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         struct tipc_node *n = l->owner;
 136
 137         if (node_active_link(n, 0) != l)
 138                 return node_active_link(n, 0);
 139         return node_active_link(n, 1);
 140 }
 141
 142 /*
 143  *  Simple non-static link routines (i.e. referenced outside this file)
 144  */
 145 int tipc_link_is_up(struct tipc_link *l_ptr)
 146 {
 147         if (!l_ptr)
 148                 return 0;
 149         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 150 }
 151
 152 int tipc_link_is_active(struct tipc_link *l)
 153 {
 154         struct tipc_node *n = l->owner;
 155
 156         return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
 157 }
 158
 159 /**
 160  * link_timeout - handle expiration of link timer
 161  * @l_ptr: pointer to link
 162  */
 163 static void link_timeout(unsigned long data)
 164 {
 165         struct tipc_link *l_ptr = (struct tipc_link *)data;
 166         struct sk_buff *skb;
 167
 168         tipc_node_lock(l_ptr->owner);
 169
 170         /* update counters used in statistical profiling of send traffic */
 171         l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->transmq);
 172         l_ptr->stats.queue_sz_counts++;
 173
 174         skb = skb_peek(&l_ptr->transmq);
 175         if (skb) {
 176                 struct tipc_msg *msg = buf_msg(skb);
 177                 u32 length = msg_size(msg);
 178
 179                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 180                     (msg_type(msg) == FIRST_FRAGMENT)) {
 181                         length = msg_size(msg_get_wrapped(msg));
 182                 }
 183                 if (length) {
 184                         l_ptr->stats.msg_lengths_total += length;
 185                         l_ptr->stats.msg_length_counts++;
 186                         if (length <= 64)
 187                                 l_ptr->stats.msg_length_profile[0]++;
 188                         else if (length <= 256)
 189                                 l_ptr->stats.msg_length_profile[1]++;
 190                         else if (length <= 1024)
 191                                 l_ptr->stats.msg_length_profile[2]++;
 192                         else if (length <= 4096)
 193                                 l_ptr->stats.msg_length_profile[3]++;
 194                         else if (length <= 16384)
 195                                 l_ptr->stats.msg_length_profile[4]++;
 196                         else if (length <= 32768)
 197                                 l_ptr->stats.msg_length_profile[5]++;
 198                         else
 199                                 l_ptr->stats.msg_length_profile[6]++;
 200                 }
 201         }
 202
 203         /* do all other link processing performed on a periodic basis */
 204         if (l_ptr->silent_intv_cnt || tipc_bclink_acks_missing(l_ptr->owner))
 205                 link_state_event(l_ptr, SILENCE_EVT);
 206         l_ptr->silent_intv_cnt++;
 207         if (skb_queue_len(&l_ptr->backlogq))
 208                 tipc_link_push_packets(l_ptr);
 209         link_set_timer(l_ptr, l_ptr->keepalive_intv);
 210         tipc_node_unlock(l_ptr->owner);
 211         tipc_link_put(l_ptr);
 212 }
 213
 214 static void link_set_timer(struct tipc_link *link, unsigned long time)
 215 {
 216         if (!mod_timer(&link->timer, jiffies + time))
 217                 tipc_link_get(link);
 218 }
 219
 220 /**
 221  * tipc_link_create - create a new link
 222  * @n_ptr: pointer to associated node
 223  * @b_ptr: pointer to associated bearer
 224  * @media_addr: media address to use when sending messages over link
 225  *
 226  * Returns pointer to link.
 227  */
 228 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 229                                    struct tipc_bearer *b_ptr,
 230                                    const struct tipc_media_addr *media_addr,
 231                                    struct sk_buff_head *inputq,
 232                                    struct sk_buff_head *namedq)
 233 {
 234         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 235         struct tipc_link *l_ptr;
 236         struct tipc_msg *msg;
 237         char *if_name;
 238         char addr_string[16];
 239         u32 peer = n_ptr->addr;
 240
 241         if (n_ptr->link_cnt >= MAX_BEARERS) {
 242                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 243                 pr_err("Cannot establish %uth link to %s. Max %u allowed.\n",
 244                        n_ptr->link_cnt, addr_string, MAX_BEARERS);
 245                 return NULL;
 246         }
 247
 248         if (n_ptr->links[b_ptr->identity].link) {
 249                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 250                 pr_err("Attempt to establish second link on <%s> to %s\n",
 251                        b_ptr->name, addr_string);
 252                 return NULL;
 253         }
 254
 255         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 256         if (!l_ptr) {
 257                 pr_warn("Link creation failed, no memory\n");
 258                 return NULL;
 259         }
 260         kref_init(&l_ptr->ref);
 261         l_ptr->addr = peer;
 262         if_name = strchr(b_ptr->name, ':') + 1;
 263         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 264                 tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
 265                 tipc_node(tn->own_addr),
 266                 if_name,
 267                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 268                 /* note: peer i/f name is updated by reset/activate message */
 269         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 270         l_ptr->owner = n_ptr;
 271         l_ptr->peer_session = INVALID_SESSION;
 272         l_ptr->bearer_id = b_ptr->identity;
 273         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 274         l_ptr->state = RESET_UNKNOWN;
 275
 276         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 277         msg = l_ptr->pmsg;
 278         tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
 279                       l_ptr->addr);
 280         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 281         msg_set_session(msg, (tn->random & 0xffff));
 282         msg_set_bearer_id(msg, b_ptr->identity);
 283         strcpy((char *)msg_data(msg), if_name);
 284         l_ptr->net_plane = b_ptr->net_plane;
 285         l_ptr->advertised_mtu = b_ptr->mtu;
 286         l_ptr->mtu = l_ptr->advertised_mtu;
 287         l_ptr->priority = b_ptr->priority;
 288         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 289         l_ptr->snd_nxt = 1;
 290         __skb_queue_head_init(&l_ptr->transmq);
 291         __skb_queue_head_init(&l_ptr->backlogq);
 292         __skb_queue_head_init(&l_ptr->deferdq);
 293         skb_queue_head_init(&l_ptr->wakeupq);
 294         l_ptr->inputq = inputq;
 295         l_ptr->namedq = namedq;
 296         skb_queue_head_init(l_ptr->inputq);
 297         link_reset_statistics(l_ptr);
 298         tipc_node_attach_link(n_ptr, l_ptr);
 299         setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr);
 300         link_state_event(l_ptr, STARTING_EVT);
 301
 302         return l_ptr;
 303 }
 304
 305 /**
 306  * tipc_link_delete - Delete a link
 307  * @l: link to be deleted
 308  */
 309 void tipc_link_delete(struct tipc_link *l)
 310 {
 311         tipc_link_reset(l);
 312         if (del_timer(&l->timer))
 313                 tipc_link_put(l);
 314         l->flags |= LINK_STOPPED;
 315         /* Delete link now, or when timer is finished: */
 316         tipc_link_reset_fragments(l);
 317         tipc_node_detach_link(l->owner, l);
 318         tipc_link_put(l);
 319 }
 320
 321 void tipc_link_delete_list(struct net *net, unsigned int bearer_id)
 322 {
 323         struct tipc_net *tn = net_generic(net, tipc_net_id);
 324         struct tipc_link *link;
 325         struct tipc_node *node;
 326
 327         rcu_read_lock();
 328         list_for_each_entry_rcu(node, &tn->node_list, list) {
 329                 tipc_node_lock(node);
 330                 link = node->links[bearer_id].link;
 331                 if (link)
 332                         tipc_link_delete(link);
 333                 tipc_node_unlock(node);
 334         }
 335         rcu_read_unlock();
 336 }
 337
 338 /**
 339  * link_schedule_user - schedule a message sender for wakeup after congestion
 340  * @link: congested link
 341  * @list: message that was attempted sent
 342  * Create pseudo msg to send back to user when congestion abates
 343  * Only consumes message if there is an error
 344  */
 345 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 346 {
 347         struct tipc_msg *msg = buf_msg(skb_peek(list));
 348         int imp = msg_importance(msg);
 349         u32 oport = msg_origport(msg);
 350         u32 addr = link_own_addr(link);
 351         struct sk_buff *skb;
 352
 353         /* This really cannot happen...  */
 354         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 355                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 356                 tipc_link_reset(link);
 357                 goto err;
 358         }
 359         /* Non-blocking sender: */
 360         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 361                 return -ELINKCONG;
 362
 363         /* Create and schedule wakeup pseudo message */
 364         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 365                               addr, addr, oport, 0, 0);
 366         if (!skb)
 367                 goto err;
 368         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 369         TIPC_SKB_CB(skb)->chain_imp = imp;
 370         skb_queue_tail(&link->wakeupq, skb);
 371         link->stats.link_congs++;
 372         return -ELINKCONG;
 373 err:
 374         __skb_queue_purge(list);
 375         return -ENOBUFS;
 376 }
 377
 378 /**
 379  * link_prepare_wakeup - prepare users for wakeup after congestion
 380  * @link: congested link
 381  * Move a number of waiting users, as permitted by available space in
 382  * the send queue, from link wait queue to node wait queue for wakeup
 383  */
 384 void link_prepare_wakeup(struct tipc_link *l)
 385 {
 386         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 387         int imp, lim;
 388         struct sk_buff *skb, *tmp;
 389
 390         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 391                 imp = TIPC_SKB_CB(skb)->chain_imp;
 392                 lim = l->window + l->backlog[imp].limit;
 393                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 394                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 395                         break;
 396                 skb_unlink(skb, &l->wakeupq);
 397                 skb_queue_tail(l->inputq, skb);
 398                 l->owner->inputq = l->inputq;
 399                 l->owner->action_flags |= TIPC_MSG_EVT;
 400         }
 401 }
 402
 403 /**
 404  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 405  * @l_ptr: pointer to link
 406  */
 407 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 408 {
 409         kfree_skb(l_ptr->reasm_buf);
 410         l_ptr->reasm_buf = NULL;
 411 }
 412
 413 void tipc_link_purge_backlog(struct tipc_link *l)
 414 {
 415         __skb_queue_purge(&l->backlogq);
 416         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 417         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 418         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 419         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 420         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 421 }
 422
 423 /**
 424  * tipc_link_purge_queues - purge all pkt queues associated with link
 425  * @l_ptr: pointer to link
 426  */
 427 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 428 {
 429         __skb_queue_purge(&l_ptr->deferdq);
 430         __skb_queue_purge(&l_ptr->transmq);
 431         tipc_link_purge_backlog(l_ptr);
 432         tipc_link_reset_fragments(l_ptr);
 433 }
 434
 435 void tipc_link_reset(struct tipc_link *l_ptr)
 436 {
 437         u32 prev_state = l_ptr->state;
 438         int was_active_link = tipc_link_is_active(l_ptr);
 439         struct tipc_node *owner = l_ptr->owner;
 440         struct tipc_link *pl = tipc_parallel_link(l_ptr);
 441
 442         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 443
 444         /* Link is down, accept any session */
 445         l_ptr->peer_session = INVALID_SESSION;
 446
 447         /* Prepare for renewed mtu size negotiation */
 448         l_ptr->mtu = l_ptr->advertised_mtu;
 449
 450         l_ptr->state = RESET_UNKNOWN;
 451
 452         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 453                 return;
 454
 455         tipc_node_link_down(l_ptr->owner, l_ptr->bearer_id);
 456         tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 457
 458         if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
 459                 l_ptr->flags |= LINK_FAILINGOVER;
 460                 l_ptr->failover_checkpt = l_ptr->rcv_nxt;
 461                 pl->failover_pkts = FIRST_FAILOVER;
 462                 pl->failover_checkpt = l_ptr->rcv_nxt;
 463                 pl->failover_skb = l_ptr->reasm_buf;
 464         } else {
 465                 kfree_skb(l_ptr->reasm_buf);
 466         }
 467         /* Clean up all queues, except inputq: */
 468         __skb_queue_purge(&l_ptr->transmq);
 469         __skb_queue_purge(&l_ptr->deferdq);
 470         if (!owner->inputq)
 471                 owner->inputq = l_ptr->inputq;
 472         skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
 473         if (!skb_queue_empty(owner->inputq))
 474                 owner->action_flags |= TIPC_MSG_EVT;
 475         tipc_link_purge_backlog(l_ptr);
 476         l_ptr->reasm_buf = NULL;
 477         l_ptr->rcv_unacked = 0;
 478         l_ptr->snd_nxt = 1;
 479         l_ptr->silent_intv_cnt = 0;
 480         l_ptr->stale_count = 0;
 481         link_reset_statistics(l_ptr);
 482 }
 483
 484 static void link_activate(struct tipc_link *link)
 485 {
 486         struct tipc_node *node = link->owner;
 487
 488         link->rcv_nxt = 1;
 489         link->stats.recv_info = 1;
 490         link->silent_intv_cnt = 0;
 491         tipc_node_link_up(node, link->bearer_id);
 492         tipc_bearer_add_dest(node->net, link->bearer_id, link->addr);
 493 }
 494
 495 /**
 496  * link_state_event - link finite state machine
 497  * @l_ptr: pointer to link
 498  * @event: state machine event to process
 499  */
 500 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 501 {
 502         struct tipc_link *other;
 503         unsigned long timer_intv = l_ptr->keepalive_intv;
 504
 505         if (l_ptr->flags & LINK_STOPPED)
 506                 return;
 507
 508         if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 509                 return;         /* Not yet. */
 510
 511         if (l_ptr->flags & LINK_FAILINGOVER)
 512                 return;
 513
 514         switch (l_ptr->state) {
 515         case WORKING_WORKING:
 516                 switch (event) {
 517                 case TRAFFIC_MSG_EVT:
 518                 case ACTIVATE_MSG:
 519                         l_ptr->silent_intv_cnt = 0;
 520                         break;
 521                 case SILENCE_EVT:
 522                         if (!l_ptr->silent_intv_cnt) {
 523                                 if (tipc_bclink_acks_missing(l_ptr->owner))
 524                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 525                                                              0, 0, 0, 0);
 526                                 break;
 527                         }
 528                         l_ptr->state = WORKING_UNKNOWN;
 529                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 530                         break;
 531                 case RESET_MSG:
 532                         pr_debug("%s<%s>, requested by peer\n",
 533                                  link_rst_msg, l_ptr->name);
 534                         tipc_link_reset(l_ptr);
 535                         l_ptr->state = RESET_RESET;
 536                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 537                                              0, 0, 0, 0);
 538                         break;
 539                 default:
 540                         pr_debug("%s%u in WW state\n", link_unk_evt, event);
 541                 }
 542                 break;
 543         case WORKING_UNKNOWN:
 544                 switch (event) {
 545                 case TRAFFIC_MSG_EVT:
 546                 case ACTIVATE_MSG:
 547                         l_ptr->state = WORKING_WORKING;
 548                         l_ptr->silent_intv_cnt = 0;
 549                         break;
 550                 case RESET_MSG:
 551                         pr_debug("%s<%s>, requested by peer while probing\n",
 552                                  link_rst_msg, l_ptr->name);
 553                         tipc_link_reset(l_ptr);
 554                         l_ptr->state = RESET_RESET;
 555                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 556                                              0, 0, 0, 0);
 557                         break;
 558                 case SILENCE_EVT:
 559                         if (!l_ptr->silent_intv_cnt) {
 560                                 l_ptr->state = WORKING_WORKING;
 561                                 if (tipc_bclink_acks_missing(l_ptr->owner))
 562                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 563                                                              0, 0, 0, 0);
 564                         } else if (l_ptr->silent_intv_cnt <
 565                                    l_ptr->abort_limit) {
 566                                 tipc_link_proto_xmit(l_ptr, STATE_MSG,
 567                                                      1, 0, 0, 0);
 568                         } else {        /* Link has failed */
 569                                 pr_debug("%s<%s>, peer not responding\n",
 570                                          link_rst_msg, l_ptr->name);
 571                                 tipc_link_reset(l_ptr);
 572                                 l_ptr->state = RESET_UNKNOWN;
 573                                 tipc_link_proto_xmit(l_ptr, RESET_MSG,
 574                                                      0, 0, 0, 0);
 575                         }
 576                         break;
 577                 default:
 578                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 579                 }
 580                 break;
 581         case RESET_UNKNOWN:
 582                 switch (event) {
 583                 case TRAFFIC_MSG_EVT:
 584                         break;
 585                 case ACTIVATE_MSG:
 586                         other = node_active_link(l_ptr->owner, 0);
 587                         if (other && link_working_unknown(other))
 588                                 break;
 589                         l_ptr->state = WORKING_WORKING;
 590                         link_activate(l_ptr);
 591                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 592                         if (l_ptr->owner->working_links == 1)
 593                                 tipc_link_sync_xmit(l_ptr);
 594                         break;
 595                 case RESET_MSG:
 596                         l_ptr->state = RESET_RESET;
 597                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 598                                              1, 0, 0, 0);
 599                         break;
 600                 case STARTING_EVT:
 601                         l_ptr->flags |= LINK_STARTED;
 602                         link_set_timer(l_ptr, timer_intv);
 603                         break;
 604                 case SILENCE_EVT:
 605                         tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0);
 606                         break;
 607                 default:
 608                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 609                 }
 610                 break;
 611         case RESET_RESET:
 612                 switch (event) {
 613                 case TRAFFIC_MSG_EVT:
 614                 case ACTIVATE_MSG:
 615                         other = node_active_link(l_ptr->owner, 0);
 616                         if (other && link_working_unknown(other))
 617                                 break;
 618                         l_ptr->state = WORKING_WORKING;
 619                         link_activate(l_ptr);
 620                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 621                         if (l_ptr->owner->working_links == 1)
 622                                 tipc_link_sync_xmit(l_ptr);
 623                         break;
 624                 case RESET_MSG:
 625                         break;
 626                 case SILENCE_EVT:
 627                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 628                                              0, 0, 0, 0);
 629                         break;
 630                 default:
 631                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 632                 }
 633                 break;
 634         default:
 635                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 636         }
 637 }
 638
 639 /**
 640  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 641  * @link: link to use
 642  * @list: chain of buffers containing message
 643  *
 644  * Consumes the buffer chain, except when returning -ELINKCONG,
 645  * since the caller then may want to make more send attempts.
 646  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 647  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 648  */
 649 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 650                      struct sk_buff_head *list)
 651 {
 652         struct tipc_msg *msg = buf_msg(skb_peek(list));
 653         unsigned int maxwin = link->window;
 654         unsigned int i, imp = msg_importance(msg);
 655         uint mtu = link->mtu;
 656         u16 ack = mod(link->rcv_nxt - 1);
 657         u16 seqno = link->snd_nxt;
 658         u16 bc_last_in = link->owner->bclink.last_in;
 659         struct tipc_media_addr *addr = &link->media_addr;
 660         struct sk_buff_head *transmq = &link->transmq;
 661         struct sk_buff_head *backlogq = &link->backlogq;
 662         struct sk_buff *skb, *bskb;
 663
 664         /* Match msg importance against this and all higher backlog limits: */
 665         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 666                 if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
 667                         return link_schedule_user(link, list);
 668         }
 669         if (unlikely(msg_size(msg) > mtu)) {
 670                 __skb_queue_purge(list);
 671                 return -EMSGSIZE;
 672         }
 673         /* Prepare each packet for sending, and add to relevant queue: */
 674         while (skb_queue_len(list)) {
 675                 skb = skb_peek(list);
 676                 msg = buf_msg(skb);
 677                 msg_set_seqno(msg, seqno);
 678                 msg_set_ack(msg, ack);
 679                 msg_set_bcast_ack(msg, bc_last_in);
 680
 681                 if (likely(skb_queue_len(transmq) < maxwin)) {
 682                         __skb_dequeue(list);
 683                         __skb_queue_tail(transmq, skb);
 684                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 685                         link->rcv_unacked = 0;
 686                         seqno++;
 687                         continue;
 688                 }
 689                 if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
 690                         kfree_skb(__skb_dequeue(list));
 691                         link->stats.sent_bundled++;
 692                         continue;
 693                 }
 694                 if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
 695                         kfree_skb(__skb_dequeue(list));
 696                         __skb_queue_tail(backlogq, bskb);
 697                         link->backlog[msg_importance(buf_msg(bskb))].len++;
 698                         link->stats.sent_bundled++;
 699                         link->stats.sent_bundles++;
 700                         continue;
 701                 }
 702                 link->backlog[imp].len += skb_queue_len(list);
 703                 skb_queue_splice_tail_init(list, backlogq);
 704         }
 705         link->snd_nxt = seqno;
 706         return 0;
 707 }
 708
 709 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
 710 {
 711         skb_queue_head_init(list);
 712         __skb_queue_tail(list, skb);
 713 }
 714
 715 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 716 {
 717         struct sk_buff_head head;
 718
 719         skb2list(skb, &head);
 720         return __tipc_link_xmit(link->owner->net, link, &head);
 721 }
 722
 723 /* tipc_link_xmit_skb(): send single buffer to destination
 724  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
 725  * messages, which will not be rejected
 726  * The only exception is datagram messages rerouted after secondary
 727  * lookup, which are rare and safe to dispose of anyway.
 728  * TODO: Return real return value, and let callers use
 729  * tipc_wait_for_sendpkt() where applicable
 730  */
 731 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 732                        u32 selector)
 733 {
 734         struct sk_buff_head head;
 735         int rc;
 736
 737         skb2list(skb, &head);
 738         rc = tipc_link_xmit(net, &head, dnode, selector);
 739         if (rc == -ELINKCONG)
 740                 kfree_skb(skb);
 741         return 0;
 742 }
 743
 744 /**
 745  * tipc_link_xmit() is the general link level function for message sending
 746  * @net: the applicable net namespace
 747  * @list: chain of buffers containing message
 748  * @dsz: amount of user data to be sent
 749  * @dnode: address of destination node
 750  * @selector: a number used for deterministic link selection
 751  * Consumes the buffer chain, except when returning -ELINKCONG
 752  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 753  */
 754 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
 755                    u32 selector)
 756 {
 757         struct tipc_link *link = NULL;
 758         struct tipc_node *node;
 759         int rc = -EHOSTUNREACH;
 760
 761         node = tipc_node_find(net, dnode);
 762         if (node) {
 763                 tipc_node_lock(node);
 764                 link = node_active_link(node, selector & 1);
 765                 if (link)
 766                         rc = __tipc_link_xmit(net, link, list);
 767                 tipc_node_unlock(node);
 768                 tipc_node_put(node);
 769         }
 770         if (link)
 771                 return rc;
 772
 773         if (likely(in_own_node(net, dnode))) {
 774                 tipc_sk_rcv(net, list);
 775                 return 0;
 776         }
 777
 778         __skb_queue_purge(list);
 779         return rc;
 780 }
 781
 782 /*
 783  * tipc_link_sync_xmit - synchronize broadcast link endpoints.
 784  *
 785  * Give a newly added peer node the sequence number where it should
 786  * start receiving and acking broadcast packets.
 787  *
 788  * Called with node locked
 789  */
 790 static void tipc_link_sync_xmit(struct tipc_link *link)
 791 {
 792         struct sk_buff *skb;
 793         struct tipc_msg *msg;
 794
 795         skb = tipc_buf_acquire(INT_H_SIZE);
 796         if (!skb)
 797                 return;
 798
 799         msg = buf_msg(skb);
 800         tipc_msg_init(link_own_addr(link), msg, BCAST_PROTOCOL, STATE_MSG,
 801                       INT_H_SIZE, link->addr);
 802         msg_set_last_bcast(msg, link->owner->bclink.acked);
 803         __tipc_link_xmit_skb(link, skb);
 804 }
 805
 806 /*
 807  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 808  * Receive the sequence number where we should start receiving and
 809  * acking broadcast packets from a newly added peer node, and open
 810  * up for reception of such packets.
 811  *
 812  * Called with node locked
 813  */
 814 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 815 {
 816         struct tipc_msg *msg = buf_msg(buf);
 817
 818         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 819         n->bclink.recv_permitted = true;
 820         kfree_skb(buf);
 821 }
 822
 823 /*
 824  * tipc_link_push_packets - push unsent packets to bearer
 825  *
 826  * Push out the unsent messages of a link where congestion
 827  * has abated. Node is locked.
 828  *
 829  * Called with node locked
 830  */
 831 void tipc_link_push_packets(struct tipc_link *link)
 832 {
 833         struct sk_buff *skb;
 834         struct tipc_msg *msg;
 835         u16 seqno = link->snd_nxt;
 836         u16 ack = mod(link->rcv_nxt - 1);
 837
 838         while (skb_queue_len(&link->transmq) < link->window) {
 839                 skb = __skb_dequeue(&link->backlogq);
 840                 if (!skb)
 841                         break;
 842                 msg = buf_msg(skb);
 843                 link->backlog[msg_importance(msg)].len--;
 844                 msg_set_ack(msg, ack);
 845                 msg_set_seqno(msg, seqno);
 846                 seqno = mod(seqno + 1);
 847                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 848                 link->rcv_unacked = 0;
 849                 __skb_queue_tail(&link->transmq, skb);
 850                 tipc_bearer_send(link->owner->net, link->bearer_id,
 851                                  skb, &link->media_addr);
 852         }
 853         link->snd_nxt = seqno;
 854 }
 855
 856 void tipc_link_reset_all(struct tipc_node *node)
 857 {
 858         char addr_string[16];
 859         u32 i;
 860
 861         tipc_node_lock(node);
 862
 863         pr_warn("Resetting all links to %s\n",
 864                 tipc_addr_string_fill(addr_string, node->addr));
 865
 866         for (i = 0; i < MAX_BEARERS; i++) {
 867                 if (node->links[i].link) {
 868                         link_print(node->links[i].link, "Resetting link\n");
 869                         tipc_link_reset(node->links[i].link);
 870                 }
 871         }
 872
 873         tipc_node_unlock(node);
 874 }
 875
 876 static void link_retransmit_failure(struct tipc_link *l_ptr,
 877                                     struct sk_buff *buf)
 878 {
 879         struct tipc_msg *msg = buf_msg(buf);
 880         struct net *net = l_ptr->owner->net;
 881
 882         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 883
 884         if (l_ptr->addr) {
 885                 /* Handle failure on standard link */
 886                 link_print(l_ptr, "Resetting link\n");
 887                 tipc_link_reset(l_ptr);
 888
 889         } else {
 890                 /* Handle failure on broadcast link */
 891                 struct tipc_node *n_ptr;
 892                 char addr_string[16];
 893
 894                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 895                 pr_cont("Outstanding acks: %lu\n",
 896                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 897
 898                 n_ptr = tipc_bclink_retransmit_to(net);
 899
 900                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 901                 pr_info("Broadcast link info for %s\n", addr_string);
 902                 pr_info("Reception permitted: %d,  Acked: %u\n",
 903                         n_ptr->bclink.recv_permitted,
 904                         n_ptr->bclink.acked);
 905                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 906                         n_ptr->bclink.last_in,
 907                         n_ptr->bclink.oos_state,
 908                         n_ptr->bclink.last_sent);
 909
 910                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 911                 l_ptr->stale_count = 0;
 912         }
 913 }
 914
 915 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 916                           u32 retransmits)
 917 {
 918         struct tipc_msg *msg;
 919
 920         if (!skb)
 921                 return;
 922
 923         msg = buf_msg(skb);
 924
 925         /* Detect repeated retransmit failures */
 926         if (l_ptr->last_retransm == msg_seqno(msg)) {
 927                 if (++l_ptr->stale_count > 100) {
 928                         link_retransmit_failure(l_ptr, skb);
 929                         return;
 930                 }
 931         } else {
 932                 l_ptr->last_retransm = msg_seqno(msg);
 933                 l_ptr->stale_count = 1;
 934         }
 935
 936         skb_queue_walk_from(&l_ptr->transmq, skb) {
 937                 if (!retransmits)
 938                         break;
 939                 msg = buf_msg(skb);
 940                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
 941                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 942                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 943                                  &l_ptr->media_addr);
 944                 retransmits--;
 945                 l_ptr->stats.retransmitted++;
 946         }
 947 }
 948
 949 /* link_synch(): check if all packets arrived before the synch
 950  *               point have been consumed
 951  * Returns true if the parallel links are synched, otherwise false
 952  */
 953 static bool link_synch(struct tipc_link *l)
 954 {
 955         unsigned int post_synch;
 956         struct tipc_link *pl;
 957
 958         pl  = tipc_parallel_link(l);
 959         if (pl == l)
 960                 goto synched;
 961
 962         /* Was last pre-synch packet added to input queue ? */
 963         if (less_eq(pl->rcv_nxt, l->synch_point))
 964                 return false;
 965
 966         /* Is it still in the input queue ? */
 967         post_synch = mod(pl->rcv_nxt - l->synch_point) - 1;
 968         if (skb_queue_len(pl->inputq) > post_synch)
 969                 return false;
 970 synched:
 971         l->flags &= ~LINK_SYNCHING;
 972         return true;
 973 }
 974
 975 static void link_retrieve_defq(struct tipc_link *link,
 976                                struct sk_buff_head *list)
 977 {
 978         u16 seq_no;
 979
 980         if (skb_queue_empty(&link->deferdq))
 981                 return;
 982
 983         seq_no = buf_seqno(skb_peek(&link->deferdq));
 984         if (seq_no == link->rcv_nxt)
 985                 skb_queue_splice_tail_init(&link->deferdq, list);
 986 }
 987
 988 /**
 989  * tipc_rcv - process TIPC packets/messages arriving from off-node
 990  * @net: the applicable net namespace
 991  * @skb: TIPC packet
 992  * @b_ptr: pointer to bearer message arrived on
 993  *
 994  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
 995  * structure (i.e. cannot be NULL), but bearer can be inactive.
 996  */
 997 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
 998 {
 999         struct tipc_net *tn = net_generic(net, tipc_net_id);
1000         struct sk_buff_head head;
1001         struct tipc_node *n_ptr;
1002         struct tipc_link *l_ptr;
1003         struct sk_buff *skb1, *tmp;
1004         struct tipc_msg *msg;
1005         u16 seq_no;
1006         u16 ackd;
1007         u32 released;
1008
1009         skb2list(skb, &head);
1010
1011         while ((skb = __skb_dequeue(&head))) {
1012                 /* Ensure message is well-formed */
1013                 if (unlikely(!tipc_msg_validate(skb)))
1014                         goto discard;
1015
1016                 /* Handle arrival of a non-unicast link message */
1017                 msg = buf_msg(skb);
1018                 if (unlikely(msg_non_seq(msg))) {
1019                         if (msg_user(msg) ==  LINK_CONFIG)
1020                                 tipc_disc_rcv(net, skb, b_ptr);
1021                         else
1022                                 tipc_bclink_rcv(net, skb);
1023                         continue;
1024                 }
1025
1026                 /* Discard unicast link messages destined for another node */
1027                 if (unlikely(!msg_short(msg) &&
1028                              (msg_destnode(msg) != tn->own_addr)))
1029                         goto discard;
1030
1031                 /* Locate neighboring node that sent message */
1032                 n_ptr = tipc_node_find(net, msg_prevnode(msg));
1033                 if (unlikely(!n_ptr))
1034                         goto discard;
1035
1036                 tipc_node_lock(n_ptr);
1037                 /* Locate unicast link endpoint that should handle message */
1038                 l_ptr = n_ptr->links[b_ptr->identity].link;
1039                 if (unlikely(!l_ptr))
1040                         goto unlock;
1041
1042                 /* Verify that communication with node is currently allowed */
1043                 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
1044                     msg_user(msg) == LINK_PROTOCOL &&
1045                     (msg_type(msg) == RESET_MSG ||
1046                     msg_type(msg) == ACTIVATE_MSG) &&
1047                     !msg_redundant_link(msg))
1048                         n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
1049
1050                 if (tipc_node_blocked(n_ptr))
1051                         goto unlock;
1052
1053                 /* Validate message sequence number info */
1054                 seq_no = msg_seqno(msg);
1055                 ackd = msg_ack(msg);
1056
1057                 /* Release acked messages */
1058                 if (unlikely(n_ptr->bclink.acked != msg_bcast_ack(msg)))
1059                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1060
1061                 released = 0;
1062                 skb_queue_walk_safe(&l_ptr->transmq, skb1, tmp) {
1063                         if (more(buf_seqno(skb1), ackd))
1064                                 break;
1065                          __skb_unlink(skb1, &l_ptr->transmq);
1066                          kfree_skb(skb1);
1067                          released = 1;
1068                 }
1069
1070                 /* Try sending any messages link endpoint has pending */
1071                 if (unlikely(skb_queue_len(&l_ptr->backlogq)))
1072                         tipc_link_push_packets(l_ptr);
1073
1074                 if (released && !skb_queue_empty(&l_ptr->wakeupq))
1075                         link_prepare_wakeup(l_ptr);
1076
1077                 /* Process the incoming packet */
1078                 if (unlikely(!link_working_working(l_ptr))) {
1079                         if (msg_user(msg) == LINK_PROTOCOL) {
1080                                 tipc_link_proto_rcv(l_ptr, skb);
1081                                 link_retrieve_defq(l_ptr, &head);
1082                                 skb = NULL;
1083                                 goto unlock;
1084                         }
1085
1086                         /* Traffic message. Conditionally activate link */
1087                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1088
1089                         if (link_working_working(l_ptr)) {
1090                                 /* Re-insert buffer in front of queue */
1091                                 __skb_queue_head(&head, skb);
1092                                 skb = NULL;
1093                                 goto unlock;
1094                         }
1095                         goto unlock;
1096                 }
1097
1098                 /* Link is now in state WORKING_WORKING */
1099                 if (unlikely(seq_no != l_ptr->rcv_nxt)) {
1100                         link_handle_out_of_seq_msg(l_ptr, skb);
1101                         link_retrieve_defq(l_ptr, &head);
1102                         skb = NULL;
1103                         goto unlock;
1104                 }
1105                 l_ptr->silent_intv_cnt = 0;
1106
1107                 /* Synchronize with parallel link if applicable */
1108                 if (unlikely((l_ptr->flags & LINK_SYNCHING) && !msg_dup(msg))) {
1109                         if (!link_synch(l_ptr))
1110                                 goto unlock;
1111                 }
1112                 l_ptr->rcv_nxt++;
1113                 if (unlikely(!skb_queue_empty(&l_ptr->deferdq)))
1114                         link_retrieve_defq(l_ptr, &head);
1115                 if (unlikely(++l_ptr->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
1116                         l_ptr->stats.sent_acks++;
1117                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1118                 }
1119                 tipc_link_input(l_ptr, skb);
1120                 skb = NULL;
1121 unlock:
1122                 tipc_node_unlock(n_ptr);
1123                 tipc_node_put(n_ptr);
1124 discard:
1125                 if (unlikely(skb))
1126                         kfree_skb(skb);
1127         }
1128 }
1129
1130 /* tipc_data_input - deliver data and name distr msgs to upper layer
1131  *
1132  * Consumes buffer if message is of right type
1133  * Node lock must be held
1134  */
1135 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
1136 {
1137         struct tipc_node *node = link->owner;
1138         struct tipc_msg *msg = buf_msg(skb);
1139         u32 dport = msg_destport(msg);
1140
1141         switch (msg_user(msg)) {
1142         case TIPC_LOW_IMPORTANCE:
1143         case TIPC_MEDIUM_IMPORTANCE:
1144         case TIPC_HIGH_IMPORTANCE:
1145         case TIPC_CRITICAL_IMPORTANCE:
1146         case CONN_MANAGER:
1147                 if (tipc_skb_queue_tail(link->inputq, skb, dport)) {
1148                         node->inputq = link->inputq;
1149                         node->action_flags |= TIPC_MSG_EVT;
1150                 }
1151                 return true;
1152         case NAME_DISTRIBUTOR:
1153                 node->bclink.recv_permitted = true;
1154                 node->namedq = link->namedq;
1155                 skb_queue_tail(link->namedq, skb);
1156                 if (skb_queue_len(link->namedq) == 1)
1157                         node->action_flags |= TIPC_NAMED_MSG_EVT;
1158                 return true;
1159         case MSG_BUNDLER:
1160         case TUNNEL_PROTOCOL:
1161         case MSG_FRAGMENTER:
1162         case BCAST_PROTOCOL:
1163                 return false;
1164         default:
1165                 pr_warn("Dropping received illegal msg type\n");
1166                 kfree_skb(skb);
1167                 return false;
1168         };
1169 }
1170
1171 /* tipc_link_input - process packet that has passed link protocol check
1172  *
1173  * Consumes buffer
1174  * Node lock must be held
1175  */
1176 static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
1177 {
1178         struct tipc_node *node = link->owner;
1179         struct tipc_msg *msg = buf_msg(skb);
1180         struct sk_buff *iskb;
1181         int pos = 0;
1182
1183         if (likely(tipc_data_input(link, skb)))
1184                 return;
1185
1186         switch (msg_user(msg)) {
1187         case TUNNEL_PROTOCOL:
1188                 if (msg_dup(msg)) {
1189                         link->flags |= LINK_SYNCHING;
1190                         link->synch_point = msg_seqno(msg_get_wrapped(msg));
1191                         kfree_skb(skb);
1192                         break;
1193                 }
1194                 if (!tipc_link_failover_rcv(link, &skb))
1195                         break;
1196                 if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
1197                         tipc_data_input(link, skb);
1198                         break;
1199                 }
1200         case MSG_BUNDLER:
1201                 link->stats.recv_bundles++;
1202                 link->stats.recv_bundled += msg_msgcnt(msg);
1203
1204                 while (tipc_msg_extract(skb, &iskb, &pos))
1205                         tipc_data_input(link, iskb);
1206                 break;
1207         case MSG_FRAGMENTER:
1208                 link->stats.recv_fragments++;
1209                 if (tipc_buf_append(&link->reasm_buf, &skb)) {
1210                         link->stats.recv_fragmented++;
1211                         tipc_data_input(link, skb);
1212                 } else if (!link->reasm_buf) {
1213                         tipc_link_reset(link);
1214                 }
1215                 break;
1216         case BCAST_PROTOCOL:
1217                 tipc_link_sync_rcv(node, skb);
1218                 break;
1219         default:
1220                 break;
1221         };
1222 }
1223
1224 /**
1225  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1226  *
1227  * Returns increase in queue length (i.e. 0 or 1)
1228  */
1229 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1230 {
1231         struct sk_buff *skb1;
1232         u16 seq_no = buf_seqno(skb);
1233
1234         /* Empty queue ? */
1235         if (skb_queue_empty(list)) {
1236                 __skb_queue_tail(list, skb);
1237                 return 1;
1238         }
1239
1240         /* Last ? */
1241         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1242                 __skb_queue_tail(list, skb);
1243                 return 1;
1244         }
1245
1246         /* Locate insertion point in queue, then insert; discard if duplicate */
1247         skb_queue_walk(list, skb1) {
1248                 u16 curr_seqno = buf_seqno(skb1);
1249
1250                 if (seq_no == curr_seqno) {
1251                         kfree_skb(skb);
1252                         return 0;
1253                 }
1254
1255                 if (less(seq_no, curr_seqno))
1256                         break;
1257         }
1258
1259         __skb_queue_before(list, skb1, skb);
1260         return 1;
1261 }
1262
1263 /*
1264  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1265  */
1266 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1267                                        struct sk_buff *buf)
1268 {
1269         u32 seq_no = buf_seqno(buf);
1270
1271         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1272                 tipc_link_proto_rcv(l_ptr, buf);
1273                 return;
1274         }
1275
1276         /* Record OOS packet arrival */
1277         l_ptr->silent_intv_cnt = 0;
1278
1279         /*
1280          * Discard packet if a duplicate; otherwise add it to deferred queue
1281          * and notify peer of gap as per protocol specification
1282          */
1283         if (less(seq_no, l_ptr->rcv_nxt)) {
1284                 l_ptr->stats.duplicates++;
1285                 kfree_skb(buf);
1286                 return;
1287         }
1288
1289         if (tipc_link_defer_pkt(&l_ptr->deferdq, buf)) {
1290                 l_ptr->stats.deferred_recv++;
1291                 if ((skb_queue_len(&l_ptr->deferdq) % TIPC_MIN_LINK_WIN) == 1)
1292                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1293         } else {
1294                 l_ptr->stats.duplicates++;
1295         }
1296 }
1297
1298 /*
1299  * Send protocol message to the other endpoint.
1300  */
1301 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1302                           u32 gap, u32 tolerance, u32 priority)
1303 {
1304         struct sk_buff *buf = NULL;
1305         struct tipc_msg *msg = l_ptr->pmsg;
1306         u32 msg_size = sizeof(l_ptr->proto_msg);
1307         int r_flag;
1308         u16 last_rcv;
1309
1310         /* Don't send protocol message during link failover */
1311         if (l_ptr->flags & LINK_FAILINGOVER)
1312                 return;
1313
1314         /* Abort non-RESET send if communication with node is prohibited */
1315         if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG))
1316                 return;
1317
1318         /* Create protocol message with "out-of-sequence" sequence number */
1319         msg_set_type(msg, msg_typ);
1320         msg_set_net_plane(msg, l_ptr->net_plane);
1321         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1322         msg_set_last_bcast(msg, tipc_bclink_get_last_sent(l_ptr->owner->net));
1323
1324         if (msg_typ == STATE_MSG) {
1325                 u16 next_sent = l_ptr->snd_nxt;
1326
1327                 if (!tipc_link_is_up(l_ptr))
1328                         return;
1329                 msg_set_next_sent(msg, next_sent);
1330                 if (!skb_queue_empty(&l_ptr->deferdq)) {
1331                         last_rcv = buf_seqno(skb_peek(&l_ptr->deferdq));
1332                         gap = mod(last_rcv - l_ptr->rcv_nxt);
1333                 }
1334                 msg_set_seq_gap(msg, gap);
1335                 if (gap)
1336                         l_ptr->stats.sent_nacks++;
1337                 msg_set_link_tolerance(msg, tolerance);
1338                 msg_set_linkprio(msg, priority);
1339                 msg_set_max_pkt(msg, l_ptr->mtu);
1340                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
1341                 msg_set_probe(msg, probe_msg != 0);
1342                 if (probe_msg)
1343                         l_ptr->stats.sent_probes++;
1344                 l_ptr->stats.sent_states++;
1345         } else {                /* RESET_MSG or ACTIVATE_MSG */
1346                 msg_set_ack(msg, mod(l_ptr->failover_checkpt - 1));
1347                 msg_set_seq_gap(msg, 0);
1348                 msg_set_next_sent(msg, 1);
1349                 msg_set_probe(msg, 0);
1350                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1351                 msg_set_linkprio(msg, l_ptr->priority);
1352                 msg_set_max_pkt(msg, l_ptr->advertised_mtu);
1353         }
1354
1355         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1356         msg_set_redundant_link(msg, r_flag);
1357         msg_set_linkprio(msg, l_ptr->priority);
1358         msg_set_size(msg, msg_size);
1359
1360         msg_set_seqno(msg, mod(l_ptr->snd_nxt + (0xffff / 2)));
1361
1362         buf = tipc_buf_acquire(msg_size);
1363         if (!buf)
1364                 return;
1365
1366         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1367         buf->priority = TC_PRIO_CONTROL;
1368         tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, buf,
1369                          &l_ptr->media_addr);
1370         l_ptr->rcv_unacked = 0;
1371         kfree_skb(buf);
1372 }
1373
1374 /*
1375  * Receive protocol message :
1376  * Note that network plane id propagates through the network, and may
1377  * change at any time. The node with lowest address rules
1378  */
1379 static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
1380                                 struct sk_buff *buf)
1381 {
1382         u32 rec_gap = 0;
1383         u32 msg_tol;
1384         struct tipc_msg *msg = buf_msg(buf);
1385
1386         if (l_ptr->flags & LINK_FAILINGOVER)
1387                 goto exit;
1388
1389         if (l_ptr->net_plane != msg_net_plane(msg))
1390                 if (link_own_addr(l_ptr) > msg_prevnode(msg))
1391                         l_ptr->net_plane = msg_net_plane(msg);
1392
1393         switch (msg_type(msg)) {
1394
1395         case RESET_MSG:
1396                 if (!link_working_unknown(l_ptr) &&
1397                     (l_ptr->peer_session != INVALID_SESSION)) {
1398                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1399                                 break; /* duplicate or old reset: ignore */
1400                 }
1401
1402                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1403                                 link_working_unknown(l_ptr))) {
1404                         /*
1405                          * peer has lost contact -- don't allow peer's links
1406                          * to reactivate before we recognize loss & clean up
1407                          */
1408                         l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
1409                 }
1410
1411                 link_state_event(l_ptr, RESET_MSG);
1412
1413                 /* fall thru' */
1414         case ACTIVATE_MSG:
1415                 /* Update link settings according other endpoint's values */
1416                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1417
1418                 msg_tol = msg_link_tolerance(msg);
1419                 if (msg_tol > l_ptr->tolerance)
1420                         link_set_supervision_props(l_ptr, msg_tol);
1421
1422                 if (msg_linkprio(msg) > l_ptr->priority)
1423                         l_ptr->priority = msg_linkprio(msg);
1424
1425                 if (l_ptr->mtu > msg_max_pkt(msg))
1426                         l_ptr->mtu = msg_max_pkt(msg);
1427
1428                 /* Synchronize broadcast link info, if not done previously */
1429                 if (!tipc_node_is_up(l_ptr->owner)) {
1430                         l_ptr->owner->bclink.last_sent =
1431                                 l_ptr->owner->bclink.last_in =
1432                                 msg_last_bcast(msg);
1433                         l_ptr->owner->bclink.oos_state = 0;
1434                 }
1435
1436                 l_ptr->peer_session = msg_session(msg);
1437                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1438
1439                 if (msg_type(msg) == ACTIVATE_MSG)
1440                         link_state_event(l_ptr, ACTIVATE_MSG);
1441                 break;
1442         case STATE_MSG:
1443
1444                 msg_tol = msg_link_tolerance(msg);
1445                 if (msg_tol)
1446                         link_set_supervision_props(l_ptr, msg_tol);
1447
1448                 if (msg_linkprio(msg) &&
1449                     (msg_linkprio(msg) != l_ptr->priority)) {
1450                         pr_debug("%s<%s>, priority change %u->%u\n",
1451                                  link_rst_msg, l_ptr->name,
1452                                  l_ptr->priority, msg_linkprio(msg));
1453                         l_ptr->priority = msg_linkprio(msg);
1454                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1455                         break;
1456                 }
1457
1458                 /* Record reception; force mismatch at next timeout: */
1459                 l_ptr->silent_intv_cnt = 0;
1460
1461                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1462                 l_ptr->stats.recv_states++;
1463                 if (link_reset_unknown(l_ptr))
1464                         break;
1465
1466                 if (less_eq(l_ptr->rcv_nxt, msg_next_sent(msg)))
1467                         rec_gap = mod(msg_next_sent(msg) - l_ptr->rcv_nxt);
1468
1469                 if (msg_probe(msg))
1470                         l_ptr->stats.recv_probes++;
1471
1472                 /* Protocol message before retransmits, reduce loss risk */
1473                 if (l_ptr->owner->bclink.recv_permitted)
1474                         tipc_bclink_update_link_state(l_ptr->owner,
1475                                                       msg_last_bcast(msg));
1476
1477                 if (rec_gap || (msg_probe(msg))) {
1478                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0,
1479                                              rec_gap, 0, 0);
1480                 }
1481                 if (msg_seq_gap(msg)) {
1482                         l_ptr->stats.recv_nacks++;
1483                         tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->transmq),
1484                                              msg_seq_gap(msg));
1485                 }
1486                 break;
1487         }
1488 exit:
1489         kfree_skb(buf);
1490 }
1491
1492
1493 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1494  * a different bearer. Owner node is locked.
1495  */
1496 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1497                                   struct tipc_msg *tunnel_hdr,
1498                                   struct tipc_msg *msg,
1499                                   u32 selector)
1500 {
1501         struct tipc_link *tunnel;
1502         struct sk_buff *skb;
1503         u32 length = msg_size(msg);
1504
1505         tunnel = node_active_link(l_ptr->owner, selector & 1);
1506         if (!tipc_link_is_up(tunnel)) {
1507                 pr_warn("%stunnel link no longer available\n", link_co_err);
1508                 return;
1509         }
1510         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1511         skb = tipc_buf_acquire(length + INT_H_SIZE);
1512         if (!skb) {
1513                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1514                 return;
1515         }
1516         skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
1517         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
1518         __tipc_link_xmit_skb(tunnel, skb);
1519 }
1520
1521
1522 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1523  * link is still active. We can do failover. Tunnel the failing link's
1524  * whole send queue via the remaining link. This way, we don't lose
1525  * any packets, and sequence order is preserved for subsequent traffic
1526  * sent over the remaining link. Owner node is locked.
1527  */
1528 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1529 {
1530         int msgcount;
1531         struct tipc_link *tunnel = node_active_link(l_ptr->owner, 0);
1532         struct tipc_msg tunnel_hdr;
1533         struct sk_buff *skb;
1534         int split_bundles;
1535
1536         if (!tunnel)
1537                 return;
1538
1539         tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
1540                       FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
1541
1542         skb_queue_walk(&l_ptr->backlogq, skb) {
1543                 msg_set_seqno(buf_msg(skb), l_ptr->snd_nxt);
1544                 l_ptr->snd_nxt = mod(l_ptr->snd_nxt + 1);
1545         }
1546         skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
1547         tipc_link_purge_backlog(l_ptr);
1548         msgcount = skb_queue_len(&l_ptr->transmq);
1549         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1550         msg_set_msgcnt(&tunnel_hdr, msgcount);
1551
1552         if (skb_queue_empty(&l_ptr->transmq)) {
1553                 skb = tipc_buf_acquire(INT_H_SIZE);
1554                 if (skb) {
1555                         skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
1556                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1557                         __tipc_link_xmit_skb(tunnel, skb);
1558                 } else {
1559                         pr_warn("%sunable to send changeover msg\n",
1560                                 link_co_err);
1561                 }
1562                 return;
1563         }
1564
1565         split_bundles = (node_active_link(l_ptr->owner, 0) !=
1566                          node_active_link(l_ptr->owner, 0));
1567
1568         skb_queue_walk(&l_ptr->transmq, skb) {
1569                 struct tipc_msg *msg = buf_msg(skb);
1570
1571                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1572                         struct tipc_msg *m = msg_get_wrapped(msg);
1573                         unchar *pos = (unchar *)m;
1574
1575                         msgcount = msg_msgcnt(msg);
1576                         while (msgcount--) {
1577                                 msg_set_seqno(m, msg_seqno(msg));
1578                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1579                                                       msg_link_selector(m));
1580                                 pos += align(msg_size(m));
1581                                 m = (struct tipc_msg *)pos;
1582                         }
1583                 } else {
1584                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1585                                               msg_link_selector(msg));
1586                 }
1587         }
1588 }
1589
1590 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1591  * duplicate of the first link's send queue via the new link. This way, we
1592  * are guaranteed that currently queued packets from a socket are delivered
1593  * before future traffic from the same socket, even if this is using the
1594  * new link. The last arriving copy of each duplicate packet is dropped at
1595  * the receiving end by the regular protocol check, so packet cardinality
1596  * and sequence order is preserved per sender/receiver socket pair.
1597  * Owner node is locked.
1598  */
1599 void tipc_link_dup_queue_xmit(struct tipc_link *link,
1600                               struct tipc_link *tnl)
1601 {
1602         struct sk_buff *skb;
1603         struct tipc_msg tnl_hdr;
1604         struct sk_buff_head *queue = &link->transmq;
1605         int mcnt;
1606         u16 seqno;
1607
1608         tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
1609                       SYNCH_MSG, INT_H_SIZE, link->addr);
1610         mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
1611         msg_set_msgcnt(&tnl_hdr, mcnt);
1612         msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
1613
1614 tunnel_queue:
1615         skb_queue_walk(queue, skb) {
1616                 struct sk_buff *outskb;
1617                 struct tipc_msg *msg = buf_msg(skb);
1618                 u32 len = msg_size(msg);
1619
1620                 msg_set_ack(msg, mod(link->rcv_nxt - 1));
1621                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
1622                 msg_set_size(&tnl_hdr, len + INT_H_SIZE);
1623                 outskb = tipc_buf_acquire(len + INT_H_SIZE);
1624                 if (outskb == NULL) {
1625                         pr_warn("%sunable to send duplicate msg\n",
1626                                 link_co_err);
1627                         return;
1628                 }
1629                 skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
1630                 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
1631                                                skb->data, len);
1632                 __tipc_link_xmit_skb(tnl, outskb);
1633                 if (!tipc_link_is_up(link))
1634                         return;
1635         }
1636         if (queue == &link->backlogq)
1637                 return;
1638         seqno = link->snd_nxt;
1639         skb_queue_walk(&link->backlogq, skb) {
1640                 msg_set_seqno(buf_msg(skb), seqno);
1641                 seqno = mod(seqno + 1);
1642         }
1643         queue = &link->backlogq;
1644         goto tunnel_queue;
1645 }
1646
1647 /*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
1648  *  Owner node is locked.
1649  */
1650 static bool tipc_link_failover_rcv(struct tipc_link *link,
1651                                    struct sk_buff **skb)
1652 {
1653         struct tipc_msg *msg = buf_msg(*skb);
1654         struct sk_buff *iskb = NULL;
1655         struct tipc_link *pl = NULL;
1656         int bearer_id = msg_bearer_id(msg);
1657         int pos = 0;
1658
1659         if (msg_type(msg) != FAILOVER_MSG) {
1660                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1661                 goto exit;
1662         }
1663         if (bearer_id >= MAX_BEARERS)
1664                 goto exit;
1665
1666         if (bearer_id == link->bearer_id)
1667                 goto exit;
1668
1669         pl = link->owner->links[bearer_id].link;
1670         if (pl && tipc_link_is_up(pl))
1671                 tipc_link_reset(pl);
1672
1673         if (link->failover_pkts == FIRST_FAILOVER)
1674                 link->failover_pkts = msg_msgcnt(msg);
1675
1676         /* Should we expect an inner packet? */
1677         if (!link->failover_pkts)
1678                 goto exit;
1679
1680         if (!tipc_msg_extract(*skb, &iskb, &pos)) {
1681                 pr_warn("%sno inner failover pkt\n", link_co_err);
1682                 *skb = NULL;
1683                 goto exit;
1684         }
1685         link->failover_pkts--;
1686         *skb = NULL;
1687
1688         /* Was this packet already delivered? */
1689         if (less(buf_seqno(iskb), link->failover_checkpt)) {
1690                 kfree_skb(iskb);
1691                 iskb = NULL;
1692                 goto exit;
1693         }
1694         if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
1695                 link->stats.recv_fragments++;
1696                 tipc_buf_append(&link->failover_skb, &iskb);
1697         }
1698 exit:
1699         if (!link->failover_pkts && pl)
1700                 pl->flags &= ~LINK_FAILINGOVER;
1701         kfree_skb(*skb);
1702         *skb = iskb;
1703         return *skb;
1704 }
1705
1706 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol)
1707 {
1708         unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
1709
1710         if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1711                 return;
1712
1713         l_ptr->tolerance = tol;
1714         l_ptr->keepalive_intv = msecs_to_jiffies(intv);
1715         l_ptr->abort_limit = tol / (jiffies_to_msecs(l_ptr->keepalive_intv));
1716 }
1717
1718 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1719 {
1720         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1721
1722         l->window = win;
1723         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1724         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1725         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1726         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1727         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1728 }
1729
1730 /* tipc_link_find_owner - locate owner node of link by link's name
1731  * @net: the applicable net namespace
1732  * @name: pointer to link name string
1733  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1734  *
1735  * Returns pointer to node owning the link, or 0 if no matching link is found.
1736  */
1737 static struct tipc_node *tipc_link_find_owner(struct net *net,
1738                                               const char *link_name,
1739                                               unsigned int *bearer_id)
1740 {
1741         struct tipc_net *tn = net_generic(net, tipc_net_id);
1742         struct tipc_link *l_ptr;
1743         struct tipc_node *n_ptr;
1744         struct tipc_node *found_node = NULL;
1745         int i;
1746
1747         *bearer_id = 0;
1748         rcu_read_lock();
1749         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1750                 tipc_node_lock(n_ptr);
1751                 for (i = 0; i < MAX_BEARERS; i++) {
1752                         l_ptr = n_ptr->links[i].link;
1753                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1754                                 *bearer_id = i;
1755                                 found_node = n_ptr;
1756                                 break;
1757                         }
1758                 }
1759                 tipc_node_unlock(n_ptr);
1760                 if (found_node)
1761                         break;
1762         }
1763         rcu_read_unlock();
1764
1765         return found_node;
1766 }
1767
1768 /**
1769  * link_reset_statistics - reset link statistics
1770  * @l_ptr: pointer to link
1771  */
1772 static void link_reset_statistics(struct tipc_link *l_ptr)
1773 {
1774         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1775         l_ptr->stats.sent_info = l_ptr->snd_nxt;
1776         l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1777 }
1778
1779 static void link_print(struct tipc_link *l_ptr, const char *str)
1780 {
1781         struct tipc_net *tn = net_generic(l_ptr->owner->net, tipc_net_id);
1782         struct tipc_bearer *b_ptr;
1783
1784         rcu_read_lock();
1785         b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]);
1786         if (b_ptr)
1787                 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name);
1788         rcu_read_unlock();
1789
1790         if (link_working_unknown(l_ptr))
1791                 pr_cont(":WU\n");
1792         else if (link_reset_reset(l_ptr))
1793                 pr_cont(":RR\n");
1794         else if (link_reset_unknown(l_ptr))
1795                 pr_cont(":RU\n");
1796         else if (link_working_working(l_ptr))
1797                 pr_cont(":WW\n");
1798         else
1799                 pr_cont("\n");
1800 }
1801
1802 /* Parse and validate nested (link) properties valid for media, bearer and link
1803  */
1804 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1805 {
1806         int err;
1807
1808         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1809                                tipc_nl_prop_policy);
1810         if (err)
1811                 return err;
1812
1813         if (props[TIPC_NLA_PROP_PRIO]) {
1814                 u32 prio;
1815
1816                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1817                 if (prio > TIPC_MAX_LINK_PRI)
1818                         return -EINVAL;
1819         }
1820
1821         if (props[TIPC_NLA_PROP_TOL]) {
1822                 u32 tol;
1823
1824                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1825                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1826                         return -EINVAL;
1827         }
1828
1829         if (props[TIPC_NLA_PROP_WIN]) {
1830                 u32 win;
1831
1832                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1833                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1834                         return -EINVAL;
1835         }
1836
1837         return 0;
1838 }
1839
1840 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1841 {
1842         int err;
1843         int res = 0;
1844         int bearer_id;
1845         char *name;
1846         struct tipc_link *link;
1847         struct tipc_node *node;
1848         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1849         struct net *net = sock_net(skb->sk);
1850
1851         if (!info->attrs[TIPC_NLA_LINK])
1852                 return -EINVAL;
1853
1854         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1855                                info->attrs[TIPC_NLA_LINK],
1856                                tipc_nl_link_policy);
1857         if (err)
1858                 return err;
1859
1860         if (!attrs[TIPC_NLA_LINK_NAME])
1861                 return -EINVAL;
1862
1863         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1864
1865         if (strcmp(name, tipc_bclink_name) == 0)
1866                 return tipc_nl_bc_link_set(net, attrs);
1867
1868         node = tipc_link_find_owner(net, name, &bearer_id);
1869         if (!node)
1870                 return -EINVAL;
1871
1872         tipc_node_lock(node);
1873
1874         link = node->links[bearer_id].link;
1875         if (!link) {
1876                 res = -EINVAL;
1877                 goto out;
1878         }
1879
1880         if (attrs[TIPC_NLA_LINK_PROP]) {
1881                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1882
1883                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1884                                               props);
1885                 if (err) {
1886                         res = err;
1887                         goto out;
1888                 }
1889
1890                 if (props[TIPC_NLA_PROP_TOL]) {
1891                         u32 tol;
1892
1893                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1894                         link_set_supervision_props(link, tol);
1895                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1896                 }
1897                 if (props[TIPC_NLA_PROP_PRIO]) {
1898                         u32 prio;
1899
1900                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1901                         link->priority = prio;
1902                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1903                 }
1904                 if (props[TIPC_NLA_PROP_WIN]) {
1905                         u32 win;
1906
1907                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1908                         tipc_link_set_queue_limits(link, win);
1909                 }
1910         }
1911
1912 out:
1913         tipc_node_unlock(node);
1914
1915         return res;
1916 }
1917
1918 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1919 {
1920         int i;
1921         struct nlattr *stats;
1922
1923         struct nla_map {
1924                 u32 key;
1925                 u32 val;
1926         };
1927
1928         struct nla_map map[] = {
1929                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1930                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1931                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1932                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1933                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1934                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1935                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1936                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1937                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1938                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1939                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1940                         s->msg_length_counts : 1},
1941                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1942                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1943                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1944                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1945                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1946                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1947                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1948                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1949                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1950                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1951                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1952                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1953                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1954                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1955                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1956                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1957                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1958                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1959                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1960                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1961                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1962                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1963                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1964         };
1965
1966         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1967         if (!stats)
1968                 return -EMSGSIZE;
1969
1970         for (i = 0; i <  ARRAY_SIZE(map); i++)
1971                 if (nla_put_u32(skb, map[i].key, map[i].val))
1972                         goto msg_full;
1973
1974         nla_nest_end(skb, stats);
1975
1976         return 0;
1977 msg_full:
1978         nla_nest_cancel(skb, stats);
1979
1980         return -EMSGSIZE;
1981 }
1982
1983 /* Caller should hold appropriate locks to protect the link */
1984 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1985                               struct tipc_link *link, int nlflags)
1986 {
1987         int err;
1988         void *hdr;
1989         struct nlattr *attrs;
1990         struct nlattr *prop;
1991         struct tipc_net *tn = net_generic(net, tipc_net_id);
1992
1993         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1994                           nlflags, TIPC_NL_LINK_GET);
1995         if (!hdr)
1996                 return -EMSGSIZE;
1997
1998         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1999         if (!attrs)
2000                 goto msg_full;
2001
2002         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2003                 goto attr_msg_full;
2004         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
2005                         tipc_cluster_mask(tn->own_addr)))
2006                 goto attr_msg_full;
2007         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2008                 goto attr_msg_full;
2009         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
2010                 goto attr_msg_full;
2011         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
2012                 goto attr_msg_full;
2013
2014         if (tipc_link_is_up(link))
2015                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2016                         goto attr_msg_full;
2017         if (tipc_link_is_active(link))
2018                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2019                         goto attr_msg_full;
2020
2021         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2022         if (!prop)
2023                 goto attr_msg_full;
2024         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2025                 goto prop_msg_full;
2026         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2027                 goto prop_msg_full;
2028         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2029                         link->window))
2030                 goto prop_msg_full;
2031         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2032                 goto prop_msg_full;
2033         nla_nest_end(msg->skb, prop);
2034
2035         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2036         if (err)
2037                 goto attr_msg_full;
2038
2039         nla_nest_end(msg->skb, attrs);
2040         genlmsg_end(msg->skb, hdr);
2041
2042         return 0;
2043
2044 prop_msg_full:
2045         nla_nest_cancel(msg->skb, prop);
2046 attr_msg_full:
2047         nla_nest_cancel(msg->skb, attrs);
2048 msg_full:
2049         genlmsg_cancel(msg->skb, hdr);
2050
2051         return -EMSGSIZE;
2052 }
2053
2054 /* Caller should hold node lock  */
2055 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2056                                     struct tipc_node *node, u32 *prev_link)
2057 {
2058         u32 i;
2059         int err;
2060
2061         for (i = *prev_link; i < MAX_BEARERS; i++) {
2062                 *prev_link = i;
2063
2064                 if (!node->links[i].link)
2065                         continue;
2066
2067                 err = __tipc_nl_add_link(net, msg,
2068                                          node->links[i].link, NLM_F_MULTI);
2069                 if (err)
2070                         return err;
2071         }
2072         *prev_link = 0;
2073
2074         return 0;
2075 }
2076
2077 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2078 {
2079         struct net *net = sock_net(skb->sk);
2080         struct tipc_net *tn = net_generic(net, tipc_net_id);
2081         struct tipc_node *node;
2082         struct tipc_nl_msg msg;
2083         u32 prev_node = cb->args[0];
2084         u32 prev_link = cb->args[1];
2085         int done = cb->args[2];
2086         int err;
2087
2088         if (done)
2089                 return 0;
2090
2091         msg.skb = skb;
2092         msg.portid = NETLINK_CB(cb->skb).portid;
2093         msg.seq = cb->nlh->nlmsg_seq;
2094
2095         rcu_read_lock();
2096         if (prev_node) {
2097                 node = tipc_node_find(net, prev_node);
2098                 if (!node) {
2099                         /* We never set seq or call nl_dump_check_consistent()
2100                          * this means that setting prev_seq here will cause the
2101                          * consistence check to fail in the netlink callback
2102                          * handler. Resulting in the last NLMSG_DONE message
2103                          * having the NLM_F_DUMP_INTR flag set.
2104                          */
2105                         cb->prev_seq = 1;
2106                         goto out;
2107                 }
2108                 tipc_node_put(node);
2109
2110                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2111                                                  list) {
2112                         tipc_node_lock(node);
2113                         err = __tipc_nl_add_node_links(net, &msg, node,
2114                                                        &prev_link);
2115                         tipc_node_unlock(node);
2116                         if (err)
2117                                 goto out;
2118
2119                         prev_node = node->addr;
2120                 }
2121         } else {
2122                 err = tipc_nl_add_bc_link(net, &msg);
2123                 if (err)
2124                         goto out;
2125
2126                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2127                         tipc_node_lock(node);
2128                         err = __tipc_nl_add_node_links(net, &msg, node,
2129                                                        &prev_link);
2130                         tipc_node_unlock(node);
2131                         if (err)
2132                                 goto out;
2133
2134                         prev_node = node->addr;
2135                 }
2136         }
2137         done = 1;
2138 out:
2139         rcu_read_unlock();
2140
2141         cb->args[0] = prev_node;
2142         cb->args[1] = prev_link;
2143         cb->args[2] = done;
2144
2145         return skb->len;
2146 }
2147
2148 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2149 {
2150         struct net *net = genl_info_net(info);
2151         struct tipc_nl_msg msg;
2152         char *name;
2153         int err;
2154
2155         msg.portid = info->snd_portid;
2156         msg.seq = info->snd_seq;
2157
2158         if (!info->attrs[TIPC_NLA_LINK_NAME])
2159                 return -EINVAL;
2160         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2161
2162         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2163         if (!msg.skb)
2164                 return -ENOMEM;
2165
2166         if (strcmp(name, tipc_bclink_name) == 0) {
2167                 err = tipc_nl_add_bc_link(net, &msg);
2168                 if (err) {
2169                         nlmsg_free(msg.skb);
2170                         return err;
2171                 }
2172         } else {
2173                 int bearer_id;
2174                 struct tipc_node *node;
2175                 struct tipc_link *link;
2176
2177                 node = tipc_link_find_owner(net, name, &bearer_id);
2178                 if (!node)
2179                         return -EINVAL;
2180
2181                 tipc_node_lock(node);
2182                 link = node->links[bearer_id].link;
2183                 if (!link) {
2184                         tipc_node_unlock(node);
2185                         nlmsg_free(msg.skb);
2186                         return -EINVAL;
2187                 }
2188
2189                 err = __tipc_nl_add_link(net, &msg, link, 0);
2190                 tipc_node_unlock(node);
2191                 if (err) {
2192                         nlmsg_free(msg.skb);
2193                         return err;
2194                 }
2195         }
2196
2197         return genlmsg_reply(msg.skb, info);
2198 }
2199
2200 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2201 {
2202         int err;
2203         char *link_name;
2204         unsigned int bearer_id;
2205         struct tipc_link *link;
2206         struct tipc_node *node;
2207         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2208         struct net *net = sock_net(skb->sk);
2209
2210         if (!info->attrs[TIPC_NLA_LINK])
2211                 return -EINVAL;
2212
2213         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2214                                info->attrs[TIPC_NLA_LINK],
2215                                tipc_nl_link_policy);
2216         if (err)
2217                 return err;
2218
2219         if (!attrs[TIPC_NLA_LINK_NAME])
2220                 return -EINVAL;
2221
2222         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2223
2224         if (strcmp(link_name, tipc_bclink_name) == 0) {
2225                 err = tipc_bclink_reset_stats(net);
2226                 if (err)
2227                         return err;
2228                 return 0;
2229         }
2230
2231         node = tipc_link_find_owner(net, link_name, &bearer_id);
2232         if (!node)
2233                 return -EINVAL;
2234
2235         tipc_node_lock(node);
2236
2237         link = node->links[bearer_id].link;
2238         if (!link) {
2239                 tipc_node_unlock(node);
2240                 return -EINVAL;
2241         }
2242
2243         link_reset_statistics(link);
2244
2245         tipc_node_unlock(node);
2246
2247         return 0;
2248 }