net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, 2012-2015, Ericsson AB
   5  * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "core.h"
  38 #include "subscr.h"
  39 #include "link.h"
  40 #include "bcast.h"
  41 #include "socket.h"
  42 #include "name_distr.h"
  43 #include "discover.h"
  44 #include "netlink.h"
  45
  46 #include <linux/pkt_sched.h>
  47
  48 /*
  49  * Error message prefixes
  50  */
  51 static const char *link_co_err = "Link changeover error, ";
  52 static const char *link_rst_msg = "Resetting link ";
  53 static const char *link_unk_evt = "Unknown link event ";
  54
  55 static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
  56         [TIPC_NLA_LINK_UNSPEC]          = { .type = NLA_UNSPEC },
  57         [TIPC_NLA_LINK_NAME] = {
  58                 .type = NLA_STRING,
  59                 .len = TIPC_MAX_LINK_NAME
  60         },
  61         [TIPC_NLA_LINK_MTU]             = { .type = NLA_U32 },
  62         [TIPC_NLA_LINK_BROADCAST]       = { .type = NLA_FLAG },
  63         [TIPC_NLA_LINK_UP]              = { .type = NLA_FLAG },
  64         [TIPC_NLA_LINK_ACTIVE]          = { .type = NLA_FLAG },
  65         [TIPC_NLA_LINK_PROP]            = { .type = NLA_NESTED },
  66         [TIPC_NLA_LINK_STATS]           = { .type = NLA_NESTED },
  67         [TIPC_NLA_LINK_RX]              = { .type = NLA_U32 },
  68         [TIPC_NLA_LINK_TX]              = { .type = NLA_U32 }
  69 };
  70
  71 /* Properties valid for media, bearar and link */
  72 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
  73         [TIPC_NLA_PROP_UNSPEC]          = { .type = NLA_UNSPEC },
  74         [TIPC_NLA_PROP_PRIO]            = { .type = NLA_U32 },
  75         [TIPC_NLA_PROP_TOL]             = { .type = NLA_U32 },
  76         [TIPC_NLA_PROP_WIN]             = { .type = NLA_U32 }
  77 };
  78
  79 /*
  80  * Out-of-range value for link session numbers
  81  */
  82 #define INVALID_SESSION 0x10000
  83
  84 /*
  85  * Link state events:
  86  */
  87 #define  STARTING_EVT    856384768      /* link processing trigger */
  88 #define  TRAFFIC_MSG_EVT 560815u        /* rx'd ??? */
  89 #define  SILENCE_EVT     560817u        /* timer dicovered silence from peer */
  90
  91 /*
  92  * State value stored in 'failover_pkts'
  93  */
  94 #define FIRST_FAILOVER 0xffffu
  95
  96 static void link_handle_out_of_seq_msg(struct tipc_link *link,
  97                                        struct sk_buff *skb);
  98 static void tipc_link_proto_rcv(struct tipc_link *link,
  99                                 struct sk_buff *skb);
 100 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol);
 101 static void link_state_event(struct tipc_link *l_ptr, u32 event);
 102 static void link_reset_statistics(struct tipc_link *l_ptr);
 103 static void link_print(struct tipc_link *l_ptr, const char *str);
 104 static void tipc_link_sync_xmit(struct tipc_link *l);
 105 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 106 static void tipc_link_input(struct tipc_link *l, struct sk_buff *skb);
 107 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb);
 108 static bool tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb);
 109 static void link_set_timer(struct tipc_link *link, unsigned long time);
 110 /*
 111  *  Simple link routines
 112  */
 113 static unsigned int align(unsigned int i)
 114 {
 115         return (i + 3) & ~3u;
 116 }
 117
 118 static void tipc_link_release(struct kref *kref)
 119 {
 120         kfree(container_of(kref, struct tipc_link, ref));
 121 }
 122
 123 static void tipc_link_get(struct tipc_link *l_ptr)
 124 {
 125         kref_get(&l_ptr->ref);
 126 }
 127
 128 static void tipc_link_put(struct tipc_link *l_ptr)
 129 {
 130         kref_put(&l_ptr->ref, tipc_link_release);
 131 }
 132
 133 static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
 134 {
 135         struct tipc_node *n = l->owner;
 136
 137         if (node_active_link(n, 0) != l)
 138                 return node_active_link(n, 0);
 139         return node_active_link(n, 1);
 140 }
 141
 142 /*
 143  *  Simple non-static link routines (i.e. referenced outside this file)
 144  */
 145 int tipc_link_is_up(struct tipc_link *l_ptr)
 146 {
 147         if (!l_ptr)
 148                 return 0;
 149         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 150 }
 151
 152 int tipc_link_is_active(struct tipc_link *l)
 153 {
 154         struct tipc_node *n = l->owner;
 155
 156         return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
 157 }
 158
 159 /**
 160  * link_timeout - handle expiration of link timer
 161  * @l_ptr: pointer to link
 162  */
 163 static void link_timeout(unsigned long data)
 164 {
 165         struct tipc_link *l_ptr = (struct tipc_link *)data;
 166         struct sk_buff *skb;
 167
 168         tipc_node_lock(l_ptr->owner);
 169
 170         /* update counters used in statistical profiling of send traffic */
 171         l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->transmq);
 172         l_ptr->stats.queue_sz_counts++;
 173
 174         skb = skb_peek(&l_ptr->transmq);
 175         if (skb) {
 176                 struct tipc_msg *msg = buf_msg(skb);
 177                 u32 length = msg_size(msg);
 178
 179                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 180                     (msg_type(msg) == FIRST_FRAGMENT)) {
 181                         length = msg_size(msg_get_wrapped(msg));
 182                 }
 183                 if (length) {
 184                         l_ptr->stats.msg_lengths_total += length;
 185                         l_ptr->stats.msg_length_counts++;
 186                         if (length <= 64)
 187                                 l_ptr->stats.msg_length_profile[0]++;
 188                         else if (length <= 256)
 189                                 l_ptr->stats.msg_length_profile[1]++;
 190                         else if (length <= 1024)
 191                                 l_ptr->stats.msg_length_profile[2]++;
 192                         else if (length <= 4096)
 193                                 l_ptr->stats.msg_length_profile[3]++;
 194                         else if (length <= 16384)
 195                                 l_ptr->stats.msg_length_profile[4]++;
 196                         else if (length <= 32768)
 197                                 l_ptr->stats.msg_length_profile[5]++;
 198                         else
 199                                 l_ptr->stats.msg_length_profile[6]++;
 200                 }
 201         }
 202
 203         /* do all other link processing performed on a periodic basis */
 204         if (l_ptr->silent_intv_cnt || tipc_bclink_acks_missing(l_ptr->owner))
 205                 link_state_event(l_ptr, SILENCE_EVT);
 206         l_ptr->silent_intv_cnt++;
 207         if (skb_queue_len(&l_ptr->backlogq))
 208                 tipc_link_push_packets(l_ptr);
 209         link_set_timer(l_ptr, l_ptr->keepalive_intv);
 210         tipc_node_unlock(l_ptr->owner);
 211         tipc_link_put(l_ptr);
 212 }
 213
 214 static void link_set_timer(struct tipc_link *link, unsigned long time)
 215 {
 216         if (!mod_timer(&link->timer, jiffies + time))
 217                 tipc_link_get(link);
 218 }
 219
 220 /**
 221  * tipc_link_create - create a new link
 222  * @n_ptr: pointer to associated node
 223  * @b_ptr: pointer to associated bearer
 224  * @media_addr: media address to use when sending messages over link
 225  *
 226  * Returns pointer to link.
 227  */
 228 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 229                                    struct tipc_bearer *b_ptr,
 230                                    const struct tipc_media_addr *media_addr,
 231                                    struct sk_buff_head *inputq,
 232                                    struct sk_buff_head *namedq)
 233 {
 234         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 235         struct tipc_link *l_ptr;
 236         struct tipc_msg *msg;
 237         char *if_name;
 238         char addr_string[16];
 239         u32 peer = n_ptr->addr;
 240
 241         if (n_ptr->link_cnt >= MAX_BEARERS) {
 242                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 243                 pr_err("Cannot establish %uth link to %s. Max %u allowed.\n",
 244                        n_ptr->link_cnt, addr_string, MAX_BEARERS);
 245                 return NULL;
 246         }
 247
 248         if (n_ptr->links[b_ptr->identity].link) {
 249                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 250                 pr_err("Attempt to establish second link on <%s> to %s\n",
 251                        b_ptr->name, addr_string);
 252                 return NULL;
 253         }
 254
 255         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 256         if (!l_ptr) {
 257                 pr_warn("Link creation failed, no memory\n");
 258                 return NULL;
 259         }
 260         kref_init(&l_ptr->ref);
 261         l_ptr->addr = peer;
 262         if_name = strchr(b_ptr->name, ':') + 1;
 263         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 264                 tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
 265                 tipc_node(tn->own_addr),
 266                 if_name,
 267                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 268                 /* note: peer i/f name is updated by reset/activate message */
 269         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 270         l_ptr->owner = n_ptr;
 271         l_ptr->peer_session = INVALID_SESSION;
 272         l_ptr->bearer_id = b_ptr->identity;
 273         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 274         l_ptr->state = RESET_UNKNOWN;
 275
 276         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 277         msg = l_ptr->pmsg;
 278         tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
 279                       l_ptr->addr);
 280         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 281         msg_set_session(msg, (tn->random & 0xffff));
 282         msg_set_bearer_id(msg, b_ptr->identity);
 283         strcpy((char *)msg_data(msg), if_name);
 284         l_ptr->net_plane = b_ptr->net_plane;
 285         l_ptr->advertised_mtu = b_ptr->mtu;
 286         l_ptr->mtu = l_ptr->advertised_mtu;
 287         l_ptr->priority = b_ptr->priority;
 288         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 289         l_ptr->snd_nxt = 1;
 290         __skb_queue_head_init(&l_ptr->transmq);
 291         __skb_queue_head_init(&l_ptr->backlogq);
 292         __skb_queue_head_init(&l_ptr->deferdq);
 293         skb_queue_head_init(&l_ptr->wakeupq);
 294         l_ptr->inputq = inputq;
 295         l_ptr->namedq = namedq;
 296         skb_queue_head_init(l_ptr->inputq);
 297         link_reset_statistics(l_ptr);
 298         tipc_node_attach_link(n_ptr, l_ptr);
 299         setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr);
 300         link_state_event(l_ptr, STARTING_EVT);
 301
 302         return l_ptr;
 303 }
 304
 305 /**
 306  * tipc_link_delete - Delete a link
 307  * @l: link to be deleted
 308  */
 309 void tipc_link_delete(struct tipc_link *l)
 310 {
 311         tipc_link_reset(l);
 312         if (del_timer(&l->timer))
 313                 tipc_link_put(l);
 314         l->flags |= LINK_STOPPED;
 315         /* Delete link now, or when timer is finished: */
 316         tipc_link_reset_fragments(l);
 317         tipc_node_detach_link(l->owner, l);
 318         tipc_link_put(l);
 319 }
 320
 321 void tipc_link_delete_list(struct net *net, unsigned int bearer_id)
 322 {
 323         struct tipc_net *tn = net_generic(net, tipc_net_id);
 324         struct tipc_link *link;
 325         struct tipc_node *node;
 326
 327         rcu_read_lock();
 328         list_for_each_entry_rcu(node, &tn->node_list, list) {
 329                 tipc_node_lock(node);
 330                 link = node->links[bearer_id].link;
 331                 if (link)
 332                         tipc_link_delete(link);
 333                 tipc_node_unlock(node);
 334         }
 335         rcu_read_unlock();
 336 }
 337
 338 /**
 339  * link_schedule_user - schedule a message sender for wakeup after congestion
 340  * @link: congested link
 341  * @list: message that was attempted sent
 342  * Create pseudo msg to send back to user when congestion abates
 343  * Does not consume buffer list
 344  */
 345 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 346 {
 347         struct tipc_msg *msg = buf_msg(skb_peek(list));
 348         int imp = msg_importance(msg);
 349         u32 oport = msg_origport(msg);
 350         u32 addr = link_own_addr(link);
 351         struct sk_buff *skb;
 352
 353         /* This really cannot happen...  */
 354         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 355                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 356                 tipc_link_reset(link);
 357                 return -ENOBUFS;
 358         }
 359         /* Non-blocking sender: */
 360         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 361                 return -ELINKCONG;
 362
 363         /* Create and schedule wakeup pseudo message */
 364         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 365                               addr, addr, oport, 0, 0);
 366         if (!skb)
 367                 return -ENOBUFS;
 368         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 369         TIPC_SKB_CB(skb)->chain_imp = imp;
 370         skb_queue_tail(&link->wakeupq, skb);
 371         link->stats.link_congs++;
 372         return -ELINKCONG;
 373 }
 374
 375 /**
 376  * link_prepare_wakeup - prepare users for wakeup after congestion
 377  * @link: congested link
 378  * Move a number of waiting users, as permitted by available space in
 379  * the send queue, from link wait queue to node wait queue for wakeup
 380  */
 381 void link_prepare_wakeup(struct tipc_link *l)
 382 {
 383         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 384         int imp, lim;
 385         struct sk_buff *skb, *tmp;
 386
 387         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 388                 imp = TIPC_SKB_CB(skb)->chain_imp;
 389                 lim = l->window + l->backlog[imp].limit;
 390                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 391                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 392                         break;
 393                 skb_unlink(skb, &l->wakeupq);
 394                 skb_queue_tail(l->inputq, skb);
 395                 l->owner->inputq = l->inputq;
 396                 l->owner->action_flags |= TIPC_MSG_EVT;
 397         }
 398 }
 399
 400 /**
 401  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 402  * @l_ptr: pointer to link
 403  */
 404 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 405 {
 406         kfree_skb(l_ptr->reasm_buf);
 407         l_ptr->reasm_buf = NULL;
 408 }
 409
 410 void tipc_link_purge_backlog(struct tipc_link *l)
 411 {
 412         __skb_queue_purge(&l->backlogq);
 413         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 414         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 415         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 416         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 417         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 418 }
 419
 420 /**
 421  * tipc_link_purge_queues - purge all pkt queues associated with link
 422  * @l_ptr: pointer to link
 423  */
 424 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 425 {
 426         __skb_queue_purge(&l_ptr->deferdq);
 427         __skb_queue_purge(&l_ptr->transmq);
 428         tipc_link_purge_backlog(l_ptr);
 429         tipc_link_reset_fragments(l_ptr);
 430 }
 431
 432 void tipc_link_reset(struct tipc_link *l_ptr)
 433 {
 434         u32 prev_state = l_ptr->state;
 435         int was_active_link = tipc_link_is_active(l_ptr);
 436         struct tipc_node *owner = l_ptr->owner;
 437         struct tipc_link *pl = tipc_parallel_link(l_ptr);
 438
 439         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 440
 441         /* Link is down, accept any session */
 442         l_ptr->peer_session = INVALID_SESSION;
 443
 444         /* Prepare for renewed mtu size negotiation */
 445         l_ptr->mtu = l_ptr->advertised_mtu;
 446
 447         l_ptr->state = RESET_UNKNOWN;
 448
 449         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 450                 return;
 451
 452         tipc_node_link_down(l_ptr->owner, l_ptr->bearer_id);
 453         tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 454
 455         if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
 456                 l_ptr->flags |= LINK_FAILINGOVER;
 457                 l_ptr->failover_checkpt = l_ptr->rcv_nxt;
 458                 pl->failover_pkts = FIRST_FAILOVER;
 459                 pl->failover_checkpt = l_ptr->rcv_nxt;
 460                 pl->failover_skb = l_ptr->reasm_buf;
 461         } else {
 462                 kfree_skb(l_ptr->reasm_buf);
 463         }
 464         /* Clean up all queues, except inputq: */
 465         __skb_queue_purge(&l_ptr->transmq);
 466         __skb_queue_purge(&l_ptr->deferdq);
 467         if (!owner->inputq)
 468                 owner->inputq = l_ptr->inputq;
 469         skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
 470         if (!skb_queue_empty(owner->inputq))
 471                 owner->action_flags |= TIPC_MSG_EVT;
 472         tipc_link_purge_backlog(l_ptr);
 473         l_ptr->reasm_buf = NULL;
 474         l_ptr->rcv_unacked = 0;
 475         l_ptr->snd_nxt = 1;
 476         l_ptr->silent_intv_cnt = 0;
 477         l_ptr->stale_count = 0;
 478         link_reset_statistics(l_ptr);
 479 }
 480
 481 static void link_activate(struct tipc_link *link)
 482 {
 483         struct tipc_node *node = link->owner;
 484
 485         link->rcv_nxt = 1;
 486         link->stats.recv_info = 1;
 487         link->silent_intv_cnt = 0;
 488         tipc_node_link_up(node, link->bearer_id);
 489         tipc_bearer_add_dest(node->net, link->bearer_id, link->addr);
 490 }
 491
 492 /**
 493  * link_state_event - link finite state machine
 494  * @l_ptr: pointer to link
 495  * @event: state machine event to process
 496  */
 497 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 498 {
 499         struct tipc_link *other;
 500         unsigned long timer_intv = l_ptr->keepalive_intv;
 501
 502         if (l_ptr->flags & LINK_STOPPED)
 503                 return;
 504
 505         if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 506                 return;         /* Not yet. */
 507
 508         if (l_ptr->flags & LINK_FAILINGOVER)
 509                 return;
 510
 511         switch (l_ptr->state) {
 512         case WORKING_WORKING:
 513                 switch (event) {
 514                 case TRAFFIC_MSG_EVT:
 515                 case ACTIVATE_MSG:
 516                         l_ptr->silent_intv_cnt = 0;
 517                         break;
 518                 case SILENCE_EVT:
 519                         if (!l_ptr->silent_intv_cnt) {
 520                                 if (tipc_bclink_acks_missing(l_ptr->owner))
 521                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 522                                                              0, 0, 0, 0);
 523                                 break;
 524                         }
 525                         l_ptr->state = WORKING_UNKNOWN;
 526                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 527                         break;
 528                 case RESET_MSG:
 529                         pr_debug("%s<%s>, requested by peer\n",
 530                                  link_rst_msg, l_ptr->name);
 531                         tipc_link_reset(l_ptr);
 532                         l_ptr->state = RESET_RESET;
 533                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 534                                              0, 0, 0, 0);
 535                         break;
 536                 default:
 537                         pr_debug("%s%u in WW state\n", link_unk_evt, event);
 538                 }
 539                 break;
 540         case WORKING_UNKNOWN:
 541                 switch (event) {
 542                 case TRAFFIC_MSG_EVT:
 543                 case ACTIVATE_MSG:
 544                         l_ptr->state = WORKING_WORKING;
 545                         l_ptr->silent_intv_cnt = 0;
 546                         break;
 547                 case RESET_MSG:
 548                         pr_debug("%s<%s>, requested by peer while probing\n",
 549                                  link_rst_msg, l_ptr->name);
 550                         tipc_link_reset(l_ptr);
 551                         l_ptr->state = RESET_RESET;
 552                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 553                                              0, 0, 0, 0);
 554                         break;
 555                 case SILENCE_EVT:
 556                         if (!l_ptr->silent_intv_cnt) {
 557                                 l_ptr->state = WORKING_WORKING;
 558                                 if (tipc_bclink_acks_missing(l_ptr->owner))
 559                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 560                                                              0, 0, 0, 0);
 561                         } else if (l_ptr->silent_intv_cnt <
 562                                    l_ptr->abort_limit) {
 563                                 tipc_link_proto_xmit(l_ptr, STATE_MSG,
 564                                                      1, 0, 0, 0);
 565                         } else {        /* Link has failed */
 566                                 pr_debug("%s<%s>, peer not responding\n",
 567                                          link_rst_msg, l_ptr->name);
 568                                 tipc_link_reset(l_ptr);
 569                                 l_ptr->state = RESET_UNKNOWN;
 570                                 tipc_link_proto_xmit(l_ptr, RESET_MSG,
 571                                                      0, 0, 0, 0);
 572                         }
 573                         break;
 574                 default:
 575                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 576                 }
 577                 break;
 578         case RESET_UNKNOWN:
 579                 switch (event) {
 580                 case TRAFFIC_MSG_EVT:
 581                         break;
 582                 case ACTIVATE_MSG:
 583                         other = node_active_link(l_ptr->owner, 0);
 584                         if (other && link_working_unknown(other))
 585                                 break;
 586                         l_ptr->state = WORKING_WORKING;
 587                         link_activate(l_ptr);
 588                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 589                         if (l_ptr->owner->working_links == 1)
 590                                 tipc_link_sync_xmit(l_ptr);
 591                         break;
 592                 case RESET_MSG:
 593                         l_ptr->state = RESET_RESET;
 594                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 595                                              1, 0, 0, 0);
 596                         break;
 597                 case STARTING_EVT:
 598                         l_ptr->flags |= LINK_STARTED;
 599                         link_set_timer(l_ptr, timer_intv);
 600                         break;
 601                 case SILENCE_EVT:
 602                         tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0);
 603                         break;
 604                 default:
 605                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 606                 }
 607                 break;
 608         case RESET_RESET:
 609                 switch (event) {
 610                 case TRAFFIC_MSG_EVT:
 611                 case ACTIVATE_MSG:
 612                         other = node_active_link(l_ptr->owner, 0);
 613                         if (other && link_working_unknown(other))
 614                                 break;
 615                         l_ptr->state = WORKING_WORKING;
 616                         link_activate(l_ptr);
 617                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 618                         if (l_ptr->owner->working_links == 1)
 619                                 tipc_link_sync_xmit(l_ptr);
 620                         break;
 621                 case RESET_MSG:
 622                         break;
 623                 case SILENCE_EVT:
 624                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 625                                              0, 0, 0, 0);
 626                         break;
 627                 default:
 628                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 629                 }
 630                 break;
 631         default:
 632                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 633         }
 634 }
 635
 636 /**
 637  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 638  * @link: link to use
 639  * @list: chain of buffers containing message
 640  *
 641  * Consumes the buffer chain, except when returning an error code,
 642  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 643  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 644  */
 645 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 646                      struct sk_buff_head *list)
 647 {
 648         struct tipc_msg *msg = buf_msg(skb_peek(list));
 649         unsigned int maxwin = link->window;
 650         unsigned int i, imp = msg_importance(msg);
 651         uint mtu = link->mtu;
 652         u16 ack = mod(link->rcv_nxt - 1);
 653         u16 seqno = link->snd_nxt;
 654         u16 bc_last_in = link->owner->bclink.last_in;
 655         struct tipc_media_addr *addr = &link->media_addr;
 656         struct sk_buff_head *transmq = &link->transmq;
 657         struct sk_buff_head *backlogq = &link->backlogq;
 658         struct sk_buff *skb, *bskb;
 659
 660         /* Match msg importance against this and all higher backlog limits: */
 661         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 662                 if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
 663                         return link_schedule_user(link, list);
 664         }
 665         if (unlikely(msg_size(msg) > mtu))
 666                 return -EMSGSIZE;
 667
 668         /* Prepare each packet for sending, and add to relevant queue: */
 669         while (skb_queue_len(list)) {
 670                 skb = skb_peek(list);
 671                 msg = buf_msg(skb);
 672                 msg_set_seqno(msg, seqno);
 673                 msg_set_ack(msg, ack);
 674                 msg_set_bcast_ack(msg, bc_last_in);
 675
 676                 if (likely(skb_queue_len(transmq) < maxwin)) {
 677                         __skb_dequeue(list);
 678                         __skb_queue_tail(transmq, skb);
 679                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 680                         link->rcv_unacked = 0;
 681                         seqno++;
 682                         continue;
 683                 }
 684                 if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
 685                         kfree_skb(__skb_dequeue(list));
 686                         link->stats.sent_bundled++;
 687                         continue;
 688                 }
 689                 if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
 690                         kfree_skb(__skb_dequeue(list));
 691                         __skb_queue_tail(backlogq, bskb);
 692                         link->backlog[msg_importance(buf_msg(bskb))].len++;
 693                         link->stats.sent_bundled++;
 694                         link->stats.sent_bundles++;
 695                         continue;
 696                 }
 697                 link->backlog[imp].len += skb_queue_len(list);
 698                 skb_queue_splice_tail_init(list, backlogq);
 699         }
 700         link->snd_nxt = seqno;
 701         return 0;
 702 }
 703
 704 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
 705 {
 706         skb_queue_head_init(list);
 707         __skb_queue_tail(list, skb);
 708 }
 709
 710 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 711 {
 712         struct sk_buff_head head;
 713
 714         skb2list(skb, &head);
 715         return __tipc_link_xmit(link->owner->net, link, &head);
 716 }
 717
 718 /* tipc_link_xmit_skb(): send single buffer to destination
 719  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
 720  * messages, which will not cause link congestion
 721  * The only exception is datagram messages rerouted after secondary
 722  * lookup, which are rare and safe to dispose of anyway.
 723  * TODO: Return real return value, and let callers use
 724  * tipc_wait_for_sendpkt() where applicable
 725  */
 726 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 727                        u32 selector)
 728 {
 729         struct sk_buff_head head;
 730         int rc;
 731
 732         skb2list(skb, &head);
 733         rc = tipc_link_xmit(net, &head, dnode, selector);
 734         if (rc)
 735                 kfree_skb(skb);
 736         return 0;
 737 }
 738
 739 /**
 740  * tipc_link_xmit() is the general link level function for message sending
 741  * @net: the applicable net namespace
 742  * @list: chain of buffers containing message
 743  * @dsz: amount of user data to be sent
 744  * @dnode: address of destination node
 745  * @selector: a number used for deterministic link selection
 746  * Consumes the buffer chain, except when returning error
 747  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 748  */
 749 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
 750                    u32 selector)
 751 {
 752         struct tipc_link *link = NULL;
 753         struct tipc_node *node;
 754         int rc = -EHOSTUNREACH;
 755
 756         node = tipc_node_find(net, dnode);
 757         if (node) {
 758                 tipc_node_lock(node);
 759                 link = node_active_link(node, selector & 1);
 760                 if (link)
 761                         rc = __tipc_link_xmit(net, link, list);
 762                 tipc_node_unlock(node);
 763                 tipc_node_put(node);
 764         }
 765         if (link)
 766                 return rc;
 767
 768         if (likely(in_own_node(net, dnode))) {
 769                 tipc_sk_rcv(net, list);
 770                 return 0;
 771         }
 772
 773         __skb_queue_purge(list);
 774         return rc;
 775 }
 776
 777 /*
 778  * tipc_link_sync_xmit - synchronize broadcast link endpoints.
 779  *
 780  * Give a newly added peer node the sequence number where it should
 781  * start receiving and acking broadcast packets.
 782  *
 783  * Called with node locked
 784  */
 785 static void tipc_link_sync_xmit(struct tipc_link *link)
 786 {
 787         struct sk_buff *skb;
 788         struct tipc_msg *msg;
 789
 790         skb = tipc_buf_acquire(INT_H_SIZE);
 791         if (!skb)
 792                 return;
 793
 794         msg = buf_msg(skb);
 795         tipc_msg_init(link_own_addr(link), msg, BCAST_PROTOCOL, STATE_MSG,
 796                       INT_H_SIZE, link->addr);
 797         msg_set_last_bcast(msg, link->owner->bclink.acked);
 798         __tipc_link_xmit_skb(link, skb);
 799 }
 800
 801 /*
 802  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 803  * Receive the sequence number where we should start receiving and
 804  * acking broadcast packets from a newly added peer node, and open
 805  * up for reception of such packets.
 806  *
 807  * Called with node locked
 808  */
 809 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 810 {
 811         struct tipc_msg *msg = buf_msg(buf);
 812
 813         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 814         n->bclink.recv_permitted = true;
 815         kfree_skb(buf);
 816 }
 817
 818 /*
 819  * tipc_link_push_packets - push unsent packets to bearer
 820  *
 821  * Push out the unsent messages of a link where congestion
 822  * has abated. Node is locked.
 823  *
 824  * Called with node locked
 825  */
 826 void tipc_link_push_packets(struct tipc_link *link)
 827 {
 828         struct sk_buff *skb;
 829         struct tipc_msg *msg;
 830         u16 seqno = link->snd_nxt;
 831         u16 ack = mod(link->rcv_nxt - 1);
 832
 833         while (skb_queue_len(&link->transmq) < link->window) {
 834                 skb = __skb_dequeue(&link->backlogq);
 835                 if (!skb)
 836                         break;
 837                 msg = buf_msg(skb);
 838                 link->backlog[msg_importance(msg)].len--;
 839                 msg_set_ack(msg, ack);
 840                 msg_set_seqno(msg, seqno);
 841                 seqno = mod(seqno + 1);
 842                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 843                 link->rcv_unacked = 0;
 844                 __skb_queue_tail(&link->transmq, skb);
 845                 tipc_bearer_send(link->owner->net, link->bearer_id,
 846                                  skb, &link->media_addr);
 847         }
 848         link->snd_nxt = seqno;
 849 }
 850
 851 void tipc_link_reset_all(struct tipc_node *node)
 852 {
 853         char addr_string[16];
 854         u32 i;
 855
 856         tipc_node_lock(node);
 857
 858         pr_warn("Resetting all links to %s\n",
 859                 tipc_addr_string_fill(addr_string, node->addr));
 860
 861         for (i = 0; i < MAX_BEARERS; i++) {
 862                 if (node->links[i].link) {
 863                         link_print(node->links[i].link, "Resetting link\n");
 864                         tipc_link_reset(node->links[i].link);
 865                 }
 866         }
 867
 868         tipc_node_unlock(node);
 869 }
 870
 871 static void link_retransmit_failure(struct tipc_link *l_ptr,
 872                                     struct sk_buff *buf)
 873 {
 874         struct tipc_msg *msg = buf_msg(buf);
 875         struct net *net = l_ptr->owner->net;
 876
 877         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 878
 879         if (l_ptr->addr) {
 880                 /* Handle failure on standard link */
 881                 link_print(l_ptr, "Resetting link\n");
 882                 tipc_link_reset(l_ptr);
 883
 884         } else {
 885                 /* Handle failure on broadcast link */
 886                 struct tipc_node *n_ptr;
 887                 char addr_string[16];
 888
 889                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 890                 pr_cont("Outstanding acks: %lu\n",
 891                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 892
 893                 n_ptr = tipc_bclink_retransmit_to(net);
 894
 895                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 896                 pr_info("Broadcast link info for %s\n", addr_string);
 897                 pr_info("Reception permitted: %d,  Acked: %u\n",
 898                         n_ptr->bclink.recv_permitted,
 899                         n_ptr->bclink.acked);
 900                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 901                         n_ptr->bclink.last_in,
 902                         n_ptr->bclink.oos_state,
 903                         n_ptr->bclink.last_sent);
 904
 905                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 906                 l_ptr->stale_count = 0;
 907         }
 908 }
 909
 910 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 911                           u32 retransmits)
 912 {
 913         struct tipc_msg *msg;
 914
 915         if (!skb)
 916                 return;
 917
 918         msg = buf_msg(skb);
 919
 920         /* Detect repeated retransmit failures */
 921         if (l_ptr->last_retransm == msg_seqno(msg)) {
 922                 if (++l_ptr->stale_count > 100) {
 923                         link_retransmit_failure(l_ptr, skb);
 924                         return;
 925                 }
 926         } else {
 927                 l_ptr->last_retransm = msg_seqno(msg);
 928                 l_ptr->stale_count = 1;
 929         }
 930
 931         skb_queue_walk_from(&l_ptr->transmq, skb) {
 932                 if (!retransmits)
 933                         break;
 934                 msg = buf_msg(skb);
 935                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
 936                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 937                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 938                                  &l_ptr->media_addr);
 939                 retransmits--;
 940                 l_ptr->stats.retransmitted++;
 941         }
 942 }
 943
 944 /* link_synch(): check if all packets arrived before the synch
 945  *               point have been consumed
 946  * Returns true if the parallel links are synched, otherwise false
 947  */
 948 static bool link_synch(struct tipc_link *l)
 949 {
 950         unsigned int post_synch;
 951         struct tipc_link *pl;
 952
 953         pl  = tipc_parallel_link(l);
 954         if (pl == l)
 955                 goto synched;
 956
 957         /* Was last pre-synch packet added to input queue ? */
 958         if (less_eq(pl->rcv_nxt, l->synch_point))
 959                 return false;
 960
 961         /* Is it still in the input queue ? */
 962         post_synch = mod(pl->rcv_nxt - l->synch_point) - 1;
 963         if (skb_queue_len(pl->inputq) > post_synch)
 964                 return false;
 965 synched:
 966         l->flags &= ~LINK_SYNCHING;
 967         return true;
 968 }
 969
 970 static void link_retrieve_defq(struct tipc_link *link,
 971                                struct sk_buff_head *list)
 972 {
 973         u16 seq_no;
 974
 975         if (skb_queue_empty(&link->deferdq))
 976                 return;
 977
 978         seq_no = buf_seqno(skb_peek(&link->deferdq));
 979         if (seq_no == link->rcv_nxt)
 980                 skb_queue_splice_tail_init(&link->deferdq, list);
 981 }
 982
 983 /**
 984  * tipc_rcv - process TIPC packets/messages arriving from off-node
 985  * @net: the applicable net namespace
 986  * @skb: TIPC packet
 987  * @b_ptr: pointer to bearer message arrived on
 988  *
 989  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
 990  * structure (i.e. cannot be NULL), but bearer can be inactive.
 991  */
 992 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
 993 {
 994         struct tipc_net *tn = net_generic(net, tipc_net_id);
 995         struct sk_buff_head head;
 996         struct tipc_node *n_ptr;
 997         struct tipc_link *l_ptr;
 998         struct sk_buff *skb1, *tmp;
 999         struct tipc_msg *msg;
1000         u16 seq_no;
1001         u16 ackd;
1002         u32 released;
1003
1004         skb2list(skb, &head);
1005
1006         while ((skb = __skb_dequeue(&head))) {
1007                 /* Ensure message is well-formed */
1008                 if (unlikely(!tipc_msg_validate(skb)))
1009                         goto discard;
1010
1011                 /* Handle arrival of a non-unicast link message */
1012                 msg = buf_msg(skb);
1013                 if (unlikely(msg_non_seq(msg))) {
1014                         if (msg_user(msg) ==  LINK_CONFIG)
1015                                 tipc_disc_rcv(net, skb, b_ptr);
1016                         else
1017                                 tipc_bclink_rcv(net, skb);
1018                         continue;
1019                 }
1020
1021                 /* Discard unicast link messages destined for another node */
1022                 if (unlikely(!msg_short(msg) &&
1023                              (msg_destnode(msg) != tn->own_addr)))
1024                         goto discard;
1025
1026                 /* Locate neighboring node that sent message */
1027                 n_ptr = tipc_node_find(net, msg_prevnode(msg));
1028                 if (unlikely(!n_ptr))
1029                         goto discard;
1030
1031                 tipc_node_lock(n_ptr);
1032                 /* Locate unicast link endpoint that should handle message */
1033                 l_ptr = n_ptr->links[b_ptr->identity].link;
1034                 if (unlikely(!l_ptr))
1035                         goto unlock;
1036
1037                 /* Verify that communication with node is currently allowed */
1038                 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
1039                     msg_user(msg) == LINK_PROTOCOL &&
1040                     (msg_type(msg) == RESET_MSG ||
1041                     msg_type(msg) == ACTIVATE_MSG) &&
1042                     !msg_redundant_link(msg))
1043                         n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
1044
1045                 if (tipc_node_blocked(n_ptr))
1046                         goto unlock;
1047
1048                 /* Validate message sequence number info */
1049                 seq_no = msg_seqno(msg);
1050                 ackd = msg_ack(msg);
1051
1052                 /* Release acked messages */
1053                 if (unlikely(n_ptr->bclink.acked != msg_bcast_ack(msg)))
1054                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1055
1056                 released = 0;
1057                 skb_queue_walk_safe(&l_ptr->transmq, skb1, tmp) {
1058                         if (more(buf_seqno(skb1), ackd))
1059                                 break;
1060                          __skb_unlink(skb1, &l_ptr->transmq);
1061                          kfree_skb(skb1);
1062                          released = 1;
1063                 }
1064
1065                 /* Try sending any messages link endpoint has pending */
1066                 if (unlikely(skb_queue_len(&l_ptr->backlogq)))
1067                         tipc_link_push_packets(l_ptr);
1068
1069                 if (released && !skb_queue_empty(&l_ptr->wakeupq))
1070                         link_prepare_wakeup(l_ptr);
1071
1072                 /* Process the incoming packet */
1073                 if (unlikely(!link_working_working(l_ptr))) {
1074                         if (msg_user(msg) == LINK_PROTOCOL) {
1075                                 tipc_link_proto_rcv(l_ptr, skb);
1076                                 link_retrieve_defq(l_ptr, &head);
1077                                 skb = NULL;
1078                                 goto unlock;
1079                         }
1080
1081                         /* Traffic message. Conditionally activate link */
1082                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1083
1084                         if (link_working_working(l_ptr)) {
1085                                 /* Re-insert buffer in front of queue */
1086                                 __skb_queue_head(&head, skb);
1087                                 skb = NULL;
1088                                 goto unlock;
1089                         }
1090                         goto unlock;
1091                 }
1092
1093                 /* Link is now in state WORKING_WORKING */
1094                 if (unlikely(seq_no != l_ptr->rcv_nxt)) {
1095                         link_handle_out_of_seq_msg(l_ptr, skb);
1096                         link_retrieve_defq(l_ptr, &head);
1097                         skb = NULL;
1098                         goto unlock;
1099                 }
1100                 l_ptr->silent_intv_cnt = 0;
1101
1102                 /* Synchronize with parallel link if applicable */
1103                 if (unlikely((l_ptr->flags & LINK_SYNCHING) && !msg_dup(msg))) {
1104                         if (!link_synch(l_ptr))
1105                                 goto unlock;
1106                 }
1107                 l_ptr->rcv_nxt++;
1108                 if (unlikely(!skb_queue_empty(&l_ptr->deferdq)))
1109                         link_retrieve_defq(l_ptr, &head);
1110                 if (unlikely(++l_ptr->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
1111                         l_ptr->stats.sent_acks++;
1112                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1113                 }
1114                 tipc_link_input(l_ptr, skb);
1115                 skb = NULL;
1116 unlock:
1117                 tipc_node_unlock(n_ptr);
1118                 tipc_node_put(n_ptr);
1119 discard:
1120                 if (unlikely(skb))
1121                         kfree_skb(skb);
1122         }
1123 }
1124
1125 /* tipc_data_input - deliver data and name distr msgs to upper layer
1126  *
1127  * Consumes buffer if message is of right type
1128  * Node lock must be held
1129  */
1130 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
1131 {
1132         struct tipc_node *node = link->owner;
1133         struct tipc_msg *msg = buf_msg(skb);
1134         u32 dport = msg_destport(msg);
1135
1136         switch (msg_user(msg)) {
1137         case TIPC_LOW_IMPORTANCE:
1138         case TIPC_MEDIUM_IMPORTANCE:
1139         case TIPC_HIGH_IMPORTANCE:
1140         case TIPC_CRITICAL_IMPORTANCE:
1141         case CONN_MANAGER:
1142                 if (tipc_skb_queue_tail(link->inputq, skb, dport)) {
1143                         node->inputq = link->inputq;
1144                         node->action_flags |= TIPC_MSG_EVT;
1145                 }
1146                 return true;
1147         case NAME_DISTRIBUTOR:
1148                 node->bclink.recv_permitted = true;
1149                 node->namedq = link->namedq;
1150                 skb_queue_tail(link->namedq, skb);
1151                 if (skb_queue_len(link->namedq) == 1)
1152                         node->action_flags |= TIPC_NAMED_MSG_EVT;
1153                 return true;
1154         case MSG_BUNDLER:
1155         case TUNNEL_PROTOCOL:
1156         case MSG_FRAGMENTER:
1157         case BCAST_PROTOCOL:
1158                 return false;
1159         default:
1160                 pr_warn("Dropping received illegal msg type\n");
1161                 kfree_skb(skb);
1162                 return false;
1163         };
1164 }
1165
1166 /* tipc_link_input - process packet that has passed link protocol check
1167  *
1168  * Consumes buffer
1169  * Node lock must be held
1170  */
1171 static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
1172 {
1173         struct tipc_node *node = link->owner;
1174         struct tipc_msg *msg = buf_msg(skb);
1175         struct sk_buff *iskb;
1176         int pos = 0;
1177
1178         if (likely(tipc_data_input(link, skb)))
1179                 return;
1180
1181         switch (msg_user(msg)) {
1182         case TUNNEL_PROTOCOL:
1183                 if (msg_dup(msg)) {
1184                         link->flags |= LINK_SYNCHING;
1185                         link->synch_point = msg_seqno(msg_get_wrapped(msg));
1186                         kfree_skb(skb);
1187                         break;
1188                 }
1189                 if (!tipc_link_failover_rcv(link, &skb))
1190                         break;
1191                 if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
1192                         tipc_data_input(link, skb);
1193                         break;
1194                 }
1195         case MSG_BUNDLER:
1196                 link->stats.recv_bundles++;
1197                 link->stats.recv_bundled += msg_msgcnt(msg);
1198
1199                 while (tipc_msg_extract(skb, &iskb, &pos))
1200                         tipc_data_input(link, iskb);
1201                 break;
1202         case MSG_FRAGMENTER:
1203                 link->stats.recv_fragments++;
1204                 if (tipc_buf_append(&link->reasm_buf, &skb)) {
1205                         link->stats.recv_fragmented++;
1206                         tipc_data_input(link, skb);
1207                 } else if (!link->reasm_buf) {
1208                         tipc_link_reset(link);
1209                 }
1210                 break;
1211         case BCAST_PROTOCOL:
1212                 tipc_link_sync_rcv(node, skb);
1213                 break;
1214         default:
1215                 break;
1216         };
1217 }
1218
1219 /**
1220  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1221  *
1222  * Returns increase in queue length (i.e. 0 or 1)
1223  */
1224 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1225 {
1226         struct sk_buff *skb1;
1227         u16 seq_no = buf_seqno(skb);
1228
1229         /* Empty queue ? */
1230         if (skb_queue_empty(list)) {
1231                 __skb_queue_tail(list, skb);
1232                 return 1;
1233         }
1234
1235         /* Last ? */
1236         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1237                 __skb_queue_tail(list, skb);
1238                 return 1;
1239         }
1240
1241         /* Locate insertion point in queue, then insert; discard if duplicate */
1242         skb_queue_walk(list, skb1) {
1243                 u16 curr_seqno = buf_seqno(skb1);
1244
1245                 if (seq_no == curr_seqno) {
1246                         kfree_skb(skb);
1247                         return 0;
1248                 }
1249
1250                 if (less(seq_no, curr_seqno))
1251                         break;
1252         }
1253
1254         __skb_queue_before(list, skb1, skb);
1255         return 1;
1256 }
1257
1258 /*
1259  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1260  */
1261 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1262                                        struct sk_buff *buf)
1263 {
1264         u32 seq_no = buf_seqno(buf);
1265
1266         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1267                 tipc_link_proto_rcv(l_ptr, buf);
1268                 return;
1269         }
1270
1271         /* Record OOS packet arrival */
1272         l_ptr->silent_intv_cnt = 0;
1273
1274         /*
1275          * Discard packet if a duplicate; otherwise add it to deferred queue
1276          * and notify peer of gap as per protocol specification
1277          */
1278         if (less(seq_no, l_ptr->rcv_nxt)) {
1279                 l_ptr->stats.duplicates++;
1280                 kfree_skb(buf);
1281                 return;
1282         }
1283
1284         if (tipc_link_defer_pkt(&l_ptr->deferdq, buf)) {
1285                 l_ptr->stats.deferred_recv++;
1286                 if ((skb_queue_len(&l_ptr->deferdq) % TIPC_MIN_LINK_WIN) == 1)
1287                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1288         } else {
1289                 l_ptr->stats.duplicates++;
1290         }
1291 }
1292
1293 /*
1294  * Send protocol message to the other endpoint.
1295  */
1296 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1297                           u32 gap, u32 tolerance, u32 priority)
1298 {
1299         struct sk_buff *buf = NULL;
1300         struct tipc_msg *msg = l_ptr->pmsg;
1301         u32 msg_size = sizeof(l_ptr->proto_msg);
1302         int r_flag;
1303         u16 last_rcv;
1304
1305         /* Don't send protocol message during link failover */
1306         if (l_ptr->flags & LINK_FAILINGOVER)
1307                 return;
1308
1309         /* Abort non-RESET send if communication with node is prohibited */
1310         if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG))
1311                 return;
1312
1313         /* Create protocol message with "out-of-sequence" sequence number */
1314         msg_set_type(msg, msg_typ);
1315         msg_set_net_plane(msg, l_ptr->net_plane);
1316         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1317         msg_set_last_bcast(msg, tipc_bclink_get_last_sent(l_ptr->owner->net));
1318
1319         if (msg_typ == STATE_MSG) {
1320                 u16 next_sent = l_ptr->snd_nxt;
1321
1322                 if (!tipc_link_is_up(l_ptr))
1323                         return;
1324                 msg_set_next_sent(msg, next_sent);
1325                 if (!skb_queue_empty(&l_ptr->deferdq)) {
1326                         last_rcv = buf_seqno(skb_peek(&l_ptr->deferdq));
1327                         gap = mod(last_rcv - l_ptr->rcv_nxt);
1328                 }
1329                 msg_set_seq_gap(msg, gap);
1330                 if (gap)
1331                         l_ptr->stats.sent_nacks++;
1332                 msg_set_link_tolerance(msg, tolerance);
1333                 msg_set_linkprio(msg, priority);
1334                 msg_set_max_pkt(msg, l_ptr->mtu);
1335                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
1336                 msg_set_probe(msg, probe_msg != 0);
1337                 if (probe_msg)
1338                         l_ptr->stats.sent_probes++;
1339                 l_ptr->stats.sent_states++;
1340         } else {                /* RESET_MSG or ACTIVATE_MSG */
1341                 msg_set_ack(msg, mod(l_ptr->failover_checkpt - 1));
1342                 msg_set_seq_gap(msg, 0);
1343                 msg_set_next_sent(msg, 1);
1344                 msg_set_probe(msg, 0);
1345                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1346                 msg_set_linkprio(msg, l_ptr->priority);
1347                 msg_set_max_pkt(msg, l_ptr->advertised_mtu);
1348         }
1349
1350         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1351         msg_set_redundant_link(msg, r_flag);
1352         msg_set_linkprio(msg, l_ptr->priority);
1353         msg_set_size(msg, msg_size);
1354
1355         msg_set_seqno(msg, mod(l_ptr->snd_nxt + (0xffff / 2)));
1356
1357         buf = tipc_buf_acquire(msg_size);
1358         if (!buf)
1359                 return;
1360
1361         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1362         buf->priority = TC_PRIO_CONTROL;
1363         tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, buf,
1364                          &l_ptr->media_addr);
1365         l_ptr->rcv_unacked = 0;
1366         kfree_skb(buf);
1367 }
1368
1369 /*
1370  * Receive protocol message :
1371  * Note that network plane id propagates through the network, and may
1372  * change at any time. The node with lowest address rules
1373  */
1374 static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
1375                                 struct sk_buff *buf)
1376 {
1377         u32 rec_gap = 0;
1378         u32 msg_tol;
1379         struct tipc_msg *msg = buf_msg(buf);
1380
1381         if (l_ptr->flags & LINK_FAILINGOVER)
1382                 goto exit;
1383
1384         if (l_ptr->net_plane != msg_net_plane(msg))
1385                 if (link_own_addr(l_ptr) > msg_prevnode(msg))
1386                         l_ptr->net_plane = msg_net_plane(msg);
1387
1388         switch (msg_type(msg)) {
1389
1390         case RESET_MSG:
1391                 if (!link_working_unknown(l_ptr) &&
1392                     (l_ptr->peer_session != INVALID_SESSION)) {
1393                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1394                                 break; /* duplicate or old reset: ignore */
1395                 }
1396
1397                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1398                                 link_working_unknown(l_ptr))) {
1399                         /*
1400                          * peer has lost contact -- don't allow peer's links
1401                          * to reactivate before we recognize loss & clean up
1402                          */
1403                         l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
1404                 }
1405
1406                 link_state_event(l_ptr, RESET_MSG);
1407
1408                 /* fall thru' */
1409         case ACTIVATE_MSG:
1410                 /* Update link settings according other endpoint's values */
1411                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1412
1413                 msg_tol = msg_link_tolerance(msg);
1414                 if (msg_tol > l_ptr->tolerance)
1415                         link_set_supervision_props(l_ptr, msg_tol);
1416
1417                 if (msg_linkprio(msg) > l_ptr->priority)
1418                         l_ptr->priority = msg_linkprio(msg);
1419
1420                 if (l_ptr->mtu > msg_max_pkt(msg))
1421                         l_ptr->mtu = msg_max_pkt(msg);
1422
1423                 /* Synchronize broadcast link info, if not done previously */
1424                 if (!tipc_node_is_up(l_ptr->owner)) {
1425                         l_ptr->owner->bclink.last_sent =
1426                                 l_ptr->owner->bclink.last_in =
1427                                 msg_last_bcast(msg);
1428                         l_ptr->owner->bclink.oos_state = 0;
1429                 }
1430
1431                 l_ptr->peer_session = msg_session(msg);
1432                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1433
1434                 if (msg_type(msg) == ACTIVATE_MSG)
1435                         link_state_event(l_ptr, ACTIVATE_MSG);
1436                 break;
1437         case STATE_MSG:
1438
1439                 msg_tol = msg_link_tolerance(msg);
1440                 if (msg_tol)
1441                         link_set_supervision_props(l_ptr, msg_tol);
1442
1443                 if (msg_linkprio(msg) &&
1444                     (msg_linkprio(msg) != l_ptr->priority)) {
1445                         pr_debug("%s<%s>, priority change %u->%u\n",
1446                                  link_rst_msg, l_ptr->name,
1447                                  l_ptr->priority, msg_linkprio(msg));
1448                         l_ptr->priority = msg_linkprio(msg);
1449                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1450                         break;
1451                 }
1452
1453                 /* Record reception; force mismatch at next timeout: */
1454                 l_ptr->silent_intv_cnt = 0;
1455
1456                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1457                 l_ptr->stats.recv_states++;
1458                 if (link_reset_unknown(l_ptr))
1459                         break;
1460
1461                 if (less_eq(l_ptr->rcv_nxt, msg_next_sent(msg)))
1462                         rec_gap = mod(msg_next_sent(msg) - l_ptr->rcv_nxt);
1463
1464                 if (msg_probe(msg))
1465                         l_ptr->stats.recv_probes++;
1466
1467                 /* Protocol message before retransmits, reduce loss risk */
1468                 if (l_ptr->owner->bclink.recv_permitted)
1469                         tipc_bclink_update_link_state(l_ptr->owner,
1470                                                       msg_last_bcast(msg));
1471
1472                 if (rec_gap || (msg_probe(msg))) {
1473                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0,
1474                                              rec_gap, 0, 0);
1475                 }
1476                 if (msg_seq_gap(msg)) {
1477                         l_ptr->stats.recv_nacks++;
1478                         tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->transmq),
1479                                              msg_seq_gap(msg));
1480                 }
1481                 break;
1482         }
1483 exit:
1484         kfree_skb(buf);
1485 }
1486
1487
1488 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1489  * a different bearer. Owner node is locked.
1490  */
1491 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1492                                   struct tipc_msg *tunnel_hdr,
1493                                   struct tipc_msg *msg,
1494                                   u32 selector)
1495 {
1496         struct tipc_link *tunnel;
1497         struct sk_buff *skb;
1498         u32 length = msg_size(msg);
1499
1500         tunnel = node_active_link(l_ptr->owner, selector & 1);
1501         if (!tipc_link_is_up(tunnel)) {
1502                 pr_warn("%stunnel link no longer available\n", link_co_err);
1503                 return;
1504         }
1505         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1506         skb = tipc_buf_acquire(length + INT_H_SIZE);
1507         if (!skb) {
1508                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1509                 return;
1510         }
1511         skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
1512         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
1513         __tipc_link_xmit_skb(tunnel, skb);
1514 }
1515
1516
1517 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1518  * link is still active. We can do failover. Tunnel the failing link's
1519  * whole send queue via the remaining link. This way, we don't lose
1520  * any packets, and sequence order is preserved for subsequent traffic
1521  * sent over the remaining link. Owner node is locked.
1522  */
1523 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1524 {
1525         int msgcount;
1526         struct tipc_link *tunnel = node_active_link(l_ptr->owner, 0);
1527         struct tipc_msg tunnel_hdr;
1528         struct sk_buff *skb;
1529         int split_bundles;
1530
1531         if (!tunnel)
1532                 return;
1533
1534         tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
1535                       FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
1536
1537         skb_queue_walk(&l_ptr->backlogq, skb) {
1538                 msg_set_seqno(buf_msg(skb), l_ptr->snd_nxt);
1539                 l_ptr->snd_nxt = mod(l_ptr->snd_nxt + 1);
1540         }
1541         skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
1542         tipc_link_purge_backlog(l_ptr);
1543         msgcount = skb_queue_len(&l_ptr->transmq);
1544         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1545         msg_set_msgcnt(&tunnel_hdr, msgcount);
1546
1547         if (skb_queue_empty(&l_ptr->transmq)) {
1548                 skb = tipc_buf_acquire(INT_H_SIZE);
1549                 if (skb) {
1550                         skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
1551                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1552                         __tipc_link_xmit_skb(tunnel, skb);
1553                 } else {
1554                         pr_warn("%sunable to send changeover msg\n",
1555                                 link_co_err);
1556                 }
1557                 return;
1558         }
1559
1560         split_bundles = (node_active_link(l_ptr->owner, 0) !=
1561                          node_active_link(l_ptr->owner, 0));
1562
1563         skb_queue_walk(&l_ptr->transmq, skb) {
1564                 struct tipc_msg *msg = buf_msg(skb);
1565
1566                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1567                         struct tipc_msg *m = msg_get_wrapped(msg);
1568                         unchar *pos = (unchar *)m;
1569
1570                         msgcount = msg_msgcnt(msg);
1571                         while (msgcount--) {
1572                                 msg_set_seqno(m, msg_seqno(msg));
1573                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1574                                                       msg_link_selector(m));
1575                                 pos += align(msg_size(m));
1576                                 m = (struct tipc_msg *)pos;
1577                         }
1578                 } else {
1579                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1580                                               msg_link_selector(msg));
1581                 }
1582         }
1583 }
1584
1585 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1586  * duplicate of the first link's send queue via the new link. This way, we
1587  * are guaranteed that currently queued packets from a socket are delivered
1588  * before future traffic from the same socket, even if this is using the
1589  * new link. The last arriving copy of each duplicate packet is dropped at
1590  * the receiving end by the regular protocol check, so packet cardinality
1591  * and sequence order is preserved per sender/receiver socket pair.
1592  * Owner node is locked.
1593  */
1594 void tipc_link_dup_queue_xmit(struct tipc_link *link,
1595                               struct tipc_link *tnl)
1596 {
1597         struct sk_buff *skb;
1598         struct tipc_msg tnl_hdr;
1599         struct sk_buff_head *queue = &link->transmq;
1600         int mcnt;
1601         u16 seqno;
1602
1603         tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
1604                       SYNCH_MSG, INT_H_SIZE, link->addr);
1605         mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
1606         msg_set_msgcnt(&tnl_hdr, mcnt);
1607         msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
1608
1609 tunnel_queue:
1610         skb_queue_walk(queue, skb) {
1611                 struct sk_buff *outskb;
1612                 struct tipc_msg *msg = buf_msg(skb);
1613                 u32 len = msg_size(msg);
1614
1615                 msg_set_ack(msg, mod(link->rcv_nxt - 1));
1616                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
1617                 msg_set_size(&tnl_hdr, len + INT_H_SIZE);
1618                 outskb = tipc_buf_acquire(len + INT_H_SIZE);
1619                 if (outskb == NULL) {
1620                         pr_warn("%sunable to send duplicate msg\n",
1621                                 link_co_err);
1622                         return;
1623                 }
1624                 skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
1625                 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
1626                                                skb->data, len);
1627                 __tipc_link_xmit_skb(tnl, outskb);
1628                 if (!tipc_link_is_up(link))
1629                         return;
1630         }
1631         if (queue == &link->backlogq)
1632                 return;
1633         seqno = link->snd_nxt;
1634         skb_queue_walk(&link->backlogq, skb) {
1635                 msg_set_seqno(buf_msg(skb), seqno);
1636                 seqno = mod(seqno + 1);
1637         }
1638         queue = &link->backlogq;
1639         goto tunnel_queue;
1640 }
1641
1642 /*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
1643  *  Owner node is locked.
1644  */
1645 static bool tipc_link_failover_rcv(struct tipc_link *link,
1646                                    struct sk_buff **skb)
1647 {
1648         struct tipc_msg *msg = buf_msg(*skb);
1649         struct sk_buff *iskb = NULL;
1650         struct tipc_link *pl = NULL;
1651         int bearer_id = msg_bearer_id(msg);
1652         int pos = 0;
1653
1654         if (msg_type(msg) != FAILOVER_MSG) {
1655                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1656                 goto exit;
1657         }
1658         if (bearer_id >= MAX_BEARERS)
1659                 goto exit;
1660
1661         if (bearer_id == link->bearer_id)
1662                 goto exit;
1663
1664         pl = link->owner->links[bearer_id].link;
1665         if (pl && tipc_link_is_up(pl))
1666                 tipc_link_reset(pl);
1667
1668         if (link->failover_pkts == FIRST_FAILOVER)
1669                 link->failover_pkts = msg_msgcnt(msg);
1670
1671         /* Should we expect an inner packet? */
1672         if (!link->failover_pkts)
1673                 goto exit;
1674
1675         if (!tipc_msg_extract(*skb, &iskb, &pos)) {
1676                 pr_warn("%sno inner failover pkt\n", link_co_err);
1677                 *skb = NULL;
1678                 goto exit;
1679         }
1680         link->failover_pkts--;
1681         *skb = NULL;
1682
1683         /* Was this packet already delivered? */
1684         if (less(buf_seqno(iskb), link->failover_checkpt)) {
1685                 kfree_skb(iskb);
1686                 iskb = NULL;
1687                 goto exit;
1688         }
1689         if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
1690                 link->stats.recv_fragments++;
1691                 tipc_buf_append(&link->failover_skb, &iskb);
1692         }
1693 exit:
1694         if (!link->failover_pkts && pl)
1695                 pl->flags &= ~LINK_FAILINGOVER;
1696         kfree_skb(*skb);
1697         *skb = iskb;
1698         return *skb;
1699 }
1700
1701 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol)
1702 {
1703         unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
1704
1705         if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1706                 return;
1707
1708         l_ptr->tolerance = tol;
1709         l_ptr->keepalive_intv = msecs_to_jiffies(intv);
1710         l_ptr->abort_limit = tol / (jiffies_to_msecs(l_ptr->keepalive_intv));
1711 }
1712
1713 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1714 {
1715         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1716
1717         l->window = win;
1718         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1719         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1720         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1721         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1722         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1723 }
1724
1725 /* tipc_link_find_owner - locate owner node of link by link's name
1726  * @net: the applicable net namespace
1727  * @name: pointer to link name string
1728  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1729  *
1730  * Returns pointer to node owning the link, or 0 if no matching link is found.
1731  */
1732 static struct tipc_node *tipc_link_find_owner(struct net *net,
1733                                               const char *link_name,
1734                                               unsigned int *bearer_id)
1735 {
1736         struct tipc_net *tn = net_generic(net, tipc_net_id);
1737         struct tipc_link *l_ptr;
1738         struct tipc_node *n_ptr;
1739         struct tipc_node *found_node = NULL;
1740         int i;
1741
1742         *bearer_id = 0;
1743         rcu_read_lock();
1744         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1745                 tipc_node_lock(n_ptr);
1746                 for (i = 0; i < MAX_BEARERS; i++) {
1747                         l_ptr = n_ptr->links[i].link;
1748                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1749                                 *bearer_id = i;
1750                                 found_node = n_ptr;
1751                                 break;
1752                         }
1753                 }
1754                 tipc_node_unlock(n_ptr);
1755                 if (found_node)
1756                         break;
1757         }
1758         rcu_read_unlock();
1759
1760         return found_node;
1761 }
1762
1763 /**
1764  * link_reset_statistics - reset link statistics
1765  * @l_ptr: pointer to link
1766  */
1767 static void link_reset_statistics(struct tipc_link *l_ptr)
1768 {
1769         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1770         l_ptr->stats.sent_info = l_ptr->snd_nxt;
1771         l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1772 }
1773
1774 static void link_print(struct tipc_link *l_ptr, const char *str)
1775 {
1776         struct tipc_net *tn = net_generic(l_ptr->owner->net, tipc_net_id);
1777         struct tipc_bearer *b_ptr;
1778
1779         rcu_read_lock();
1780         b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]);
1781         if (b_ptr)
1782                 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name);
1783         rcu_read_unlock();
1784
1785         if (link_working_unknown(l_ptr))
1786                 pr_cont(":WU\n");
1787         else if (link_reset_reset(l_ptr))
1788                 pr_cont(":RR\n");
1789         else if (link_reset_unknown(l_ptr))
1790                 pr_cont(":RU\n");
1791         else if (link_working_working(l_ptr))
1792                 pr_cont(":WW\n");
1793         else
1794                 pr_cont("\n");
1795 }
1796
1797 /* Parse and validate nested (link) properties valid for media, bearer and link
1798  */
1799 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1800 {
1801         int err;
1802
1803         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1804                                tipc_nl_prop_policy);
1805         if (err)
1806                 return err;
1807
1808         if (props[TIPC_NLA_PROP_PRIO]) {
1809                 u32 prio;
1810
1811                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1812                 if (prio > TIPC_MAX_LINK_PRI)
1813                         return -EINVAL;
1814         }
1815
1816         if (props[TIPC_NLA_PROP_TOL]) {
1817                 u32 tol;
1818
1819                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1820                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1821                         return -EINVAL;
1822         }
1823
1824         if (props[TIPC_NLA_PROP_WIN]) {
1825                 u32 win;
1826
1827                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1828                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1829                         return -EINVAL;
1830         }
1831
1832         return 0;
1833 }
1834
1835 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1836 {
1837         int err;
1838         int res = 0;
1839         int bearer_id;
1840         char *name;
1841         struct tipc_link *link;
1842         struct tipc_node *node;
1843         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1844         struct net *net = sock_net(skb->sk);
1845
1846         if (!info->attrs[TIPC_NLA_LINK])
1847                 return -EINVAL;
1848
1849         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1850                                info->attrs[TIPC_NLA_LINK],
1851                                tipc_nl_link_policy);
1852         if (err)
1853                 return err;
1854
1855         if (!attrs[TIPC_NLA_LINK_NAME])
1856                 return -EINVAL;
1857
1858         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1859
1860         if (strcmp(name, tipc_bclink_name) == 0)
1861                 return tipc_nl_bc_link_set(net, attrs);
1862
1863         node = tipc_link_find_owner(net, name, &bearer_id);
1864         if (!node)
1865                 return -EINVAL;
1866
1867         tipc_node_lock(node);
1868
1869         link = node->links[bearer_id].link;
1870         if (!link) {
1871                 res = -EINVAL;
1872                 goto out;
1873         }
1874
1875         if (attrs[TIPC_NLA_LINK_PROP]) {
1876                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1877
1878                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1879                                               props);
1880                 if (err) {
1881                         res = err;
1882                         goto out;
1883                 }
1884
1885                 if (props[TIPC_NLA_PROP_TOL]) {
1886                         u32 tol;
1887
1888                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1889                         link_set_supervision_props(link, tol);
1890                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1891                 }
1892                 if (props[TIPC_NLA_PROP_PRIO]) {
1893                         u32 prio;
1894
1895                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1896                         link->priority = prio;
1897                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1898                 }
1899                 if (props[TIPC_NLA_PROP_WIN]) {
1900                         u32 win;
1901
1902                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1903                         tipc_link_set_queue_limits(link, win);
1904                 }
1905         }
1906
1907 out:
1908         tipc_node_unlock(node);
1909
1910         return res;
1911 }
1912
1913 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1914 {
1915         int i;
1916         struct nlattr *stats;
1917
1918         struct nla_map {
1919                 u32 key;
1920                 u32 val;
1921         };
1922
1923         struct nla_map map[] = {
1924                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1925                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1926                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1927                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1928                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1929                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1930                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1931                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1932                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1933                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1934                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1935                         s->msg_length_counts : 1},
1936                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1937                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1938                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1939                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1940                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1941                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1942                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1943                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1944                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1945                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1946                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1947                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1948                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1949                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1950                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1951                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1952                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1953                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1954                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1955                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1956                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1957                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1958                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1959         };
1960
1961         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1962         if (!stats)
1963                 return -EMSGSIZE;
1964
1965         for (i = 0; i <  ARRAY_SIZE(map); i++)
1966                 if (nla_put_u32(skb, map[i].key, map[i].val))
1967                         goto msg_full;
1968
1969         nla_nest_end(skb, stats);
1970
1971         return 0;
1972 msg_full:
1973         nla_nest_cancel(skb, stats);
1974
1975         return -EMSGSIZE;
1976 }
1977
1978 /* Caller should hold appropriate locks to protect the link */
1979 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1980                               struct tipc_link *link, int nlflags)
1981 {
1982         int err;
1983         void *hdr;
1984         struct nlattr *attrs;
1985         struct nlattr *prop;
1986         struct tipc_net *tn = net_generic(net, tipc_net_id);
1987
1988         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
1989                           nlflags, TIPC_NL_LINK_GET);
1990         if (!hdr)
1991                 return -EMSGSIZE;
1992
1993         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
1994         if (!attrs)
1995                 goto msg_full;
1996
1997         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
1998                 goto attr_msg_full;
1999         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
2000                         tipc_cluster_mask(tn->own_addr)))
2001                 goto attr_msg_full;
2002         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2003                 goto attr_msg_full;
2004         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
2005                 goto attr_msg_full;
2006         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
2007                 goto attr_msg_full;
2008
2009         if (tipc_link_is_up(link))
2010                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2011                         goto attr_msg_full;
2012         if (tipc_link_is_active(link))
2013                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2014                         goto attr_msg_full;
2015
2016         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2017         if (!prop)
2018                 goto attr_msg_full;
2019         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2020                 goto prop_msg_full;
2021         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2022                 goto prop_msg_full;
2023         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2024                         link->window))
2025                 goto prop_msg_full;
2026         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2027                 goto prop_msg_full;
2028         nla_nest_end(msg->skb, prop);
2029
2030         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2031         if (err)
2032                 goto attr_msg_full;
2033
2034         nla_nest_end(msg->skb, attrs);
2035         genlmsg_end(msg->skb, hdr);
2036
2037         return 0;
2038
2039 prop_msg_full:
2040         nla_nest_cancel(msg->skb, prop);
2041 attr_msg_full:
2042         nla_nest_cancel(msg->skb, attrs);
2043 msg_full:
2044         genlmsg_cancel(msg->skb, hdr);
2045
2046         return -EMSGSIZE;
2047 }
2048
2049 /* Caller should hold node lock  */
2050 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2051                                     struct tipc_node *node, u32 *prev_link)
2052 {
2053         u32 i;
2054         int err;
2055
2056         for (i = *prev_link; i < MAX_BEARERS; i++) {
2057                 *prev_link = i;
2058
2059                 if (!node->links[i].link)
2060                         continue;
2061
2062                 err = __tipc_nl_add_link(net, msg,
2063                                          node->links[i].link, NLM_F_MULTI);
2064                 if (err)
2065                         return err;
2066         }
2067         *prev_link = 0;
2068
2069         return 0;
2070 }
2071
2072 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2073 {
2074         struct net *net = sock_net(skb->sk);
2075         struct tipc_net *tn = net_generic(net, tipc_net_id);
2076         struct tipc_node *node;
2077         struct tipc_nl_msg msg;
2078         u32 prev_node = cb->args[0];
2079         u32 prev_link = cb->args[1];
2080         int done = cb->args[2];
2081         int err;
2082
2083         if (done)
2084                 return 0;
2085
2086         msg.skb = skb;
2087         msg.portid = NETLINK_CB(cb->skb).portid;
2088         msg.seq = cb->nlh->nlmsg_seq;
2089
2090         rcu_read_lock();
2091         if (prev_node) {
2092                 node = tipc_node_find(net, prev_node);
2093                 if (!node) {
2094                         /* We never set seq or call nl_dump_check_consistent()
2095                          * this means that setting prev_seq here will cause the
2096                          * consistence check to fail in the netlink callback
2097                          * handler. Resulting in the last NLMSG_DONE message
2098                          * having the NLM_F_DUMP_INTR flag set.
2099                          */
2100                         cb->prev_seq = 1;
2101                         goto out;
2102                 }
2103                 tipc_node_put(node);
2104
2105                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2106                                                  list) {
2107                         tipc_node_lock(node);
2108                         err = __tipc_nl_add_node_links(net, &msg, node,
2109                                                        &prev_link);
2110                         tipc_node_unlock(node);
2111                         if (err)
2112                                 goto out;
2113
2114                         prev_node = node->addr;
2115                 }
2116         } else {
2117                 err = tipc_nl_add_bc_link(net, &msg);
2118                 if (err)
2119                         goto out;
2120
2121                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2122                         tipc_node_lock(node);
2123                         err = __tipc_nl_add_node_links(net, &msg, node,
2124                                                        &prev_link);
2125                         tipc_node_unlock(node);
2126                         if (err)
2127                                 goto out;
2128
2129                         prev_node = node->addr;
2130                 }
2131         }
2132         done = 1;
2133 out:
2134         rcu_read_unlock();
2135
2136         cb->args[0] = prev_node;
2137         cb->args[1] = prev_link;
2138         cb->args[2] = done;
2139
2140         return skb->len;
2141 }
2142
2143 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2144 {
2145         struct net *net = genl_info_net(info);
2146         struct tipc_nl_msg msg;
2147         char *name;
2148         int err;
2149
2150         msg.portid = info->snd_portid;
2151         msg.seq = info->snd_seq;
2152
2153         if (!info->attrs[TIPC_NLA_LINK_NAME])
2154                 return -EINVAL;
2155         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2156
2157         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2158         if (!msg.skb)
2159                 return -ENOMEM;
2160
2161         if (strcmp(name, tipc_bclink_name) == 0) {
2162                 err = tipc_nl_add_bc_link(net, &msg);
2163                 if (err) {
2164                         nlmsg_free(msg.skb);
2165                         return err;
2166                 }
2167         } else {
2168                 int bearer_id;
2169                 struct tipc_node *node;
2170                 struct tipc_link *link;
2171
2172                 node = tipc_link_find_owner(net, name, &bearer_id);
2173                 if (!node)
2174                         return -EINVAL;
2175
2176                 tipc_node_lock(node);
2177                 link = node->links[bearer_id].link;
2178                 if (!link) {
2179                         tipc_node_unlock(node);
2180                         nlmsg_free(msg.skb);
2181                         return -EINVAL;
2182                 }
2183
2184                 err = __tipc_nl_add_link(net, &msg, link, 0);
2185                 tipc_node_unlock(node);
2186                 if (err) {
2187                         nlmsg_free(msg.skb);
2188                         return err;
2189                 }
2190         }
2191
2192         return genlmsg_reply(msg.skb, info);
2193 }
2194
2195 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2196 {
2197         int err;
2198         char *link_name;
2199         unsigned int bearer_id;
2200         struct tipc_link *link;
2201         struct tipc_node *node;
2202         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2203         struct net *net = sock_net(skb->sk);
2204
2205         if (!info->attrs[TIPC_NLA_LINK])
2206                 return -EINVAL;
2207
2208         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2209                                info->attrs[TIPC_NLA_LINK],
2210                                tipc_nl_link_policy);
2211         if (err)
2212                 return err;
2213
2214         if (!attrs[TIPC_NLA_LINK_NAME])
2215                 return -EINVAL;
2216
2217         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2218
2219         if (strcmp(link_name, tipc_bclink_name) == 0) {
2220                 err = tipc_bclink_reset_stats(net);
2221                 if (err)
2222                         return err;
2223                 return 0;
2224         }
2225
2226         node = tipc_link_find_owner(net, link_name, &bearer_id);
2227         if (!node)
2228                 return -EINVAL;
2229
2230         tipc_node_lock(node);
2231
2232         link = node->links[bearer_id].link;
2233         if (!link) {
2234                 tipc_node_unlock(node);
2235                 return -EINVAL;
2236         }
2237
2238         link_reset_statistics(link);
2239
2240         tipc_node_unlock(node);
2241
2242         return 0;
2243 }