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  TIMEOUT_EVT     560817u        /* link timer expired */
  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 /*
 110  *  Simple link routines
 111  */
 112 static unsigned int align(unsigned int i)
 113 {
 114         return (i + 3) & ~3u;
 115 }
 116
 117 static void tipc_link_release(struct kref *kref)
 118 {
 119         kfree(container_of(kref, struct tipc_link, ref));
 120 }
 121
 122 static void tipc_link_get(struct tipc_link *l_ptr)
 123 {
 124         kref_get(&l_ptr->ref);
 125 }
 126
 127 static void tipc_link_put(struct tipc_link *l_ptr)
 128 {
 129         kref_put(&l_ptr->ref, tipc_link_release);
 130 }
 131
 132 static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
 133 {
 134         if (l->owner->active_links[0] != l)
 135                 return l->owner->active_links[0];
 136         return l->owner->active_links[1];
 137 }
 138
 139 /*
 140  *  Simple non-static link routines (i.e. referenced outside this file)
 141  */
 142 int tipc_link_is_up(struct tipc_link *l_ptr)
 143 {
 144         if (!l_ptr)
 145                 return 0;
 146         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 147 }
 148
 149 int tipc_link_is_active(struct tipc_link *l_ptr)
 150 {
 151         return  (l_ptr->owner->active_links[0] == l_ptr) ||
 152                 (l_ptr->owner->active_links[1] == l_ptr);
 153 }
 154
 155 /**
 156  * link_timeout - handle expiration of link timer
 157  * @l_ptr: pointer to link
 158  */
 159 static void link_timeout(unsigned long data)
 160 {
 161         struct tipc_link *l_ptr = (struct tipc_link *)data;
 162         struct sk_buff *skb;
 163
 164         tipc_node_lock(l_ptr->owner);
 165
 166         /* update counters used in statistical profiling of send traffic */
 167         l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->transmq);
 168         l_ptr->stats.queue_sz_counts++;
 169
 170         skb = skb_peek(&l_ptr->transmq);
 171         if (skb) {
 172                 struct tipc_msg *msg = buf_msg(skb);
 173                 u32 length = msg_size(msg);
 174
 175                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 176                     (msg_type(msg) == FIRST_FRAGMENT)) {
 177                         length = msg_size(msg_get_wrapped(msg));
 178                 }
 179                 if (length) {
 180                         l_ptr->stats.msg_lengths_total += length;
 181                         l_ptr->stats.msg_length_counts++;
 182                         if (length <= 64)
 183                                 l_ptr->stats.msg_length_profile[0]++;
 184                         else if (length <= 256)
 185                                 l_ptr->stats.msg_length_profile[1]++;
 186                         else if (length <= 1024)
 187                                 l_ptr->stats.msg_length_profile[2]++;
 188                         else if (length <= 4096)
 189                                 l_ptr->stats.msg_length_profile[3]++;
 190                         else if (length <= 16384)
 191                                 l_ptr->stats.msg_length_profile[4]++;
 192                         else if (length <= 32768)
 193                                 l_ptr->stats.msg_length_profile[5]++;
 194                         else
 195                                 l_ptr->stats.msg_length_profile[6]++;
 196                 }
 197         }
 198
 199         /* do all other link processing performed on a periodic basis */
 200         link_state_event(l_ptr, TIMEOUT_EVT);
 201
 202         if (skb_queue_len(&l_ptr->backlogq))
 203                 tipc_link_push_packets(l_ptr);
 204
 205         tipc_node_unlock(l_ptr->owner);
 206         tipc_link_put(l_ptr);
 207 }
 208
 209 static void link_set_timer(struct tipc_link *link, unsigned long time)
 210 {
 211         if (!mod_timer(&link->timer, jiffies + time))
 212                 tipc_link_get(link);
 213 }
 214
 215 /**
 216  * tipc_link_create - create a new link
 217  * @n_ptr: pointer to associated node
 218  * @b_ptr: pointer to associated bearer
 219  * @media_addr: media address to use when sending messages over link
 220  *
 221  * Returns pointer to link.
 222  */
 223 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 224                                    struct tipc_bearer *b_ptr,
 225                                    const struct tipc_media_addr *media_addr)
 226 {
 227         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 228         struct tipc_link *l_ptr;
 229         struct tipc_msg *msg;
 230         char *if_name;
 231         char addr_string[16];
 232         u32 peer = n_ptr->addr;
 233
 234         if (n_ptr->link_cnt >= MAX_BEARERS) {
 235                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 236                 pr_err("Attempt to establish %uth link to %s. Max %u allowed.\n",
 237                         n_ptr->link_cnt, addr_string, MAX_BEARERS);
 238                 return NULL;
 239         }
 240
 241         if (n_ptr->links[b_ptr->identity]) {
 242                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 243                 pr_err("Attempt to establish second link on <%s> to %s\n",
 244                        b_ptr->name, addr_string);
 245                 return NULL;
 246         }
 247
 248         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 249         if (!l_ptr) {
 250                 pr_warn("Link creation failed, no memory\n");
 251                 return NULL;
 252         }
 253         kref_init(&l_ptr->ref);
 254         l_ptr->addr = peer;
 255         if_name = strchr(b_ptr->name, ':') + 1;
 256         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 257                 tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
 258                 tipc_node(tn->own_addr),
 259                 if_name,
 260                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 261                 /* note: peer i/f name is updated by reset/activate message */
 262         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 263         l_ptr->owner = n_ptr;
 264         l_ptr->checkpoint = 1;
 265         l_ptr->peer_session = INVALID_SESSION;
 266         l_ptr->bearer_id = b_ptr->identity;
 267         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 268         l_ptr->state = RESET_UNKNOWN;
 269
 270         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 271         msg = l_ptr->pmsg;
 272         tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
 273                       l_ptr->addr);
 274         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 275         msg_set_session(msg, (tn->random & 0xffff));
 276         msg_set_bearer_id(msg, b_ptr->identity);
 277         strcpy((char *)msg_data(msg), if_name);
 278         l_ptr->net_plane = b_ptr->net_plane;
 279         l_ptr->advertised_mtu = b_ptr->mtu;
 280         l_ptr->mtu = l_ptr->advertised_mtu;
 281         l_ptr->priority = b_ptr->priority;
 282         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 283         l_ptr->next_out_no = 1;
 284         __skb_queue_head_init(&l_ptr->transmq);
 285         __skb_queue_head_init(&l_ptr->backlogq);
 286         __skb_queue_head_init(&l_ptr->deferdq);
 287         skb_queue_head_init(&l_ptr->wakeupq);
 288         skb_queue_head_init(&l_ptr->inputq);
 289         skb_queue_head_init(&l_ptr->namedq);
 290         link_reset_statistics(l_ptr);
 291         tipc_node_attach_link(n_ptr, l_ptr);
 292         setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr);
 293         link_state_event(l_ptr, STARTING_EVT);
 294
 295         return l_ptr;
 296 }
 297
 298 /**
 299  * tipc_link_delete - Delete a link
 300  * @l: link to be deleted
 301  */
 302 void tipc_link_delete(struct tipc_link *l)
 303 {
 304         tipc_link_reset(l);
 305         if (del_timer(&l->timer))
 306                 tipc_link_put(l);
 307         l->flags |= LINK_STOPPED;
 308         /* Delete link now, or when timer is finished: */
 309         tipc_link_reset_fragments(l);
 310         tipc_node_detach_link(l->owner, l);
 311         tipc_link_put(l);
 312 }
 313
 314 void tipc_link_delete_list(struct net *net, unsigned int bearer_id)
 315 {
 316         struct tipc_net *tn = net_generic(net, tipc_net_id);
 317         struct tipc_link *link;
 318         struct tipc_node *node;
 319
 320         rcu_read_lock();
 321         list_for_each_entry_rcu(node, &tn->node_list, list) {
 322                 tipc_node_lock(node);
 323                 link = node->links[bearer_id];
 324                 if (link)
 325                         tipc_link_delete(link);
 326                 tipc_node_unlock(node);
 327         }
 328         rcu_read_unlock();
 329 }
 330
 331 /**
 332  * link_schedule_user - schedule a message sender for wakeup after congestion
 333  * @link: congested link
 334  * @list: message that was attempted sent
 335  * Create pseudo msg to send back to user when congestion abates
 336  * Only consumes message if there is an error
 337  */
 338 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 339 {
 340         struct tipc_msg *msg = buf_msg(skb_peek(list));
 341         int imp = msg_importance(msg);
 342         u32 oport = msg_origport(msg);
 343         u32 addr = link_own_addr(link);
 344         struct sk_buff *skb;
 345
 346         /* This really cannot happen...  */
 347         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 348                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 349                 tipc_link_reset(link);
 350                 goto err;
 351         }
 352         /* Non-blocking sender: */
 353         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 354                 return -ELINKCONG;
 355
 356         /* Create and schedule wakeup pseudo message */
 357         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 358                               addr, addr, oport, 0, 0);
 359         if (!skb)
 360                 goto err;
 361         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 362         TIPC_SKB_CB(skb)->chain_imp = imp;
 363         skb_queue_tail(&link->wakeupq, skb);
 364         link->stats.link_congs++;
 365         return -ELINKCONG;
 366 err:
 367         __skb_queue_purge(list);
 368         return -ENOBUFS;
 369 }
 370
 371 /**
 372  * link_prepare_wakeup - prepare users for wakeup after congestion
 373  * @link: congested link
 374  * Move a number of waiting users, as permitted by available space in
 375  * the send queue, from link wait queue to node wait queue for wakeup
 376  */
 377 void link_prepare_wakeup(struct tipc_link *l)
 378 {
 379         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 380         int imp, lim;
 381         struct sk_buff *skb, *tmp;
 382
 383         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 384                 imp = TIPC_SKB_CB(skb)->chain_imp;
 385                 lim = l->window + l->backlog[imp].limit;
 386                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 387                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 388                         break;
 389                 skb_unlink(skb, &l->wakeupq);
 390                 skb_queue_tail(&l->inputq, skb);
 391                 l->owner->inputq = &l->inputq;
 392                 l->owner->action_flags |= TIPC_MSG_EVT;
 393         }
 394 }
 395
 396 /**
 397  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 398  * @l_ptr: pointer to link
 399  */
 400 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 401 {
 402         kfree_skb(l_ptr->reasm_buf);
 403         l_ptr->reasm_buf = NULL;
 404 }
 405
 406 static void tipc_link_purge_backlog(struct tipc_link *l)
 407 {
 408         __skb_queue_purge(&l->backlogq);
 409         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 410         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 411         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 412         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 413         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 414 }
 415
 416 /**
 417  * tipc_link_purge_queues - purge all pkt queues associated with link
 418  * @l_ptr: pointer to link
 419  */
 420 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 421 {
 422         __skb_queue_purge(&l_ptr->deferdq);
 423         __skb_queue_purge(&l_ptr->transmq);
 424         tipc_link_purge_backlog(l_ptr);
 425         tipc_link_reset_fragments(l_ptr);
 426 }
 427
 428 void tipc_link_reset(struct tipc_link *l_ptr)
 429 {
 430         u32 prev_state = l_ptr->state;
 431         int was_active_link = tipc_link_is_active(l_ptr);
 432         struct tipc_node *owner = l_ptr->owner;
 433         struct tipc_link *pl = tipc_parallel_link(l_ptr);
 434
 435         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 436
 437         /* Link is down, accept any session */
 438         l_ptr->peer_session = INVALID_SESSION;
 439
 440         /* Prepare for renewed mtu size negotiation */
 441         l_ptr->mtu = l_ptr->advertised_mtu;
 442
 443         l_ptr->state = RESET_UNKNOWN;
 444
 445         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 446                 return;
 447
 448         tipc_node_link_down(l_ptr->owner, l_ptr);
 449         tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 450
 451         if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
 452                 l_ptr->flags |= LINK_FAILINGOVER;
 453                 l_ptr->failover_checkpt = l_ptr->next_in_no;
 454                 pl->failover_pkts = FIRST_FAILOVER;
 455                 pl->failover_checkpt = l_ptr->next_in_no;
 456                 pl->failover_skb = l_ptr->reasm_buf;
 457         } else {
 458                 kfree_skb(l_ptr->reasm_buf);
 459         }
 460         /* Clean up all queues, except inputq: */
 461         __skb_queue_purge(&l_ptr->transmq);
 462         __skb_queue_purge(&l_ptr->deferdq);
 463         if (!owner->inputq)
 464                 owner->inputq = &l_ptr->inputq;
 465         skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
 466         if (!skb_queue_empty(owner->inputq))
 467                 owner->action_flags |= TIPC_MSG_EVT;
 468         tipc_link_purge_backlog(l_ptr);
 469         l_ptr->reasm_buf = NULL;
 470         l_ptr->rcv_unacked = 0;
 471         l_ptr->checkpoint = 1;
 472         l_ptr->next_out_no = 1;
 473         l_ptr->fsm_msg_cnt = 0;
 474         l_ptr->stale_count = 0;
 475         link_reset_statistics(l_ptr);
 476 }
 477
 478 static void link_activate(struct tipc_link *link)
 479 {
 480         struct tipc_node *node = link->owner;
 481
 482         link->next_in_no = 1;
 483         link->stats.recv_info = 1;
 484         tipc_node_link_up(node, link);
 485         tipc_bearer_add_dest(node->net, link->bearer_id, link->addr);
 486 }
 487
 488 /**
 489  * link_state_event - link finite state machine
 490  * @l_ptr: pointer to link
 491  * @event: state machine event to process
 492  */
 493 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 494 {
 495         struct tipc_link *other;
 496         unsigned long cont_intv = l_ptr->cont_intv;
 497
 498         if (l_ptr->flags & LINK_STOPPED)
 499                 return;
 500
 501         if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 502                 return;         /* Not yet. */
 503
 504         if (l_ptr->flags & LINK_FAILINGOVER) {
 505                 if (event == TIMEOUT_EVT)
 506                         link_set_timer(l_ptr, cont_intv);
 507                 return;
 508         }
 509
 510         switch (l_ptr->state) {
 511         case WORKING_WORKING:
 512                 switch (event) {
 513                 case TRAFFIC_MSG_EVT:
 514                 case ACTIVATE_MSG:
 515                         break;
 516                 case TIMEOUT_EVT:
 517                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 518                                 l_ptr->checkpoint = l_ptr->next_in_no;
 519                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 520                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 521                                                              0, 0, 0, 0);
 522                                         l_ptr->fsm_msg_cnt++;
 523                                 }
 524                                 link_set_timer(l_ptr, cont_intv);
 525                                 break;
 526                         }
 527                         l_ptr->state = WORKING_UNKNOWN;
 528                         l_ptr->fsm_msg_cnt = 0;
 529                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 530                         l_ptr->fsm_msg_cnt++;
 531                         link_set_timer(l_ptr, cont_intv);
 532                         break;
 533                 case RESET_MSG:
 534                         pr_debug("%s<%s>, requested by peer\n",
 535                                  link_rst_msg, l_ptr->name);
 536                         tipc_link_reset(l_ptr);
 537                         l_ptr->state = RESET_RESET;
 538                         l_ptr->fsm_msg_cnt = 0;
 539                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 540                                              0, 0, 0, 0);
 541                         l_ptr->fsm_msg_cnt++;
 542                         link_set_timer(l_ptr, cont_intv);
 543                         break;
 544                 default:
 545                         pr_debug("%s%u in WW state\n", link_unk_evt, event);
 546                 }
 547                 break;
 548         case WORKING_UNKNOWN:
 549                 switch (event) {
 550                 case TRAFFIC_MSG_EVT:
 551                 case ACTIVATE_MSG:
 552                         l_ptr->state = WORKING_WORKING;
 553                         l_ptr->fsm_msg_cnt = 0;
 554                         link_set_timer(l_ptr, cont_intv);
 555                         break;
 556                 case RESET_MSG:
 557                         pr_debug("%s<%s>, requested by peer while probing\n",
 558                                  link_rst_msg, l_ptr->name);
 559                         tipc_link_reset(l_ptr);
 560                         l_ptr->state = RESET_RESET;
 561                         l_ptr->fsm_msg_cnt = 0;
 562                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 563                                              0, 0, 0, 0);
 564                         l_ptr->fsm_msg_cnt++;
 565                         link_set_timer(l_ptr, cont_intv);
 566                         break;
 567                 case TIMEOUT_EVT:
 568                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 569                                 l_ptr->state = WORKING_WORKING;
 570                                 l_ptr->fsm_msg_cnt = 0;
 571                                 l_ptr->checkpoint = l_ptr->next_in_no;
 572                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 573                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 574                                                              0, 0, 0, 0);
 575                                         l_ptr->fsm_msg_cnt++;
 576                                 }
 577                                 link_set_timer(l_ptr, cont_intv);
 578                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 579                                 tipc_link_proto_xmit(l_ptr, STATE_MSG,
 580                                                      1, 0, 0, 0);
 581                                 l_ptr->fsm_msg_cnt++;
 582                                 link_set_timer(l_ptr, cont_intv);
 583                         } else {        /* Link has failed */
 584                                 pr_debug("%s<%s>, peer not responding\n",
 585                                          link_rst_msg, l_ptr->name);
 586                                 tipc_link_reset(l_ptr);
 587                                 l_ptr->state = RESET_UNKNOWN;
 588                                 l_ptr->fsm_msg_cnt = 0;
 589                                 tipc_link_proto_xmit(l_ptr, RESET_MSG,
 590                                                      0, 0, 0, 0);
 591                                 l_ptr->fsm_msg_cnt++;
 592                                 link_set_timer(l_ptr, cont_intv);
 593                         }
 594                         break;
 595                 default:
 596                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 597                 }
 598                 break;
 599         case RESET_UNKNOWN:
 600                 switch (event) {
 601                 case TRAFFIC_MSG_EVT:
 602                         break;
 603                 case ACTIVATE_MSG:
 604                         other = l_ptr->owner->active_links[0];
 605                         if (other && link_working_unknown(other))
 606                                 break;
 607                         l_ptr->state = WORKING_WORKING;
 608                         l_ptr->fsm_msg_cnt = 0;
 609                         link_activate(l_ptr);
 610                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 611                         l_ptr->fsm_msg_cnt++;
 612                         if (l_ptr->owner->working_links == 1)
 613                                 tipc_link_sync_xmit(l_ptr);
 614                         link_set_timer(l_ptr, cont_intv);
 615                         break;
 616                 case RESET_MSG:
 617                         l_ptr->state = RESET_RESET;
 618                         l_ptr->fsm_msg_cnt = 0;
 619                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 620                                              1, 0, 0, 0);
 621                         l_ptr->fsm_msg_cnt++;
 622                         link_set_timer(l_ptr, cont_intv);
 623                         break;
 624                 case STARTING_EVT:
 625                         l_ptr->flags |= LINK_STARTED;
 626                         l_ptr->fsm_msg_cnt++;
 627                         link_set_timer(l_ptr, cont_intv);
 628                         break;
 629                 case TIMEOUT_EVT:
 630                         tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0);
 631                         l_ptr->fsm_msg_cnt++;
 632                         link_set_timer(l_ptr, cont_intv);
 633                         break;
 634                 default:
 635                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 636                 }
 637                 break;
 638         case RESET_RESET:
 639                 switch (event) {
 640                 case TRAFFIC_MSG_EVT:
 641                 case ACTIVATE_MSG:
 642                         other = l_ptr->owner->active_links[0];
 643                         if (other && link_working_unknown(other))
 644                                 break;
 645                         l_ptr->state = WORKING_WORKING;
 646                         l_ptr->fsm_msg_cnt = 0;
 647                         link_activate(l_ptr);
 648                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 649                         l_ptr->fsm_msg_cnt++;
 650                         if (l_ptr->owner->working_links == 1)
 651                                 tipc_link_sync_xmit(l_ptr);
 652                         link_set_timer(l_ptr, cont_intv);
 653                         break;
 654                 case RESET_MSG:
 655                         break;
 656                 case TIMEOUT_EVT:
 657                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 658                                              0, 0, 0, 0);
 659                         l_ptr->fsm_msg_cnt++;
 660                         link_set_timer(l_ptr, cont_intv);
 661                         break;
 662                 default:
 663                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 664                 }
 665                 break;
 666         default:
 667                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 668         }
 669 }
 670
 671 /**
 672  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 673  * @link: link to use
 674  * @list: chain of buffers containing message
 675  *
 676  * Consumes the buffer chain, except when returning -ELINKCONG,
 677  * since the caller then may want to make more send attempts.
 678  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 679  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 680  */
 681 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 682                      struct sk_buff_head *list)
 683 {
 684         struct tipc_msg *msg = buf_msg(skb_peek(list));
 685         unsigned int maxwin = link->window;
 686         unsigned int imp = msg_importance(msg);
 687         uint mtu = link->mtu;
 688         u16 ack = mod(link->next_in_no - 1);
 689         u16 seqno = link->next_out_no;
 690         u16 bc_last_in = link->owner->bclink.last_in;
 691         struct tipc_media_addr *addr = &link->media_addr;
 692         struct sk_buff_head *transmq = &link->transmq;
 693         struct sk_buff_head *backlogq = &link->backlogq;
 694         struct sk_buff *skb, *tmp;
 695
 696         /* Match backlog limit against msg importance: */
 697         if (unlikely(link->backlog[imp].len >= link->backlog[imp].limit))
 698                 return link_schedule_user(link, list);
 699
 700         if (unlikely(msg_size(msg) > mtu)) {
 701                 __skb_queue_purge(list);
 702                 return -EMSGSIZE;
 703         }
 704         /* Prepare each packet for sending, and add to relevant queue: */
 705         skb_queue_walk_safe(list, skb, tmp) {
 706                 __skb_unlink(skb, list);
 707                 msg = buf_msg(skb);
 708                 msg_set_seqno(msg, seqno);
 709                 msg_set_ack(msg, ack);
 710                 msg_set_bcast_ack(msg, bc_last_in);
 711
 712                 if (likely(skb_queue_len(transmq) < maxwin)) {
 713                         __skb_queue_tail(transmq, skb);
 714                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 715                         link->rcv_unacked = 0;
 716                         seqno++;
 717                         continue;
 718                 }
 719                 if (tipc_msg_bundle(skb_peek_tail(backlogq), skb, mtu)) {
 720                         link->stats.sent_bundled++;
 721                         continue;
 722                 }
 723                 if (tipc_msg_make_bundle(&skb, mtu, link->addr)) {
 724                         link->stats.sent_bundled++;
 725                         link->stats.sent_bundles++;
 726                         imp = msg_importance(buf_msg(skb));
 727                 }
 728                 __skb_queue_tail(backlogq, skb);
 729                 link->backlog[imp].len++;
 730                 seqno++;
 731         }
 732         link->next_out_no = seqno;
 733         return 0;
 734 }
 735
 736 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
 737 {
 738         skb_queue_head_init(list);
 739         __skb_queue_tail(list, skb);
 740 }
 741
 742 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 743 {
 744         struct sk_buff_head head;
 745
 746         skb2list(skb, &head);
 747         return __tipc_link_xmit(link->owner->net, link, &head);
 748 }
 749
 750 /* tipc_link_xmit_skb(): send single buffer to destination
 751  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
 752  * messages, which will not be rejected
 753  * The only exception is datagram messages rerouted after secondary
 754  * lookup, which are rare and safe to dispose of anyway.
 755  * TODO: Return real return value, and let callers use
 756  * tipc_wait_for_sendpkt() where applicable
 757  */
 758 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 759                        u32 selector)
 760 {
 761         struct sk_buff_head head;
 762         int rc;
 763
 764         skb2list(skb, &head);
 765         rc = tipc_link_xmit(net, &head, dnode, selector);
 766         if (rc == -ELINKCONG)
 767                 kfree_skb(skb);
 768         return 0;
 769 }
 770
 771 /**
 772  * tipc_link_xmit() is the general link level function for message sending
 773  * @net: the applicable net namespace
 774  * @list: chain of buffers containing message
 775  * @dsz: amount of user data to be sent
 776  * @dnode: address of destination node
 777  * @selector: a number used for deterministic link selection
 778  * Consumes the buffer chain, except when returning -ELINKCONG
 779  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 780  */
 781 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
 782                    u32 selector)
 783 {
 784         struct tipc_link *link = NULL;
 785         struct tipc_node *node;
 786         int rc = -EHOSTUNREACH;
 787
 788         node = tipc_node_find(net, dnode);
 789         if (node) {
 790                 tipc_node_lock(node);
 791                 link = node->active_links[selector & 1];
 792                 if (link)
 793                         rc = __tipc_link_xmit(net, link, list);
 794                 tipc_node_unlock(node);
 795                 tipc_node_put(node);
 796         }
 797         if (link)
 798                 return rc;
 799
 800         if (likely(in_own_node(net, dnode))) {
 801                 tipc_sk_rcv(net, list);
 802                 return 0;
 803         }
 804
 805         __skb_queue_purge(list);
 806         return rc;
 807 }
 808
 809 /*
 810  * tipc_link_sync_xmit - synchronize broadcast link endpoints.
 811  *
 812  * Give a newly added peer node the sequence number where it should
 813  * start receiving and acking broadcast packets.
 814  *
 815  * Called with node locked
 816  */
 817 static void tipc_link_sync_xmit(struct tipc_link *link)
 818 {
 819         struct sk_buff *skb;
 820         struct tipc_msg *msg;
 821
 822         skb = tipc_buf_acquire(INT_H_SIZE);
 823         if (!skb)
 824                 return;
 825
 826         msg = buf_msg(skb);
 827         tipc_msg_init(link_own_addr(link), msg, BCAST_PROTOCOL, STATE_MSG,
 828                       INT_H_SIZE, link->addr);
 829         msg_set_last_bcast(msg, link->owner->bclink.acked);
 830         __tipc_link_xmit_skb(link, skb);
 831 }
 832
 833 /*
 834  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 835  * Receive the sequence number where we should start receiving and
 836  * acking broadcast packets from a newly added peer node, and open
 837  * up for reception of such packets.
 838  *
 839  * Called with node locked
 840  */
 841 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 842 {
 843         struct tipc_msg *msg = buf_msg(buf);
 844
 845         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 846         n->bclink.recv_permitted = true;
 847         kfree_skb(buf);
 848 }
 849
 850 /*
 851  * tipc_link_push_packets - push unsent packets to bearer
 852  *
 853  * Push out the unsent messages of a link where congestion
 854  * has abated. Node is locked.
 855  *
 856  * Called with node locked
 857  */
 858 void tipc_link_push_packets(struct tipc_link *link)
 859 {
 860         struct sk_buff *skb;
 861         struct tipc_msg *msg;
 862         u16 ack = mod(link->next_in_no - 1);
 863
 864         while (skb_queue_len(&link->transmq) < link->window) {
 865                 skb = __skb_dequeue(&link->backlogq);
 866                 if (!skb)
 867                         break;
 868                 msg = buf_msg(skb);
 869                 link->backlog[msg_importance(msg)].len--;
 870                 msg_set_ack(msg, ack);
 871                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 872                 link->rcv_unacked = 0;
 873                 __skb_queue_tail(&link->transmq, skb);
 874                 tipc_bearer_send(link->owner->net, link->bearer_id,
 875                                  skb, &link->media_addr);
 876         }
 877 }
 878
 879 void tipc_link_reset_all(struct tipc_node *node)
 880 {
 881         char addr_string[16];
 882         u32 i;
 883
 884         tipc_node_lock(node);
 885
 886         pr_warn("Resetting all links to %s\n",
 887                 tipc_addr_string_fill(addr_string, node->addr));
 888
 889         for (i = 0; i < MAX_BEARERS; i++) {
 890                 if (node->links[i]) {
 891                         link_print(node->links[i], "Resetting link\n");
 892                         tipc_link_reset(node->links[i]);
 893                 }
 894         }
 895
 896         tipc_node_unlock(node);
 897 }
 898
 899 static void link_retransmit_failure(struct tipc_link *l_ptr,
 900                                     struct sk_buff *buf)
 901 {
 902         struct tipc_msg *msg = buf_msg(buf);
 903         struct net *net = l_ptr->owner->net;
 904
 905         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 906
 907         if (l_ptr->addr) {
 908                 /* Handle failure on standard link */
 909                 link_print(l_ptr, "Resetting link\n");
 910                 tipc_link_reset(l_ptr);
 911
 912         } else {
 913                 /* Handle failure on broadcast link */
 914                 struct tipc_node *n_ptr;
 915                 char addr_string[16];
 916
 917                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 918                 pr_cont("Outstanding acks: %lu\n",
 919                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 920
 921                 n_ptr = tipc_bclink_retransmit_to(net);
 922
 923                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 924                 pr_info("Broadcast link info for %s\n", addr_string);
 925                 pr_info("Reception permitted: %d,  Acked: %u\n",
 926                         n_ptr->bclink.recv_permitted,
 927                         n_ptr->bclink.acked);
 928                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 929                         n_ptr->bclink.last_in,
 930                         n_ptr->bclink.oos_state,
 931                         n_ptr->bclink.last_sent);
 932
 933                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 934                 l_ptr->stale_count = 0;
 935         }
 936 }
 937
 938 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 939                           u32 retransmits)
 940 {
 941         struct tipc_msg *msg;
 942
 943         if (!skb)
 944                 return;
 945
 946         msg = buf_msg(skb);
 947
 948         /* Detect repeated retransmit failures */
 949         if (l_ptr->last_retransmitted == msg_seqno(msg)) {
 950                 if (++l_ptr->stale_count > 100) {
 951                         link_retransmit_failure(l_ptr, skb);
 952                         return;
 953                 }
 954         } else {
 955                 l_ptr->last_retransmitted = msg_seqno(msg);
 956                 l_ptr->stale_count = 1;
 957         }
 958
 959         skb_queue_walk_from(&l_ptr->transmq, skb) {
 960                 if (!retransmits)
 961                         break;
 962                 msg = buf_msg(skb);
 963                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
 964                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 965                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 966                                  &l_ptr->media_addr);
 967                 retransmits--;
 968                 l_ptr->stats.retransmitted++;
 969         }
 970 }
 971
 972 /* link_synch(): check if all packets arrived before the synch
 973  *               point have been consumed
 974  * Returns true if the parallel links are synched, otherwise false
 975  */
 976 static bool link_synch(struct tipc_link *l)
 977 {
 978         unsigned int post_synch;
 979         struct tipc_link *pl;
 980
 981         pl  = tipc_parallel_link(l);
 982         if (pl == l)
 983                 goto synched;
 984
 985         /* Was last pre-synch packet added to input queue ? */
 986         if (less_eq(pl->next_in_no, l->synch_point))
 987                 return false;
 988
 989         /* Is it still in the input queue ? */
 990         post_synch = mod(pl->next_in_no - l->synch_point) - 1;
 991         if (skb_queue_len(&pl->inputq) > post_synch)
 992                 return false;
 993 synched:
 994         l->flags &= ~LINK_SYNCHING;
 995         return true;
 996 }
 997
 998 static void link_retrieve_defq(struct tipc_link *link,
 999                                struct sk_buff_head *list)
1000 {
1001         u16 seq_no;
1002
1003         if (skb_queue_empty(&link->deferdq))
1004                 return;
1005
1006         seq_no = buf_seqno(skb_peek(&link->deferdq));
1007         if (seq_no == link->next_in_no)
1008                 skb_queue_splice_tail_init(&link->deferdq, list);
1009 }
1010
1011 /**
1012  * tipc_rcv - process TIPC packets/messages arriving from off-node
1013  * @net: the applicable net namespace
1014  * @skb: TIPC packet
1015  * @b_ptr: pointer to bearer message arrived on
1016  *
1017  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1018  * structure (i.e. cannot be NULL), but bearer can be inactive.
1019  */
1020 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
1021 {
1022         struct tipc_net *tn = net_generic(net, tipc_net_id);
1023         struct sk_buff_head head;
1024         struct tipc_node *n_ptr;
1025         struct tipc_link *l_ptr;
1026         struct sk_buff *skb1, *tmp;
1027         struct tipc_msg *msg;
1028         u16 seq_no;
1029         u16 ackd;
1030         u32 released;
1031
1032         skb2list(skb, &head);
1033
1034         while ((skb = __skb_dequeue(&head))) {
1035                 /* Ensure message is well-formed */
1036                 if (unlikely(!tipc_msg_validate(skb)))
1037                         goto discard;
1038
1039                 /* Handle arrival of a non-unicast link message */
1040                 msg = buf_msg(skb);
1041                 if (unlikely(msg_non_seq(msg))) {
1042                         if (msg_user(msg) ==  LINK_CONFIG)
1043                                 tipc_disc_rcv(net, skb, b_ptr);
1044                         else
1045                                 tipc_bclink_rcv(net, skb);
1046                         continue;
1047                 }
1048
1049                 /* Discard unicast link messages destined for another node */
1050                 if (unlikely(!msg_short(msg) &&
1051                              (msg_destnode(msg) != tn->own_addr)))
1052                         goto discard;
1053
1054                 /* Locate neighboring node that sent message */
1055                 n_ptr = tipc_node_find(net, msg_prevnode(msg));
1056                 if (unlikely(!n_ptr))
1057                         goto discard;
1058
1059                 tipc_node_lock(n_ptr);
1060                 /* Locate unicast link endpoint that should handle message */
1061                 l_ptr = n_ptr->links[b_ptr->identity];
1062                 if (unlikely(!l_ptr))
1063                         goto unlock;
1064
1065                 /* Verify that communication with node is currently allowed */
1066                 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
1067                     msg_user(msg) == LINK_PROTOCOL &&
1068                     (msg_type(msg) == RESET_MSG ||
1069                     msg_type(msg) == ACTIVATE_MSG) &&
1070                     !msg_redundant_link(msg))
1071                         n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
1072
1073                 if (tipc_node_blocked(n_ptr))
1074                         goto unlock;
1075
1076                 /* Validate message sequence number info */
1077                 seq_no = msg_seqno(msg);
1078                 ackd = msg_ack(msg);
1079
1080                 /* Release acked messages */
1081                 if (unlikely(n_ptr->bclink.acked != msg_bcast_ack(msg)))
1082                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1083
1084                 released = 0;
1085                 skb_queue_walk_safe(&l_ptr->transmq, skb1, tmp) {
1086                         if (more(buf_seqno(skb1), ackd))
1087                                 break;
1088                          __skb_unlink(skb1, &l_ptr->transmq);
1089                          kfree_skb(skb1);
1090                          released = 1;
1091                 }
1092
1093                 /* Try sending any messages link endpoint has pending */
1094                 if (unlikely(skb_queue_len(&l_ptr->backlogq)))
1095                         tipc_link_push_packets(l_ptr);
1096
1097                 if (released && !skb_queue_empty(&l_ptr->wakeupq))
1098                         link_prepare_wakeup(l_ptr);
1099
1100                 /* Process the incoming packet */
1101                 if (unlikely(!link_working_working(l_ptr))) {
1102                         if (msg_user(msg) == LINK_PROTOCOL) {
1103                                 tipc_link_proto_rcv(l_ptr, skb);
1104                                 link_retrieve_defq(l_ptr, &head);
1105                                 skb = NULL;
1106                                 goto unlock;
1107                         }
1108
1109                         /* Traffic message. Conditionally activate link */
1110                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1111
1112                         if (link_working_working(l_ptr)) {
1113                                 /* Re-insert buffer in front of queue */
1114                                 __skb_queue_head(&head, skb);
1115                                 skb = NULL;
1116                                 goto unlock;
1117                         }
1118                         goto unlock;
1119                 }
1120
1121                 /* Link is now in state WORKING_WORKING */
1122                 if (unlikely(seq_no != l_ptr->next_in_no)) {
1123                         link_handle_out_of_seq_msg(l_ptr, skb);
1124                         link_retrieve_defq(l_ptr, &head);
1125                         skb = NULL;
1126                         goto unlock;
1127                 }
1128                 /* Synchronize with parallel link if applicable */
1129                 if (unlikely((l_ptr->flags & LINK_SYNCHING) && !msg_dup(msg))) {
1130                         if (!link_synch(l_ptr))
1131                                 goto unlock;
1132                 }
1133                 l_ptr->next_in_no++;
1134                 if (unlikely(!skb_queue_empty(&l_ptr->deferdq)))
1135                         link_retrieve_defq(l_ptr, &head);
1136                 if (unlikely(++l_ptr->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
1137                         l_ptr->stats.sent_acks++;
1138                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1139                 }
1140                 tipc_link_input(l_ptr, skb);
1141                 skb = NULL;
1142 unlock:
1143                 tipc_node_unlock(n_ptr);
1144                 tipc_node_put(n_ptr);
1145 discard:
1146                 if (unlikely(skb))
1147                         kfree_skb(skb);
1148         }
1149 }
1150
1151 /* tipc_data_input - deliver data and name distr msgs to upper layer
1152  *
1153  * Consumes buffer if message is of right type
1154  * Node lock must be held
1155  */
1156 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
1157 {
1158         struct tipc_node *node = link->owner;
1159         struct tipc_msg *msg = buf_msg(skb);
1160         u32 dport = msg_destport(msg);
1161
1162         switch (msg_user(msg)) {
1163         case TIPC_LOW_IMPORTANCE:
1164         case TIPC_MEDIUM_IMPORTANCE:
1165         case TIPC_HIGH_IMPORTANCE:
1166         case TIPC_CRITICAL_IMPORTANCE:
1167         case CONN_MANAGER:
1168                 if (tipc_skb_queue_tail(&link->inputq, skb, dport)) {
1169                         node->inputq = &link->inputq;
1170                         node->action_flags |= TIPC_MSG_EVT;
1171                 }
1172                 return true;
1173         case NAME_DISTRIBUTOR:
1174                 node->bclink.recv_permitted = true;
1175                 node->namedq = &link->namedq;
1176                 skb_queue_tail(&link->namedq, skb);
1177                 if (skb_queue_len(&link->namedq) == 1)
1178                         node->action_flags |= TIPC_NAMED_MSG_EVT;
1179                 return true;
1180         case MSG_BUNDLER:
1181         case TUNNEL_PROTOCOL:
1182         case MSG_FRAGMENTER:
1183         case BCAST_PROTOCOL:
1184                 return false;
1185         default:
1186                 pr_warn("Dropping received illegal msg type\n");
1187                 kfree_skb(skb);
1188                 return false;
1189         };
1190 }
1191
1192 /* tipc_link_input - process packet that has passed link protocol check
1193  *
1194  * Consumes buffer
1195  * Node lock must be held
1196  */
1197 static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
1198 {
1199         struct tipc_node *node = link->owner;
1200         struct tipc_msg *msg = buf_msg(skb);
1201         struct sk_buff *iskb;
1202         int pos = 0;
1203
1204         if (likely(tipc_data_input(link, skb)))
1205                 return;
1206
1207         switch (msg_user(msg)) {
1208         case TUNNEL_PROTOCOL:
1209                 if (msg_dup(msg)) {
1210                         link->flags |= LINK_SYNCHING;
1211                         link->synch_point = msg_seqno(msg_get_wrapped(msg));
1212                         kfree_skb(skb);
1213                         break;
1214                 }
1215                 if (!tipc_link_failover_rcv(link, &skb))
1216                         break;
1217                 if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
1218                         tipc_data_input(link, skb);
1219                         break;
1220                 }
1221         case MSG_BUNDLER:
1222                 link->stats.recv_bundles++;
1223                 link->stats.recv_bundled += msg_msgcnt(msg);
1224
1225                 while (tipc_msg_extract(skb, &iskb, &pos))
1226                         tipc_data_input(link, iskb);
1227                 break;
1228         case MSG_FRAGMENTER:
1229                 link->stats.recv_fragments++;
1230                 if (tipc_buf_append(&link->reasm_buf, &skb)) {
1231                         link->stats.recv_fragmented++;
1232                         tipc_data_input(link, skb);
1233                 } else if (!link->reasm_buf) {
1234                         tipc_link_reset(link);
1235                 }
1236                 break;
1237         case BCAST_PROTOCOL:
1238                 tipc_link_sync_rcv(node, skb);
1239                 break;
1240         default:
1241                 break;
1242         };
1243 }
1244
1245 /**
1246  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1247  *
1248  * Returns increase in queue length (i.e. 0 or 1)
1249  */
1250 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1251 {
1252         struct sk_buff *skb1;
1253         u16 seq_no = buf_seqno(skb);
1254
1255         /* Empty queue ? */
1256         if (skb_queue_empty(list)) {
1257                 __skb_queue_tail(list, skb);
1258                 return 1;
1259         }
1260
1261         /* Last ? */
1262         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1263                 __skb_queue_tail(list, skb);
1264                 return 1;
1265         }
1266
1267         /* Locate insertion point in queue, then insert; discard if duplicate */
1268         skb_queue_walk(list, skb1) {
1269                 u16 curr_seqno = buf_seqno(skb1);
1270
1271                 if (seq_no == curr_seqno) {
1272                         kfree_skb(skb);
1273                         return 0;
1274                 }
1275
1276                 if (less(seq_no, curr_seqno))
1277                         break;
1278         }
1279
1280         __skb_queue_before(list, skb1, skb);
1281         return 1;
1282 }
1283
1284 /*
1285  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1286  */
1287 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1288                                        struct sk_buff *buf)
1289 {
1290         u32 seq_no = buf_seqno(buf);
1291
1292         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1293                 tipc_link_proto_rcv(l_ptr, buf);
1294                 return;
1295         }
1296
1297         /* Record OOS packet arrival (force mismatch on next timeout) */
1298         l_ptr->checkpoint--;
1299
1300         /*
1301          * Discard packet if a duplicate; otherwise add it to deferred queue
1302          * and notify peer of gap as per protocol specification
1303          */
1304         if (less(seq_no, l_ptr->next_in_no)) {
1305                 l_ptr->stats.duplicates++;
1306                 kfree_skb(buf);
1307                 return;
1308         }
1309
1310         if (tipc_link_defer_pkt(&l_ptr->deferdq, buf)) {
1311                 l_ptr->stats.deferred_recv++;
1312                 if ((skb_queue_len(&l_ptr->deferdq) % TIPC_MIN_LINK_WIN) == 1)
1313                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1314         } else {
1315                 l_ptr->stats.duplicates++;
1316         }
1317 }
1318
1319 /*
1320  * Send protocol message to the other endpoint.
1321  */
1322 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1323                           u32 gap, u32 tolerance, u32 priority)
1324 {
1325         struct sk_buff *buf = NULL;
1326         struct tipc_msg *msg = l_ptr->pmsg;
1327         u32 msg_size = sizeof(l_ptr->proto_msg);
1328         int r_flag;
1329         u16 last_rcv;
1330
1331         /* Don't send protocol message during link failover */
1332         if (l_ptr->flags & LINK_FAILINGOVER)
1333                 return;
1334
1335         /* Abort non-RESET send if communication with node is prohibited */
1336         if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG))
1337                 return;
1338
1339         /* Create protocol message with "out-of-sequence" sequence number */
1340         msg_set_type(msg, msg_typ);
1341         msg_set_net_plane(msg, l_ptr->net_plane);
1342         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1343         msg_set_last_bcast(msg, tipc_bclink_get_last_sent(l_ptr->owner->net));
1344
1345         if (msg_typ == STATE_MSG) {
1346                 u16 next_sent = l_ptr->next_out_no;
1347
1348                 if (!tipc_link_is_up(l_ptr))
1349                         return;
1350                 if (skb_queue_len(&l_ptr->backlogq))
1351                         next_sent = buf_seqno(skb_peek(&l_ptr->backlogq));
1352                 msg_set_next_sent(msg, next_sent);
1353                 if (!skb_queue_empty(&l_ptr->deferdq)) {
1354                         last_rcv = buf_seqno(skb_peek(&l_ptr->deferdq));
1355                         gap = mod(last_rcv - l_ptr->next_in_no);
1356                 }
1357                 msg_set_seq_gap(msg, gap);
1358                 if (gap)
1359                         l_ptr->stats.sent_nacks++;
1360                 msg_set_link_tolerance(msg, tolerance);
1361                 msg_set_linkprio(msg, priority);
1362                 msg_set_max_pkt(msg, l_ptr->mtu);
1363                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1364                 msg_set_probe(msg, probe_msg != 0);
1365                 if (probe_msg)
1366                         l_ptr->stats.sent_probes++;
1367                 l_ptr->stats.sent_states++;
1368         } else {                /* RESET_MSG or ACTIVATE_MSG */
1369                 msg_set_ack(msg, mod(l_ptr->failover_checkpt - 1));
1370                 msg_set_seq_gap(msg, 0);
1371                 msg_set_next_sent(msg, 1);
1372                 msg_set_probe(msg, 0);
1373                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1374                 msg_set_linkprio(msg, l_ptr->priority);
1375                 msg_set_max_pkt(msg, l_ptr->advertised_mtu);
1376         }
1377
1378         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1379         msg_set_redundant_link(msg, r_flag);
1380         msg_set_linkprio(msg, l_ptr->priority);
1381         msg_set_size(msg, msg_size);
1382
1383         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1384
1385         buf = tipc_buf_acquire(msg_size);
1386         if (!buf)
1387                 return;
1388
1389         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1390         buf->priority = TC_PRIO_CONTROL;
1391         tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, buf,
1392                          &l_ptr->media_addr);
1393         l_ptr->rcv_unacked = 0;
1394         kfree_skb(buf);
1395 }
1396
1397 /*
1398  * Receive protocol message :
1399  * Note that network plane id propagates through the network, and may
1400  * change at any time. The node with lowest address rules
1401  */
1402 static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
1403                                 struct sk_buff *buf)
1404 {
1405         u32 rec_gap = 0;
1406         u32 msg_tol;
1407         struct tipc_msg *msg = buf_msg(buf);
1408
1409         if (l_ptr->flags & LINK_FAILINGOVER)
1410                 goto exit;
1411
1412         if (l_ptr->net_plane != msg_net_plane(msg))
1413                 if (link_own_addr(l_ptr) > msg_prevnode(msg))
1414                         l_ptr->net_plane = msg_net_plane(msg);
1415
1416         switch (msg_type(msg)) {
1417
1418         case RESET_MSG:
1419                 if (!link_working_unknown(l_ptr) &&
1420                     (l_ptr->peer_session != INVALID_SESSION)) {
1421                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1422                                 break; /* duplicate or old reset: ignore */
1423                 }
1424
1425                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1426                                 link_working_unknown(l_ptr))) {
1427                         /*
1428                          * peer has lost contact -- don't allow peer's links
1429                          * to reactivate before we recognize loss & clean up
1430                          */
1431                         l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
1432                 }
1433
1434                 link_state_event(l_ptr, RESET_MSG);
1435
1436                 /* fall thru' */
1437         case ACTIVATE_MSG:
1438                 /* Update link settings according other endpoint's values */
1439                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1440
1441                 msg_tol = msg_link_tolerance(msg);
1442                 if (msg_tol > l_ptr->tolerance)
1443                         link_set_supervision_props(l_ptr, msg_tol);
1444
1445                 if (msg_linkprio(msg) > l_ptr->priority)
1446                         l_ptr->priority = msg_linkprio(msg);
1447
1448                 if (l_ptr->mtu > msg_max_pkt(msg))
1449                         l_ptr->mtu = msg_max_pkt(msg);
1450
1451                 /* Synchronize broadcast link info, if not done previously */
1452                 if (!tipc_node_is_up(l_ptr->owner)) {
1453                         l_ptr->owner->bclink.last_sent =
1454                                 l_ptr->owner->bclink.last_in =
1455                                 msg_last_bcast(msg);
1456                         l_ptr->owner->bclink.oos_state = 0;
1457                 }
1458
1459                 l_ptr->peer_session = msg_session(msg);
1460                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1461
1462                 if (msg_type(msg) == ACTIVATE_MSG)
1463                         link_state_event(l_ptr, ACTIVATE_MSG);
1464                 break;
1465         case STATE_MSG:
1466
1467                 msg_tol = msg_link_tolerance(msg);
1468                 if (msg_tol)
1469                         link_set_supervision_props(l_ptr, msg_tol);
1470
1471                 if (msg_linkprio(msg) &&
1472                     (msg_linkprio(msg) != l_ptr->priority)) {
1473                         pr_debug("%s<%s>, priority change %u->%u\n",
1474                                  link_rst_msg, l_ptr->name,
1475                                  l_ptr->priority, msg_linkprio(msg));
1476                         l_ptr->priority = msg_linkprio(msg);
1477                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1478                         break;
1479                 }
1480
1481                 /* Record reception; force mismatch at next timeout: */
1482                 l_ptr->checkpoint--;
1483
1484                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1485                 l_ptr->stats.recv_states++;
1486                 if (link_reset_unknown(l_ptr))
1487                         break;
1488
1489                 if (less_eq(l_ptr->next_in_no, msg_next_sent(msg)))
1490                         rec_gap = mod(msg_next_sent(msg) - l_ptr->next_in_no);
1491
1492                 if (msg_probe(msg))
1493                         l_ptr->stats.recv_probes++;
1494
1495                 /* Protocol message before retransmits, reduce loss risk */
1496                 if (l_ptr->owner->bclink.recv_permitted)
1497                         tipc_bclink_update_link_state(l_ptr->owner,
1498                                                       msg_last_bcast(msg));
1499
1500                 if (rec_gap || (msg_probe(msg))) {
1501                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0,
1502                                              rec_gap, 0, 0);
1503                 }
1504                 if (msg_seq_gap(msg)) {
1505                         l_ptr->stats.recv_nacks++;
1506                         tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->transmq),
1507                                              msg_seq_gap(msg));
1508                 }
1509                 break;
1510         }
1511 exit:
1512         kfree_skb(buf);
1513 }
1514
1515
1516 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1517  * a different bearer. Owner node is locked.
1518  */
1519 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1520                                   struct tipc_msg *tunnel_hdr,
1521                                   struct tipc_msg *msg,
1522                                   u32 selector)
1523 {
1524         struct tipc_link *tunnel;
1525         struct sk_buff *skb;
1526         u32 length = msg_size(msg);
1527
1528         tunnel = l_ptr->owner->active_links[selector & 1];
1529         if (!tipc_link_is_up(tunnel)) {
1530                 pr_warn("%stunnel link no longer available\n", link_co_err);
1531                 return;
1532         }
1533         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1534         skb = tipc_buf_acquire(length + INT_H_SIZE);
1535         if (!skb) {
1536                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1537                 return;
1538         }
1539         skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
1540         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
1541         __tipc_link_xmit_skb(tunnel, skb);
1542 }
1543
1544
1545 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1546  * link is still active. We can do failover. Tunnel the failing link's
1547  * whole send queue via the remaining link. This way, we don't lose
1548  * any packets, and sequence order is preserved for subsequent traffic
1549  * sent over the remaining link. Owner node is locked.
1550  */
1551 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1552 {
1553         int msgcount;
1554         struct tipc_link *tunnel = l_ptr->owner->active_links[0];
1555         struct tipc_msg tunnel_hdr;
1556         struct sk_buff *skb;
1557         int split_bundles;
1558
1559         if (!tunnel)
1560                 return;
1561
1562         tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
1563                       FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
1564         skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
1565         tipc_link_purge_backlog(l_ptr);
1566         msgcount = skb_queue_len(&l_ptr->transmq);
1567         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1568         msg_set_msgcnt(&tunnel_hdr, msgcount);
1569
1570         if (skb_queue_empty(&l_ptr->transmq)) {
1571                 skb = tipc_buf_acquire(INT_H_SIZE);
1572                 if (skb) {
1573                         skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
1574                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1575                         __tipc_link_xmit_skb(tunnel, skb);
1576                 } else {
1577                         pr_warn("%sunable to send changeover msg\n",
1578                                 link_co_err);
1579                 }
1580                 return;
1581         }
1582
1583         split_bundles = (l_ptr->owner->active_links[0] !=
1584                          l_ptr->owner->active_links[1]);
1585
1586         skb_queue_walk(&l_ptr->transmq, skb) {
1587                 struct tipc_msg *msg = buf_msg(skb);
1588
1589                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1590                         struct tipc_msg *m = msg_get_wrapped(msg);
1591                         unchar *pos = (unchar *)m;
1592
1593                         msgcount = msg_msgcnt(msg);
1594                         while (msgcount--) {
1595                                 msg_set_seqno(m, msg_seqno(msg));
1596                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1597                                                       msg_link_selector(m));
1598                                 pos += align(msg_size(m));
1599                                 m = (struct tipc_msg *)pos;
1600                         }
1601                 } else {
1602                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1603                                               msg_link_selector(msg));
1604                 }
1605         }
1606 }
1607
1608 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1609  * duplicate of the first link's send queue via the new link. This way, we
1610  * are guaranteed that currently queued packets from a socket are delivered
1611  * before future traffic from the same socket, even if this is using the
1612  * new link. The last arriving copy of each duplicate packet is dropped at
1613  * the receiving end by the regular protocol check, so packet cardinality
1614  * and sequence order is preserved per sender/receiver socket pair.
1615  * Owner node is locked.
1616  */
1617 void tipc_link_dup_queue_xmit(struct tipc_link *link,
1618                               struct tipc_link *tnl)
1619 {
1620         struct sk_buff *skb;
1621         struct tipc_msg tnl_hdr;
1622         struct sk_buff_head *queue = &link->transmq;
1623         int mcnt;
1624
1625         tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
1626                       SYNCH_MSG, INT_H_SIZE, link->addr);
1627         mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
1628         msg_set_msgcnt(&tnl_hdr, mcnt);
1629         msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
1630
1631 tunnel_queue:
1632         skb_queue_walk(queue, skb) {
1633                 struct sk_buff *outskb;
1634                 struct tipc_msg *msg = buf_msg(skb);
1635                 u32 len = msg_size(msg);
1636
1637                 msg_set_ack(msg, mod(link->next_in_no - 1));
1638                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
1639                 msg_set_size(&tnl_hdr, len + INT_H_SIZE);
1640                 outskb = tipc_buf_acquire(len + INT_H_SIZE);
1641                 if (outskb == NULL) {
1642                         pr_warn("%sunable to send duplicate msg\n",
1643                                 link_co_err);
1644                         return;
1645                 }
1646                 skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
1647                 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
1648                                                skb->data, len);
1649                 __tipc_link_xmit_skb(tnl, outskb);
1650                 if (!tipc_link_is_up(link))
1651                         return;
1652         }
1653         if (queue == &link->backlogq)
1654                 return;
1655         queue = &link->backlogq;
1656         goto tunnel_queue;
1657 }
1658
1659 /*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
1660  *  Owner node is locked.
1661  */
1662 static bool tipc_link_failover_rcv(struct tipc_link *link,
1663                                    struct sk_buff **skb)
1664 {
1665         struct tipc_msg *msg = buf_msg(*skb);
1666         struct sk_buff *iskb = NULL;
1667         struct tipc_link *pl = NULL;
1668         int bearer_id = msg_bearer_id(msg);
1669         int pos = 0;
1670
1671         if (msg_type(msg) != FAILOVER_MSG) {
1672                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1673                 goto exit;
1674         }
1675         if (bearer_id >= MAX_BEARERS)
1676                 goto exit;
1677
1678         if (bearer_id == link->bearer_id)
1679                 goto exit;
1680
1681         pl = link->owner->links[bearer_id];
1682         if (pl && tipc_link_is_up(pl))
1683                 tipc_link_reset(pl);
1684
1685         if (link->failover_pkts == FIRST_FAILOVER)
1686                 link->failover_pkts = msg_msgcnt(msg);
1687
1688         /* Should we expect an inner packet? */
1689         if (!link->failover_pkts)
1690                 goto exit;
1691
1692         if (!tipc_msg_extract(*skb, &iskb, &pos)) {
1693                 pr_warn("%sno inner failover pkt\n", link_co_err);
1694                 *skb = NULL;
1695                 goto exit;
1696         }
1697         link->failover_pkts--;
1698         *skb = NULL;
1699
1700         /* Was this packet already delivered? */
1701         if (less(buf_seqno(iskb), link->failover_checkpt)) {
1702                 kfree_skb(iskb);
1703                 iskb = NULL;
1704                 goto exit;
1705         }
1706         if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
1707                 link->stats.recv_fragments++;
1708                 tipc_buf_append(&link->failover_skb, &iskb);
1709         }
1710 exit:
1711         if (!link->failover_pkts && pl)
1712                 pl->flags &= ~LINK_FAILINGOVER;
1713         kfree_skb(*skb);
1714         *skb = iskb;
1715         return *skb;
1716 }
1717
1718 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol)
1719 {
1720         unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
1721
1722         if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1723                 return;
1724
1725         l_ptr->tolerance = tol;
1726         l_ptr->cont_intv = msecs_to_jiffies(intv);
1727         l_ptr->abort_limit = tol / (jiffies_to_msecs(l_ptr->cont_intv));
1728 }
1729
1730 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1731 {
1732         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1733
1734         l->window = win;
1735         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1736         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1737         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1738         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1739         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1740 }
1741
1742 /* tipc_link_find_owner - locate owner node of link by link's name
1743  * @net: the applicable net namespace
1744  * @name: pointer to link name string
1745  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1746  *
1747  * Returns pointer to node owning the link, or 0 if no matching link is found.
1748  */
1749 static struct tipc_node *tipc_link_find_owner(struct net *net,
1750                                               const char *link_name,
1751                                               unsigned int *bearer_id)
1752 {
1753         struct tipc_net *tn = net_generic(net, tipc_net_id);
1754         struct tipc_link *l_ptr;
1755         struct tipc_node *n_ptr;
1756         struct tipc_node *found_node = NULL;
1757         int i;
1758
1759         *bearer_id = 0;
1760         rcu_read_lock();
1761         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1762                 tipc_node_lock(n_ptr);
1763                 for (i = 0; i < MAX_BEARERS; i++) {
1764                         l_ptr = n_ptr->links[i];
1765                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1766                                 *bearer_id = i;
1767                                 found_node = n_ptr;
1768                                 break;
1769                         }
1770                 }
1771                 tipc_node_unlock(n_ptr);
1772                 if (found_node)
1773                         break;
1774         }
1775         rcu_read_unlock();
1776
1777         return found_node;
1778 }
1779
1780 /**
1781  * link_reset_statistics - reset link statistics
1782  * @l_ptr: pointer to link
1783  */
1784 static void link_reset_statistics(struct tipc_link *l_ptr)
1785 {
1786         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1787         l_ptr->stats.sent_info = l_ptr->next_out_no;
1788         l_ptr->stats.recv_info = l_ptr->next_in_no;
1789 }
1790
1791 static void link_print(struct tipc_link *l_ptr, const char *str)
1792 {
1793         struct tipc_net *tn = net_generic(l_ptr->owner->net, tipc_net_id);
1794         struct tipc_bearer *b_ptr;
1795
1796         rcu_read_lock();
1797         b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]);
1798         if (b_ptr)
1799                 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name);
1800         rcu_read_unlock();
1801
1802         if (link_working_unknown(l_ptr))
1803                 pr_cont(":WU\n");
1804         else if (link_reset_reset(l_ptr))
1805                 pr_cont(":RR\n");
1806         else if (link_reset_unknown(l_ptr))
1807                 pr_cont(":RU\n");
1808         else if (link_working_working(l_ptr))
1809                 pr_cont(":WW\n");
1810         else
1811                 pr_cont("\n");
1812 }
1813
1814 /* Parse and validate nested (link) properties valid for media, bearer and link
1815  */
1816 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1817 {
1818         int err;
1819
1820         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1821                                tipc_nl_prop_policy);
1822         if (err)
1823                 return err;
1824
1825         if (props[TIPC_NLA_PROP_PRIO]) {
1826                 u32 prio;
1827
1828                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1829                 if (prio > TIPC_MAX_LINK_PRI)
1830                         return -EINVAL;
1831         }
1832
1833         if (props[TIPC_NLA_PROP_TOL]) {
1834                 u32 tol;
1835
1836                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1837                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1838                         return -EINVAL;
1839         }
1840
1841         if (props[TIPC_NLA_PROP_WIN]) {
1842                 u32 win;
1843
1844                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1845                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1846                         return -EINVAL;
1847         }
1848
1849         return 0;
1850 }
1851
1852 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1853 {
1854         int err;
1855         int res = 0;
1856         int bearer_id;
1857         char *name;
1858         struct tipc_link *link;
1859         struct tipc_node *node;
1860         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1861         struct net *net = sock_net(skb->sk);
1862
1863         if (!info->attrs[TIPC_NLA_LINK])
1864                 return -EINVAL;
1865
1866         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1867                                info->attrs[TIPC_NLA_LINK],
1868                                tipc_nl_link_policy);
1869         if (err)
1870                 return err;
1871
1872         if (!attrs[TIPC_NLA_LINK_NAME])
1873                 return -EINVAL;
1874
1875         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1876
1877         if (strcmp(name, tipc_bclink_name) == 0)
1878                 return tipc_nl_bc_link_set(net, attrs);
1879
1880         node = tipc_link_find_owner(net, name, &bearer_id);
1881         if (!node)
1882                 return -EINVAL;
1883
1884         tipc_node_lock(node);
1885
1886         link = node->links[bearer_id];
1887         if (!link) {
1888                 res = -EINVAL;
1889                 goto out;
1890         }
1891
1892         if (attrs[TIPC_NLA_LINK_PROP]) {
1893                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1894
1895                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1896                                               props);
1897                 if (err) {
1898                         res = err;
1899                         goto out;
1900                 }
1901
1902                 if (props[TIPC_NLA_PROP_TOL]) {
1903                         u32 tol;
1904
1905                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1906                         link_set_supervision_props(link, tol);
1907                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1908                 }
1909                 if (props[TIPC_NLA_PROP_PRIO]) {
1910                         u32 prio;
1911
1912                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1913                         link->priority = prio;
1914                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1915                 }
1916                 if (props[TIPC_NLA_PROP_WIN]) {
1917                         u32 win;
1918
1919                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1920                         tipc_link_set_queue_limits(link, win);
1921                 }
1922         }
1923
1924 out:
1925         tipc_node_unlock(node);
1926
1927         return res;
1928 }
1929
1930 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1931 {
1932         int i;
1933         struct nlattr *stats;
1934
1935         struct nla_map {
1936                 u32 key;
1937                 u32 val;
1938         };
1939
1940         struct nla_map map[] = {
1941                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1942                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1943                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1944                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1945                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1946                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1947                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1948                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1949                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1950                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1951                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1952                         s->msg_length_counts : 1},
1953                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1954                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1955                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1956                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1957                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1958                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1959                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1960                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1961                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1962                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1963                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1964                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1965                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1966                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1967                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1968                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1969                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1970                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1971                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1972                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1973                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1974                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1975                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1976         };
1977
1978         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1979         if (!stats)
1980                 return -EMSGSIZE;
1981
1982         for (i = 0; i <  ARRAY_SIZE(map); i++)
1983                 if (nla_put_u32(skb, map[i].key, map[i].val))
1984                         goto msg_full;
1985
1986         nla_nest_end(skb, stats);
1987
1988         return 0;
1989 msg_full:
1990         nla_nest_cancel(skb, stats);
1991
1992         return -EMSGSIZE;
1993 }
1994
1995 /* Caller should hold appropriate locks to protect the link */
1996 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1997                               struct tipc_link *link, int nlflags)
1998 {
1999         int err;
2000         void *hdr;
2001         struct nlattr *attrs;
2002         struct nlattr *prop;
2003         struct tipc_net *tn = net_generic(net, tipc_net_id);
2004
2005         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2006                           nlflags, TIPC_NL_LINK_GET);
2007         if (!hdr)
2008                 return -EMSGSIZE;
2009
2010         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
2011         if (!attrs)
2012                 goto msg_full;
2013
2014         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2015                 goto attr_msg_full;
2016         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
2017                         tipc_cluster_mask(tn->own_addr)))
2018                 goto attr_msg_full;
2019         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2020                 goto attr_msg_full;
2021         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->next_in_no))
2022                 goto attr_msg_full;
2023         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->next_out_no))
2024                 goto attr_msg_full;
2025
2026         if (tipc_link_is_up(link))
2027                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2028                         goto attr_msg_full;
2029         if (tipc_link_is_active(link))
2030                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2031                         goto attr_msg_full;
2032
2033         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2034         if (!prop)
2035                 goto attr_msg_full;
2036         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2037                 goto prop_msg_full;
2038         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2039                 goto prop_msg_full;
2040         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2041                         link->window))
2042                 goto prop_msg_full;
2043         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2044                 goto prop_msg_full;
2045         nla_nest_end(msg->skb, prop);
2046
2047         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2048         if (err)
2049                 goto attr_msg_full;
2050
2051         nla_nest_end(msg->skb, attrs);
2052         genlmsg_end(msg->skb, hdr);
2053
2054         return 0;
2055
2056 prop_msg_full:
2057         nla_nest_cancel(msg->skb, prop);
2058 attr_msg_full:
2059         nla_nest_cancel(msg->skb, attrs);
2060 msg_full:
2061         genlmsg_cancel(msg->skb, hdr);
2062
2063         return -EMSGSIZE;
2064 }
2065
2066 /* Caller should hold node lock  */
2067 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2068                                     struct tipc_node *node, u32 *prev_link)
2069 {
2070         u32 i;
2071         int err;
2072
2073         for (i = *prev_link; i < MAX_BEARERS; i++) {
2074                 *prev_link = i;
2075
2076                 if (!node->links[i])
2077                         continue;
2078
2079                 err = __tipc_nl_add_link(net, msg, node->links[i], NLM_F_MULTI);
2080                 if (err)
2081                         return err;
2082         }
2083         *prev_link = 0;
2084
2085         return 0;
2086 }
2087
2088 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2089 {
2090         struct net *net = sock_net(skb->sk);
2091         struct tipc_net *tn = net_generic(net, tipc_net_id);
2092         struct tipc_node *node;
2093         struct tipc_nl_msg msg;
2094         u32 prev_node = cb->args[0];
2095         u32 prev_link = cb->args[1];
2096         int done = cb->args[2];
2097         int err;
2098
2099         if (done)
2100                 return 0;
2101
2102         msg.skb = skb;
2103         msg.portid = NETLINK_CB(cb->skb).portid;
2104         msg.seq = cb->nlh->nlmsg_seq;
2105
2106         rcu_read_lock();
2107         if (prev_node) {
2108                 node = tipc_node_find(net, prev_node);
2109                 if (!node) {
2110                         /* We never set seq or call nl_dump_check_consistent()
2111                          * this means that setting prev_seq here will cause the
2112                          * consistence check to fail in the netlink callback
2113                          * handler. Resulting in the last NLMSG_DONE message
2114                          * having the NLM_F_DUMP_INTR flag set.
2115                          */
2116                         cb->prev_seq = 1;
2117                         goto out;
2118                 }
2119                 tipc_node_put(node);
2120
2121                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2122                                                  list) {
2123                         tipc_node_lock(node);
2124                         err = __tipc_nl_add_node_links(net, &msg, node,
2125                                                        &prev_link);
2126                         tipc_node_unlock(node);
2127                         if (err)
2128                                 goto out;
2129
2130                         prev_node = node->addr;
2131                 }
2132         } else {
2133                 err = tipc_nl_add_bc_link(net, &msg);
2134                 if (err)
2135                         goto out;
2136
2137                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2138                         tipc_node_lock(node);
2139                         err = __tipc_nl_add_node_links(net, &msg, node,
2140                                                        &prev_link);
2141                         tipc_node_unlock(node);
2142                         if (err)
2143                                 goto out;
2144
2145                         prev_node = node->addr;
2146                 }
2147         }
2148         done = 1;
2149 out:
2150         rcu_read_unlock();
2151
2152         cb->args[0] = prev_node;
2153         cb->args[1] = prev_link;
2154         cb->args[2] = done;
2155
2156         return skb->len;
2157 }
2158
2159 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2160 {
2161         struct net *net = genl_info_net(info);
2162         struct tipc_nl_msg msg;
2163         char *name;
2164         int err;
2165
2166         msg.portid = info->snd_portid;
2167         msg.seq = info->snd_seq;
2168
2169         if (!info->attrs[TIPC_NLA_LINK_NAME])
2170                 return -EINVAL;
2171         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2172
2173         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2174         if (!msg.skb)
2175                 return -ENOMEM;
2176
2177         if (strcmp(name, tipc_bclink_name) == 0) {
2178                 err = tipc_nl_add_bc_link(net, &msg);
2179                 if (err) {
2180                         nlmsg_free(msg.skb);
2181                         return err;
2182                 }
2183         } else {
2184                 int bearer_id;
2185                 struct tipc_node *node;
2186                 struct tipc_link *link;
2187
2188                 node = tipc_link_find_owner(net, name, &bearer_id);
2189                 if (!node)
2190                         return -EINVAL;
2191
2192                 tipc_node_lock(node);
2193                 link = node->links[bearer_id];
2194                 if (!link) {
2195                         tipc_node_unlock(node);
2196                         nlmsg_free(msg.skb);
2197                         return -EINVAL;
2198                 }
2199
2200                 err = __tipc_nl_add_link(net, &msg, link, 0);
2201                 tipc_node_unlock(node);
2202                 if (err) {
2203                         nlmsg_free(msg.skb);
2204                         return err;
2205                 }
2206         }
2207
2208         return genlmsg_reply(msg.skb, info);
2209 }
2210
2211 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2212 {
2213         int err;
2214         char *link_name;
2215         unsigned int bearer_id;
2216         struct tipc_link *link;
2217         struct tipc_node *node;
2218         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2219         struct net *net = sock_net(skb->sk);
2220
2221         if (!info->attrs[TIPC_NLA_LINK])
2222                 return -EINVAL;
2223
2224         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2225                                info->attrs[TIPC_NLA_LINK],
2226                                tipc_nl_link_policy);
2227         if (err)
2228                 return err;
2229
2230         if (!attrs[TIPC_NLA_LINK_NAME])
2231                 return -EINVAL;
2232
2233         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2234
2235         if (strcmp(link_name, tipc_bclink_name) == 0) {
2236                 err = tipc_bclink_reset_stats(net);
2237                 if (err)
2238                         return err;
2239                 return 0;
2240         }
2241
2242         node = tipc_link_find_owner(net, link_name, &bearer_id);
2243         if (!node)
2244                 return -EINVAL;
2245
2246         tipc_node_lock(node);
2247
2248         link = node->links[bearer_id];
2249         if (!link) {
2250                 tipc_node_unlock(node);
2251                 return -EINVAL;
2252         }
2253
2254         link_reset_statistics(link);
2255
2256         tipc_node_unlock(node);
2257
2258         return 0;
2259 }