kernel/net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, 2012-2015, Ericsson AB
   5  * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "core.h"
  38 #include "subscr.h"
  39 #include "link.h"
  40 #include "bcast.h"
  41 #include "socket.h"
  42 #include "name_distr.h"
  43 #include "discover.h"
  44 #include "netlink.h"
  45
  46 #include <linux/pkt_sched.h>
  47
  48 /*
  49  * Error message prefixes
  50  */
  51 static const char *link_co_err = "Link changeover error, ";
  52 static const char *link_rst_msg = "Resetting link ";
  53 static const char *link_unk_evt = "Unknown link event ";
  54
  55 static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
  56         [TIPC_NLA_LINK_UNSPEC]          = { .type = NLA_UNSPEC },
  57         [TIPC_NLA_LINK_NAME] = {
  58                 .type = NLA_STRING,
  59                 .len = TIPC_MAX_LINK_NAME
  60         },
  61         [TIPC_NLA_LINK_MTU]             = { .type = NLA_U32 },
  62         [TIPC_NLA_LINK_BROADCAST]       = { .type = NLA_FLAG },
  63         [TIPC_NLA_LINK_UP]              = { .type = NLA_FLAG },
  64         [TIPC_NLA_LINK_ACTIVE]          = { .type = NLA_FLAG },
  65         [TIPC_NLA_LINK_PROP]            = { .type = NLA_NESTED },
  66         [TIPC_NLA_LINK_STATS]           = { .type = NLA_NESTED },
  67         [TIPC_NLA_LINK_RX]              = { .type = NLA_U32 },
  68         [TIPC_NLA_LINK_TX]              = { .type = NLA_U32 }
  69 };
  70
  71 /* Properties valid for media, bearar and link */
  72 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
  73         [TIPC_NLA_PROP_UNSPEC]          = { .type = NLA_UNSPEC },
  74         [TIPC_NLA_PROP_PRIO]            = { .type = NLA_U32 },
  75         [TIPC_NLA_PROP_TOL]             = { .type = NLA_U32 },
  76         [TIPC_NLA_PROP_WIN]             = { .type = NLA_U32 }
  77 };
  78
  79 /*
  80  * Out-of-range value for link session numbers
  81  */
  82 #define INVALID_SESSION 0x10000
  83
  84 /*
  85  * Link state events:
  86  */
  87 #define  STARTING_EVT    856384768      /* link processing trigger */
  88 #define  TRAFFIC_MSG_EVT 560815u        /* rx'd ??? */
  89 #define  TIMEOUT_EVT     560817u        /* link timer expired */
  90
  91 /*
  92  * State value stored in 'failover_pkts'
  93  */
  94 #define FIRST_FAILOVER 0xffffu
  95
  96 static void link_handle_out_of_seq_msg(struct tipc_link *link,
  97                                        struct sk_buff *skb);
  98 static void tipc_link_proto_rcv(struct tipc_link *link,
  99                                 struct sk_buff *skb);
 100 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol);
 101 static void link_state_event(struct tipc_link *l_ptr, u32 event);
 102 static void link_reset_statistics(struct tipc_link *l_ptr);
 103 static void link_print(struct tipc_link *l_ptr, const char *str);
 104 static void tipc_link_sync_xmit(struct tipc_link *l);
 105 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 106 static void tipc_link_input(struct tipc_link *l, struct sk_buff *skb);
 107 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb);
 108 static bool tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb);
 109 /*
 110  *  Simple link routines
 111  */
 112 static unsigned int align(unsigned int i)
 113 {
 114         return (i + 3) & ~3u;
 115 }
 116
 117 static void tipc_link_release(struct kref *kref)
 118 {
 119         kfree(container_of(kref, struct tipc_link, ref));
 120 }
 121
 122 static void tipc_link_get(struct tipc_link *l_ptr)
 123 {
 124         kref_get(&l_ptr->ref);
 125 }
 126
 127 static void tipc_link_put(struct tipc_link *l_ptr)
 128 {
 129         kref_put(&l_ptr->ref, tipc_link_release);
 130 }
 131
 132 static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
 133 {
 134         if (l->owner->active_links[0] != l)
 135                 return l->owner->active_links[0];
 136         return l->owner->active_links[1];
 137 }
 138
 139 /*
 140  *  Simple non-static link routines (i.e. referenced outside this file)
 141  */
 142 int tipc_link_is_up(struct tipc_link *l_ptr)
 143 {
 144         if (!l_ptr)
 145                 return 0;
 146         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 147 }
 148
 149 int tipc_link_is_active(struct tipc_link *l_ptr)
 150 {
 151         return  (l_ptr->owner->active_links[0] == l_ptr) ||
 152                 (l_ptr->owner->active_links[1] == l_ptr);
 153 }
 154
 155 /**
 156  * link_timeout - handle expiration of link timer
 157  * @l_ptr: pointer to link
 158  */
 159 static void link_timeout(unsigned long data)
 160 {
 161         struct tipc_link *l_ptr = (struct tipc_link *)data;
 162         struct sk_buff *skb;
 163
 164         tipc_node_lock(l_ptr->owner);
 165
 166         /* update counters used in statistical profiling of send traffic */
 167         l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->transmq);
 168         l_ptr->stats.queue_sz_counts++;
 169
 170         skb = skb_peek(&l_ptr->transmq);
 171         if (skb) {
 172                 struct tipc_msg *msg = buf_msg(skb);
 173                 u32 length = msg_size(msg);
 174
 175                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 176                     (msg_type(msg) == FIRST_FRAGMENT)) {
 177                         length = msg_size(msg_get_wrapped(msg));
 178                 }
 179                 if (length) {
 180                         l_ptr->stats.msg_lengths_total += length;
 181                         l_ptr->stats.msg_length_counts++;
 182                         if (length <= 64)
 183                                 l_ptr->stats.msg_length_profile[0]++;
 184                         else if (length <= 256)
 185                                 l_ptr->stats.msg_length_profile[1]++;
 186                         else if (length <= 1024)
 187                                 l_ptr->stats.msg_length_profile[2]++;
 188                         else if (length <= 4096)
 189                                 l_ptr->stats.msg_length_profile[3]++;
 190                         else if (length <= 16384)
 191                                 l_ptr->stats.msg_length_profile[4]++;
 192                         else if (length <= 32768)
 193                                 l_ptr->stats.msg_length_profile[5]++;
 194                         else
 195                                 l_ptr->stats.msg_length_profile[6]++;
 196                 }
 197         }
 198
 199         /* do all other link processing performed on a periodic basis */
 200         link_state_event(l_ptr, TIMEOUT_EVT);
 201
 202         if (skb_queue_len(&l_ptr->backlogq))
 203                 tipc_link_push_packets(l_ptr);
 204
 205         tipc_node_unlock(l_ptr->owner);
 206         tipc_link_put(l_ptr);
 207 }
 208
 209 static void link_set_timer(struct tipc_link *link, unsigned long time)
 210 {
 211         if (!mod_timer(&link->timer, jiffies + time))
 212                 tipc_link_get(link);
 213 }
 214
 215 /**
 216  * tipc_link_create - create a new link
 217  * @n_ptr: pointer to associated node
 218  * @b_ptr: pointer to associated bearer
 219  * @media_addr: media address to use when sending messages over link
 220  *
 221  * Returns pointer to link.
 222  */
 223 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 224                                    struct tipc_bearer *b_ptr,
 225                                    const struct tipc_media_addr *media_addr)
 226 {
 227         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 228         struct tipc_link *l_ptr;
 229         struct tipc_msg *msg;
 230         char *if_name;
 231         char addr_string[16];
 232         u32 peer = n_ptr->addr;
 233
 234         if (n_ptr->link_cnt >= MAX_BEARERS) {
 235                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 236                 pr_err("Attempt to establish %uth link to %s. Max %u allowed.\n",
 237                         n_ptr->link_cnt, addr_string, MAX_BEARERS);
 238                 return NULL;
 239         }
 240
 241         if (n_ptr->links[b_ptr->identity]) {
 242                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 243                 pr_err("Attempt to establish second link on <%s> to %s\n",
 244                        b_ptr->name, addr_string);
 245                 return NULL;
 246         }
 247
 248         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 249         if (!l_ptr) {
 250                 pr_warn("Link creation failed, no memory\n");
 251                 return NULL;
 252         }
 253         kref_init(&l_ptr->ref);
 254         l_ptr->addr = peer;
 255         if_name = strchr(b_ptr->name, ':') + 1;
 256         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 257                 tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
 258                 tipc_node(tn->own_addr),
 259                 if_name,
 260                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 261                 /* note: peer i/f name is updated by reset/activate message */
 262         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 263         l_ptr->owner = n_ptr;
 264         l_ptr->checkpoint = 1;
 265         l_ptr->peer_session = INVALID_SESSION;
 266         l_ptr->bearer_id = b_ptr->identity;
 267         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 268         l_ptr->state = RESET_UNKNOWN;
 269
 270         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 271         msg = l_ptr->pmsg;
 272         tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
 273                       l_ptr->addr);
 274         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 275         msg_set_session(msg, (tn->random & 0xffff));
 276         msg_set_bearer_id(msg, b_ptr->identity);
 277         strcpy((char *)msg_data(msg), if_name);
 278         l_ptr->net_plane = b_ptr->net_plane;
 279         l_ptr->advertised_mtu = b_ptr->mtu;
 280         l_ptr->mtu = l_ptr->advertised_mtu;
 281         l_ptr->priority = b_ptr->priority;
 282         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 283         l_ptr->next_out_no = 1;
 284         __skb_queue_head_init(&l_ptr->transmq);
 285         __skb_queue_head_init(&l_ptr->backlogq);
 286         __skb_queue_head_init(&l_ptr->deferdq);
 287         skb_queue_head_init(&l_ptr->wakeupq);
 288         skb_queue_head_init(&l_ptr->inputq);
 289         skb_queue_head_init(&l_ptr->namedq);
 290         link_reset_statistics(l_ptr);
 291         tipc_node_attach_link(n_ptr, l_ptr);
 292         setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr);
 293         link_state_event(l_ptr, STARTING_EVT);
 294
 295         return l_ptr;
 296 }
 297
 298 /**
 299  * tipc_link_delete - Delete a link
 300  * @l: link to be deleted
 301  */
 302 void tipc_link_delete(struct tipc_link *l)
 303 {
 304         tipc_link_reset(l);
 305         if (del_timer(&l->timer))
 306                 tipc_link_put(l);
 307         l->flags |= LINK_STOPPED;
 308         /* Delete link now, or when timer is finished: */
 309         tipc_link_reset_fragments(l);
 310         tipc_node_detach_link(l->owner, l);
 311         tipc_link_put(l);
 312 }
 313
 314 void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
 315                            bool shutting_down)
 316 {
 317         struct tipc_net *tn = net_generic(net, tipc_net_id);
 318         struct tipc_link *link;
 319         struct tipc_node *node;
 320
 321         rcu_read_lock();
 322         list_for_each_entry_rcu(node, &tn->node_list, list) {
 323                 tipc_node_lock(node);
 324                 link = node->links[bearer_id];
 325                 if (link)
 326                         tipc_link_delete(link);
 327                 tipc_node_unlock(node);
 328         }
 329         rcu_read_unlock();
 330 }
 331
 332 /**
 333  * link_schedule_user - schedule a message sender for wakeup after congestion
 334  * @link: congested link
 335  * @list: message that was attempted sent
 336  * Create pseudo msg to send back to user when congestion abates
 337  * Only consumes message if there is an error
 338  */
 339 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 340 {
 341         struct tipc_msg *msg = buf_msg(skb_peek(list));
 342         int imp = msg_importance(msg);
 343         u32 oport = msg_origport(msg);
 344         u32 addr = link_own_addr(link);
 345         struct sk_buff *skb;
 346
 347         /* This really cannot happen...  */
 348         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 349                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 350                 tipc_link_reset(link);
 351                 goto err;
 352         }
 353         /* Non-blocking sender: */
 354         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 355                 return -ELINKCONG;
 356
 357         /* Create and schedule wakeup pseudo message */
 358         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 359                               addr, addr, oport, 0, 0);
 360         if (!skb)
 361                 goto err;
 362         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 363         TIPC_SKB_CB(skb)->chain_imp = imp;
 364         skb_queue_tail(&link->wakeupq, skb);
 365         link->stats.link_congs++;
 366         return -ELINKCONG;
 367 err:
 368         __skb_queue_purge(list);
 369         return -ENOBUFS;
 370 }
 371
 372 /**
 373  * link_prepare_wakeup - prepare users for wakeup after congestion
 374  * @link: congested link
 375  * Move a number of waiting users, as permitted by available space in
 376  * the send queue, from link wait queue to node wait queue for wakeup
 377  */
 378 void link_prepare_wakeup(struct tipc_link *l)
 379 {
 380         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 381         int imp, lim;
 382         struct sk_buff *skb, *tmp;
 383
 384         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 385                 imp = TIPC_SKB_CB(skb)->chain_imp;
 386                 lim = l->window + l->backlog[imp].limit;
 387                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 388                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 389                         break;
 390                 skb_unlink(skb, &l->wakeupq);
 391                 skb_queue_tail(&l->inputq, skb);
 392                 l->owner->inputq = &l->inputq;
 393                 l->owner->action_flags |= TIPC_MSG_EVT;
 394         }
 395 }
 396
 397 /**
 398  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 399  * @l_ptr: pointer to link
 400  */
 401 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 402 {
 403         kfree_skb(l_ptr->reasm_buf);
 404         l_ptr->reasm_buf = NULL;
 405 }
 406
 407 static void tipc_link_purge_backlog(struct tipc_link *l)
 408 {
 409         __skb_queue_purge(&l->backlogq);
 410         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 411         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 412         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 413         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 414         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 415 }
 416
 417 /**
 418  * tipc_link_purge_queues - purge all pkt queues associated with link
 419  * @l_ptr: pointer to link
 420  */
 421 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 422 {
 423         __skb_queue_purge(&l_ptr->deferdq);
 424         __skb_queue_purge(&l_ptr->transmq);
 425         tipc_link_purge_backlog(l_ptr);
 426         tipc_link_reset_fragments(l_ptr);
 427 }
 428
 429 void tipc_link_reset(struct tipc_link *l_ptr)
 430 {
 431         u32 prev_state = l_ptr->state;
 432         int was_active_link = tipc_link_is_active(l_ptr);
 433         struct tipc_node *owner = l_ptr->owner;
 434         struct tipc_link *pl = tipc_parallel_link(l_ptr);
 435
 436         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 437
 438         /* Link is down, accept any session */
 439         l_ptr->peer_session = INVALID_SESSION;
 440
 441         /* Prepare for renewed mtu size negotiation */
 442         l_ptr->mtu = l_ptr->advertised_mtu;
 443
 444         l_ptr->state = RESET_UNKNOWN;
 445
 446         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 447                 return;
 448
 449         tipc_node_link_down(l_ptr->owner, l_ptr);
 450         tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 451
 452         if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
 453                 l_ptr->flags |= LINK_FAILINGOVER;
 454                 l_ptr->failover_checkpt = l_ptr->next_in_no;
 455                 pl->failover_pkts = FIRST_FAILOVER;
 456                 pl->failover_checkpt = l_ptr->next_in_no;
 457                 pl->failover_skb = l_ptr->reasm_buf;
 458         } else {
 459                 kfree_skb(l_ptr->reasm_buf);
 460         }
 461         /* Clean up all queues, except inputq: */
 462         __skb_queue_purge(&l_ptr->transmq);
 463         __skb_queue_purge(&l_ptr->deferdq);
 464         if (!owner->inputq)
 465                 owner->inputq = &l_ptr->inputq;
 466         skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
 467         if (!skb_queue_empty(owner->inputq))
 468                 owner->action_flags |= TIPC_MSG_EVT;
 469         tipc_link_purge_backlog(l_ptr);
 470         l_ptr->reasm_buf = NULL;
 471         l_ptr->rcv_unacked = 0;
 472         l_ptr->checkpoint = 1;
 473         l_ptr->next_out_no = 1;
 474         l_ptr->fsm_msg_cnt = 0;
 475         l_ptr->stale_count = 0;
 476         link_reset_statistics(l_ptr);
 477 }
 478
 479 void tipc_link_reset_list(struct net *net, unsigned int bearer_id)
 480 {
 481         struct tipc_net *tn = net_generic(net, tipc_net_id);
 482         struct tipc_link *l_ptr;
 483         struct tipc_node *n_ptr;
 484
 485         rcu_read_lock();
 486         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
 487                 tipc_node_lock(n_ptr);
 488                 l_ptr = n_ptr->links[bearer_id];
 489                 if (l_ptr)
 490                         tipc_link_reset(l_ptr);
 491                 tipc_node_unlock(n_ptr);
 492         }
 493         rcu_read_unlock();
 494 }
 495
 496 static void link_activate(struct tipc_link *link)
 497 {
 498         struct tipc_node *node = link->owner;
 499
 500         link->next_in_no = 1;
 501         link->stats.recv_info = 1;
 502         tipc_node_link_up(node, link);
 503         tipc_bearer_add_dest(node->net, link->bearer_id, link->addr);
 504 }
 505
 506 /**
 507  * link_state_event - link finite state machine
 508  * @l_ptr: pointer to link
 509  * @event: state machine event to process
 510  */
 511 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 512 {
 513         struct tipc_link *other;
 514         unsigned long cont_intv = l_ptr->cont_intv;
 515
 516         if (l_ptr->flags & LINK_STOPPED)
 517                 return;
 518
 519         if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 520                 return;         /* Not yet. */
 521
 522         if (l_ptr->flags & LINK_FAILINGOVER) {
 523                 if (event == TIMEOUT_EVT)
 524                         link_set_timer(l_ptr, cont_intv);
 525                 return;
 526         }
 527
 528         switch (l_ptr->state) {
 529         case WORKING_WORKING:
 530                 switch (event) {
 531                 case TRAFFIC_MSG_EVT:
 532                 case ACTIVATE_MSG:
 533                         break;
 534                 case TIMEOUT_EVT:
 535                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 536                                 l_ptr->checkpoint = l_ptr->next_in_no;
 537                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 538                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 539                                                              0, 0, 0, 0);
 540                                         l_ptr->fsm_msg_cnt++;
 541                                 }
 542                                 link_set_timer(l_ptr, cont_intv);
 543                                 break;
 544                         }
 545                         l_ptr->state = WORKING_UNKNOWN;
 546                         l_ptr->fsm_msg_cnt = 0;
 547                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 548                         l_ptr->fsm_msg_cnt++;
 549                         link_set_timer(l_ptr, cont_intv / 4);
 550                         break;
 551                 case RESET_MSG:
 552                         pr_debug("%s<%s>, requested by peer\n",
 553                                  link_rst_msg, l_ptr->name);
 554                         tipc_link_reset(l_ptr);
 555                         l_ptr->state = RESET_RESET;
 556                         l_ptr->fsm_msg_cnt = 0;
 557                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 558                                              0, 0, 0, 0);
 559                         l_ptr->fsm_msg_cnt++;
 560                         link_set_timer(l_ptr, cont_intv);
 561                         break;
 562                 default:
 563                         pr_debug("%s%u in WW state\n", link_unk_evt, event);
 564                 }
 565                 break;
 566         case WORKING_UNKNOWN:
 567                 switch (event) {
 568                 case TRAFFIC_MSG_EVT:
 569                 case ACTIVATE_MSG:
 570                         l_ptr->state = WORKING_WORKING;
 571                         l_ptr->fsm_msg_cnt = 0;
 572                         link_set_timer(l_ptr, cont_intv);
 573                         break;
 574                 case RESET_MSG:
 575                         pr_debug("%s<%s>, requested by peer while probing\n",
 576                                  link_rst_msg, l_ptr->name);
 577                         tipc_link_reset(l_ptr);
 578                         l_ptr->state = RESET_RESET;
 579                         l_ptr->fsm_msg_cnt = 0;
 580                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 581                                              0, 0, 0, 0);
 582                         l_ptr->fsm_msg_cnt++;
 583                         link_set_timer(l_ptr, cont_intv);
 584                         break;
 585                 case TIMEOUT_EVT:
 586                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 587                                 l_ptr->state = WORKING_WORKING;
 588                                 l_ptr->fsm_msg_cnt = 0;
 589                                 l_ptr->checkpoint = l_ptr->next_in_no;
 590                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 591                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 592                                                              0, 0, 0, 0);
 593                                         l_ptr->fsm_msg_cnt++;
 594                                 }
 595                                 link_set_timer(l_ptr, cont_intv);
 596                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 597                                 tipc_link_proto_xmit(l_ptr, STATE_MSG,
 598                                                      1, 0, 0, 0);
 599                                 l_ptr->fsm_msg_cnt++;
 600                                 link_set_timer(l_ptr, cont_intv / 4);
 601                         } else {        /* Link has failed */
 602                                 pr_debug("%s<%s>, peer not responding\n",
 603                                          link_rst_msg, l_ptr->name);
 604                                 tipc_link_reset(l_ptr);
 605                                 l_ptr->state = RESET_UNKNOWN;
 606                                 l_ptr->fsm_msg_cnt = 0;
 607                                 tipc_link_proto_xmit(l_ptr, RESET_MSG,
 608                                                      0, 0, 0, 0);
 609                                 l_ptr->fsm_msg_cnt++;
 610                                 link_set_timer(l_ptr, cont_intv);
 611                         }
 612                         break;
 613                 default:
 614                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 615                 }
 616                 break;
 617         case RESET_UNKNOWN:
 618                 switch (event) {
 619                 case TRAFFIC_MSG_EVT:
 620                         break;
 621                 case ACTIVATE_MSG:
 622                         other = l_ptr->owner->active_links[0];
 623                         if (other && link_working_unknown(other))
 624                                 break;
 625                         l_ptr->state = WORKING_WORKING;
 626                         l_ptr->fsm_msg_cnt = 0;
 627                         link_activate(l_ptr);
 628                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 629                         l_ptr->fsm_msg_cnt++;
 630                         if (l_ptr->owner->working_links == 1)
 631                                 tipc_link_sync_xmit(l_ptr);
 632                         link_set_timer(l_ptr, cont_intv);
 633                         break;
 634                 case RESET_MSG:
 635                         l_ptr->state = RESET_RESET;
 636                         l_ptr->fsm_msg_cnt = 0;
 637                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 638                                              1, 0, 0, 0);
 639                         l_ptr->fsm_msg_cnt++;
 640                         link_set_timer(l_ptr, cont_intv);
 641                         break;
 642                 case STARTING_EVT:
 643                         l_ptr->flags |= LINK_STARTED;
 644                         l_ptr->fsm_msg_cnt++;
 645                         link_set_timer(l_ptr, cont_intv);
 646                         break;
 647                 case TIMEOUT_EVT:
 648                         tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0);
 649                         l_ptr->fsm_msg_cnt++;
 650                         link_set_timer(l_ptr, cont_intv);
 651                         break;
 652                 default:
 653                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 654                 }
 655                 break;
 656         case RESET_RESET:
 657                 switch (event) {
 658                 case TRAFFIC_MSG_EVT:
 659                 case ACTIVATE_MSG:
 660                         other = l_ptr->owner->active_links[0];
 661                         if (other && link_working_unknown(other))
 662                                 break;
 663                         l_ptr->state = WORKING_WORKING;
 664                         l_ptr->fsm_msg_cnt = 0;
 665                         link_activate(l_ptr);
 666                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 667                         l_ptr->fsm_msg_cnt++;
 668                         if (l_ptr->owner->working_links == 1)
 669                                 tipc_link_sync_xmit(l_ptr);
 670                         link_set_timer(l_ptr, cont_intv);
 671                         break;
 672                 case RESET_MSG:
 673                         break;
 674                 case TIMEOUT_EVT:
 675                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 676                                              0, 0, 0, 0);
 677                         l_ptr->fsm_msg_cnt++;
 678                         link_set_timer(l_ptr, cont_intv);
 679                         break;
 680                 default:
 681                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 682                 }
 683                 break;
 684         default:
 685                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 686         }
 687 }
 688
 689 /**
 690  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 691  * @link: link to use
 692  * @list: chain of buffers containing message
 693  *
 694  * Consumes the buffer chain, except when returning -ELINKCONG,
 695  * since the caller then may want to make more send attempts.
 696  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 697  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 698  */
 699 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 700                      struct sk_buff_head *list)
 701 {
 702         struct tipc_msg *msg = buf_msg(skb_peek(list));
 703         unsigned int maxwin = link->window;
 704         unsigned int imp = msg_importance(msg);
 705         uint mtu = link->mtu;
 706         uint ack = mod(link->next_in_no - 1);
 707         uint seqno = link->next_out_no;
 708         uint bc_last_in = link->owner->bclink.last_in;
 709         struct tipc_media_addr *addr = &link->media_addr;
 710         struct sk_buff_head *transmq = &link->transmq;
 711         struct sk_buff_head *backlogq = &link->backlogq;
 712         struct sk_buff *skb, *tmp;
 713
 714         /* Match backlog limit against msg importance: */
 715         if (unlikely(link->backlog[imp].len >= link->backlog[imp].limit))
 716                 return link_schedule_user(link, list);
 717
 718         if (unlikely(msg_size(msg) > mtu)) {
 719                 __skb_queue_purge(list);
 720                 return -EMSGSIZE;
 721         }
 722         /* Prepare each packet for sending, and add to relevant queue: */
 723         skb_queue_walk_safe(list, skb, tmp) {
 724                 __skb_unlink(skb, list);
 725                 msg = buf_msg(skb);
 726                 msg_set_seqno(msg, seqno);
 727                 msg_set_ack(msg, ack);
 728                 msg_set_bcast_ack(msg, bc_last_in);
 729
 730                 if (likely(skb_queue_len(transmq) < maxwin)) {
 731                         __skb_queue_tail(transmq, skb);
 732                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 733                         link->rcv_unacked = 0;
 734                         seqno++;
 735                         continue;
 736                 }
 737                 if (tipc_msg_bundle(skb_peek_tail(backlogq), skb, mtu)) {
 738                         link->stats.sent_bundled++;
 739                         continue;
 740                 }
 741                 if (tipc_msg_make_bundle(&skb, mtu, link->addr)) {
 742                         link->stats.sent_bundled++;
 743                         link->stats.sent_bundles++;
 744                         imp = msg_importance(buf_msg(skb));
 745                 }
 746                 __skb_queue_tail(backlogq, skb);
 747                 link->backlog[imp].len++;
 748                 seqno++;
 749         }
 750         link->next_out_no = seqno;
 751         return 0;
 752 }
 753
 754 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
 755 {
 756         skb_queue_head_init(list);
 757         __skb_queue_tail(list, skb);
 758 }
 759
 760 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 761 {
 762         struct sk_buff_head head;
 763
 764         skb2list(skb, &head);
 765         return __tipc_link_xmit(link->owner->net, link, &head);
 766 }
 767
 768 /* tipc_link_xmit_skb(): send single buffer to destination
 769  * Buffers sent via this functon are generally TIPC_SYSTEM_IMPORTANCE
 770  * messages, which will not be rejected
 771  * The only exception is datagram messages rerouted after secondary
 772  * lookup, which are rare and safe to dispose of anyway.
 773  * TODO: Return real return value, and let callers use
 774  * tipc_wait_for_sendpkt() where applicable
 775  */
 776 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 777                        u32 selector)
 778 {
 779         struct sk_buff_head head;
 780         int rc;
 781
 782         skb2list(skb, &head);
 783         rc = tipc_link_xmit(net, &head, dnode, selector);
 784         if (rc == -ELINKCONG)
 785                 kfree_skb(skb);
 786         return 0;
 787 }
 788
 789 /**
 790  * tipc_link_xmit() is the general link level function for message sending
 791  * @net: the applicable net namespace
 792  * @list: chain of buffers containing message
 793  * @dsz: amount of user data to be sent
 794  * @dnode: address of destination node
 795  * @selector: a number used for deterministic link selection
 796  * Consumes the buffer chain, except when returning -ELINKCONG
 797  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 798  */
 799 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
 800                    u32 selector)
 801 {
 802         struct tipc_link *link = NULL;
 803         struct tipc_node *node;
 804         int rc = -EHOSTUNREACH;
 805
 806         node = tipc_node_find(net, dnode);
 807         if (node) {
 808                 tipc_node_lock(node);
 809                 link = node->active_links[selector & 1];
 810                 if (link)
 811                         rc = __tipc_link_xmit(net, link, list);
 812                 tipc_node_unlock(node);
 813                 tipc_node_put(node);
 814         }
 815         if (link)
 816                 return rc;
 817
 818         if (likely(in_own_node(net, dnode))) {
 819                 tipc_sk_rcv(net, list);
 820                 return 0;
 821         }
 822
 823         __skb_queue_purge(list);
 824         return rc;
 825 }
 826
 827 /*
 828  * tipc_link_sync_xmit - synchronize broadcast link endpoints.
 829  *
 830  * Give a newly added peer node the sequence number where it should
 831  * start receiving and acking broadcast packets.
 832  *
 833  * Called with node locked
 834  */
 835 static void tipc_link_sync_xmit(struct tipc_link *link)
 836 {
 837         struct sk_buff *skb;
 838         struct tipc_msg *msg;
 839
 840         skb = tipc_buf_acquire(INT_H_SIZE);
 841         if (!skb)
 842                 return;
 843
 844         msg = buf_msg(skb);
 845         tipc_msg_init(link_own_addr(link), msg, BCAST_PROTOCOL, STATE_MSG,
 846                       INT_H_SIZE, link->addr);
 847         msg_set_last_bcast(msg, link->owner->bclink.acked);
 848         __tipc_link_xmit_skb(link, skb);
 849 }
 850
 851 /*
 852  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 853  * Receive the sequence number where we should start receiving and
 854  * acking broadcast packets from a newly added peer node, and open
 855  * up for reception of such packets.
 856  *
 857  * Called with node locked
 858  */
 859 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 860 {
 861         struct tipc_msg *msg = buf_msg(buf);
 862
 863         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 864         n->bclink.recv_permitted = true;
 865         kfree_skb(buf);
 866 }
 867
 868 /*
 869  * tipc_link_push_packets - push unsent packets to bearer
 870  *
 871  * Push out the unsent messages of a link where congestion
 872  * has abated. Node is locked.
 873  *
 874  * Called with node locked
 875  */
 876 void tipc_link_push_packets(struct tipc_link *link)
 877 {
 878         struct sk_buff *skb;
 879         struct tipc_msg *msg;
 880         unsigned int ack = mod(link->next_in_no - 1);
 881
 882         while (skb_queue_len(&link->transmq) < link->window) {
 883                 skb = __skb_dequeue(&link->backlogq);
 884                 if (!skb)
 885                         break;
 886                 msg = buf_msg(skb);
 887                 link->backlog[msg_importance(msg)].len--;
 888                 msg_set_ack(msg, ack);
 889                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 890                 link->rcv_unacked = 0;
 891                 __skb_queue_tail(&link->transmq, skb);
 892                 tipc_bearer_send(link->owner->net, link->bearer_id,
 893                                  skb, &link->media_addr);
 894         }
 895 }
 896
 897 void tipc_link_reset_all(struct tipc_node *node)
 898 {
 899         char addr_string[16];
 900         u32 i;
 901
 902         tipc_node_lock(node);
 903
 904         pr_warn("Resetting all links to %s\n",
 905                 tipc_addr_string_fill(addr_string, node->addr));
 906
 907         for (i = 0; i < MAX_BEARERS; i++) {
 908                 if (node->links[i]) {
 909                         link_print(node->links[i], "Resetting link\n");
 910                         tipc_link_reset(node->links[i]);
 911                 }
 912         }
 913
 914         tipc_node_unlock(node);
 915 }
 916
 917 static void link_retransmit_failure(struct tipc_link *l_ptr,
 918                                     struct sk_buff *buf)
 919 {
 920         struct tipc_msg *msg = buf_msg(buf);
 921         struct net *net = l_ptr->owner->net;
 922
 923         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 924
 925         if (l_ptr->addr) {
 926                 /* Handle failure on standard link */
 927                 link_print(l_ptr, "Resetting link\n");
 928                 tipc_link_reset(l_ptr);
 929
 930         } else {
 931                 /* Handle failure on broadcast link */
 932                 struct tipc_node *n_ptr;
 933                 char addr_string[16];
 934
 935                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 936                 pr_cont("Outstanding acks: %lu\n",
 937                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 938
 939                 n_ptr = tipc_bclink_retransmit_to(net);
 940
 941                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 942                 pr_info("Broadcast link info for %s\n", addr_string);
 943                 pr_info("Reception permitted: %d,  Acked: %u\n",
 944                         n_ptr->bclink.recv_permitted,
 945                         n_ptr->bclink.acked);
 946                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 947                         n_ptr->bclink.last_in,
 948                         n_ptr->bclink.oos_state,
 949                         n_ptr->bclink.last_sent);
 950
 951                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 952                 l_ptr->stale_count = 0;
 953         }
 954 }
 955
 956 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 957                           u32 retransmits)
 958 {
 959         struct tipc_msg *msg;
 960
 961         if (!skb)
 962                 return;
 963
 964         msg = buf_msg(skb);
 965
 966         /* Detect repeated retransmit failures */
 967         if (l_ptr->last_retransmitted == msg_seqno(msg)) {
 968                 if (++l_ptr->stale_count > 100) {
 969                         link_retransmit_failure(l_ptr, skb);
 970                         return;
 971                 }
 972         } else {
 973                 l_ptr->last_retransmitted = msg_seqno(msg);
 974                 l_ptr->stale_count = 1;
 975         }
 976
 977         skb_queue_walk_from(&l_ptr->transmq, skb) {
 978                 if (!retransmits)
 979                         break;
 980                 msg = buf_msg(skb);
 981                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
 982                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 983                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 984                                  &l_ptr->media_addr);
 985                 retransmits--;
 986                 l_ptr->stats.retransmitted++;
 987         }
 988 }
 989
 990 /* link_synch(): check if all packets arrived before the synch
 991  *               point have been consumed
 992  * Returns true if the parallel links are synched, otherwise false
 993  */
 994 static bool link_synch(struct tipc_link *l)
 995 {
 996         unsigned int post_synch;
 997         struct tipc_link *pl;
 998
 999         pl  = tipc_parallel_link(l);
1000         if (pl == l)
1001                 goto synched;
1002
1003         /* Was last pre-synch packet added to input queue ? */
1004         if (less_eq(pl->next_in_no, l->synch_point))
1005                 return false;
1006
1007         /* Is it still in the input queue ? */
1008         post_synch = mod(pl->next_in_no - l->synch_point) - 1;
1009         if (skb_queue_len(&pl->inputq) > post_synch)
1010                 return false;
1011 synched:
1012         l->flags &= ~LINK_SYNCHING;
1013         return true;
1014 }
1015
1016 static void link_retrieve_defq(struct tipc_link *link,
1017                                struct sk_buff_head *list)
1018 {
1019         u32 seq_no;
1020
1021         if (skb_queue_empty(&link->deferdq))
1022                 return;
1023
1024         seq_no = buf_seqno(skb_peek(&link->deferdq));
1025         if (seq_no == mod(link->next_in_no))
1026                 skb_queue_splice_tail_init(&link->deferdq, list);
1027 }
1028
1029 /**
1030  * tipc_rcv - process TIPC packets/messages arriving from off-node
1031  * @net: the applicable net namespace
1032  * @skb: TIPC packet
1033  * @b_ptr: pointer to bearer message arrived on
1034  *
1035  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1036  * structure (i.e. cannot be NULL), but bearer can be inactive.
1037  */
1038 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
1039 {
1040         struct tipc_net *tn = net_generic(net, tipc_net_id);
1041         struct sk_buff_head head;
1042         struct tipc_node *n_ptr;
1043         struct tipc_link *l_ptr;
1044         struct sk_buff *skb1, *tmp;
1045         struct tipc_msg *msg;
1046         u32 seq_no;
1047         u32 ackd;
1048         u32 released;
1049
1050         skb2list(skb, &head);
1051
1052         while ((skb = __skb_dequeue(&head))) {
1053                 /* Ensure message is well-formed */
1054                 if (unlikely(!tipc_msg_validate(skb)))
1055                         goto discard;
1056
1057                 /* Handle arrival of a non-unicast link message */
1058                 msg = buf_msg(skb);
1059                 if (unlikely(msg_non_seq(msg))) {
1060                         if (msg_user(msg) ==  LINK_CONFIG)
1061                                 tipc_disc_rcv(net, skb, b_ptr);
1062                         else
1063                                 tipc_bclink_rcv(net, skb);
1064                         continue;
1065                 }
1066
1067                 /* Discard unicast link messages destined for another node */
1068                 if (unlikely(!msg_short(msg) &&
1069                              (msg_destnode(msg) != tn->own_addr)))
1070                         goto discard;
1071
1072                 /* Locate neighboring node that sent message */
1073                 n_ptr = tipc_node_find(net, msg_prevnode(msg));
1074                 if (unlikely(!n_ptr))
1075                         goto discard;
1076
1077                 tipc_node_lock(n_ptr);
1078                 /* Locate unicast link endpoint that should handle message */
1079                 l_ptr = n_ptr->links[b_ptr->identity];
1080                 if (unlikely(!l_ptr))
1081                         goto unlock;
1082
1083                 /* Verify that communication with node is currently allowed */
1084                 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
1085                     msg_user(msg) == LINK_PROTOCOL &&
1086                     (msg_type(msg) == RESET_MSG ||
1087                     msg_type(msg) == ACTIVATE_MSG) &&
1088                     !msg_redundant_link(msg))
1089                         n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
1090
1091                 if (tipc_node_blocked(n_ptr))
1092                         goto unlock;
1093
1094                 /* Validate message sequence number info */
1095                 seq_no = msg_seqno(msg);
1096                 ackd = msg_ack(msg);
1097
1098                 /* Release acked messages */
1099                 if (unlikely(n_ptr->bclink.acked != msg_bcast_ack(msg)))
1100                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1101
1102                 released = 0;
1103                 skb_queue_walk_safe(&l_ptr->transmq, skb1, tmp) {
1104                         if (more(buf_seqno(skb1), ackd))
1105                                 break;
1106                          __skb_unlink(skb1, &l_ptr->transmq);
1107                          kfree_skb(skb1);
1108                          released = 1;
1109                 }
1110
1111                 /* Try sending any messages link endpoint has pending */
1112                 if (unlikely(skb_queue_len(&l_ptr->backlogq)))
1113                         tipc_link_push_packets(l_ptr);
1114
1115                 if (released && !skb_queue_empty(&l_ptr->wakeupq))
1116                         link_prepare_wakeup(l_ptr);
1117
1118                 /* Process the incoming packet */
1119                 if (unlikely(!link_working_working(l_ptr))) {
1120                         if (msg_user(msg) == LINK_PROTOCOL) {
1121                                 tipc_link_proto_rcv(l_ptr, skb);
1122                                 link_retrieve_defq(l_ptr, &head);
1123                                 skb = NULL;
1124                                 goto unlock;
1125                         }
1126
1127                         /* Traffic message. Conditionally activate link */
1128                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1129
1130                         if (link_working_working(l_ptr)) {
1131                                 /* Re-insert buffer in front of queue */
1132                                 __skb_queue_head(&head, skb);
1133                                 skb = NULL;
1134                                 goto unlock;
1135                         }
1136                         goto unlock;
1137                 }
1138
1139                 /* Link is now in state WORKING_WORKING */
1140                 if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
1141                         link_handle_out_of_seq_msg(l_ptr, skb);
1142                         link_retrieve_defq(l_ptr, &head);
1143                         skb = NULL;
1144                         goto unlock;
1145                 }
1146                 /* Synchronize with parallel link if applicable */
1147                 if (unlikely((l_ptr->flags & LINK_SYNCHING) && !msg_dup(msg))) {
1148                         if (!link_synch(l_ptr))
1149                                 goto unlock;
1150                 }
1151                 l_ptr->next_in_no++;
1152                 if (unlikely(!skb_queue_empty(&l_ptr->deferdq)))
1153                         link_retrieve_defq(l_ptr, &head);
1154                 if (unlikely(++l_ptr->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
1155                         l_ptr->stats.sent_acks++;
1156                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1157                 }
1158                 tipc_link_input(l_ptr, skb);
1159                 skb = NULL;
1160 unlock:
1161                 tipc_node_unlock(n_ptr);
1162                 tipc_node_put(n_ptr);
1163 discard:
1164                 if (unlikely(skb))
1165                         kfree_skb(skb);
1166         }
1167 }
1168
1169 /* tipc_data_input - deliver data and name distr msgs to upper layer
1170  *
1171  * Consumes buffer if message is of right type
1172  * Node lock must be held
1173  */
1174 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
1175 {
1176         struct tipc_node *node = link->owner;
1177         struct tipc_msg *msg = buf_msg(skb);
1178         u32 dport = msg_destport(msg);
1179
1180         switch (msg_user(msg)) {
1181         case TIPC_LOW_IMPORTANCE:
1182         case TIPC_MEDIUM_IMPORTANCE:
1183         case TIPC_HIGH_IMPORTANCE:
1184         case TIPC_CRITICAL_IMPORTANCE:
1185         case CONN_MANAGER:
1186                 if (tipc_skb_queue_tail(&link->inputq, skb, dport)) {
1187                         node->inputq = &link->inputq;
1188                         node->action_flags |= TIPC_MSG_EVT;
1189                 }
1190                 return true;
1191         case NAME_DISTRIBUTOR:
1192                 node->bclink.recv_permitted = true;
1193                 node->namedq = &link->namedq;
1194                 skb_queue_tail(&link->namedq, skb);
1195                 if (skb_queue_len(&link->namedq) == 1)
1196                         node->action_flags |= TIPC_NAMED_MSG_EVT;
1197                 return true;
1198         case MSG_BUNDLER:
1199         case TUNNEL_PROTOCOL:
1200         case MSG_FRAGMENTER:
1201         case BCAST_PROTOCOL:
1202                 return false;
1203         default:
1204                 pr_warn("Dropping received illegal msg type\n");
1205                 kfree_skb(skb);
1206                 return false;
1207         };
1208 }
1209
1210 /* tipc_link_input - process packet that has passed link protocol check
1211  *
1212  * Consumes buffer
1213  * Node lock must be held
1214  */
1215 static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
1216 {
1217         struct tipc_node *node = link->owner;
1218         struct tipc_msg *msg = buf_msg(skb);
1219         struct sk_buff *iskb;
1220         int pos = 0;
1221
1222         if (likely(tipc_data_input(link, skb)))
1223                 return;
1224
1225         switch (msg_user(msg)) {
1226         case TUNNEL_PROTOCOL:
1227                 if (msg_dup(msg)) {
1228                         link->flags |= LINK_SYNCHING;
1229                         link->synch_point = msg_seqno(msg_get_wrapped(msg));
1230                         kfree_skb(skb);
1231                         break;
1232                 }
1233                 if (!tipc_link_failover_rcv(link, &skb))
1234                         break;
1235                 if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
1236                         tipc_data_input(link, skb);
1237                         break;
1238                 }
1239         case MSG_BUNDLER:
1240                 link->stats.recv_bundles++;
1241                 link->stats.recv_bundled += msg_msgcnt(msg);
1242
1243                 while (tipc_msg_extract(skb, &iskb, &pos))
1244                         tipc_data_input(link, iskb);
1245                 break;
1246         case MSG_FRAGMENTER:
1247                 link->stats.recv_fragments++;
1248                 if (tipc_buf_append(&link->reasm_buf, &skb)) {
1249                         link->stats.recv_fragmented++;
1250                         tipc_data_input(link, skb);
1251                 } else if (!link->reasm_buf) {
1252                         tipc_link_reset(link);
1253                 }
1254                 break;
1255         case BCAST_PROTOCOL:
1256                 tipc_link_sync_rcv(node, skb);
1257                 break;
1258         default:
1259                 break;
1260         };
1261 }
1262
1263 /**
1264  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1265  *
1266  * Returns increase in queue length (i.e. 0 or 1)
1267  */
1268 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1269 {
1270         struct sk_buff *skb1;
1271         u32 seq_no = buf_seqno(skb);
1272
1273         /* Empty queue ? */
1274         if (skb_queue_empty(list)) {
1275                 __skb_queue_tail(list, skb);
1276                 return 1;
1277         }
1278
1279         /* Last ? */
1280         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1281                 __skb_queue_tail(list, skb);
1282                 return 1;
1283         }
1284
1285         /* Locate insertion point in queue, then insert; discard if duplicate */
1286         skb_queue_walk(list, skb1) {
1287                 u32 curr_seqno = buf_seqno(skb1);
1288
1289                 if (seq_no == curr_seqno) {
1290                         kfree_skb(skb);
1291                         return 0;
1292                 }
1293
1294                 if (less(seq_no, curr_seqno))
1295                         break;
1296         }
1297
1298         __skb_queue_before(list, skb1, skb);
1299         return 1;
1300 }
1301
1302 /*
1303  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1304  */
1305 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1306                                        struct sk_buff *buf)
1307 {
1308         u32 seq_no = buf_seqno(buf);
1309
1310         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1311                 tipc_link_proto_rcv(l_ptr, buf);
1312                 return;
1313         }
1314
1315         /* Record OOS packet arrival (force mismatch on next timeout) */
1316         l_ptr->checkpoint--;
1317
1318         /*
1319          * Discard packet if a duplicate; otherwise add it to deferred queue
1320          * and notify peer of gap as per protocol specification
1321          */
1322         if (less(seq_no, mod(l_ptr->next_in_no))) {
1323                 l_ptr->stats.duplicates++;
1324                 kfree_skb(buf);
1325                 return;
1326         }
1327
1328         if (tipc_link_defer_pkt(&l_ptr->deferdq, buf)) {
1329                 l_ptr->stats.deferred_recv++;
1330                 if ((skb_queue_len(&l_ptr->deferdq) % TIPC_MIN_LINK_WIN) == 1)
1331                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1332         } else {
1333                 l_ptr->stats.duplicates++;
1334         }
1335 }
1336
1337 /*
1338  * Send protocol message to the other endpoint.
1339  */
1340 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1341                           u32 gap, u32 tolerance, u32 priority)
1342 {
1343         struct sk_buff *buf = NULL;
1344         struct tipc_msg *msg = l_ptr->pmsg;
1345         u32 msg_size = sizeof(l_ptr->proto_msg);
1346         int r_flag;
1347
1348         /* Don't send protocol message during link failover */
1349         if (l_ptr->flags & LINK_FAILINGOVER)
1350                 return;
1351
1352         /* Abort non-RESET send if communication with node is prohibited */
1353         if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG))
1354                 return;
1355
1356         /* Create protocol message with "out-of-sequence" sequence number */
1357         msg_set_type(msg, msg_typ);
1358         msg_set_net_plane(msg, l_ptr->net_plane);
1359         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1360         msg_set_last_bcast(msg, tipc_bclink_get_last_sent(l_ptr->owner->net));
1361
1362         if (msg_typ == STATE_MSG) {
1363                 u32 next_sent = mod(l_ptr->next_out_no);
1364
1365                 if (!tipc_link_is_up(l_ptr))
1366                         return;
1367                 if (skb_queue_len(&l_ptr->backlogq))
1368                         next_sent = buf_seqno(skb_peek(&l_ptr->backlogq));
1369                 msg_set_next_sent(msg, next_sent);
1370                 if (!skb_queue_empty(&l_ptr->deferdq)) {
1371                         u32 rec = buf_seqno(skb_peek(&l_ptr->deferdq));
1372                         gap = mod(rec - mod(l_ptr->next_in_no));
1373                 }
1374                 msg_set_seq_gap(msg, gap);
1375                 if (gap)
1376                         l_ptr->stats.sent_nacks++;
1377                 msg_set_link_tolerance(msg, tolerance);
1378                 msg_set_linkprio(msg, priority);
1379                 msg_set_max_pkt(msg, l_ptr->mtu);
1380                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1381                 msg_set_probe(msg, probe_msg != 0);
1382                 if (probe_msg)
1383                         l_ptr->stats.sent_probes++;
1384                 l_ptr->stats.sent_states++;
1385         } else {                /* RESET_MSG or ACTIVATE_MSG */
1386                 msg_set_ack(msg, mod(l_ptr->failover_checkpt - 1));
1387                 msg_set_seq_gap(msg, 0);
1388                 msg_set_next_sent(msg, 1);
1389                 msg_set_probe(msg, 0);
1390                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1391                 msg_set_linkprio(msg, l_ptr->priority);
1392                 msg_set_max_pkt(msg, l_ptr->advertised_mtu);
1393         }
1394
1395         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1396         msg_set_redundant_link(msg, r_flag);
1397         msg_set_linkprio(msg, l_ptr->priority);
1398         msg_set_size(msg, msg_size);
1399
1400         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1401
1402         buf = tipc_buf_acquire(msg_size);
1403         if (!buf)
1404                 return;
1405
1406         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1407         buf->priority = TC_PRIO_CONTROL;
1408         tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, buf,
1409                          &l_ptr->media_addr);
1410         l_ptr->rcv_unacked = 0;
1411         kfree_skb(buf);
1412 }
1413
1414 /*
1415  * Receive protocol message :
1416  * Note that network plane id propagates through the network, and may
1417  * change at any time. The node with lowest address rules
1418  */
1419 static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
1420                                 struct sk_buff *buf)
1421 {
1422         u32 rec_gap = 0;
1423         u32 msg_tol;
1424         struct tipc_msg *msg = buf_msg(buf);
1425
1426         if (l_ptr->flags & LINK_FAILINGOVER)
1427                 goto exit;
1428
1429         if (l_ptr->net_plane != msg_net_plane(msg))
1430                 if (link_own_addr(l_ptr) > msg_prevnode(msg))
1431                         l_ptr->net_plane = msg_net_plane(msg);
1432
1433         switch (msg_type(msg)) {
1434
1435         case RESET_MSG:
1436                 if (!link_working_unknown(l_ptr) &&
1437                     (l_ptr->peer_session != INVALID_SESSION)) {
1438                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1439                                 break; /* duplicate or old reset: ignore */
1440                 }
1441
1442                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1443                                 link_working_unknown(l_ptr))) {
1444                         /*
1445                          * peer has lost contact -- don't allow peer's links
1446                          * to reactivate before we recognize loss & clean up
1447                          */
1448                         l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
1449                 }
1450
1451                 link_state_event(l_ptr, RESET_MSG);
1452
1453                 /* fall thru' */
1454         case ACTIVATE_MSG:
1455                 /* Update link settings according other endpoint's values */
1456                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1457
1458                 msg_tol = msg_link_tolerance(msg);
1459                 if (msg_tol > l_ptr->tolerance)
1460                         link_set_supervision_props(l_ptr, msg_tol);
1461
1462                 if (msg_linkprio(msg) > l_ptr->priority)
1463                         l_ptr->priority = msg_linkprio(msg);
1464
1465                 if (l_ptr->mtu > msg_max_pkt(msg))
1466                         l_ptr->mtu = msg_max_pkt(msg);
1467
1468                 /* Synchronize broadcast link info, if not done previously */
1469                 if (!tipc_node_is_up(l_ptr->owner)) {
1470                         l_ptr->owner->bclink.last_sent =
1471                                 l_ptr->owner->bclink.last_in =
1472                                 msg_last_bcast(msg);
1473                         l_ptr->owner->bclink.oos_state = 0;
1474                 }
1475
1476                 l_ptr->peer_session = msg_session(msg);
1477                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1478
1479                 if (msg_type(msg) == ACTIVATE_MSG)
1480                         link_state_event(l_ptr, ACTIVATE_MSG);
1481                 break;
1482         case STATE_MSG:
1483
1484                 msg_tol = msg_link_tolerance(msg);
1485                 if (msg_tol)
1486                         link_set_supervision_props(l_ptr, msg_tol);
1487
1488                 if (msg_linkprio(msg) &&
1489                     (msg_linkprio(msg) != l_ptr->priority)) {
1490                         pr_debug("%s<%s>, priority change %u->%u\n",
1491                                  link_rst_msg, l_ptr->name,
1492                                  l_ptr->priority, msg_linkprio(msg));
1493                         l_ptr->priority = msg_linkprio(msg);
1494                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1495                         break;
1496                 }
1497
1498                 /* Record reception; force mismatch at next timeout: */
1499                 l_ptr->checkpoint--;
1500
1501                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1502                 l_ptr->stats.recv_states++;
1503                 if (link_reset_unknown(l_ptr))
1504                         break;
1505
1506                 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
1507                         rec_gap = mod(msg_next_sent(msg) -
1508                                       mod(l_ptr->next_in_no));
1509                 }
1510
1511                 if (msg_probe(msg))
1512                         l_ptr->stats.recv_probes++;
1513
1514                 /* Protocol message before retransmits, reduce loss risk */
1515                 if (l_ptr->owner->bclink.recv_permitted)
1516                         tipc_bclink_update_link_state(l_ptr->owner,
1517                                                       msg_last_bcast(msg));
1518
1519                 if (rec_gap || (msg_probe(msg))) {
1520                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0,
1521                                              rec_gap, 0, 0);
1522                 }
1523                 if (msg_seq_gap(msg)) {
1524                         l_ptr->stats.recv_nacks++;
1525                         tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->transmq),
1526                                              msg_seq_gap(msg));
1527                 }
1528                 break;
1529         }
1530 exit:
1531         kfree_skb(buf);
1532 }
1533
1534
1535 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1536  * a different bearer. Owner node is locked.
1537  */
1538 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1539                                   struct tipc_msg *tunnel_hdr,
1540                                   struct tipc_msg *msg,
1541                                   u32 selector)
1542 {
1543         struct tipc_link *tunnel;
1544         struct sk_buff *skb;
1545         u32 length = msg_size(msg);
1546
1547         tunnel = l_ptr->owner->active_links[selector & 1];
1548         if (!tipc_link_is_up(tunnel)) {
1549                 pr_warn("%stunnel link no longer available\n", link_co_err);
1550                 return;
1551         }
1552         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1553         skb = tipc_buf_acquire(length + INT_H_SIZE);
1554         if (!skb) {
1555                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1556                 return;
1557         }
1558         skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
1559         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
1560         __tipc_link_xmit_skb(tunnel, skb);
1561 }
1562
1563
1564 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1565  * link is still active. We can do failover. Tunnel the failing link's
1566  * whole send queue via the remaining link. This way, we don't lose
1567  * any packets, and sequence order is preserved for subsequent traffic
1568  * sent over the remaining link. Owner node is locked.
1569  */
1570 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1571 {
1572         int msgcount;
1573         struct tipc_link *tunnel = l_ptr->owner->active_links[0];
1574         struct tipc_msg tunnel_hdr;
1575         struct sk_buff *skb;
1576         int split_bundles;
1577
1578         if (!tunnel)
1579                 return;
1580
1581         tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
1582                       FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
1583         skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
1584         tipc_link_purge_backlog(l_ptr);
1585         msgcount = skb_queue_len(&l_ptr->transmq);
1586         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1587         msg_set_msgcnt(&tunnel_hdr, msgcount);
1588
1589         if (skb_queue_empty(&l_ptr->transmq)) {
1590                 skb = tipc_buf_acquire(INT_H_SIZE);
1591                 if (skb) {
1592                         skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
1593                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1594                         __tipc_link_xmit_skb(tunnel, skb);
1595                 } else {
1596                         pr_warn("%sunable to send changeover msg\n",
1597                                 link_co_err);
1598                 }
1599                 return;
1600         }
1601
1602         split_bundles = (l_ptr->owner->active_links[0] !=
1603                          l_ptr->owner->active_links[1]);
1604
1605         skb_queue_walk(&l_ptr->transmq, skb) {
1606                 struct tipc_msg *msg = buf_msg(skb);
1607
1608                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1609                         struct tipc_msg *m = msg_get_wrapped(msg);
1610                         unchar *pos = (unchar *)m;
1611
1612                         msgcount = msg_msgcnt(msg);
1613                         while (msgcount--) {
1614                                 msg_set_seqno(m, msg_seqno(msg));
1615                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1616                                                       msg_link_selector(m));
1617                                 pos += align(msg_size(m));
1618                                 m = (struct tipc_msg *)pos;
1619                         }
1620                 } else {
1621                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1622                                               msg_link_selector(msg));
1623                 }
1624         }
1625 }
1626
1627 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1628  * duplicate of the first link's send queue via the new link. This way, we
1629  * are guaranteed that currently queued packets from a socket are delivered
1630  * before future traffic from the same socket, even if this is using the
1631  * new link. The last arriving copy of each duplicate packet is dropped at
1632  * the receiving end by the regular protocol check, so packet cardinality
1633  * and sequence order is preserved per sender/receiver socket pair.
1634  * Owner node is locked.
1635  */
1636 void tipc_link_dup_queue_xmit(struct tipc_link *link,
1637                               struct tipc_link *tnl)
1638 {
1639         struct sk_buff *skb;
1640         struct tipc_msg tnl_hdr;
1641         struct sk_buff_head *queue = &link->transmq;
1642         int mcnt;
1643
1644         tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
1645                       SYNCH_MSG, INT_H_SIZE, link->addr);
1646         mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
1647         msg_set_msgcnt(&tnl_hdr, mcnt);
1648         msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
1649
1650 tunnel_queue:
1651         skb_queue_walk(queue, skb) {
1652                 struct sk_buff *outskb;
1653                 struct tipc_msg *msg = buf_msg(skb);
1654                 u32 len = msg_size(msg);
1655
1656                 msg_set_ack(msg, mod(link->next_in_no - 1));
1657                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
1658                 msg_set_size(&tnl_hdr, len + INT_H_SIZE);
1659                 outskb = tipc_buf_acquire(len + INT_H_SIZE);
1660                 if (outskb == NULL) {
1661                         pr_warn("%sunable to send duplicate msg\n",
1662                                 link_co_err);
1663                         return;
1664                 }
1665                 skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
1666                 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
1667                                                skb->data, len);
1668                 __tipc_link_xmit_skb(tnl, outskb);
1669                 if (!tipc_link_is_up(link))
1670                         return;
1671         }
1672         if (queue == &link->backlogq)
1673                 return;
1674         queue = &link->backlogq;
1675         goto tunnel_queue;
1676 }
1677
1678 /*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
1679  *  Owner node is locked.
1680  */
1681 static bool tipc_link_failover_rcv(struct tipc_link *link,
1682                                    struct sk_buff **skb)
1683 {
1684         struct tipc_msg *msg = buf_msg(*skb);
1685         struct sk_buff *iskb = NULL;
1686         struct tipc_link *pl = NULL;
1687         int bearer_id = msg_bearer_id(msg);
1688         int pos = 0;
1689
1690         if (msg_type(msg) != FAILOVER_MSG) {
1691                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1692                 goto exit;
1693         }
1694         if (bearer_id >= MAX_BEARERS)
1695                 goto exit;
1696
1697         if (bearer_id == link->bearer_id)
1698                 goto exit;
1699
1700         pl = link->owner->links[bearer_id];
1701         if (pl && tipc_link_is_up(pl))
1702                 tipc_link_reset(pl);
1703
1704         if (link->failover_pkts == FIRST_FAILOVER)
1705                 link->failover_pkts = msg_msgcnt(msg);
1706
1707         /* Should we expect an inner packet? */
1708         if (!link->failover_pkts)
1709                 goto exit;
1710
1711         if (!tipc_msg_extract(*skb, &iskb, &pos)) {
1712                 pr_warn("%sno inner failover pkt\n", link_co_err);
1713                 *skb = NULL;
1714                 goto exit;
1715         }
1716         link->failover_pkts--;
1717         *skb = NULL;
1718
1719         /* Was this packet already delivered? */
1720         if (less(buf_seqno(iskb), link->failover_checkpt)) {
1721                 kfree_skb(iskb);
1722                 iskb = NULL;
1723                 goto exit;
1724         }
1725         if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
1726                 link->stats.recv_fragments++;
1727                 tipc_buf_append(&link->failover_skb, &iskb);
1728         }
1729 exit:
1730         if (!link->failover_pkts && pl)
1731                 pl->flags &= ~LINK_FAILINGOVER;
1732         kfree_skb(*skb);
1733         *skb = iskb;
1734         return *skb;
1735 }
1736
1737 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol)
1738 {
1739         unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
1740
1741         if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1742                 return;
1743
1744         l_ptr->tolerance = tol;
1745         l_ptr->cont_intv = msecs_to_jiffies(intv);
1746         l_ptr->abort_limit = tol / (jiffies_to_msecs(l_ptr->cont_intv) / 4);
1747 }
1748
1749 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1750 {
1751         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1752
1753         l->window = win;
1754         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1755         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1756         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1757         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1758         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1759 }
1760
1761 /* tipc_link_find_owner - locate owner node of link by link's name
1762  * @net: the applicable net namespace
1763  * @name: pointer to link name string
1764  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1765  *
1766  * Returns pointer to node owning the link, or 0 if no matching link is found.
1767  */
1768 static struct tipc_node *tipc_link_find_owner(struct net *net,
1769                                               const char *link_name,
1770                                               unsigned int *bearer_id)
1771 {
1772         struct tipc_net *tn = net_generic(net, tipc_net_id);
1773         struct tipc_link *l_ptr;
1774         struct tipc_node *n_ptr;
1775         struct tipc_node *found_node = NULL;
1776         int i;
1777
1778         *bearer_id = 0;
1779         rcu_read_lock();
1780         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1781                 tipc_node_lock(n_ptr);
1782                 for (i = 0; i < MAX_BEARERS; i++) {
1783                         l_ptr = n_ptr->links[i];
1784                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1785                                 *bearer_id = i;
1786                                 found_node = n_ptr;
1787                                 break;
1788                         }
1789                 }
1790                 tipc_node_unlock(n_ptr);
1791                 if (found_node)
1792                         break;
1793         }
1794         rcu_read_unlock();
1795
1796         return found_node;
1797 }
1798
1799 /**
1800  * link_reset_statistics - reset link statistics
1801  * @l_ptr: pointer to link
1802  */
1803 static void link_reset_statistics(struct tipc_link *l_ptr)
1804 {
1805         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1806         l_ptr->stats.sent_info = l_ptr->next_out_no;
1807         l_ptr->stats.recv_info = l_ptr->next_in_no;
1808 }
1809
1810 static void link_print(struct tipc_link *l_ptr, const char *str)
1811 {
1812         struct tipc_net *tn = net_generic(l_ptr->owner->net, tipc_net_id);
1813         struct tipc_bearer *b_ptr;
1814
1815         rcu_read_lock();
1816         b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]);
1817         if (b_ptr)
1818                 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name);
1819         rcu_read_unlock();
1820
1821         if (link_working_unknown(l_ptr))
1822                 pr_cont(":WU\n");
1823         else if (link_reset_reset(l_ptr))
1824                 pr_cont(":RR\n");
1825         else if (link_reset_unknown(l_ptr))
1826                 pr_cont(":RU\n");
1827         else if (link_working_working(l_ptr))
1828                 pr_cont(":WW\n");
1829         else
1830                 pr_cont("\n");
1831 }
1832
1833 /* Parse and validate nested (link) properties valid for media, bearer and link
1834  */
1835 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1836 {
1837         int err;
1838
1839         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1840                                tipc_nl_prop_policy);
1841         if (err)
1842                 return err;
1843
1844         if (props[TIPC_NLA_PROP_PRIO]) {
1845                 u32 prio;
1846
1847                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1848                 if (prio > TIPC_MAX_LINK_PRI)
1849                         return -EINVAL;
1850         }
1851
1852         if (props[TIPC_NLA_PROP_TOL]) {
1853                 u32 tol;
1854
1855                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1856                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1857                         return -EINVAL;
1858         }
1859
1860         if (props[TIPC_NLA_PROP_WIN]) {
1861                 u32 win;
1862
1863                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1864                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1865                         return -EINVAL;
1866         }
1867
1868         return 0;
1869 }
1870
1871 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1872 {
1873         int err;
1874         int res = 0;
1875         int bearer_id;
1876         char *name;
1877         struct tipc_link *link;
1878         struct tipc_node *node;
1879         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1880         struct net *net = sock_net(skb->sk);
1881
1882         if (!info->attrs[TIPC_NLA_LINK])
1883                 return -EINVAL;
1884
1885         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1886                                info->attrs[TIPC_NLA_LINK],
1887                                tipc_nl_link_policy);
1888         if (err)
1889                 return err;
1890
1891         if (!attrs[TIPC_NLA_LINK_NAME])
1892                 return -EINVAL;
1893
1894         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1895
1896         node = tipc_link_find_owner(net, name, &bearer_id);
1897         if (!node)
1898                 return -EINVAL;
1899
1900         tipc_node_lock(node);
1901
1902         link = node->links[bearer_id];
1903         if (!link) {
1904                 res = -EINVAL;
1905                 goto out;
1906         }
1907
1908         if (attrs[TIPC_NLA_LINK_PROP]) {
1909                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1910
1911                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1912                                               props);
1913                 if (err) {
1914                         res = err;
1915                         goto out;
1916                 }
1917
1918                 if (props[TIPC_NLA_PROP_TOL]) {
1919                         u32 tol;
1920
1921                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1922                         link_set_supervision_props(link, tol);
1923                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1924                 }
1925                 if (props[TIPC_NLA_PROP_PRIO]) {
1926                         u32 prio;
1927
1928                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1929                         link->priority = prio;
1930                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1931                 }
1932                 if (props[TIPC_NLA_PROP_WIN]) {
1933                         u32 win;
1934
1935                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1936                         tipc_link_set_queue_limits(link, win);
1937                 }
1938         }
1939
1940 out:
1941         tipc_node_unlock(node);
1942
1943         return res;
1944 }
1945
1946 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1947 {
1948         int i;
1949         struct nlattr *stats;
1950
1951         struct nla_map {
1952                 u32 key;
1953                 u32 val;
1954         };
1955
1956         struct nla_map map[] = {
1957                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1958                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1959                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1960                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1961                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1962                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1963                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1964                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1965                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1966                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1967                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1968                         s->msg_length_counts : 1},
1969                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1970                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1971                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1972                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1973                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1974                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1975                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1976                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1977                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1978                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1979                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1980                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1981                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1982                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1983                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1984                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1985                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1986                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1987                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1988                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1989                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1990                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1991                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1992         };
1993
1994         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1995         if (!stats)
1996                 return -EMSGSIZE;
1997
1998         for (i = 0; i <  ARRAY_SIZE(map); i++)
1999                 if (nla_put_u32(skb, map[i].key, map[i].val))
2000                         goto msg_full;
2001
2002         nla_nest_end(skb, stats);
2003
2004         return 0;
2005 msg_full:
2006         nla_nest_cancel(skb, stats);
2007
2008         return -EMSGSIZE;
2009 }
2010
2011 /* Caller should hold appropriate locks to protect the link */
2012 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
2013                               struct tipc_link *link, int nlflags)
2014 {
2015         int err;
2016         void *hdr;
2017         struct nlattr *attrs;
2018         struct nlattr *prop;
2019         struct tipc_net *tn = net_generic(net, tipc_net_id);
2020
2021         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2022                           nlflags, TIPC_NL_LINK_GET);
2023         if (!hdr)
2024                 return -EMSGSIZE;
2025
2026         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
2027         if (!attrs)
2028                 goto msg_full;
2029
2030         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2031                 goto attr_msg_full;
2032         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
2033                         tipc_cluster_mask(tn->own_addr)))
2034                 goto attr_msg_full;
2035         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2036                 goto attr_msg_full;
2037         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->next_in_no))
2038                 goto attr_msg_full;
2039         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->next_out_no))
2040                 goto attr_msg_full;
2041
2042         if (tipc_link_is_up(link))
2043                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2044                         goto attr_msg_full;
2045         if (tipc_link_is_active(link))
2046                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2047                         goto attr_msg_full;
2048
2049         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2050         if (!prop)
2051                 goto attr_msg_full;
2052         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2053                 goto prop_msg_full;
2054         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2055                 goto prop_msg_full;
2056         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2057                         link->window))
2058                 goto prop_msg_full;
2059         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2060                 goto prop_msg_full;
2061         nla_nest_end(msg->skb, prop);
2062
2063         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2064         if (err)
2065                 goto attr_msg_full;
2066
2067         nla_nest_end(msg->skb, attrs);
2068         genlmsg_end(msg->skb, hdr);
2069
2070         return 0;
2071
2072 prop_msg_full:
2073         nla_nest_cancel(msg->skb, prop);
2074 attr_msg_full:
2075         nla_nest_cancel(msg->skb, attrs);
2076 msg_full:
2077         genlmsg_cancel(msg->skb, hdr);
2078
2079         return -EMSGSIZE;
2080 }
2081
2082 /* Caller should hold node lock  */
2083 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2084                                     struct tipc_node *node, u32 *prev_link)
2085 {
2086         u32 i;
2087         int err;
2088
2089         for (i = *prev_link; i < MAX_BEARERS; i++) {
2090                 *prev_link = i;
2091
2092                 if (!node->links[i])
2093                         continue;
2094
2095                 err = __tipc_nl_add_link(net, msg, node->links[i], NLM_F_MULTI);
2096                 if (err)
2097                         return err;
2098         }
2099         *prev_link = 0;
2100
2101         return 0;
2102 }
2103
2104 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2105 {
2106         struct net *net = sock_net(skb->sk);
2107         struct tipc_net *tn = net_generic(net, tipc_net_id);
2108         struct tipc_node *node;
2109         struct tipc_nl_msg msg;
2110         u32 prev_node = cb->args[0];
2111         u32 prev_link = cb->args[1];
2112         int done = cb->args[2];
2113         int err;
2114
2115         if (done)
2116                 return 0;
2117
2118         msg.skb = skb;
2119         msg.portid = NETLINK_CB(cb->skb).portid;
2120         msg.seq = cb->nlh->nlmsg_seq;
2121
2122         rcu_read_lock();
2123         if (prev_node) {
2124                 node = tipc_node_find(net, prev_node);
2125                 if (!node) {
2126                         /* We never set seq or call nl_dump_check_consistent()
2127                          * this means that setting prev_seq here will cause the
2128                          * consistence check to fail in the netlink callback
2129                          * handler. Resulting in the last NLMSG_DONE message
2130                          * having the NLM_F_DUMP_INTR flag set.
2131                          */
2132                         cb->prev_seq = 1;
2133                         goto out;
2134                 }
2135                 tipc_node_put(node);
2136
2137                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2138                                                  list) {
2139                         tipc_node_lock(node);
2140                         err = __tipc_nl_add_node_links(net, &msg, node,
2141                                                        &prev_link);
2142                         tipc_node_unlock(node);
2143                         if (err)
2144                                 goto out;
2145
2146                         prev_node = node->addr;
2147                 }
2148         } else {
2149                 err = tipc_nl_add_bc_link(net, &msg);
2150                 if (err)
2151                         goto out;
2152
2153                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2154                         tipc_node_lock(node);
2155                         err = __tipc_nl_add_node_links(net, &msg, node,
2156                                                        &prev_link);
2157                         tipc_node_unlock(node);
2158                         if (err)
2159                                 goto out;
2160
2161                         prev_node = node->addr;
2162                 }
2163         }
2164         done = 1;
2165 out:
2166         rcu_read_unlock();
2167
2168         cb->args[0] = prev_node;
2169         cb->args[1] = prev_link;
2170         cb->args[2] = done;
2171
2172         return skb->len;
2173 }
2174
2175 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2176 {
2177         struct net *net = genl_info_net(info);
2178         struct sk_buff *ans_skb;
2179         struct tipc_nl_msg msg;
2180         struct tipc_link *link;
2181         struct tipc_node *node;
2182         char *name;
2183         int bearer_id;
2184         int err;
2185
2186         if (!info->attrs[TIPC_NLA_LINK_NAME])
2187                 return -EINVAL;
2188
2189         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2190         node = tipc_link_find_owner(net, name, &bearer_id);
2191         if (!node)
2192                 return -EINVAL;
2193
2194         ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2195         if (!ans_skb)
2196                 return -ENOMEM;
2197
2198         msg.skb = ans_skb;
2199         msg.portid = info->snd_portid;
2200         msg.seq = info->snd_seq;
2201
2202         tipc_node_lock(node);
2203         link = node->links[bearer_id];
2204         if (!link) {
2205                 err = -EINVAL;
2206                 goto err_out;
2207         }
2208
2209         err = __tipc_nl_add_link(net, &msg, link, 0);
2210         if (err)
2211                 goto err_out;
2212
2213         tipc_node_unlock(node);
2214
2215         return genlmsg_reply(ans_skb, info);
2216
2217 err_out:
2218         tipc_node_unlock(node);
2219         nlmsg_free(ans_skb);
2220
2221         return err;
2222 }
2223
2224 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2225 {
2226         int err;
2227         char *link_name;
2228         unsigned int bearer_id;
2229         struct tipc_link *link;
2230         struct tipc_node *node;
2231         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2232         struct net *net = sock_net(skb->sk);
2233
2234         if (!info->attrs[TIPC_NLA_LINK])
2235                 return -EINVAL;
2236
2237         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2238                                info->attrs[TIPC_NLA_LINK],
2239                                tipc_nl_link_policy);
2240         if (err)
2241                 return err;
2242
2243         if (!attrs[TIPC_NLA_LINK_NAME])
2244                 return -EINVAL;
2245
2246         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2247
2248         if (strcmp(link_name, tipc_bclink_name) == 0) {
2249                 err = tipc_bclink_reset_stats(net);
2250                 if (err)
2251                         return err;
2252                 return 0;
2253         }
2254
2255         node = tipc_link_find_owner(net, link_name, &bearer_id);
2256         if (!node)
2257                 return -EINVAL;
2258
2259         tipc_node_lock(node);
2260
2261         link = node->links[bearer_id];
2262         if (!link) {
2263                 tipc_node_unlock(node);
2264                 return -EINVAL;
2265         }
2266
2267         link_reset_statistics(link);
2268
2269         tipc_node_unlock(node);
2270
2271         return 0;
2272 }