 }
 536                 break;
 537         case WORKING_UNKNOWN:
 538                 switch (event) {
 539                 case TRAFFIC_MSG_EVT:
 540                 case ACTIVATE_MSG:
 541                         l_ptr->state = WORKING_WORKING;
 542                         l_ptr->silent_intv_cnt = 0;
 543                         break;
 544                 case RESET_MSG:
 545                         pr_debug("%s<%s>, requested by peer while probing\n",
 546                                  link_rst_msg, l_ptr->name);
 547                         tipc_link_reset(l_ptr);
 548                         l_ptr->state = RESET_RESET;
 549                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 550                                              0, 0, 0, 0);
 551                         break;
 552                 case SILENCE_EVT:
 553                         if (!l_ptr->silent_intv_cnt) {
 554                                 l_ptr->state = WORKING_WORKING;
 555                                 if (tipc_bclink_acks_missing(l_ptr->owner))
 556                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 557                                                              0, 0, 0, 0);
 558                         } else if (l_ptr->silent_intv_cnt <
 559                                    l_ptr->abort_limit) {
 560                                 tipc_link_proto_xmit(l_ptr, STATE_MSG,
 561                                                      1, 0, 0, 0);
 562                         } else {        /* Link has failed */
 563                                 pr_debug("%s<%s>, peer not responding\n",
 564                                          link_rst_msg, l_ptr->name);
 565                                 tipc_link_reset(l_ptr);
 566                                 l_ptr->state = RESET_UNKNOWN;
 567                                 tipc_link_proto_xmit(l_ptr, RESET_MSG,
 568                                                      0, 0, 0, 0);
 569                         }
 570                         break;
 571                 default:
 572                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 573                 }
 574                 break;
 575         case RESET_UNKNOWN:
 576                 switch (event) {
 577                 case TRAFFIC_MSG_EVT:
 578                         break;
 579                 case ACTIVATE_MSG:
 580                         other = l_ptr->owner->active_links[0];
 581                         if (other && link_working_unknown(other))
 582                                 break;
 583                         l_ptr->state = WORKING_WORKING;
 584                         link_activate(l_ptr);
 585                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 586                         if (l_ptr->owner->working_links == 1)
 587                                 tipc_link_sync_xmit(l_ptr);
 588                         break;
 589                 case RESET_MSG:
 590                         l_ptr->state = RESET_RESET;
 591                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 592                                              1, 0, 0, 0);
 593                         break;
 594                 case STARTING_EVT:
 595                         l_ptr->flags |= LINK_STARTED;
 596                         link_set_timer(l_ptr, timer_intv);
 597                         break;
 598                 case SILENCE_EVT:
 599                         tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0);
 600                         break;
 601                 default:
 602                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 603                 }
 604                 break;
 605         case RESET_RESET:
 606                 switch (event) {
 607                 case TRAFFIC_MSG_EVT:
 608                 case ACTIVATE_MSG:
 609                         other = l_ptr->owner->active_links[0];
 610                         if (other && link_working_unknown(other))
 611                                 break;
 612                         l_ptr->state = WORKING_WORKING;
 613                         link_activate(l_ptr);
 614                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 615                         if (l_ptr->owner->working_links == 1)
 616                                 tipc_link_sync_xmit(l_ptr);
 617                         break;
 618                 case RESET_MSG:
 619                         break;
 620                 case SILENCE_EVT:
 621                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 622                                              0, 0, 0, 0);
 623                         break;
 624                 default:
 625                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 626                 }
 627                 break;
 628         default:
 629                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 630         }
 631 }
 632
 633 /**
 634  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 635  * @link: link to use
 636  * @list: chain of buffers containing message
 637  *
 638  * Consumes the buffer chain, except when returning -ELINKCONG,
 639  * since the caller then may want to make more send attempts.
 640  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 641  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 642  */
 643 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 644                      struct sk_buff_head *list)
 645 {
 646         struct tipc_msg *msg = buf_msg(skb_peek(list));
 647         unsigned int maxwin = link->window;
 648         unsigned int i, imp = msg_importance(msg);
 649         uint mtu = link->mtu;
 650         u16 ack = mod(link->rcv_nxt - 1);
 651         u16 seqno = link->snd_nxt;
 652         u16 bc_last_in = link->owner->bclink.last_in;
 653         struct tipc_media_addr *addr = &link->media_addr;
 654         struct sk_buff_head *transmq = &link->transmq;
 655         struct sk_buff_head *backlogq = &link->backlogq;
 656         struct sk_buff *skb, *bskb;
 657
 658         /* Match msg importance against this and all higher backlog limits: */
 659         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 660                 if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
 661                         return link_schedule_user(link, list);
 662         }
 663         if (unlikely(msg_size(msg) > mtu)) {
 664                 __skb_queue_purge(list);
 665                 return -EMSGSIZE;
 666         }
 667         /* Prepare each packet for sending, and add to relevant queue: */
 668         while (skb_queue_len(list)) {
 669                 skb = skb_peek(list);
 670                 msg = buf_msg(skb);
 671                 msg_set_seqno(msg, seqno);
 672                 msg_set_ack(msg, ack);
 673                 msg_set_bcast_ack(msg, bc_last_in);
 674
 675                 if (likely(skb_queue_len(transmq) < maxwin)) {
 676                         __skb_dequeue(list);
 677                         __skb_queue_tail(transmq, skb);
 678                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 679                         link->rcv_unacked = 0;
 680                         seqno++;
 681                         continue;
 682                 }
 683                 if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
 684                         kfree_skb(__skb_dequeue(list));
 685                         link->stats.sent_bundled++;
 686                         continue;
 687                 }
 688                 if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
 689                         kfree_skb(__skb_dequeue(list));
 690                         __skb_queue_tail(backlogq, bskb);
 691                         link->backlog[msg_importance(buf_msg(bskb))].len++;
 692                         link->stats.sent_bundled++;
 693                         link->stats.sent_bundles++;
 694                         continue;
 695                 }
 696                 link->backlog[imp].len += skb_queue_len(list);
 697                 skb_queue_splice_tail_init(list, backlogq);
 698         }
 699         link->snd_nxt = seqno;
 700         return 0;
 701 }
 702
 703 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
 704 {
 705         skb_queue_head_init(list);
 706         __skb_queue_tail(list, skb);
 707 }
 708
 709 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 710 {
 711         struct sk_buff_head head;
 712
 713         skb2list(skb, &head);
 714         return __tipc_link_xmit(link->owner->net, link, &head);
 715 }
 716
 717 /* tipc_link_xmit_skb(): send single buffer to destination
 718  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
 719  * messages, which will not be rejected
 720  * The only exception is datagram messages rerouted after secondary
 721  * lookup, which are rare and safe to dispose of anyway.
 722  * TODO: Return real return value, and let callers use
 723  * tipc_wait_for_sendpkt() where applicable
 724  */
 725 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 726                        u32 selector)
 727 {
 728         struct sk_buff_head head;
 729         int rc;
 730
 731         skb2list(skb, &head);
 732         rc = tipc_link_xmit(net, &head, dnode, selector);
 733         if (rc == -ELINKCONG)
 734                 kfree_skb(skb);
 735         return 0;
 736 }
 737
 738 /**
 739  * tipc_link_xmit() is the general link level function for message sending
 740  * @net: the applicable net namespace
 741  * @list: chain of buffers containing message
 742  * @dsz: amount of user data to be sent
 743  * @dnode: address of destination node
 744  * @selector: a number used for deterministic link selection
 745  * Consumes the buffer chain, except when returning -ELINKCONG
 746  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 747  */
 748 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
 749                    u32 selector)
 750 {
 751         struct tipc_link *link = NULL;
 752         struct tipc_node *node;
 753         int rc = -EHOSTUNREACH;
 754
 755         node = tipc_node_find(net, dnode);
 756         if (node) {
 757                 tipc_node_lock(node);
 758                 link = node->active_links[selector & 1];
 759                 if (link)
 760                         rc = __tipc_link_xmit(net, link, list);
 761                 tipc_node_unlock(node);
 762                 tipc_node_put(node);
 763         }
 764         if (link)
 765                 return rc;
 766
 767         if (likely(in_own_node(net, dnode))) {
 768                 tipc_sk_rcv(net, list);
 769                 return 0;
 770         }
 771
 772         __skb_queue_purge(list);
 773         return rc;
 774 }
 775
 776 /*
 777  * tipc_link_sync_xmit - synchronize broadcast link endpoints.
 778  *
 779  * Give a newly added peer node the sequence number where it should
 780  * start receiving and acking broadcast packets.
 781  *
 782  * Called with node locked
 783  */
 784 static void tipc_link_sync_xmit(struct tipc_link *link)
 785 {
 786         struct sk_buff *skb;
 787         struct tipc_msg *msg;
 788
 789         skb = tipc_buf_acquire(INT_H_SIZE);
 790         if (!skb)
 791                 return;
 792
 793         msg = buf_msg(skb);
 794         tipc_msg_init(link_own_addr(link), msg, BCAST_PROTOCOL, STATE_MSG,
 795                       INT_H_SIZE, link->addr);
 796         msg_set_last_bcast(msg, link->owner->bclink.acked);
 797         __tipc_link_xmit_skb(link, skb);
 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_reset_all(struct tipc_node *node)
 851 {
 852         char addr_string[16];
 853         u32 i;
 854
 855         tipc_node_lock(node);
 856
 857         pr_warn("Resetting all links to %s\n",
 858                 tipc_addr_string_fill(addr_string, node->addr));
 859
 860         for (i = 0; i < MAX_BEARERS; i++) {
 861                 if (node->links[i]) {
 862                         link_print(node->links[i], "Resetting link\n");
 863                         tipc_link_reset(node->links[i]);
 864                 }
 865         }
 866
 867         tipc_node_unlock(node);
 868 }
 869
 870 static void link_retransmit_failure(struct tipc_link *l_ptr,
 871                                     struct sk_buff *buf)
 872 {
 873         struct tipc_msg *msg = buf_msg(buf);
 874         struct net *net = l_ptr->owner->net;
 875
 876         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 877
 878         if (l_ptr->addr) {
 879                 /* Handle failure on standard link */
 880                 link_print(l_ptr, "Resetting link\n");
 881                 tipc_link_reset(l_ptr);
 882
 883         } else {
 884                 /* Handle failure on broadcast link */
 885                 struct tipc_node *n_ptr;
 886                 char addr_string[16];
 887
 888                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 889                 pr_cont("Outstanding acks: %lu\n",
 890                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 891
 892                 n_ptr = tipc_bclink_retransmit_to(net);
 893
 894                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 895                 pr_info("Broadcast link info for %s\n", addr_string);
 896                 pr_info("Reception permitted: %d,  Acked: %u\n",
 897                         n_ptr->bclink.recv_permitted,
 898                         n_ptr->bclink.acked);
 899                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 900                         n_ptr->bclink.last_in,
 901                         n_ptr->bclink.oos_state,
 902                         n_ptr->bclink.last_sent);
 903
 904                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 905                 l_ptr->stale_count = 0;
 906         }
 907 }
 908
 909 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 910                           u32 retransmits)
 911 {
 912         struct tipc_msg *msg;
 913
 914         if (!skb)
 915                 return;
 916
 917         msg = buf_msg(skb);
 918
 919         /* Detect repeated retransmit failures */
 920         if (l_ptr->last_retransm == msg_seqno(msg)) {
 921                 if (++l_ptr->stale_count > 100) {
 922                         link_retransmit_failure(l_ptr, skb);
 923                         return;
 924                 }
 925         } else {
 926                 l_ptr->last_retransm = msg_seqno(msg);
 927                 l_ptr->stale_count = 1;
 928         }
 929
 930         skb_queue_walk_from(&l_ptr->transmq, skb) {
 931                 if (!retransmits)
 932                         break;
 933                 msg = buf_msg(skb);
 934                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
 935                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 936                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 937                                  &l_ptr->media_addr);
 938                 retransmits--;
 939                 l_ptr->stats.retransmitted++;
 940         }
 941 }
 942
 943 /* link_synch(): check if all packets arrived before the synch
 944  *               point have been consumed
 945  * Returns true if the parallel links are synched, otherwise false
 946  */
 947 static bool link_synch(struct tipc_link *l)
 948 {
 949         unsigned int post_synch;
 950         struct tipc_link *pl;
 951
 952         pl  = tipc_parallel_link(l);
 953         if (pl == l)
 954                 goto synched;
 955
 956         /* Was last pre-synch packet added to input queue ? */
 957         if (less_eq(pl->rcv_nxt, l->synch_point))
 958                 return false;
 959
 960         /* Is it still in the input queue ? */
 961         post_synch = mod(pl->rcv_nxt - l->synch_point) - 1;
 962         if (skb_queue_len(&pl->inputq) > post_synch)
 963                 return false;
 964 synched:
 965         l->flags &= ~LINK_SYNCHING;
 966         return true;
 967 }
 968
 969 static void link_retrieve_defq(struct tipc_link *link,
 970                                struct sk_buff_head *list)
 971 {
 972         u16 seq_no;
 973
 974         if (skb_queue_empty(&link->deferdq))
 975                 return;
 976
 977         seq_no = buf_seqno(skb_peek(&link->deferdq));
 978         if (seq_no == link->rcv_nxt)
 979                 skb_queue_splice_tail_init(&link->deferdq, list);
 980 }
 981
 982 /**
 983  * tipc_rcv - process TIPC packets/messages arriving from off-node
 984  * @net: the applicable net namespace
 985  * @skb: TIPC packet
 986  * @b_ptr: pointer to bearer message arrived on
 987  *
 988  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
 989  * structure (i.e. cannot be NULL), but bearer can be inactive.
 990  */
 991 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
 992 {
 993         struct tipc_net *tn = net_generic(net, tipc_net_id);
 994         struct sk_buff_head head;
 995         struct tipc_node *n_ptr;
 996         struct tipc_link *l_ptr;
 997         struct sk_buff *skb1, *tmp;
 998         struct tipc_msg *msg;
 999         u16 seq_no;
1000         u16 ackd;
1001         u32 released;
1002
1003         skb2list(skb, &head);
1004
1005         while ((skb = __skb_dequeue(&head))) {
1006                 /* Ensure message is well-formed */
1007                 if (unlikely(!tipc_msg_validate(skb)))
1008                         goto discard;
1009
1010                 /* Handle arrival of a non-unicast link message */
1011                 msg = buf_msg(skb);
1012                 if (unlikely(msg_non_seq(msg))) {
1013                         if (msg_user(msg) ==  LINK_CONFIG)
1014                                 tipc_disc_rcv(net, skb, b_ptr);
1015                         else
1016                                 tipc_bclink_rcv(net, skb);
1017                         continue;
1018                 }
1019
1020                 /* Discard unicast link messages destined for another node */
1021                 if (unlikely(!msg_short(msg) &&
1022                              (msg_destnode(msg) != tn->own_addr)))
1023                         goto discard;
1024
1025                 /* Locate neighboring node that sent message */
1026                 n_ptr = tipc_node_find(net, msg_prevnode(msg));
1027                 if (unlikely(!n_ptr))
1028                         goto discard;
1029
1030                 tipc_node_lock(n_ptr);
1031                 /* Locate unicast link endpoint that should handle message */
1032                 l_ptr = n_ptr->links[b_ptr->identity];
1033                 if (unlikely(!l_ptr))
1034                         goto unlock;
1035
1036                 /* Verify that communication with node is currently allowed */
1037                 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
1038                     msg_user(msg) == LINK_PROTOCOL &&
1039                     (msg_type(msg) == RESET_MSG ||
1040                     msg_type(msg) == ACTIVATE_MSG) &&
1041                     !msg_redundant_link(msg))
1042                         n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
1043
1044                 if (tipc_node_blocked(n_ptr))
1045                         goto unlock;
1046
1047                 /* Validate message sequence number info */
1048                 seq_no = msg_seqno(msg);
1049                 ackd = msg_ack(msg);
1050
1051                 /* Release acked messages */
1052                 if (unlikely(n_ptr->bclink.acked != msg_bcast_ack(msg)))
1053                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1054
1055                 released = 0;
1056                 skb_queue_walk_safe(&l_ptr->transmq, skb1, tmp) {
1057                         if (more(buf_seqno(skb1), ackd))
1058                                 break;
1059                          __skb_unlink(skb1, &l_ptr->transmq);
1060                          kfree_skb(skb1);
1061                          released = 1;
1062                 }
1063
1064                 /* Try sending any messages link endpoint has pending */
1065                 if (unlikely(skb_queue_len(&l_ptr->backlogq)))
1066                         tipc_link_push_packets(l_ptr);
1067
1068                 if (released && !skb_queue_empty(&l_ptr->wakeupq))
1069                         link_prepare_wakeup(l_ptr);
1070
1071                 /* Process the incoming packet */
1072                 if (unlikely(!link_working_working(l_ptr))) {
1073                         if (msg_user(msg) == LINK_PROTOCOL) {
1074                                 tipc_link_proto_rcv(l_ptr, skb);
1075                                 link_retrieve_defq(l_ptr, &head);
1076                                 skb = NULL;
1077                                 goto unlock;
1078                         }
1079
1080                         /* Traffic message. Conditionally activate link */
1081                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1082
1083                         if (link_working_working(l_ptr)) {
1084                                 /* Re-insert buffer in front of queue */
1085                                 __skb_queue_head(&head, skb);
1086                                 skb = NULL;
1087                                 goto unlock;
1088                         }
1089                         goto unlock;
1090                 }
1091
1092                 /* Link is now in state WORKING_WORKING */
1093                 if (unlikely(seq_no != l_ptr->rcv_nxt)) {
1094                         link_handle_out_of_seq_msg(l_ptr, skb);
1095                         link_retrieve_defq(l_ptr, &head);
1096                         skb = NULL;
1097                         goto unlock;
1098                 }
1099                 l_ptr->silent_intv_cnt = 0;
1100
1101                 /* Synchronize with parallel link if applicable */
1102                 if (unlikely((l_ptr->flags & LINK_SYNCHING) && !msg_dup(msg))) {
1103                         if (!link_synch(l_ptr))
1104                                 goto unlock;
1105                 }
1106                 l_ptr->rcv_nxt++;
1107                 if (unlikely(!skb_queue_empty(&l_ptr->deferdq)))
1108                         link_retrieve_defq(l_ptr, &head);
1109                 if (unlikely(++l_ptr->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
1110                         l_ptr->stats.sent_acks++;
1111                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1112                 }
1113                 tipc_link_input(l_ptr, skb);
1114                 skb = NULL;
1115 unlock:
1116                 tipc_node_unlock(n_ptr);
1117                 tipc_node_put(n_ptr);
1118 discard:
1119                 if (unlikely(skb))
1120                         kfree_skb(skb);
1121         }
1122 }
1123
1124 /* tipc_data_input - deliver data and name distr msgs to upper layer
1125  *
1126  * Consumes buffer if message is of right type
1127  * Node lock must be held
1128  */
1129 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
1130 {
1131         struct tipc_node *node = link->owner;
1132         struct tipc_msg *msg = buf_msg(skb);
1133         u32 dport = msg_destport(msg);
1134
1135         switch (msg_user(msg)) {
1136         case TIPC_LOW_IMPORTANCE:
1137         case TIPC_MEDIUM_IMPORTANCE:
1138         case TIPC_HIGH_IMPORTANCE:
1139         case TIPC_CRITICAL_IMPORTANCE:
1140         case CONN_MANAGER:
1141                 if (tipc_skb_queue_tail(&link->inputq, skb, dport)) {
1142                         node->inputq = &link->inputq;
1143                         node->action_flags |= TIPC_MSG_EVT;
1144                 }
1145                 return true;
1146         case NAME_DISTRIBUTOR:
1147                 node->bclink.recv_permitted = true;
1148                 node->namedq = &link->namedq;
1149                 skb_queue_tail(&link->namedq, skb);
1150                 if (skb_queue_len(&link->namedq) == 1)
1151                         node->action_flags |= TIPC_NAMED_MSG_EVT;
1152                 return true;
1153         case MSG_BUNDLER:
1154         case TUNNEL_PROTOCOL:
1155         case MSG_FRAGMENTER:
1156         case BCAST_PROTOCOL:
1157                 return false;
1158         default:
1159                 pr_warn("Dropping received illegal msg type\n");
1160                 kfree_skb(skb);
1161                 return false;
1162         };
1163 }
1164
1165 /* tipc_link_input - process packet that has passed link protocol check
1166  *
1167  * Consumes buffer
1168  * Node lock must be held
1169  */
1170 static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
1171 {
1172         struct tipc_node *node = link->owner;
1173         struct tipc_msg *msg = buf_msg(skb);
1174         struct sk_buff *iskb;
1175         int pos = 0;
1176
1177         if (likely(tipc_data_input(link, skb)))
1178                 return;
1179
1180         switch (msg_user(msg)) {
1181         case TUNNEL_PROTOCOL:
1182                 if (msg_dup(msg)) {
1183                         link->flags |= LINK_SYNCHING;
1184                         link->synch_point = msg_seqno(msg_get_wrapped(msg));
1185                         kfree_skb(skb);
1186                         break;
1187                 }
1188                 if (!tipc_link_failover_rcv(link, &skb))
1189                         break;
1190                 if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
1191                         tipc_data_input(link, skb);
1192                         break;
1193                 }
1194         case MSG_BUNDLER:
1195                 link->stats.recv_bundles++;
1196                 link->stats.recv_bundled += msg_msgcnt(msg);
1197
1198                 while (tipc_msg_extract(skb, &iskb, &pos))
1199                         tipc_data_input(link, iskb);
1200                 break;
1201         case MSG_FRAGMENTER:
1202                 link->stats.recv_fragments++;
1203                 if (tipc_buf_append(&link->reasm_buf, &skb)) {
1204                         link->stats.recv_fragmented++;
1205                         tipc_data_input(link, skb);
1206                 } else if (!link->reasm_buf) {
1207                         tipc_link_reset(link);
1208                 }
1209                 break;
1210         case BCAST_PROTOCOL:
1211                 tipc_link_sync_rcv(node, skb);
1212                 break;
1213         default:
1214                 break;
1215         };
1216 }
1217
1218 /**
1219  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1220  *
1221  * Returns increase in queue length (i.e. 0 or 1)
1222  */
1223 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1224 {
1225         struct sk_buff *skb1;
1226         u16 seq_no = buf_seqno(skb);
1227
1228         /* Empty queue ? */
1229         if (skb_queue_empty(list)) {
1230                 __skb_queue_tail(list, skb);
1231                 return 1;
1232         }
1233
1234         /* Last ? */
1235         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1236                 __skb_queue_tail(list, skb);
1237                 return 1;
1238         }
1239
1240         /* Locate insertion point in queue, then insert; discard if duplicate */
1241         skb_queue_walk(list, skb1) {
1242                 u16 curr_seqno = buf_seqno(skb1);
1243
1244                 if (seq_no == curr_seqno) {
1245                         kfree_skb(skb);
1246                         return 0;
1247                 }
1248
1249                 if (less(seq_no, curr_seqno))
1250                         break;
1251         }
1252
1253         __skb_queue_before(list, skb1, skb);
1254         return 1;
1255 }
1256
1257 /*
1258  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1259  */
1260 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1261                                        struct sk_buff *buf)
1262 {
1263         u32 seq_no = buf_seqno(buf);
1264
1265         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1266                 tipc_link_proto_rcv(l_ptr, buf);
1267                 return;
1268         }
1269
1270         /* Record OOS packet arrival */
1271         l_ptr->silent_intv_cnt = 0;
1272
1273         /*
1274          * Discard packet if a duplicate; otherwise add it to deferred queue
1275          * and notify peer of gap as per protocol specification
1276          */
1277         if (less(seq_no, l_ptr->rcv_nxt)) {
1278                 l_ptr->stats.duplicates++;
1279                 kfree_skb(buf);
1280                 return;
1281         }
1282
1283         if (tipc_link_defer_pkt(&l_ptr->deferdq, buf)) {
1284                 l_ptr->stats.deferred_recv++;
1285                 if ((skb_queue_len(&l_ptr->deferdq) % TIPC_MIN_LINK_WIN) == 1)
1286                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1287         } else {
1288                 l_ptr->stats.duplicates++;
1289         }
1290 }
1291
1292 /*
1293  * Send protocol message to the other endpoint.
1294  */
1295 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1296                           u32 gap, u32 tolerance, u32 priority)
1297 {
1298         struct sk_buff *buf = NULL;
1299         struct tipc_msg *msg = l_ptr->pmsg;
1300         u32 msg_size = sizeof(l_ptr->proto_msg);
1301         int r_flag;
1302         u16 last_rcv;
1303
1304         /* Don't send protocol message during link failover */
1305         if (l_ptr->flags & LINK_FAILINGOVER)
1306                 return;
1307
1308         /* Abort non-RESET send if communication with node is prohibited */
1309         if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG))
1310                 return;
1311
1312         /* Create protocol message with "out-of-sequence" sequence number */
1313         msg_set_type(msg, msg_typ);
1314         msg_set_net_plane(msg, l_ptr->net_plane);
1315         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1316         msg_set_last_bcast(msg, tipc_bclink_get_last_sent(l_ptr->owner->net));
1317
1318         if (msg_typ == STATE_MSG) {
1319                 u16 next_sent = l_ptr->snd_nxt;
1320
1321                 if (!tipc_link_is_up(l_ptr))
1322                         return;
1323                 if (skb_queue_len(&l_ptr->backlogq))
1324                         next_sent = buf_seqno(skb_peek(&l_ptr->backlogq));
1325                 msg_set_next_sent(msg, next_sent);
1326                 if (!skb_queue_empty(&l_ptr->deferdq)) {
1327                         last_rcv = buf_seqno(skb_peek(&l_ptr->deferdq));
1328                         gap = mod(last_rcv - l_ptr->rcv_nxt);
1329                 }
1330                 msg_set_seq_gap(msg, gap);
1331                 if (gap)
1332                         l_ptr->stats.sent_nacks++;
1333                 msg_set_link_tolerance(msg, tolerance);
1334                 msg_set_linkprio(msg, priority);
1335                 msg_set_max_pkt(msg, l_ptr->mtu);
1336                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
1337                 msg_set_probe(msg, probe_msg != 0);
1338                 if (probe_msg)
1339                         l_ptr->stats.sent_probes++;
1340                 l_ptr->stats.sent_states++;
1341         } else {                /* RESET_MSG or ACTIVATE_MSG */
1342                 msg_set_ack(msg, mod(l_ptr->failover_checkpt - 1));
1343                 msg_set_seq_gap(msg, 0);
1344                 msg_set_next_sent(msg, 1);
1345                 msg_set_probe(msg, 0);
1346                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1347                 msg_set_linkprio(msg, l_ptr->priority);
1348                 msg_set_max_pkt(msg, l_ptr->advertised_mtu);
1349         }
1350
1351         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1352         msg_set_redundant_link(msg, r_flag);
1353         msg_set_linkprio(msg, l_ptr->priority);
1354         msg_set_size(msg, msg_size);
1355
1356         msg_set_seqno(msg, mod(l_ptr->snd_nxt + (0xffff / 2)));
1357
1358         buf = tipc_buf_acquire(msg_size);
1359         if (!buf)
1360                 return;
1361
1362         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1363         buf->priority = TC_PRIO_CONTROL;
1364         tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, buf,
1365                          &l_ptr->media_addr);
1366         l_ptr->rcv_unacked = 0;
1367         kfree_skb(buf);
1368 }
1369
1370 /*
1371  * Receive protocol message :
1372  * Note that network plane id propagates through the network, and may
1373  * change at any time. The node with lowest address rules
1374  */
1375 static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
1376                                 struct sk_buff *buf)
1377 {
1378         u32 rec_gap = 0;
1379         u32 msg_tol;
1380         struct tipc_msg *msg = buf_msg(buf);
1381
1382         if (l_ptr->flags & LINK_FAILINGOVER)
1383                 goto exit;
1384
1385         if (l_ptr->net_plane != msg_net_plane(msg))
1386                 if (link_own_addr(l_ptr) > msg_prevnode(msg))
1387                         l_ptr->net_plane = msg_net_plane(msg);
1388
1389         switch (msg_type(msg)) {
1390
1391         case RESET_MSG:
1392                 if (!link_working_unknown(l_ptr) &&
1393                     (l_ptr->peer_session != INVALID_SESSION)) {
1394                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1395                                 break; /* duplicate or old reset: ignore */
1396                 }
1397
1398                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1399                                 link_working_unknown(l_ptr))) {
1400                         /*
1401                          * peer has lost contact -- don't allow peer's links
1402                          * to reactivate before we recognize loss & clean up
1403                          */
1404                         l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
1405                 }
1406
1407                 link_state_event(l_ptr, RESET_MSG);
1408
1409                 /* fall thru' */
1410         case ACTIVATE_MSG:
1411                 /* Update link settings according other endpoint's values */
1412                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1413
1414                 msg_tol = msg_link_tolerance(msg);
1415                 if (msg_tol > l_ptr->tolerance)
1416                         link_set_supervision_props(l_ptr, msg_tol);
1417
1418                 if (msg_linkprio(msg) > l_ptr->priority)
1419                         l_ptr->priority = msg_linkprio(msg);
1420
1421                 if (l_ptr->mtu > msg_max_pkt(msg))
1422                         l_ptr->mtu = msg_max_pkt(msg);
1423
1424                 /* Synchronize broadcast link info, if not done previously */
1425                 if (!tipc_node_is_up(l_ptr->owner)) {
1426                         l_ptr->owner->bclink.last_sent =
1427                                 l_ptr->owner->bclink.last_in =
1428                                 msg_last_bcast(msg);
1429                         l_ptr->owner->bclink.oos_state = 0;
1430                 }
1431
1432                 l_ptr->peer_session = msg_session(msg);
1433                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1434
1435                 if (msg_type(msg) == ACTIVATE_MSG)
1436                         link_state_event(l_ptr, ACTIVATE_MSG);
1437                 break;
1438         case STATE_MSG:
1439
1440                 msg_tol = msg_link_tolerance(msg);
1441                 if (msg_tol)
1442                         link_set_supervision_props(l_ptr, msg_tol);
1443
1444                 if (msg_linkprio(msg) &&
1445                     (msg_linkprio(msg) != l_ptr->priority)) {
1446                         pr_debug("%s<%s>, priority change %u->%u\n",
1447                                  link_rst_msg, l_ptr->name,
1448                                  l_ptr->priority, msg_linkprio(msg));
1449                         l_ptr->priority = msg_linkprio(msg);
1450                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1451                         break;
1452                 }
1453
1454                 /* Record reception; force mismatch at next timeout: */
1455                 l_ptr->silent_intv_cnt = 0;
1456
1457                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1458                 l_ptr->stats.recv_states++;
1459                 if (link_reset_unknown(l_ptr))
1460                         break;
1461
1462                 if (less_eq(l_ptr->rcv_nxt, msg_next_sent(msg)))
1463                         rec_gap = mod(msg_next_sent(msg) - l_ptr->rcv_nxt);
1464
1465                 if (msg_probe(msg))
1466                         l_ptr->stats.recv_probes++;
1467
1468                 /* Protocol message before retransmits, reduce loss risk */
1469                 if (l_ptr->owner->bclink.recv_permitted)
1470                         tipc_bclink_update_link_state(l_ptr->owner,
1471                                                       msg_last_bcast(msg));
1472
1473                 if (rec_gap || (msg_probe(msg))) {
1474                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0,
1475                                              rec_gap, 0, 0);
1476                 }
1477                 if (msg_seq_gap(msg)) {
1478                         l_ptr->stats.recv_nacks++;
1479                         tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->transmq),
1480                                              msg_seq_gap(msg));
1481                 }
1482                 break;
1483         }
1484 exit:
1485         kfree_skb(buf);
1486 }
1487
1488
1489 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1490  * a different bearer. Owner node is locked.
1491  */
1492 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1493                                   struct tipc_msg *tunnel_hdr,
1494                                   struct tipc_msg *msg,
1495                                   u32 selector)
1496 {
1497         struct tipc_link *tunnel;
1498         struct sk_buff *skb;
1499         u32 length = msg_size(msg);
1500
1501         tunnel = l_ptr->owner->active_links[selector & 1];
1502         if (!tipc_link_is_up(tunnel)) {
1503                 pr_warn("%stunnel link no longer available\n", link_co_err);
1504                 return;
1505         }
1506         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1507         skb = tipc_buf_acquire(length + INT_H_SIZE);
1508         if (!skb) {
1509                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1510                 return;
1511         }
1512         skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
1513         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
1514         __tipc_link_xmit_skb(tunnel, skb);
1515 }
1516
1517
1518 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1519  * link is still active. We can do failover. Tunnel the failing link's
1520  * whole send queue via the remaining link. This way, we don't lose
1521  * any packets, and sequence order is preserved for subsequent traffic
1522  * sent over the remaining link. Owner node is locked.
1523  */
1524 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1525 {
1526         int msgcount;
1527         struct tipc_link *tunnel = l_ptr->owner->active_links[0];
1528         struct tipc_msg tunnel_hdr;
1529         struct sk_buff *skb;
1530         int split_bundles;
1531
1532         if (!tunnel)
1533                 return;
1534
1535         tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
1536                       FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
1537
1538         skb_queue_walk(&l_ptr->backlogq, skb) {
1539                 msg_set_seqno(buf_msg(skb), l_ptr->snd_nxt);
1540                 l_ptr->snd_nxt = mod(l_ptr->snd_nxt + 1);
1541         }
1542         skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
1543         tipc_link_purge_backlog(l_ptr);
1544         msgcount = skb_queue_len(&l_ptr->transmq);
1545         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1546         msg_set_msgcnt(&tunnel_hdr, msgcount);
1547
1548         if (skb_queue_empty(&l_ptr->transmq)) {
1549                 skb = tipc_buf_acquire(INT_H_SIZE);
1550                 if (skb) {
1551                         skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
1552                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1553                         __tipc_link_xmit_skb(tunnel, skb);
1554                 } else {
1555                         pr_warn("%sunable to send changeover msg\n",
1556                                 link_co_err);
1557                 }
1558                 return;
1559         }
1560
1561         split_bundles = (l_ptr->owner->active_links[0] !=
1562                          l_ptr->owner->active_links[1]);
1563
1564         skb_queue_walk(&l_ptr->transmq, skb) {
1565                 struct tipc_msg *msg = buf_msg(skb);
1566
1567                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1568                         struct tipc_msg *m = msg_get_wrapped(msg);
1569                         unchar *pos = (unchar *)m;
1570
1571                         msgcount = msg_msgcnt(msg);
1572                         while (msgcount--) {
1573                                 msg_set_seqno(m, msg_seqno(msg));
1574                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1575                                                       msg_link_selector(m));
1576                                 pos += align(msg_size(m));
1577                                 m = (struct tipc_msg *)pos;
1578                         }
1579                 } else {
1580                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1581                                               msg_link_selector(msg));
1582                 }
1583         }
1584 }
1585
1586 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1587  * duplicate of the first link's send queue via the new link. This way, we
1588  * are guaranteed that currently queued packets from a socket are delivered
1589  * before future traffic from the same socket, even if this is using the
1590  * new link. The last arriving copy of each duplicate packet is dropped at
1591  * the receiving end by the regular protocol check, so packet cardinality
1592  * and sequence order is preserved per sender/receiver socket pair.
1593  * Owner node is locked.
1594  */
1595 void tipc_link_dup_queue_xmit(struct tipc_link *link,
1596                               struct tipc_link *tnl)
1597 {
1598         struct sk_buff *skb;
1599         struct tipc_msg tnl_hdr;
1600         struct sk_buff_head *queue = &link->transmq;
1601         int mcnt;
1602         u16 seqno;
1603
1604         tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
1605                       SYNCH_MSG, INT_H_SIZE, link->addr);
1606         mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
1607         msg_set_msgcnt(&tnl_hdr, mcnt);
1608         msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
1609
1610 tunnel_queue:
1611         skb_queue_walk(queue, skb) {
1612                 struct sk_buff *outskb;
1613                 struct tipc_msg *msg = buf_msg(skb);
1614                 u32 len = msg_size(msg);
1615
1616                 msg_set_ack(msg, mod(link->rcv_nxt - 1));
1617                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
1618                 msg_set_size(&tnl_hdr, len + INT_H_SIZE);
1619                 outskb = tipc_buf_acquire(len + INT_H_SIZE);
1620                 if (outskb == NULL) {
1621                         pr_warn("%sunable to send duplicate msg\n",
1622                                 link_co_err);
1623                         return;
1624                 }
1625                 skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
1626                 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
1627                                                skb->data, len);
1628                 __tipc_link_xmit_skb(tnl, outskb);
1629                 if (!tipc_link_is_up(link))
1630                         return;
1631         }
1632         if (queue == &link->backlogq)
1633                 return;
1634         seqno = link->snd_nxt;
1635         skb_queue_walk(&link->backlogq, skb) {
1636                 msg_set_seqno(buf_msg(skb), seqno);
1637                 seqno = mod(seqno + 1);
1638         }
1639         queue = &link->backlogq;
1640         goto tunnel_queue;
1641 }
1642
1643 /*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
1644  *  Owner node is locked.
1645  */
1646 static bool tipc_link_failover_rcv(struct tipc_link *link,
1647                                    struct sk_buff **skb)
1648 {
1649         struct tipc_msg *msg = buf_msg(*skb);
1650         struct sk_buff *iskb = NULL;
1651         struct tipc_link *pl = NULL;
1652         int bearer_id = msg_bearer_id(msg);
1653         int pos = 0;
1654
1655         if (msg_type(msg) != FAILOVER_MSG) {
1656                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1657                 goto exit;
1658         }
1659         if (bearer_id >= MAX_BEARERS)
1660                 goto exit;
1661
1662         if (bearer_id == link->bearer_id)
1663                 goto exit;
1664
1665         pl = link->owner->links[bearer_id];
1666         if (pl && tipc_link_is_up(pl))
1667                 tipc_link_reset(pl);
1668
1669         if (link->failover_pkts == FIRST_FAILOVER)
1670                 link->failover_pkts = msg_msgcnt(msg);
1671
1672         /* Should we expect an inner packet? */
1673         if (!link->failover_pkts)
1674                 goto exit;
1675
1676         if (!tipc_msg_extract(*skb, &iskb, &pos)) {
1677                 pr_warn("%sno inner failover pkt\n", link_co_err);
1678                 *skb = NULL;
1679                 goto exit;
1680         }
1681         link->failover_pkts--;
1682         *skb = NULL;
1683
1684         /* Was this packet already delivered? */
1685         if (less(buf_seqno(iskb), link->failover_checkpt)) {
1686                 kfree_skb(iskb);
1687                 iskb = NULL;
1688                 goto exit;
1689         }
1690         if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
1691                 link->stats.recv_fragments++;
1692                 tipc_buf_append(&link->failover_skb, &iskb);
1693         }
1694 exit:
1695         if (!link->failover_pkts && pl)
1696                 pl->flags &= ~LINK_FAILINGOVER;
1697         kfree_skb(*skb);
1698         *skb = iskb;
1699         return *skb;
1700 }
1701
1702 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol)
1703 {
1704         unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
1705
1706         if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1707                 return;
1708
1709         l_ptr->tolerance = tol;
1710         l_ptr->keepalive_intv = msecs_to_jiffies(intv);
1711         l_ptr->abort_limit = tol / (jiffies_to_msecs(l_ptr->keepalive_intv));
1712 }
1713
1714 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1715 {
1716         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1717
1718         l->window = win;
1719         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1720         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1721         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1722         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1723         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1724 }
1725
1726 /* tipc_link_find_owner - locate owner node of link by link's name
1727  * @net: the applicable net namespace
1728  * @name: pointer to link name string
1729  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1730  *
1731  * Returns pointer to node owning the link, or 0 if no matching link is found.
1732  */
1733 static struct tipc_node *tipc_link_find_owner(struct net *net,
1734                                               const char *link_name,
1735                                               unsigned int *bearer_id)
1736 {
1737         struct tipc_net *tn = net_generic(net, tipc_net_id);
1738         struct tipc_link *l_ptr;
1739         struct tipc_node *n_ptr;
1740         struct tipc_node *found_node = NULL;
1741         int i;
1742
1743         *bearer_id = 0;
1744         rcu_read_lock();
1745         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1746                 tipc_node_lock(n_ptr);
1747                 for (i = 0; i < MAX_BEARERS; i++) {
1748                         l_ptr = n_ptr->links[i];
1749                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1750                                 *bearer_id = i;
1751                                 found_node = n_ptr;
1752                                 break;
1753                         }
1754                 }
1755                 tipc_node_unlock(n_ptr);
1756                 if (found_node)
1757                         break;
1758         }
1759         rcu_read_unlock();
1760
1761         return found_node;
1762 }
1763
1764 /**
1765  * link_reset_statistics - reset link statistics
1766  * @l_ptr: pointer to link
1767  */
1768 static void link_reset_statistics(struct tipc_link *l_ptr)
1769 {
1770         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1771         l_ptr->stats.sent_info = l_ptr->snd_nxt;
1772         l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1773 }
1774
1775 static void link_print(struct tipc_link *l_ptr, const char *str)
1776 {
1777         struct tipc_net *tn = net_generic(l_ptr->owner->net, tipc_net_id);
1778         struct tipc_bearer *b_ptr;
1779
1780         rcu_read_lock();
1781         b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]);
1782         if (b_ptr)
1783                 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name);
1784         rcu_read_unlock();
1785
1786         if (link_working_unknown(l_ptr))
1787                 pr_cont(":WU\n");
1788         else if (link_reset_reset(l_ptr))
1789                 pr_cont(":RR\n");
1790         else if (link_reset_unknown(l_ptr))
1791                 pr_cont(":RU\n");
1792         else if (link_working_working(l_ptr))
1793                 pr_cont(":WW\n");
1794         else
1795                 pr_cont("\n");
1796 }
1797
1798 /* Parse and validate nested (link) properties valid for media, bearer and link
1799  */
1800 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1801 {
1802         int err;
1803
1804         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1805                                tipc_nl_prop_policy);
1806         if (err)
1807                 return err;
1808
1809         if (props[TIPC_NLA_PROP_PRIO]) {
1810                 u32 prio;
1811
1812                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1813                 if (prio > TIPC_MAX_LINK_PRI)
1814                         return -EINVAL;
1815         }
1816
1817         if (props[TIPC_NLA_PROP_TOL]) {
1818                 u32 tol;
1819
1820                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1821                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1822                         return -EINVAL;
1823         }
1824
1825         if (props[TIPC_NLA_PROP_WIN]) {
1826                 u32 win;
1827
1828                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1829                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1830                         return -EINVAL;
1831         }
1832
1833         return 0;
1834 }
1835
1836 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1837 {
1838         int err;
1839         int res = 0;
1840         int bearer_id;
1841         char *name;
1842         struct tipc_link *link;
1843         struct tipc_node *node;
1844         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1845         struct net *net = sock_net(skb->sk);
1846
1847         if (!info->attrs[TIPC_NLA_LINK])
1848                 return -EINVAL;
1849
1850         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1851                                info->attrs[TIPC_NLA_LINK],
1852                                tipc_nl_link_policy);
1853         if (err)
1854                 return err;
1855
1856         if (!attrs[TIPC_NLA_LINK_NAME])
1857                 return -EINVAL;
1858
1859         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1860
1861         if (strcmp(name, tipc_bclink_name) == 0)
1862                 return tipc_nl_bc_link_set(net, attrs);
1863
1864         node = tipc_link_find_owner(net, name, &bearer_id);
1865         if (!node)
1866                 return -EINVAL;
1867
1868         tipc_node_lock(node);
1869
1870         link = node->links[bearer_id];
1871         if (!link) {
1872                 res = -EINVAL;
1873                 goto out;
1874         }
1875
1876         if (attrs[TIPC_NLA_LINK_PROP]) {
1877                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1878
1879                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1880                                               props);
1881                 if (err) {
1882                         res = err;
1883                         goto out;
1884                 }
1885
1886                 if (props[TIPC_NLA_PROP_TOL]) {
1887                         u32 tol;
1888
1889                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1890                         link_set_supervision_props(link, tol);
1891                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1892                 }
1893                 if (props[TIPC_NLA_PROP_PRIO]) {
1894                         u32 prio;
1895
1896                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1897                         link->priority = prio;
1898                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1899                 }
1900                 if (props[TIPC_NLA_PROP_WIN]) {
1901                         u32 win;
1902
1903                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1904                         tipc_link_set_queue_limits(link, win);
1905                 }
1906         }
1907
1908 out:
1909         tipc_node_unlock(node);
1910
1911         return res;
1912 }
1913
1914 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1915 {
1916         int i;
1917         struct nlattr *stats;
1918
1919         struct nla_map {
1920                 u32 key;
1921                 u32 val;
1922         };
1923
1924         struct nla_map map[] = {
1925                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1926                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1927                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1928                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1929                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1930                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1931                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1932                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1933                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1934                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1935                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1936                         s->msg_length_counts : 1},
1937                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1938                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1939                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1940                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1941                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1942                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1943                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1944                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1945                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1946                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1947                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1948                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1949                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1950                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1951                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1952                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1953                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1954                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1955                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1956                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1957                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1958                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1959                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1960         };
1961
1962         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1963         if (!stats)
1964                 return -EMSGSIZE;
1965
1966         for (i = 0; i <  ARRAY_SIZE(map); i++)
1967                 if (nla_put_u32(skb, map[i].key, map[i].val))
1968                         goto msg_full;
1969
1970         nla_nest_end(skb, stats);
1971
1972         return 0;
1973 msg_full:
1974         nla_nest_cancel(skb, stats);
1975
1976         return -EMSGSIZE;
1977 }
1978
1979 /* Caller should hold appropriate locks to protect the link */
1980 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1981                               struct tipc_link *link, int nlflags)
1982 {
1983         int err;
1984         void *hdr;
1985         struct nlattr *attrs;
1986         struct nlattr *prop;
1987         struct tipc_net *tn = net_generic(net, tipc_net_id);
1988
1989         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1990                           nlflags, TIPC_NL_LINK_GET);
1991         if (!hdr)
1992                 return -EMSGSIZE;
1993
1994         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1995         if (!attrs)
1996                 goto msg_full;
1997
1998         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1999                 goto attr_msg_full;
2000         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
2001                         tipc_cluster_mask(tn->own_addr)))
2002                 goto attr_msg_full;
2003         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2004                 goto attr_msg_full;
2005         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
2006                 goto attr_msg_full;
2007         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
2008                 goto attr_msg_full;
2009
2010         if (tipc_link_is_up(link))
2011                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2012                         goto attr_msg_full;
2013         if (tipc_link_is_active(link))
2014                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2015                         goto attr_msg_full;
2016
2017         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2018         if (!prop)
2019                 goto attr_msg_full;
2020         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2021                 goto prop_msg_full;
2022         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2023                 goto prop_msg_full;
2024         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2025                         link->window))
2026                 goto prop_msg_full;
2027         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2028                 goto prop_msg_full;
2029         nla_nest_end(msg->skb, prop);
2030
2031         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2032         if (err)
2033                 goto attr_msg_full;
2034
2035         nla_nest_end(msg->skb, attrs);
2036         genlmsg_end(msg->skb, hdr);
2037
2038         return 0;
2039
2040 prop_msg_full:
2041         nla_nest_cancel(msg->skb, prop);
2042 attr_msg_full:
2043         nla_nest_cancel(msg->skb, attrs);
2044 msg_full:
2045         genlmsg_cancel(msg->skb, hdr);
2046
2047         return -EMSGSIZE;
2048 }
2049
2050 /* Caller should hold node lock  */
2051 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2052                                     struct tipc_node *node, u32 *prev_link)
2053 {
2054         u32 i;
2055         int err;
2056
2057         for (i = *prev_link; i < MAX_BEARERS; i++) {
2058                 *prev_link = i;
2059
2060                 if (!node->links[i])
2061                         continue;
2062
2063                 err = __tipc_nl_add_link(net, msg, node->links[i], NLM_F_MULTI);
2064                 if (err)
2065                         return err;
2066         }
2067         *prev_link = 0;
2068
2069         return 0;
2070 }
2071
2072 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2073 {
2074         struct net *net = sock_net(skb->sk);
2075         struct tipc_net *tn = net_generic(net, tipc_net_id);
2076         struct tipc_node *node;
2077         struct tipc_nl_msg msg;
2078         u32 prev_node = cb->args[0];
2079         u32 prev_link = cb->args[1];
2080         int done = cb->args[2];
2081         int err;
2082
2083         if (done)
2084                 return 0;
2085
2086         msg.skb = skb;
2087         msg.portid = NETLINK_CB(cb->skb).portid;
2088         msg.seq = cb->nlh->nlmsg_seq;
2089
2090         rcu_read_lock();
2091         if (prev_node) {
2092                 node = tipc_node_find(net, prev_node);
2093                 if (!node) {
2094                         /* We never set seq or call nl_dump_check_consistent()
2095                          * this means that setting prev_seq here will cause the
2096                          * consistence check to fail in the netlink callback
2097                          * handler. Resulting in the last NLMSG_DONE message
2098                          * having the NLM_F_DUMP_INTR flag set.
2099                          */
2100                         cb->prev_seq = 1;
2101                         goto out;
2102                 }
2103                 tipc_node_put(node);
2104
2105                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2106                                                  list) {
2107                         tipc_node_lock(node);
2108                         err = __tipc_nl_add_node_links(net, &msg, node,
2109                                                        &prev_link);
2110                         tipc_node_unlock(node);
2111                         if (err)
2112                                 goto out;
2113
2114                         prev_node = node->addr;
2115                 }
2116         } else {
2117                 err = tipc_nl_add_bc_link(net, &msg);
2118                 if (err)
2119                         goto out;
2120
2121                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2122                         tipc_node_lock(node);
2123                         err = __tipc_nl_add_node_links(net, &msg, node,
2124                                                        &prev_link);
2125                         tipc_node_unlock(node);
2126                         if (err)
2127                                 goto out;
2128
2129                         prev_node = node->addr;
2130                 }
2131         }
2132         done = 1;
2133 out:
2134         rcu_read_unlock();
2135
2136         cb->args[0] = prev_node;
2137         cb->args[1] = prev_link;
2138         cb->args[2] = done;
2139
2140         return skb->len;
2141 }
2142
2143 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2144 {
2145         struct net *net = genl_info_net(info);
2146         struct tipc_nl_msg msg;
2147         char *name;
2148         int err;
2149
2150         msg.portid = info->snd_portid;
2151         msg.seq = info->snd_seq;
2152
2153         if (!info->attrs[TIPC_NLA_LINK_NAME])
2154                 return -EINVAL;
2155         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2156
2157         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2158         if (!msg.skb)
2159                 return -ENOMEM;
2160
2161         if (strcmp(name, tipc_bclink_name) == 0) {
2162                 err = tipc_nl_add_bc_link(net, &msg);
2163                 if (err) {
2164                         nlmsg_free(msg.skb);
2165                         return err;
2166                 }
2167         } else {
2168                 int bearer_id;
2169                 struct tipc_node *node;
2170                 struct tipc_link *link;
2171
2172                 node = tipc_link_find_owner(net, name, &bearer_id);
2173                 if (!node)
2174                         return -EINVAL;
2175
2176                 tipc_node_lock(node);
2177                 link = node->links[bearer_id];
2178                 if (!link) {
2179                         tipc_node_unlock(node);
2180                         nlmsg_free(msg.skb);
2181                         return -EINVAL;
2182                 }
2183
2184                 err = __tipc_nl_add_link(net, &msg, link, 0);
2185                 tipc_node_unlock(node);
2186                 if (err) {
2187                         nlmsg_free(msg.skb);
2188                         return err;
2189                 }
2190         }
2191
2192         return genlmsg_reply(msg.skb, info);
2193 }
2194
2195 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2196 {
2197         int err;
2198         char *link_name;
2199         unsigned int bearer_id;
2200         struct tipc_link *link;
2201         struct tipc_node *node;
2202         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2203         struct net *net = sock_net(skb->sk);
2204
2205         if (!info->attrs[TIPC_NLA_LINK])
2206                 return -EINVAL;
2207
2208         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2209                                info->attrs[TIPC_NLA_LINK],
2210                                tipc_nl_link_policy);
2211         if (err)
2212                 return err;
2213
2214         if (!attrs[TIPC_NLA_LINK_NAME])
2215                 return -EINVAL;
2216
2217         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2218
2219         if (strcmp(link_name, tipc_bclink_name) == 0) {
2220                 err = tipc_bclink_reset_stats(net);
2221                 if (err)
2222                         return err;
2223                 return 0;
2224         }
2225
2226         node = tipc_link_find_owner(net, link_name, &bearer_id);
2227         if (!node)
2228                 return -EINVAL;
2229
2230         tipc_node_lock(node);
2231
2232         link = node->links[bearer_id];
2233         if (!link) {
2234                 tipc_node_unlock(node);
2235                 return -EINVAL;
2236         }
2237
2238         link_reset_statistics(link);
2239
2240         tipc_node_unlock(node);
2241
2242         return 0;
2243 }