net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, 2012-2014, 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 "link.h"
  39 #include "bcast.h"
  40 #include "socket.h"
  41 #include "name_distr.h"
  42 #include "discover.h"
  43 #include "config.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  * The following two 'message types' is really just implementation
  93  * data conveniently stored in the message header.
  94  * They must not be considered part of the protocol
  95  */
  96 #define OPEN_MSG   0
  97 #define CLOSED_MSG 1
  98
  99 /*
 100  * State value stored in 'exp_msg_count'
 101  */
 102 #define START_CHANGEOVER 100000u
 103
 104 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
 105                                        struct sk_buff *buf);
 106 static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf);
 107 static int  tipc_link_tunnel_rcv(struct tipc_node *n_ptr,
 108                                  struct sk_buff **buf);
 109 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance);
 110 static void link_state_event(struct tipc_link *l_ptr, u32 event);
 111 static void link_reset_statistics(struct tipc_link *l_ptr);
 112 static void link_print(struct tipc_link *l_ptr, const char *str);
 113 static void tipc_link_sync_xmit(struct tipc_link *l);
 114 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 115 static int tipc_link_input(struct tipc_link *l, struct sk_buff *buf);
 116 static int tipc_link_prepare_input(struct tipc_link *l, struct sk_buff **buf);
 117
 118 /*
 119  *  Simple link routines
 120  */
 121 static unsigned int align(unsigned int i)
 122 {
 123         return (i + 3) & ~3u;
 124 }
 125
 126 static void link_init_max_pkt(struct tipc_link *l_ptr)
 127 {
 128         struct tipc_bearer *b_ptr;
 129         u32 max_pkt;
 130
 131         rcu_read_lock();
 132         b_ptr = rcu_dereference_rtnl(bearer_list[l_ptr->bearer_id]);
 133         if (!b_ptr) {
 134                 rcu_read_unlock();
 135                 return;
 136         }
 137         max_pkt = (b_ptr->mtu & ~3);
 138         rcu_read_unlock();
 139
 140         if (max_pkt > MAX_MSG_SIZE)
 141                 max_pkt = MAX_MSG_SIZE;
 142
 143         l_ptr->max_pkt_target = max_pkt;
 144         if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
 145                 l_ptr->max_pkt = l_ptr->max_pkt_target;
 146         else
 147                 l_ptr->max_pkt = MAX_PKT_DEFAULT;
 148
 149         l_ptr->max_pkt_probes = 0;
 150 }
 151
 152 static u32 link_next_sent(struct tipc_link *l_ptr)
 153 {
 154         if (l_ptr->next_out)
 155                 return buf_seqno(l_ptr->next_out);
 156         return mod(l_ptr->next_out_no);
 157 }
 158
 159 static u32 link_last_sent(struct tipc_link *l_ptr)
 160 {
 161         return mod(link_next_sent(l_ptr) - 1);
 162 }
 163
 164 /*
 165  *  Simple non-static link routines (i.e. referenced outside this file)
 166  */
 167 int tipc_link_is_up(struct tipc_link *l_ptr)
 168 {
 169         if (!l_ptr)
 170                 return 0;
 171         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 172 }
 173
 174 int tipc_link_is_active(struct tipc_link *l_ptr)
 175 {
 176         return  (l_ptr->owner->active_links[0] == l_ptr) ||
 177                 (l_ptr->owner->active_links[1] == l_ptr);
 178 }
 179
 180 /**
 181  * link_timeout - handle expiration of link timer
 182  * @l_ptr: pointer to link
 183  */
 184 static void link_timeout(struct tipc_link *l_ptr)
 185 {
 186         tipc_node_lock(l_ptr->owner);
 187
 188         /* update counters used in statistical profiling of send traffic */
 189         l_ptr->stats.accu_queue_sz += l_ptr->out_queue_size;
 190         l_ptr->stats.queue_sz_counts++;
 191
 192         if (l_ptr->first_out) {
 193                 struct tipc_msg *msg = buf_msg(l_ptr->first_out);
 194                 u32 length = msg_size(msg);
 195
 196                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 197                     (msg_type(msg) == FIRST_FRAGMENT)) {
 198                         length = msg_size(msg_get_wrapped(msg));
 199                 }
 200                 if (length) {
 201                         l_ptr->stats.msg_lengths_total += length;
 202                         l_ptr->stats.msg_length_counts++;
 203                         if (length <= 64)
 204                                 l_ptr->stats.msg_length_profile[0]++;
 205                         else if (length <= 256)
 206                                 l_ptr->stats.msg_length_profile[1]++;
 207                         else if (length <= 1024)
 208                                 l_ptr->stats.msg_length_profile[2]++;
 209                         else if (length <= 4096)
 210                                 l_ptr->stats.msg_length_profile[3]++;
 211                         else if (length <= 16384)
 212                                 l_ptr->stats.msg_length_profile[4]++;
 213                         else if (length <= 32768)
 214                                 l_ptr->stats.msg_length_profile[5]++;
 215                         else
 216                                 l_ptr->stats.msg_length_profile[6]++;
 217                 }
 218         }
 219
 220         /* do all other link processing performed on a periodic basis */
 221
 222         link_state_event(l_ptr, TIMEOUT_EVT);
 223
 224         if (l_ptr->next_out)
 225                 tipc_link_push_queue(l_ptr);
 226
 227         tipc_node_unlock(l_ptr->owner);
 228 }
 229
 230 static void link_set_timer(struct tipc_link *l_ptr, u32 time)
 231 {
 232         k_start_timer(&l_ptr->timer, time);
 233 }
 234
 235 /**
 236  * tipc_link_create - create a new link
 237  * @n_ptr: pointer to associated node
 238  * @b_ptr: pointer to associated bearer
 239  * @media_addr: media address to use when sending messages over link
 240  *
 241  * Returns pointer to link.
 242  */
 243 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 244                                    struct tipc_bearer *b_ptr,
 245                                    const struct tipc_media_addr *media_addr)
 246 {
 247         struct tipc_link *l_ptr;
 248         struct tipc_msg *msg;
 249         char *if_name;
 250         char addr_string[16];
 251         u32 peer = n_ptr->addr;
 252
 253         if (n_ptr->link_cnt >= MAX_BEARERS) {
 254                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 255                 pr_err("Attempt to establish %uth link to %s. Max %u allowed.\n",
 256                         n_ptr->link_cnt, addr_string, MAX_BEARERS);
 257                 return NULL;
 258         }
 259
 260         if (n_ptr->links[b_ptr->identity]) {
 261                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 262                 pr_err("Attempt to establish second link on <%s> to %s\n",
 263                        b_ptr->name, addr_string);
 264                 return NULL;
 265         }
 266
 267         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 268         if (!l_ptr) {
 269                 pr_warn("Link creation failed, no memory\n");
 270                 return NULL;
 271         }
 272
 273         l_ptr->addr = peer;
 274         if_name = strchr(b_ptr->name, ':') + 1;
 275         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 276                 tipc_zone(tipc_own_addr), tipc_cluster(tipc_own_addr),
 277                 tipc_node(tipc_own_addr),
 278                 if_name,
 279                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 280                 /* note: peer i/f name is updated by reset/activate message */
 281         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 282         l_ptr->owner = n_ptr;
 283         l_ptr->checkpoint = 1;
 284         l_ptr->peer_session = INVALID_SESSION;
 285         l_ptr->bearer_id = b_ptr->identity;
 286         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 287         l_ptr->state = RESET_UNKNOWN;
 288
 289         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 290         msg = l_ptr->pmsg;
 291         tipc_msg_init(msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE, l_ptr->addr);
 292         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 293         msg_set_session(msg, (tipc_random & 0xffff));
 294         msg_set_bearer_id(msg, b_ptr->identity);
 295         strcpy((char *)msg_data(msg), if_name);
 296
 297         l_ptr->priority = b_ptr->priority;
 298         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 299
 300         l_ptr->net_plane = b_ptr->net_plane;
 301         link_init_max_pkt(l_ptr);
 302
 303         l_ptr->next_out_no = 1;
 304         __skb_queue_head_init(&l_ptr->waiting_sks);
 305
 306         link_reset_statistics(l_ptr);
 307
 308         tipc_node_attach_link(n_ptr, l_ptr);
 309
 310         k_init_timer(&l_ptr->timer, (Handler)link_timeout,
 311                      (unsigned long)l_ptr);
 312
 313         link_state_event(l_ptr, STARTING_EVT);
 314
 315         return l_ptr;
 316 }
 317
 318 void tipc_link_delete_list(unsigned int bearer_id, bool shutting_down)
 319 {
 320         struct tipc_link *l_ptr;
 321         struct tipc_node *n_ptr;
 322
 323         rcu_read_lock();
 324         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 325                 tipc_node_lock(n_ptr);
 326                 l_ptr = n_ptr->links[bearer_id];
 327                 if (l_ptr) {
 328                         tipc_link_reset(l_ptr);
 329                         if (shutting_down || !tipc_node_is_up(n_ptr)) {
 330                                 tipc_node_detach_link(l_ptr->owner, l_ptr);
 331                                 tipc_link_reset_fragments(l_ptr);
 332                                 tipc_node_unlock(n_ptr);
 333
 334                                 /* Nobody else can access this link now: */
 335                                 del_timer_sync(&l_ptr->timer);
 336                                 kfree(l_ptr);
 337                         } else {
 338                                 /* Detach/delete when failover is finished: */
 339                                 l_ptr->flags |= LINK_STOPPED;
 340                                 tipc_node_unlock(n_ptr);
 341                                 del_timer_sync(&l_ptr->timer);
 342                         }
 343                         continue;
 344                 }
 345                 tipc_node_unlock(n_ptr);
 346         }
 347         rcu_read_unlock();
 348 }
 349
 350 /**
 351  * link_schedule_user - schedule user for wakeup after congestion
 352  * @link: congested link
 353  * @oport: sending port
 354  * @chain_sz: size of buffer chain that was attempted sent
 355  * @imp: importance of message attempted sent
 356  * Create pseudo msg to send back to user when congestion abates
 357  */
 358 static bool link_schedule_user(struct tipc_link *link, u32 oport,
 359                                uint chain_sz, uint imp)
 360 {
 361         struct sk_buff *buf;
 362
 363         buf = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0, tipc_own_addr,
 364                               tipc_own_addr, oport, 0, 0);
 365         if (!buf)
 366                 return false;
 367         TIPC_SKB_CB(buf)->chain_sz = chain_sz;
 368         TIPC_SKB_CB(buf)->chain_imp = imp;
 369         __skb_queue_tail(&link->waiting_sks, buf);
 370         link->stats.link_congs++;
 371         return true;
 372 }
 373
 374 /**
 375  * link_prepare_wakeup - prepare users for wakeup after congestion
 376  * @link: congested link
 377  * Move a number of waiting users, as permitted by available space in
 378  * the send queue, from link wait queue to node wait queue for wakeup
 379  */
 380 static void link_prepare_wakeup(struct tipc_link *link)
 381 {
 382         struct sk_buff_head *wq = &link->waiting_sks;
 383         struct sk_buff *buf;
 384         uint pend_qsz = link->out_queue_size;
 385
 386         for (buf = skb_peek(wq); buf; buf = skb_peek(wq)) {
 387                 if (pend_qsz >= link->queue_limit[TIPC_SKB_CB(buf)->chain_imp])
 388                         break;
 389                 pend_qsz += TIPC_SKB_CB(buf)->chain_sz;
 390                 __skb_queue_tail(&link->owner->waiting_sks, __skb_dequeue(wq));
 391         }
 392 }
 393
 394 /**
 395  * link_release_outqueue - purge link's outbound message queue
 396  * @l_ptr: pointer to link
 397  */
 398 static void link_release_outqueue(struct tipc_link *l_ptr)
 399 {
 400         kfree_skb_list(l_ptr->first_out);
 401         l_ptr->first_out = NULL;
 402         l_ptr->out_queue_size = 0;
 403 }
 404
 405 /**
 406  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 407  * @l_ptr: pointer to link
 408  */
 409 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 410 {
 411         kfree_skb(l_ptr->reasm_buf);
 412         l_ptr->reasm_buf = NULL;
 413 }
 414
 415 /**
 416  * tipc_link_purge_queues - purge all pkt queues associated with link
 417  * @l_ptr: pointer to link
 418  */
 419 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 420 {
 421         kfree_skb_list(l_ptr->oldest_deferred_in);
 422         kfree_skb_list(l_ptr->first_out);
 423         tipc_link_reset_fragments(l_ptr);
 424         kfree_skb(l_ptr->proto_msg_queue);
 425         l_ptr->proto_msg_queue = NULL;
 426 }
 427
 428 void tipc_link_reset(struct tipc_link *l_ptr)
 429 {
 430         u32 prev_state = l_ptr->state;
 431         u32 checkpoint = l_ptr->next_in_no;
 432         int was_active_link = tipc_link_is_active(l_ptr);
 433         struct tipc_node *owner = l_ptr->owner;
 434
 435         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 436
 437         /* Link is down, accept any session */
 438         l_ptr->peer_session = INVALID_SESSION;
 439
 440         /* Prepare for max packet size negotiation */
 441         link_init_max_pkt(l_ptr);
 442
 443         l_ptr->state = RESET_UNKNOWN;
 444
 445         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 446                 return;
 447
 448         tipc_node_link_down(l_ptr->owner, l_ptr);
 449         tipc_bearer_remove_dest(l_ptr->bearer_id, l_ptr->addr);
 450
 451         if (was_active_link && tipc_node_active_links(l_ptr->owner)) {
 452                 l_ptr->reset_checkpoint = checkpoint;
 453                 l_ptr->exp_msg_count = START_CHANGEOVER;
 454         }
 455
 456         /* Clean up all queues: */
 457         link_release_outqueue(l_ptr);
 458         kfree_skb(l_ptr->proto_msg_queue);
 459         l_ptr->proto_msg_queue = NULL;
 460         kfree_skb_list(l_ptr->oldest_deferred_in);
 461         if (!skb_queue_empty(&l_ptr->waiting_sks)) {
 462                 skb_queue_splice_init(&l_ptr->waiting_sks, &owner->waiting_sks);
 463                 owner->action_flags |= TIPC_WAKEUP_USERS;
 464         }
 465         l_ptr->retransm_queue_head = 0;
 466         l_ptr->retransm_queue_size = 0;
 467         l_ptr->last_out = NULL;
 468         l_ptr->first_out = NULL;
 469         l_ptr->next_out = NULL;
 470         l_ptr->unacked_window = 0;
 471         l_ptr->checkpoint = 1;
 472         l_ptr->next_out_no = 1;
 473         l_ptr->deferred_inqueue_sz = 0;
 474         l_ptr->oldest_deferred_in = NULL;
 475         l_ptr->newest_deferred_in = NULL;
 476         l_ptr->fsm_msg_cnt = 0;
 477         l_ptr->stale_count = 0;
 478         link_reset_statistics(l_ptr);
 479 }
 480
 481 void tipc_link_reset_list(unsigned int bearer_id)
 482 {
 483         struct tipc_link *l_ptr;
 484         struct tipc_node *n_ptr;
 485
 486         rcu_read_lock();
 487         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
 488                 tipc_node_lock(n_ptr);
 489                 l_ptr = n_ptr->links[bearer_id];
 490                 if (l_ptr)
 491                         tipc_link_reset(l_ptr);
 492                 tipc_node_unlock(n_ptr);
 493         }
 494         rcu_read_unlock();
 495 }
 496
 497 static void link_activate(struct tipc_link *l_ptr)
 498 {
 499         l_ptr->next_in_no = l_ptr->stats.recv_info = 1;
 500         tipc_node_link_up(l_ptr->owner, l_ptr);
 501         tipc_bearer_add_dest(l_ptr->bearer_id, l_ptr->addr);
 502 }
 503
 504 /**
 505  * link_state_event - link finite state machine
 506  * @l_ptr: pointer to link
 507  * @event: state machine event to process
 508  */
 509 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 510 {
 511         struct tipc_link *other;
 512         u32 cont_intv = l_ptr->continuity_interval;
 513
 514         if (l_ptr->flags & LINK_STOPPED)
 515                 return;
 516
 517         if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 518                 return;         /* Not yet. */
 519
 520         /* Check whether changeover is going on */
 521         if (l_ptr->exp_msg_count) {
 522                 if (event == TIMEOUT_EVT)
 523                         link_set_timer(l_ptr, cont_intv);
 524                 return;
 525         }
 526
 527         switch (l_ptr->state) {
 528         case WORKING_WORKING:
 529                 switch (event) {
 530                 case TRAFFIC_MSG_EVT:
 531                 case ACTIVATE_MSG:
 532                         break;
 533                 case TIMEOUT_EVT:
 534                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 535                                 l_ptr->checkpoint = l_ptr->next_in_no;
 536                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 537                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 538                                                              0, 0, 0, 0, 0);
 539                                         l_ptr->fsm_msg_cnt++;
 540                                 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
 541                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 542                                                              1, 0, 0, 0, 0);
 543                                         l_ptr->fsm_msg_cnt++;
 544                                 }
 545                                 link_set_timer(l_ptr, cont_intv);
 546                                 break;
 547                         }
 548                         l_ptr->state = WORKING_UNKNOWN;
 549                         l_ptr->fsm_msg_cnt = 0;
 550                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 551                         l_ptr->fsm_msg_cnt++;
 552                         link_set_timer(l_ptr, cont_intv / 4);
 553                         break;
 554                 case RESET_MSG:
 555                         pr_info("%s<%s>, requested by peer\n", link_rst_msg,
 556                                 l_ptr->name);
 557                         tipc_link_reset(l_ptr);
 558                         l_ptr->state = RESET_RESET;
 559                         l_ptr->fsm_msg_cnt = 0;
 560                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 561                                              0, 0, 0, 0, 0);
 562                         l_ptr->fsm_msg_cnt++;
 563                         link_set_timer(l_ptr, cont_intv);
 564                         break;
 565                 default:
 566                         pr_err("%s%u in WW state\n", link_unk_evt, event);
 567                 }
 568                 break;
 569         case WORKING_UNKNOWN:
 570                 switch (event) {
 571                 case TRAFFIC_MSG_EVT:
 572                 case ACTIVATE_MSG:
 573                         l_ptr->state = WORKING_WORKING;
 574                         l_ptr->fsm_msg_cnt = 0;
 575                         link_set_timer(l_ptr, cont_intv);
 576                         break;
 577                 case RESET_MSG:
 578                         pr_info("%s<%s>, requested by peer while probing\n",
 579                                 link_rst_msg, l_ptr->name);
 580                         tipc_link_reset(l_ptr);
 581                         l_ptr->state = RESET_RESET;
 582                         l_ptr->fsm_msg_cnt = 0;
 583                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 584                                              0, 0, 0, 0, 0);
 585                         l_ptr->fsm_msg_cnt++;
 586                         link_set_timer(l_ptr, cont_intv);
 587                         break;
 588                 case TIMEOUT_EVT:
 589                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 590                                 l_ptr->state = WORKING_WORKING;
 591                                 l_ptr->fsm_msg_cnt = 0;
 592                                 l_ptr->checkpoint = l_ptr->next_in_no;
 593                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 594                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 595                                                              0, 0, 0, 0, 0);
 596                                         l_ptr->fsm_msg_cnt++;
 597                                 }
 598                                 link_set_timer(l_ptr, cont_intv);
 599                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 600                                 tipc_link_proto_xmit(l_ptr, STATE_MSG,
 601                                                      1, 0, 0, 0, 0);
 602                                 l_ptr->fsm_msg_cnt++;
 603                                 link_set_timer(l_ptr, cont_intv / 4);
 604                         } else {        /* Link has failed */
 605                                 pr_warn("%s<%s>, peer not responding\n",
 606                                         link_rst_msg, l_ptr->name);
 607                                 tipc_link_reset(l_ptr);
 608                                 l_ptr->state = RESET_UNKNOWN;
 609                                 l_ptr->fsm_msg_cnt = 0;
 610                                 tipc_link_proto_xmit(l_ptr, RESET_MSG,
 611                                                      0, 0, 0, 0, 0);
 612                                 l_ptr->fsm_msg_cnt++;
 613                                 link_set_timer(l_ptr, cont_intv);
 614                         }
 615                         break;
 616                 default:
 617                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 618                 }
 619                 break;
 620         case RESET_UNKNOWN:
 621                 switch (event) {
 622                 case TRAFFIC_MSG_EVT:
 623                         break;
 624                 case ACTIVATE_MSG:
 625                         other = l_ptr->owner->active_links[0];
 626                         if (other && link_working_unknown(other))
 627                                 break;
 628                         l_ptr->state = WORKING_WORKING;
 629                         l_ptr->fsm_msg_cnt = 0;
 630                         link_activate(l_ptr);
 631                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 632                         l_ptr->fsm_msg_cnt++;
 633                         if (l_ptr->owner->working_links == 1)
 634                                 tipc_link_sync_xmit(l_ptr);
 635                         link_set_timer(l_ptr, cont_intv);
 636                         break;
 637                 case RESET_MSG:
 638                         l_ptr->state = RESET_RESET;
 639                         l_ptr->fsm_msg_cnt = 0;
 640                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 641                                              1, 0, 0, 0, 0);
 642                         l_ptr->fsm_msg_cnt++;
 643                         link_set_timer(l_ptr, cont_intv);
 644                         break;
 645                 case STARTING_EVT:
 646                         l_ptr->flags |= LINK_STARTED;
 647                         /* fall through */
 648                 case TIMEOUT_EVT:
 649                         tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
 650                         l_ptr->fsm_msg_cnt++;
 651                         link_set_timer(l_ptr, cont_intv);
 652                         break;
 653                 default:
 654                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 655                 }
 656                 break;
 657         case RESET_RESET:
 658                 switch (event) {
 659                 case TRAFFIC_MSG_EVT:
 660                 case ACTIVATE_MSG:
 661                         other = l_ptr->owner->active_links[0];
 662                         if (other && link_working_unknown(other))
 663                                 break;
 664                         l_ptr->state = WORKING_WORKING;
 665                         l_ptr->fsm_msg_cnt = 0;
 666                         link_activate(l_ptr);
 667                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 668                         l_ptr->fsm_msg_cnt++;
 669                         if (l_ptr->owner->working_links == 1)
 670                                 tipc_link_sync_xmit(l_ptr);
 671                         link_set_timer(l_ptr, cont_intv);
 672                         break;
 673                 case RESET_MSG:
 674                         break;
 675                 case TIMEOUT_EVT:
 676                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 677                                              0, 0, 0, 0, 0);
 678                         l_ptr->fsm_msg_cnt++;
 679                         link_set_timer(l_ptr, cont_intv);
 680                         break;
 681                 default:
 682                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 683                 }
 684                 break;
 685         default:
 686                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 687         }
 688 }
 689
 690 /* tipc_link_cong: determine return value and how to treat the
 691  * sent buffer during link congestion.
 692  * - For plain, errorless user data messages we keep the buffer and
 693  *   return -ELINKONG.
 694  * - For all other messages we discard the buffer and return -EHOSTUNREACH
 695  * - For TIPC internal messages we also reset the link
 696  */
 697 static int tipc_link_cong(struct tipc_link *link, struct sk_buff *buf)
 698 {
 699         struct tipc_msg *msg = buf_msg(buf);
 700         uint imp = tipc_msg_tot_importance(msg);
 701         u32 oport = msg_tot_origport(msg);
 702
 703         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 704                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 705                 tipc_link_reset(link);
 706                 goto drop;
 707         }
 708         if (unlikely(msg_errcode(msg)))
 709                 goto drop;
 710         if (unlikely(msg_reroute_cnt(msg)))
 711                 goto drop;
 712         if (TIPC_SKB_CB(buf)->wakeup_pending)
 713                 return -ELINKCONG;
 714         if (link_schedule_user(link, oport, TIPC_SKB_CB(buf)->chain_sz, imp))
 715                 return -ELINKCONG;
 716 drop:
 717         kfree_skb_list(buf);
 718         return -EHOSTUNREACH;
 719 }
 720
 721 /**
 722  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 723  * @link: link to use
 724  * @buf: chain of buffers containing message
 725  * Consumes the buffer chain, except when returning -ELINKCONG
 726  * Returns 0 if success, otherwise errno: -ELINKCONG, -EMSGSIZE (plain socket
 727  * user data messages) or -EHOSTUNREACH (all other messages/senders)
 728  * Only the socket functions tipc_send_stream() and tipc_send_packet() need
 729  * to act on the return value, since they may need to do more send attempts.
 730  */
 731 int __tipc_link_xmit(struct tipc_link *link, struct sk_buff *buf)
 732 {
 733         struct tipc_msg *msg = buf_msg(buf);
 734         uint psz = msg_size(msg);
 735         uint qsz = link->out_queue_size;
 736         uint sndlim = link->queue_limit[0];
 737         uint imp = tipc_msg_tot_importance(msg);
 738         uint mtu = link->max_pkt;
 739         uint ack = mod(link->next_in_no - 1);
 740         uint seqno = link->next_out_no;
 741         uint bc_last_in = link->owner->bclink.last_in;
 742         struct tipc_media_addr *addr = &link->media_addr;
 743         struct sk_buff *next = buf->next;
 744
 745         /* Match queue limits against msg importance: */
 746         if (unlikely(qsz >= link->queue_limit[imp]))
 747                 return tipc_link_cong(link, buf);
 748
 749         /* Has valid packet limit been used ? */
 750         if (unlikely(psz > mtu)) {
 751                 kfree_skb_list(buf);
 752                 return -EMSGSIZE;
 753         }
 754
 755         /* Prepare each packet for sending, and add to outqueue: */
 756         while (buf) {
 757                 next = buf->next;
 758                 msg = buf_msg(buf);
 759                 msg_set_word(msg, 2, ((ack << 16) | mod(seqno)));
 760                 msg_set_bcast_ack(msg, bc_last_in);
 761
 762                 if (!link->first_out) {
 763                         link->first_out = buf;
 764                 } else if (qsz < sndlim) {
 765                         link->last_out->next = buf;
 766                 } else if (tipc_msg_bundle(link->last_out, buf, mtu)) {
 767                         link->stats.sent_bundled++;
 768                         buf = next;
 769                         next = buf->next;
 770                         continue;
 771                 } else if (tipc_msg_make_bundle(&buf, mtu, link->addr)) {
 772                         link->stats.sent_bundled++;
 773                         link->stats.sent_bundles++;
 774                         link->last_out->next = buf;
 775                         if (!link->next_out)
 776                                 link->next_out = buf;
 777                 } else {
 778                         link->last_out->next = buf;
 779                         if (!link->next_out)
 780                                 link->next_out = buf;
 781                 }
 782
 783                 /* Send packet if possible: */
 784                 if (likely(++qsz <= sndlim)) {
 785                         tipc_bearer_send(link->bearer_id, buf, addr);
 786                         link->next_out = next;
 787                         link->unacked_window = 0;
 788                 }
 789                 seqno++;
 790                 link->last_out = buf;
 791                 buf = next;
 792         }
 793         link->next_out_no = seqno;
 794         link->out_queue_size = qsz;
 795         return 0;
 796 }
 797
 798 /**
 799  * tipc_link_xmit() is the general link level function for message sending
 800  * @buf: chain of buffers containing message
 801  * @dsz: amount of user data to be sent
 802  * @dnode: address of destination node
 803  * @selector: a number used for deterministic link selection
 804  * Consumes the buffer chain, except when returning -ELINKCONG
 805  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 806  */
 807 int tipc_link_xmit(struct sk_buff *buf, u32 dnode, u32 selector)
 808 {
 809         struct tipc_link *link = NULL;
 810         struct tipc_node *node;
 811         int rc = -EHOSTUNREACH;
 812
 813         node = tipc_node_find(dnode);
 814         if (node) {
 815                 tipc_node_lock(node);
 816                 link = node->active_links[selector & 1];
 817                 if (link)
 818                         rc = __tipc_link_xmit(link, buf);
 819                 tipc_node_unlock(node);
 820         }
 821
 822         if (link)
 823                 return rc;
 824
 825         if (likely(in_own_node(dnode)))
 826                 return tipc_sk_rcv(buf);
 827
 828         kfree_skb_list(buf);
 829         return rc;
 830 }
 831
 832 /*
 833  * tipc_link_sync_xmit - synchronize broadcast link endpoints.
 834  *
 835  * Give a newly added peer node the sequence number where it should
 836  * start receiving and acking broadcast packets.
 837  *
 838  * Called with node locked
 839  */
 840 static void tipc_link_sync_xmit(struct tipc_link *link)
 841 {
 842         struct sk_buff *buf;
 843         struct tipc_msg *msg;
 844
 845         buf = tipc_buf_acquire(INT_H_SIZE);
 846         if (!buf)
 847                 return;
 848
 849         msg = buf_msg(buf);
 850         tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG, INT_H_SIZE, link->addr);
 851         msg_set_last_bcast(msg, link->owner->bclink.acked);
 852         __tipc_link_xmit(link, buf);
 853 }
 854
 855 /*
 856  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 857  * Receive the sequence number where we should start receiving and
 858  * acking broadcast packets from a newly added peer node, and open
 859  * up for reception of such packets.
 860  *
 861  * Called with node locked
 862  */
 863 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 864 {
 865         struct tipc_msg *msg = buf_msg(buf);
 866
 867         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 868         n->bclink.recv_permitted = true;
 869         kfree_skb(buf);
 870 }
 871
 872 /*
 873  * tipc_link_push_packet: Push one unsent packet to the media
 874  */
 875 static u32 tipc_link_push_packet(struct tipc_link *l_ptr)
 876 {
 877         struct sk_buff *buf = l_ptr->first_out;
 878         u32 r_q_size = l_ptr->retransm_queue_size;
 879         u32 r_q_head = l_ptr->retransm_queue_head;
 880
 881         /* Step to position where retransmission failed, if any,    */
 882         /* consider that buffers may have been released in meantime */
 883         if (r_q_size && buf) {
 884                 u32 last = lesser(mod(r_q_head + r_q_size),
 885                                   link_last_sent(l_ptr));
 886                 u32 first = buf_seqno(buf);
 887
 888                 while (buf && less(first, r_q_head)) {
 889                         first = mod(first + 1);
 890                         buf = buf->next;
 891                 }
 892                 l_ptr->retransm_queue_head = r_q_head = first;
 893                 l_ptr->retransm_queue_size = r_q_size = mod(last - first);
 894         }
 895
 896         /* Continue retransmission now, if there is anything: */
 897         if (r_q_size && buf) {
 898                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
 899                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
 900                 tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr);
 901                 l_ptr->retransm_queue_head = mod(++r_q_head);
 902                 l_ptr->retransm_queue_size = --r_q_size;
 903                 l_ptr->stats.retransmitted++;
 904                 return 0;
 905         }
 906
 907         /* Send deferred protocol message, if any: */
 908         buf = l_ptr->proto_msg_queue;
 909         if (buf) {
 910                 msg_set_ack(buf_msg(buf), mod(l_ptr->next_in_no - 1));
 911                 msg_set_bcast_ack(buf_msg(buf), l_ptr->owner->bclink.last_in);
 912                 tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr);
 913                 l_ptr->unacked_window = 0;
 914                 kfree_skb(buf);
 915                 l_ptr->proto_msg_queue = NULL;
 916                 return 0;
 917         }
 918
 919         /* Send one deferred data message, if send window not full: */
 920         buf = l_ptr->next_out;
 921         if (buf) {
 922                 struct tipc_msg *msg = buf_msg(buf);
 923                 u32 next = msg_seqno(msg);
 924                 u32 first = buf_seqno(l_ptr->first_out);
 925
 926                 if (mod(next - first) < l_ptr->queue_limit[0]) {
 927                         msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
 928                         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 929                         tipc_bearer_send(l_ptr->bearer_id, buf,
 930                                          &l_ptr->media_addr);
 931                         if (msg_user(msg) == MSG_BUNDLER)
 932                                 msg_set_type(msg, BUNDLE_CLOSED);
 933                         l_ptr->next_out = buf->next;
 934                         return 0;
 935                 }
 936         }
 937         return 1;
 938 }
 939
 940 /*
 941  * push_queue(): push out the unsent messages of a link where
 942  *               congestion has abated. Node is locked
 943  */
 944 void tipc_link_push_queue(struct tipc_link *l_ptr)
 945 {
 946         u32 res;
 947
 948         do {
 949                 res = tipc_link_push_packet(l_ptr);
 950         } while (!res);
 951 }
 952
 953 void tipc_link_reset_all(struct tipc_node *node)
 954 {
 955         char addr_string[16];
 956         u32 i;
 957
 958         tipc_node_lock(node);
 959
 960         pr_warn("Resetting all links to %s\n",
 961                 tipc_addr_string_fill(addr_string, node->addr));
 962
 963         for (i = 0; i < MAX_BEARERS; i++) {
 964                 if (node->links[i]) {
 965                         link_print(node->links[i], "Resetting link\n");
 966                         tipc_link_reset(node->links[i]);
 967                 }
 968         }
 969
 970         tipc_node_unlock(node);
 971 }
 972
 973 static void link_retransmit_failure(struct tipc_link *l_ptr,
 974                                     struct sk_buff *buf)
 975 {
 976         struct tipc_msg *msg = buf_msg(buf);
 977
 978         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 979
 980         if (l_ptr->addr) {
 981                 /* Handle failure on standard link */
 982                 link_print(l_ptr, "Resetting link\n");
 983                 tipc_link_reset(l_ptr);
 984
 985         } else {
 986                 /* Handle failure on broadcast link */
 987                 struct tipc_node *n_ptr;
 988                 char addr_string[16];
 989
 990                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 991                 pr_cont("Outstanding acks: %lu\n",
 992                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 993
 994                 n_ptr = tipc_bclink_retransmit_to();
 995                 tipc_node_lock(n_ptr);
 996
 997                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 998                 pr_info("Broadcast link info for %s\n", addr_string);
 999                 pr_info("Reception permitted: %d,  Acked: %u\n",
1000                         n_ptr->bclink.recv_permitted,
1001                         n_ptr->bclink.acked);
1002                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
1003                         n_ptr->bclink.last_in,
1004                         n_ptr->bclink.oos_state,
1005                         n_ptr->bclink.last_sent);
1006
1007                 tipc_node_unlock(n_ptr);
1008
1009                 tipc_bclink_set_flags(TIPC_BCLINK_RESET);
1010                 l_ptr->stale_count = 0;
1011         }
1012 }
1013
1014 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *buf,
1015                           u32 retransmits)
1016 {
1017         struct tipc_msg *msg;
1018
1019         if (!buf)
1020                 return;
1021
1022         msg = buf_msg(buf);
1023
1024         /* Detect repeated retransmit failures */
1025         if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1026                 if (++l_ptr->stale_count > 100) {
1027                         link_retransmit_failure(l_ptr, buf);
1028                         return;
1029                 }
1030         } else {
1031                 l_ptr->last_retransmitted = msg_seqno(msg);
1032                 l_ptr->stale_count = 1;
1033         }
1034
1035         while (retransmits && (buf != l_ptr->next_out) && buf) {
1036                 msg = buf_msg(buf);
1037                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1038                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1039                 tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr);
1040                 buf = buf->next;
1041                 retransmits--;
1042                 l_ptr->stats.retransmitted++;
1043         }
1044
1045         l_ptr->retransm_queue_head = l_ptr->retransm_queue_size = 0;
1046 }
1047
1048 /**
1049  * link_insert_deferred_queue - insert deferred messages back into receive chain
1050  */
1051 static struct sk_buff *link_insert_deferred_queue(struct tipc_link *l_ptr,
1052                                                   struct sk_buff *buf)
1053 {
1054         u32 seq_no;
1055
1056         if (l_ptr->oldest_deferred_in == NULL)
1057                 return buf;
1058
1059         seq_no = buf_seqno(l_ptr->oldest_deferred_in);
1060         if (seq_no == mod(l_ptr->next_in_no)) {
1061                 l_ptr->newest_deferred_in->next = buf;
1062                 buf = l_ptr->oldest_deferred_in;
1063                 l_ptr->oldest_deferred_in = NULL;
1064                 l_ptr->deferred_inqueue_sz = 0;
1065         }
1066         return buf;
1067 }
1068
1069 /**
1070  * link_recv_buf_validate - validate basic format of received message
1071  *
1072  * This routine ensures a TIPC message has an acceptable header, and at least
1073  * as much data as the header indicates it should.  The routine also ensures
1074  * that the entire message header is stored in the main fragment of the message
1075  * buffer, to simplify future access to message header fields.
1076  *
1077  * Note: Having extra info present in the message header or data areas is OK.
1078  * TIPC will ignore the excess, under the assumption that it is optional info
1079  * introduced by a later release of the protocol.
1080  */
1081 static int link_recv_buf_validate(struct sk_buff *buf)
1082 {
1083         static u32 min_data_hdr_size[8] = {
1084                 SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
1085                 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1086                 };
1087
1088         struct tipc_msg *msg;
1089         u32 tipc_hdr[2];
1090         u32 size;
1091         u32 hdr_size;
1092         u32 min_hdr_size;
1093
1094         /* If this packet comes from the defer queue, the skb has already
1095          * been validated
1096          */
1097         if (unlikely(TIPC_SKB_CB(buf)->deferred))
1098                 return 1;
1099
1100         if (unlikely(buf->len < MIN_H_SIZE))
1101                 return 0;
1102
1103         msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1104         if (msg == NULL)
1105                 return 0;
1106
1107         if (unlikely(msg_version(msg) != TIPC_VERSION))
1108                 return 0;
1109
1110         size = msg_size(msg);
1111         hdr_size = msg_hdr_sz(msg);
1112         min_hdr_size = msg_isdata(msg) ?
1113                 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1114
1115         if (unlikely((hdr_size < min_hdr_size) ||
1116                      (size < hdr_size) ||
1117                      (buf->len < size) ||
1118                      (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1119                 return 0;
1120
1121         return pskb_may_pull(buf, hdr_size);
1122 }
1123
1124 /**
1125  * tipc_rcv - process TIPC packets/messages arriving from off-node
1126  * @head: pointer to message buffer chain
1127  * @b_ptr: pointer to bearer message arrived on
1128  *
1129  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1130  * structure (i.e. cannot be NULL), but bearer can be inactive.
1131  */
1132 void tipc_rcv(struct sk_buff *head, struct tipc_bearer *b_ptr)
1133 {
1134         while (head) {
1135                 struct tipc_node *n_ptr;
1136                 struct tipc_link *l_ptr;
1137                 struct sk_buff *crs;
1138                 struct sk_buff *buf = head;
1139                 struct tipc_msg *msg;
1140                 u32 seq_no;
1141                 u32 ackd;
1142                 u32 released = 0;
1143
1144                 head = head->next;
1145                 buf->next = NULL;
1146
1147                 /* Ensure message is well-formed */
1148                 if (unlikely(!link_recv_buf_validate(buf)))
1149                         goto discard;
1150
1151                 /* Ensure message data is a single contiguous unit */
1152                 if (unlikely(skb_linearize(buf)))
1153                         goto discard;
1154
1155                 /* Handle arrival of a non-unicast link message */
1156                 msg = buf_msg(buf);
1157
1158                 if (unlikely(msg_non_seq(msg))) {
1159                         if (msg_user(msg) ==  LINK_CONFIG)
1160                                 tipc_disc_rcv(buf, b_ptr);
1161                         else
1162                                 tipc_bclink_rcv(buf);
1163                         continue;
1164                 }
1165
1166                 /* Discard unicast link messages destined for another node */
1167                 if (unlikely(!msg_short(msg) &&
1168                              (msg_destnode(msg) != tipc_own_addr)))
1169                         goto discard;
1170
1171                 /* Locate neighboring node that sent message */
1172                 n_ptr = tipc_node_find(msg_prevnode(msg));
1173                 if (unlikely(!n_ptr))
1174                         goto discard;
1175                 tipc_node_lock(n_ptr);
1176
1177                 /* Locate unicast link endpoint that should handle message */
1178                 l_ptr = n_ptr->links[b_ptr->identity];
1179                 if (unlikely(!l_ptr))
1180                         goto unlock_discard;
1181
1182                 /* Verify that communication with node is currently allowed */
1183                 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
1184                     msg_user(msg) == LINK_PROTOCOL &&
1185                     (msg_type(msg) == RESET_MSG ||
1186                     msg_type(msg) == ACTIVATE_MSG) &&
1187                     !msg_redundant_link(msg))
1188                         n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
1189
1190                 if (tipc_node_blocked(n_ptr))
1191                         goto unlock_discard;
1192
1193                 /* Validate message sequence number info */
1194                 seq_no = msg_seqno(msg);
1195                 ackd = msg_ack(msg);
1196
1197                 /* Release acked messages */
1198                 if (n_ptr->bclink.recv_permitted)
1199                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1200
1201                 crs = l_ptr->first_out;
1202                 while ((crs != l_ptr->next_out) &&
1203                        less_eq(buf_seqno(crs), ackd)) {
1204                         struct sk_buff *next = crs->next;
1205                         kfree_skb(crs);
1206                         crs = next;
1207                         released++;
1208                 }
1209                 if (released) {
1210                         l_ptr->first_out = crs;
1211                         l_ptr->out_queue_size -= released;
1212                 }
1213
1214                 /* Try sending any messages link endpoint has pending */
1215                 if (unlikely(l_ptr->next_out))
1216                         tipc_link_push_queue(l_ptr);
1217
1218                 if (released && !skb_queue_empty(&l_ptr->waiting_sks)) {
1219                         link_prepare_wakeup(l_ptr);
1220                         l_ptr->owner->action_flags |= TIPC_WAKEUP_USERS;
1221                 }
1222
1223                 /* Process the incoming packet */
1224                 if (unlikely(!link_working_working(l_ptr))) {
1225                         if (msg_user(msg) == LINK_PROTOCOL) {
1226                                 tipc_link_proto_rcv(l_ptr, buf);
1227                                 head = link_insert_deferred_queue(l_ptr, head);
1228                                 tipc_node_unlock(n_ptr);
1229                                 continue;
1230                         }
1231
1232                         /* Traffic message. Conditionally activate link */
1233                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1234
1235                         if (link_working_working(l_ptr)) {
1236                                 /* Re-insert buffer in front of queue */
1237                                 buf->next = head;
1238                                 head = buf;
1239                                 tipc_node_unlock(n_ptr);
1240                                 continue;
1241                         }
1242                         goto unlock_discard;
1243                 }
1244
1245                 /* Link is now in state WORKING_WORKING */
1246                 if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
1247                         link_handle_out_of_seq_msg(l_ptr, buf);
1248                         head = link_insert_deferred_queue(l_ptr, head);
1249                         tipc_node_unlock(n_ptr);
1250                         continue;
1251                 }
1252                 l_ptr->next_in_no++;
1253                 if (unlikely(l_ptr->oldest_deferred_in))
1254                         head = link_insert_deferred_queue(l_ptr, head);
1255
1256                 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1257                         l_ptr->stats.sent_acks++;
1258                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1259                 }
1260
1261                 if (tipc_link_prepare_input(l_ptr, &buf)) {
1262                         tipc_node_unlock(n_ptr);
1263                         continue;
1264                 }
1265                 tipc_node_unlock(n_ptr);
1266                 msg = buf_msg(buf);
1267                 if (tipc_link_input(l_ptr, buf) != 0)
1268                         goto discard;
1269                 continue;
1270 unlock_discard:
1271                 tipc_node_unlock(n_ptr);
1272 discard:
1273                 kfree_skb(buf);
1274         }
1275 }
1276
1277 /**
1278  * tipc_link_prepare_input - process TIPC link messages
1279  *
1280  * returns nonzero if the message was consumed
1281  *
1282  * Node lock must be held
1283  */
1284 static int tipc_link_prepare_input(struct tipc_link *l, struct sk_buff **buf)
1285 {
1286         struct tipc_node *n;
1287         struct tipc_msg *msg;
1288         int res = -EINVAL;
1289
1290         n = l->owner;
1291         msg = buf_msg(*buf);
1292         switch (msg_user(msg)) {
1293         case CHANGEOVER_PROTOCOL:
1294                 if (tipc_link_tunnel_rcv(n, buf))
1295                         res = 0;
1296                 break;
1297         case MSG_FRAGMENTER:
1298                 l->stats.recv_fragments++;
1299                 if (tipc_buf_append(&l->reasm_buf, buf)) {
1300                         l->stats.recv_fragmented++;
1301                         res = 0;
1302                 } else if (!l->reasm_buf) {
1303                         tipc_link_reset(l);
1304                 }
1305                 break;
1306         case MSG_BUNDLER:
1307                 l->stats.recv_bundles++;
1308                 l->stats.recv_bundled += msg_msgcnt(msg);
1309                 res = 0;
1310                 break;
1311         case NAME_DISTRIBUTOR:
1312                 n->bclink.recv_permitted = true;
1313                 res = 0;
1314                 break;
1315         case BCAST_PROTOCOL:
1316                 tipc_link_sync_rcv(n, *buf);
1317                 break;
1318         default:
1319                 res = 0;
1320         }
1321         return res;
1322 }
1323 /**
1324  * tipc_link_input - Deliver message too higher layers
1325  */
1326 static int tipc_link_input(struct tipc_link *l, struct sk_buff *buf)
1327 {
1328         struct tipc_msg *msg = buf_msg(buf);
1329         int res = 0;
1330
1331         switch (msg_user(msg)) {
1332         case TIPC_LOW_IMPORTANCE:
1333         case TIPC_MEDIUM_IMPORTANCE:
1334         case TIPC_HIGH_IMPORTANCE:
1335         case TIPC_CRITICAL_IMPORTANCE:
1336         case CONN_MANAGER:
1337                 tipc_sk_rcv(buf);
1338                 break;
1339         case NAME_DISTRIBUTOR:
1340                 tipc_named_rcv(buf);
1341                 break;
1342         case MSG_BUNDLER:
1343                 tipc_link_bundle_rcv(buf);
1344                 break;
1345         default:
1346                 res = -EINVAL;
1347         }
1348         return res;
1349 }
1350
1351 /**
1352  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1353  *
1354  * Returns increase in queue length (i.e. 0 or 1)
1355  */
1356 u32 tipc_link_defer_pkt(struct sk_buff **head, struct sk_buff **tail,
1357                         struct sk_buff *buf)
1358 {
1359         struct sk_buff *queue_buf;
1360         struct sk_buff **prev;
1361         u32 seq_no = buf_seqno(buf);
1362
1363         buf->next = NULL;
1364
1365         /* Empty queue ? */
1366         if (*head == NULL) {
1367                 *head = *tail = buf;
1368                 return 1;
1369         }
1370
1371         /* Last ? */
1372         if (less(buf_seqno(*tail), seq_no)) {
1373                 (*tail)->next = buf;
1374                 *tail = buf;
1375                 return 1;
1376         }
1377
1378         /* Locate insertion point in queue, then insert; discard if duplicate */
1379         prev = head;
1380         queue_buf = *head;
1381         for (;;) {
1382                 u32 curr_seqno = buf_seqno(queue_buf);
1383
1384                 if (seq_no == curr_seqno) {
1385                         kfree_skb(buf);
1386                         return 0;
1387                 }
1388
1389                 if (less(seq_no, curr_seqno))
1390                         break;
1391
1392                 prev = &queue_buf->next;
1393                 queue_buf = queue_buf->next;
1394         }
1395
1396         buf->next = queue_buf;
1397         *prev = buf;
1398         return 1;
1399 }
1400
1401 /*
1402  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1403  */
1404 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1405                                        struct sk_buff *buf)
1406 {
1407         u32 seq_no = buf_seqno(buf);
1408
1409         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1410                 tipc_link_proto_rcv(l_ptr, buf);
1411                 return;
1412         }
1413
1414         /* Record OOS packet arrival (force mismatch on next timeout) */
1415         l_ptr->checkpoint--;
1416
1417         /*
1418          * Discard packet if a duplicate; otherwise add it to deferred queue
1419          * and notify peer of gap as per protocol specification
1420          */
1421         if (less(seq_no, mod(l_ptr->next_in_no))) {
1422                 l_ptr->stats.duplicates++;
1423                 kfree_skb(buf);
1424                 return;
1425         }
1426
1427         if (tipc_link_defer_pkt(&l_ptr->oldest_deferred_in,
1428                                 &l_ptr->newest_deferred_in, buf)) {
1429                 l_ptr->deferred_inqueue_sz++;
1430                 l_ptr->stats.deferred_recv++;
1431                 TIPC_SKB_CB(buf)->deferred = true;
1432                 if ((l_ptr->deferred_inqueue_sz % 16) == 1)
1433                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1434         } else
1435                 l_ptr->stats.duplicates++;
1436 }
1437
1438 /*
1439  * Send protocol message to the other endpoint.
1440  */
1441 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1442                           u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
1443 {
1444         struct sk_buff *buf = NULL;
1445         struct tipc_msg *msg = l_ptr->pmsg;
1446         u32 msg_size = sizeof(l_ptr->proto_msg);
1447         int r_flag;
1448
1449         /* Discard any previous message that was deferred due to congestion */
1450         if (l_ptr->proto_msg_queue) {
1451                 kfree_skb(l_ptr->proto_msg_queue);
1452                 l_ptr->proto_msg_queue = NULL;
1453         }
1454
1455         /* Don't send protocol message during link changeover */
1456         if (l_ptr->exp_msg_count)
1457                 return;
1458
1459         /* Abort non-RESET send if communication with node is prohibited */
1460         if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG))
1461                 return;
1462
1463         /* Create protocol message with "out-of-sequence" sequence number */
1464         msg_set_type(msg, msg_typ);
1465         msg_set_net_plane(msg, l_ptr->net_plane);
1466         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1467         msg_set_last_bcast(msg, tipc_bclink_get_last_sent());
1468
1469         if (msg_typ == STATE_MSG) {
1470                 u32 next_sent = mod(l_ptr->next_out_no);
1471
1472                 if (!tipc_link_is_up(l_ptr))
1473                         return;
1474                 if (l_ptr->next_out)
1475                         next_sent = buf_seqno(l_ptr->next_out);
1476                 msg_set_next_sent(msg, next_sent);
1477                 if (l_ptr->oldest_deferred_in) {
1478                         u32 rec = buf_seqno(l_ptr->oldest_deferred_in);
1479                         gap = mod(rec - mod(l_ptr->next_in_no));
1480                 }
1481                 msg_set_seq_gap(msg, gap);
1482                 if (gap)
1483                         l_ptr->stats.sent_nacks++;
1484                 msg_set_link_tolerance(msg, tolerance);
1485                 msg_set_linkprio(msg, priority);
1486                 msg_set_max_pkt(msg, ack_mtu);
1487                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1488                 msg_set_probe(msg, probe_msg != 0);
1489                 if (probe_msg) {
1490                         u32 mtu = l_ptr->max_pkt;
1491
1492                         if ((mtu < l_ptr->max_pkt_target) &&
1493                             link_working_working(l_ptr) &&
1494                             l_ptr->fsm_msg_cnt) {
1495                                 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1496                                 if (l_ptr->max_pkt_probes == 10) {
1497                                         l_ptr->max_pkt_target = (msg_size - 4);
1498                                         l_ptr->max_pkt_probes = 0;
1499                                         msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1500                                 }
1501                                 l_ptr->max_pkt_probes++;
1502                         }
1503
1504                         l_ptr->stats.sent_probes++;
1505                 }
1506                 l_ptr->stats.sent_states++;
1507         } else {                /* RESET_MSG or ACTIVATE_MSG */
1508                 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
1509                 msg_set_seq_gap(msg, 0);
1510                 msg_set_next_sent(msg, 1);
1511                 msg_set_probe(msg, 0);
1512                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1513                 msg_set_linkprio(msg, l_ptr->priority);
1514                 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
1515         }
1516
1517         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1518         msg_set_redundant_link(msg, r_flag);
1519         msg_set_linkprio(msg, l_ptr->priority);
1520         msg_set_size(msg, msg_size);
1521
1522         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1523
1524         buf = tipc_buf_acquire(msg_size);
1525         if (!buf)
1526                 return;
1527
1528         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1529         buf->priority = TC_PRIO_CONTROL;
1530
1531         tipc_bearer_send(l_ptr->bearer_id, buf, &l_ptr->media_addr);
1532         l_ptr->unacked_window = 0;
1533         kfree_skb(buf);
1534 }
1535
1536 /*
1537  * Receive protocol message :
1538  * Note that network plane id propagates through the network, and may
1539  * change at any time. The node with lowest address rules
1540  */
1541 static void tipc_link_proto_rcv(struct tipc_link *l_ptr, struct sk_buff *buf)
1542 {
1543         u32 rec_gap = 0;
1544         u32 max_pkt_info;
1545         u32 max_pkt_ack;
1546         u32 msg_tol;
1547         struct tipc_msg *msg = buf_msg(buf);
1548
1549         /* Discard protocol message during link changeover */
1550         if (l_ptr->exp_msg_count)
1551                 goto exit;
1552
1553         if (l_ptr->net_plane != msg_net_plane(msg))
1554                 if (tipc_own_addr > msg_prevnode(msg))
1555                         l_ptr->net_plane = msg_net_plane(msg);
1556
1557         switch (msg_type(msg)) {
1558
1559         case RESET_MSG:
1560                 if (!link_working_unknown(l_ptr) &&
1561                     (l_ptr->peer_session != INVALID_SESSION)) {
1562                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1563                                 break; /* duplicate or old reset: ignore */
1564                 }
1565
1566                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1567                                 link_working_unknown(l_ptr))) {
1568                         /*
1569                          * peer has lost contact -- don't allow peer's links
1570                          * to reactivate before we recognize loss & clean up
1571                          */
1572                         l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
1573                 }
1574
1575                 link_state_event(l_ptr, RESET_MSG);
1576
1577                 /* fall thru' */
1578         case ACTIVATE_MSG:
1579                 /* Update link settings according other endpoint's values */
1580                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1581
1582                 msg_tol = msg_link_tolerance(msg);
1583                 if (msg_tol > l_ptr->tolerance)
1584                         link_set_supervision_props(l_ptr, msg_tol);
1585
1586                 if (msg_linkprio(msg) > l_ptr->priority)
1587                         l_ptr->priority = msg_linkprio(msg);
1588
1589                 max_pkt_info = msg_max_pkt(msg);
1590                 if (max_pkt_info) {
1591                         if (max_pkt_info < l_ptr->max_pkt_target)
1592                                 l_ptr->max_pkt_target = max_pkt_info;
1593                         if (l_ptr->max_pkt > l_ptr->max_pkt_target)
1594                                 l_ptr->max_pkt = l_ptr->max_pkt_target;
1595                 } else {
1596                         l_ptr->max_pkt = l_ptr->max_pkt_target;
1597                 }
1598
1599                 /* Synchronize broadcast link info, if not done previously */
1600                 if (!tipc_node_is_up(l_ptr->owner)) {
1601                         l_ptr->owner->bclink.last_sent =
1602                                 l_ptr->owner->bclink.last_in =
1603                                 msg_last_bcast(msg);
1604                         l_ptr->owner->bclink.oos_state = 0;
1605                 }
1606
1607                 l_ptr->peer_session = msg_session(msg);
1608                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1609
1610                 if (msg_type(msg) == ACTIVATE_MSG)
1611                         link_state_event(l_ptr, ACTIVATE_MSG);
1612                 break;
1613         case STATE_MSG:
1614
1615                 msg_tol = msg_link_tolerance(msg);
1616                 if (msg_tol)
1617                         link_set_supervision_props(l_ptr, msg_tol);
1618
1619                 if (msg_linkprio(msg) &&
1620                     (msg_linkprio(msg) != l_ptr->priority)) {
1621                         pr_warn("%s<%s>, priority change %u->%u\n",
1622                                 link_rst_msg, l_ptr->name, l_ptr->priority,
1623                                 msg_linkprio(msg));
1624                         l_ptr->priority = msg_linkprio(msg);
1625                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1626                         break;
1627                 }
1628
1629                 /* Record reception; force mismatch at next timeout: */
1630                 l_ptr->checkpoint--;
1631
1632                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1633                 l_ptr->stats.recv_states++;
1634                 if (link_reset_unknown(l_ptr))
1635                         break;
1636
1637                 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
1638                         rec_gap = mod(msg_next_sent(msg) -
1639                                       mod(l_ptr->next_in_no));
1640                 }
1641
1642                 max_pkt_ack = msg_max_pkt(msg);
1643                 if (max_pkt_ack > l_ptr->max_pkt) {
1644                         l_ptr->max_pkt = max_pkt_ack;
1645                         l_ptr->max_pkt_probes = 0;
1646                 }
1647
1648                 max_pkt_ack = 0;
1649                 if (msg_probe(msg)) {
1650                         l_ptr->stats.recv_probes++;
1651                         if (msg_size(msg) > sizeof(l_ptr->proto_msg))
1652                                 max_pkt_ack = msg_size(msg);
1653                 }
1654
1655                 /* Protocol message before retransmits, reduce loss risk */
1656                 if (l_ptr->owner->bclink.recv_permitted)
1657                         tipc_bclink_update_link_state(l_ptr->owner,
1658                                                       msg_last_bcast(msg));
1659
1660                 if (rec_gap || (msg_probe(msg))) {
1661                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, rec_gap, 0,
1662                                              0, max_pkt_ack);
1663                 }
1664                 if (msg_seq_gap(msg)) {
1665                         l_ptr->stats.recv_nacks++;
1666                         tipc_link_retransmit(l_ptr, l_ptr->first_out,
1667                                              msg_seq_gap(msg));
1668                 }
1669                 break;
1670         }
1671 exit:
1672         kfree_skb(buf);
1673 }
1674
1675
1676 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1677  * a different bearer. Owner node is locked.
1678  */
1679 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1680                                   struct tipc_msg *tunnel_hdr,
1681                                   struct tipc_msg *msg,
1682                                   u32 selector)
1683 {
1684         struct tipc_link *tunnel;
1685         struct sk_buff *buf;
1686         u32 length = msg_size(msg);
1687
1688         tunnel = l_ptr->owner->active_links[selector & 1];
1689         if (!tipc_link_is_up(tunnel)) {
1690                 pr_warn("%stunnel link no longer available\n", link_co_err);
1691                 return;
1692         }
1693         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1694         buf = tipc_buf_acquire(length + INT_H_SIZE);
1695         if (!buf) {
1696                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1697                 return;
1698         }
1699         skb_copy_to_linear_data(buf, tunnel_hdr, INT_H_SIZE);
1700         skb_copy_to_linear_data_offset(buf, INT_H_SIZE, msg, length);
1701         __tipc_link_xmit(tunnel, buf);
1702 }
1703
1704
1705 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1706  * link is still active. We can do failover. Tunnel the failing link's
1707  * whole send queue via the remaining link. This way, we don't lose
1708  * any packets, and sequence order is preserved for subsequent traffic
1709  * sent over the remaining link. Owner node is locked.
1710  */
1711 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1712 {
1713         u32 msgcount = l_ptr->out_queue_size;
1714         struct sk_buff *crs = l_ptr->first_out;
1715         struct tipc_link *tunnel = l_ptr->owner->active_links[0];
1716         struct tipc_msg tunnel_hdr;
1717         int split_bundles;
1718
1719         if (!tunnel)
1720                 return;
1721
1722         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
1723                  ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
1724         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1725         msg_set_msgcnt(&tunnel_hdr, msgcount);
1726
1727         if (!l_ptr->first_out) {
1728                 struct sk_buff *buf;
1729
1730                 buf = tipc_buf_acquire(INT_H_SIZE);
1731                 if (buf) {
1732                         skb_copy_to_linear_data(buf, &tunnel_hdr, INT_H_SIZE);
1733                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1734                         __tipc_link_xmit(tunnel, buf);
1735                 } else {
1736                         pr_warn("%sunable to send changeover msg\n",
1737                                 link_co_err);
1738                 }
1739                 return;
1740         }
1741
1742         split_bundles = (l_ptr->owner->active_links[0] !=
1743                          l_ptr->owner->active_links[1]);
1744
1745         while (crs) {
1746                 struct tipc_msg *msg = buf_msg(crs);
1747
1748                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1749                         struct tipc_msg *m = msg_get_wrapped(msg);
1750                         unchar *pos = (unchar *)m;
1751
1752                         msgcount = msg_msgcnt(msg);
1753                         while (msgcount--) {
1754                                 msg_set_seqno(m, msg_seqno(msg));
1755                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1756                                                       msg_link_selector(m));
1757                                 pos += align(msg_size(m));
1758                                 m = (struct tipc_msg *)pos;
1759                         }
1760                 } else {
1761                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1762                                               msg_link_selector(msg));
1763                 }
1764                 crs = crs->next;
1765         }
1766 }
1767
1768 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1769  * duplicate of the first link's send queue via the new link. This way, we
1770  * are guaranteed that currently queued packets from a socket are delivered
1771  * before future traffic from the same socket, even if this is using the
1772  * new link. The last arriving copy of each duplicate packet is dropped at
1773  * the receiving end by the regular protocol check, so packet cardinality
1774  * and sequence order is preserved per sender/receiver socket pair.
1775  * Owner node is locked.
1776  */
1777 void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr,
1778                               struct tipc_link *tunnel)
1779 {
1780         struct sk_buff *iter;
1781         struct tipc_msg tunnel_hdr;
1782
1783         tipc_msg_init(&tunnel_hdr, CHANGEOVER_PROTOCOL,
1784                  DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
1785         msg_set_msgcnt(&tunnel_hdr, l_ptr->out_queue_size);
1786         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1787         iter = l_ptr->first_out;
1788         while (iter) {
1789                 struct sk_buff *outbuf;
1790                 struct tipc_msg *msg = buf_msg(iter);
1791                 u32 length = msg_size(msg);
1792
1793                 if (msg_user(msg) == MSG_BUNDLER)
1794                         msg_set_type(msg, CLOSED_MSG);
1795                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));   /* Update */
1796                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1797                 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
1798                 outbuf = tipc_buf_acquire(length + INT_H_SIZE);
1799                 if (outbuf == NULL) {
1800                         pr_warn("%sunable to send duplicate msg\n",
1801                                 link_co_err);
1802                         return;
1803                 }
1804                 skb_copy_to_linear_data(outbuf, &tunnel_hdr, INT_H_SIZE);
1805                 skb_copy_to_linear_data_offset(outbuf, INT_H_SIZE, iter->data,
1806                                                length);
1807                 __tipc_link_xmit(tunnel, outbuf);
1808                 if (!tipc_link_is_up(l_ptr))
1809                         return;
1810                 iter = iter->next;
1811         }
1812 }
1813
1814 /**
1815  * buf_extract - extracts embedded TIPC message from another message
1816  * @skb: encapsulating message buffer
1817  * @from_pos: offset to extract from
1818  *
1819  * Returns a new message buffer containing an embedded message.  The
1820  * encapsulating message itself is left unchanged.
1821  */
1822 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
1823 {
1824         struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
1825         u32 size = msg_size(msg);
1826         struct sk_buff *eb;
1827
1828         eb = tipc_buf_acquire(size);
1829         if (eb)
1830                 skb_copy_to_linear_data(eb, msg, size);
1831         return eb;
1832 }
1833
1834
1835
1836 /* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet.
1837  * Owner node is locked.
1838  */
1839 static void tipc_link_dup_rcv(struct tipc_link *l_ptr,
1840                               struct sk_buff *t_buf)
1841 {
1842         struct sk_buff *buf;
1843
1844         if (!tipc_link_is_up(l_ptr))
1845                 return;
1846
1847         buf = buf_extract(t_buf, INT_H_SIZE);
1848         if (buf == NULL) {
1849                 pr_warn("%sfailed to extract inner dup pkt\n", link_co_err);
1850                 return;
1851         }
1852
1853         /* Add buffer to deferred queue, if applicable: */
1854         link_handle_out_of_seq_msg(l_ptr, buf);
1855 }
1856
1857 /*  tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet
1858  *  Owner node is locked.
1859  */
1860 static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
1861                                               struct sk_buff *t_buf)
1862 {
1863         struct tipc_msg *t_msg = buf_msg(t_buf);
1864         struct sk_buff *buf = NULL;
1865         struct tipc_msg *msg;
1866
1867         if (tipc_link_is_up(l_ptr))
1868                 tipc_link_reset(l_ptr);
1869
1870         /* First failover packet? */
1871         if (l_ptr->exp_msg_count == START_CHANGEOVER)
1872                 l_ptr->exp_msg_count = msg_msgcnt(t_msg);
1873
1874         /* Should there be an inner packet? */
1875         if (l_ptr->exp_msg_count) {
1876                 l_ptr->exp_msg_count--;
1877                 buf = buf_extract(t_buf, INT_H_SIZE);
1878                 if (buf == NULL) {
1879                         pr_warn("%sno inner failover pkt\n", link_co_err);
1880                         goto exit;
1881                 }
1882                 msg = buf_msg(buf);
1883
1884                 if (less(msg_seqno(msg), l_ptr->reset_checkpoint)) {
1885                         kfree_skb(buf);
1886                         buf = NULL;
1887                         goto exit;
1888                 }
1889                 if (msg_user(msg) == MSG_FRAGMENTER) {
1890                         l_ptr->stats.recv_fragments++;
1891                         tipc_buf_append(&l_ptr->reasm_buf, &buf);
1892                 }
1893         }
1894 exit:
1895         if ((l_ptr->exp_msg_count == 0) && (l_ptr->flags & LINK_STOPPED)) {
1896                 tipc_node_detach_link(l_ptr->owner, l_ptr);
1897                 kfree(l_ptr);
1898         }
1899         return buf;
1900 }
1901
1902 /*  tipc_link_tunnel_rcv(): Receive a tunnelled packet, sent
1903  *  via other link as result of a failover (ORIGINAL_MSG) or
1904  *  a new active link (DUPLICATE_MSG). Failover packets are
1905  *  returned to the active link for delivery upwards.
1906  *  Owner node is locked.
1907  */
1908 static int tipc_link_tunnel_rcv(struct tipc_node *n_ptr,
1909                                 struct sk_buff **buf)
1910 {
1911         struct sk_buff *t_buf = *buf;
1912         struct tipc_link *l_ptr;
1913         struct tipc_msg *t_msg = buf_msg(t_buf);
1914         u32 bearer_id = msg_bearer_id(t_msg);
1915
1916         *buf = NULL;
1917
1918         if (bearer_id >= MAX_BEARERS)
1919                 goto exit;
1920
1921         l_ptr = n_ptr->links[bearer_id];
1922         if (!l_ptr)
1923                 goto exit;
1924
1925         if (msg_type(t_msg) == DUPLICATE_MSG)
1926                 tipc_link_dup_rcv(l_ptr, t_buf);
1927         else if (msg_type(t_msg) == ORIGINAL_MSG)
1928                 *buf = tipc_link_failover_rcv(l_ptr, t_buf);
1929         else
1930                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1931 exit:
1932         kfree_skb(t_buf);
1933         return *buf != NULL;
1934 }
1935
1936 /*
1937  *  Bundler functionality:
1938  */
1939 void tipc_link_bundle_rcv(struct sk_buff *buf)
1940 {
1941         u32 msgcount = msg_msgcnt(buf_msg(buf));
1942         u32 pos = INT_H_SIZE;
1943         struct sk_buff *obuf;
1944         struct tipc_msg *omsg;
1945
1946         while (msgcount--) {
1947                 obuf = buf_extract(buf, pos);
1948                 if (obuf == NULL) {
1949                         pr_warn("Link unable to unbundle message(s)\n");
1950                         break;
1951                 }
1952                 omsg = buf_msg(obuf);
1953                 pos += align(msg_size(omsg));
1954                 if (msg_isdata(omsg)) {
1955                         if (unlikely(msg_type(omsg) == TIPC_MCAST_MSG))
1956                                 tipc_sk_mcast_rcv(obuf);
1957                         else
1958                                 tipc_sk_rcv(obuf);
1959                 } else if (msg_user(omsg) == CONN_MANAGER) {
1960                         tipc_sk_rcv(obuf);
1961                 } else if (msg_user(omsg) == NAME_DISTRIBUTOR) {
1962                         tipc_named_rcv(obuf);
1963                 } else {
1964                         pr_warn("Illegal bundled msg: %u\n", msg_user(omsg));
1965                         kfree_skb(obuf);
1966                 }
1967         }
1968         kfree_skb(buf);
1969 }
1970
1971 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tolerance)
1972 {
1973         if ((tolerance < TIPC_MIN_LINK_TOL) || (tolerance > TIPC_MAX_LINK_TOL))
1974                 return;
1975
1976         l_ptr->tolerance = tolerance;
1977         l_ptr->continuity_interval =
1978                 ((tolerance / 4) > 500) ? 500 : tolerance / 4;
1979         l_ptr->abort_limit = tolerance / (l_ptr->continuity_interval / 4);
1980 }
1981
1982 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
1983 {
1984         /* Data messages from this node, inclusive FIRST_FRAGM */
1985         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
1986         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
1987         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
1988         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
1989         /* Transiting data messages,inclusive FIRST_FRAGM */
1990         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
1991         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
1992         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
1993         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
1994         l_ptr->queue_limit[CONN_MANAGER] = 1200;
1995         l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
1996         l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
1997         /* FRAGMENT and LAST_FRAGMENT packets */
1998         l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
1999 }
2000
2001 /* tipc_link_find_owner - locate owner node of link by link's name
2002  * @name: pointer to link name string
2003  * @bearer_id: pointer to index in 'node->links' array where the link was found.
2004  *
2005  * Returns pointer to node owning the link, or 0 if no matching link is found.
2006  */
2007 static struct tipc_node *tipc_link_find_owner(const char *link_name,
2008                                               unsigned int *bearer_id)
2009 {
2010         struct tipc_link *l_ptr;
2011         struct tipc_node *n_ptr;
2012         struct tipc_node *found_node = 0;
2013         int i;
2014
2015         *bearer_id = 0;
2016         rcu_read_lock();
2017         list_for_each_entry_rcu(n_ptr, &tipc_node_list, list) {
2018                 tipc_node_lock(n_ptr);
2019                 for (i = 0; i < MAX_BEARERS; i++) {
2020                         l_ptr = n_ptr->links[i];
2021                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
2022                                 *bearer_id = i;
2023                                 found_node = n_ptr;
2024                                 break;
2025                         }
2026                 }
2027                 tipc_node_unlock(n_ptr);
2028                 if (found_node)
2029                         break;
2030         }
2031         rcu_read_unlock();
2032
2033         return found_node;
2034 }
2035
2036 /**
2037  * link_value_is_valid -- validate proposed link tolerance/priority/window
2038  *
2039  * @cmd: value type (TIPC_CMD_SET_LINK_*)
2040  * @new_value: the new value
2041  *
2042  * Returns 1 if value is within range, 0 if not.
2043  */
2044 static int link_value_is_valid(u16 cmd, u32 new_value)
2045 {
2046         switch (cmd) {
2047         case TIPC_CMD_SET_LINK_TOL:
2048                 return (new_value >= TIPC_MIN_LINK_TOL) &&
2049                         (new_value <= TIPC_MAX_LINK_TOL);
2050         case TIPC_CMD_SET_LINK_PRI:
2051                 return (new_value <= TIPC_MAX_LINK_PRI);
2052         case TIPC_CMD_SET_LINK_WINDOW:
2053                 return (new_value >= TIPC_MIN_LINK_WIN) &&
2054                         (new_value <= TIPC_MAX_LINK_WIN);
2055         }
2056         return 0;
2057 }
2058
2059 /**
2060  * link_cmd_set_value - change priority/tolerance/window for link/bearer/media
2061  * @name: ptr to link, bearer, or media name
2062  * @new_value: new value of link, bearer, or media setting
2063  * @cmd: which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*)
2064  *
2065  * Caller must hold RTNL lock to ensure link/bearer/media is not deleted.
2066  *
2067  * Returns 0 if value updated and negative value on error.
2068  */
2069 static int link_cmd_set_value(const char *name, u32 new_value, u16 cmd)
2070 {
2071         struct tipc_node *node;
2072         struct tipc_link *l_ptr;
2073         struct tipc_bearer *b_ptr;
2074         struct tipc_media *m_ptr;
2075         int bearer_id;
2076         int res = 0;
2077
2078         node = tipc_link_find_owner(name, &bearer_id);
2079         if (node) {
2080                 tipc_node_lock(node);
2081                 l_ptr = node->links[bearer_id];
2082
2083                 if (l_ptr) {
2084                         switch (cmd) {
2085                         case TIPC_CMD_SET_LINK_TOL:
2086                                 link_set_supervision_props(l_ptr, new_value);
2087                                 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2088                                                      new_value, 0, 0);
2089                                 break;
2090                         case TIPC_CMD_SET_LINK_PRI:
2091                                 l_ptr->priority = new_value;
2092                                 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2093                                                      0, new_value, 0);
2094                                 break;
2095                         case TIPC_CMD_SET_LINK_WINDOW:
2096                                 tipc_link_set_queue_limits(l_ptr, new_value);
2097                                 break;
2098                         default:
2099                                 res = -EINVAL;
2100                                 break;
2101                         }
2102                 }
2103                 tipc_node_unlock(node);
2104                 return res;
2105         }
2106
2107         b_ptr = tipc_bearer_find(name);
2108         if (b_ptr) {
2109                 switch (cmd) {
2110                 case TIPC_CMD_SET_LINK_TOL:
2111                         b_ptr->tolerance = new_value;
2112                         break;
2113                 case TIPC_CMD_SET_LINK_PRI:
2114                         b_ptr->priority = new_value;
2115                         break;
2116                 case TIPC_CMD_SET_LINK_WINDOW:
2117                         b_ptr->window = new_value;
2118                         break;
2119                 default:
2120                         res = -EINVAL;
2121                         break;
2122                 }
2123                 return res;
2124         }
2125
2126         m_ptr = tipc_media_find(name);
2127         if (!m_ptr)
2128                 return -ENODEV;
2129         switch (cmd) {
2130         case TIPC_CMD_SET_LINK_TOL:
2131                 m_ptr->tolerance = new_value;
2132                 break;
2133         case TIPC_CMD_SET_LINK_PRI:
2134                 m_ptr->priority = new_value;
2135                 break;
2136         case TIPC_CMD_SET_LINK_WINDOW:
2137                 m_ptr->window = new_value;
2138                 break;
2139         default:
2140                 res = -EINVAL;
2141                 break;
2142         }
2143         return res;
2144 }
2145
2146 struct sk_buff *tipc_link_cmd_config(const void *req_tlv_area, int req_tlv_space,
2147                                      u16 cmd)
2148 {
2149         struct tipc_link_config *args;
2150         u32 new_value;
2151         int res;
2152
2153         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2154                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2155
2156         args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2157         new_value = ntohl(args->value);
2158
2159         if (!link_value_is_valid(cmd, new_value))
2160                 return tipc_cfg_reply_error_string(
2161                         "cannot change, value invalid");
2162
2163         if (!strcmp(args->name, tipc_bclink_name)) {
2164                 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2165                     (tipc_bclink_set_queue_limits(new_value) == 0))
2166                         return tipc_cfg_reply_none();
2167                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2168                                                    " (cannot change setting on broadcast link)");
2169         }
2170
2171         res = link_cmd_set_value(args->name, new_value, cmd);
2172         if (res)
2173                 return tipc_cfg_reply_error_string("cannot change link setting");
2174
2175         return tipc_cfg_reply_none();
2176 }
2177
2178 /**
2179  * link_reset_statistics - reset link statistics
2180  * @l_ptr: pointer to link
2181  */
2182 static void link_reset_statistics(struct tipc_link *l_ptr)
2183 {
2184         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2185         l_ptr->stats.sent_info = l_ptr->next_out_no;
2186         l_ptr->stats.recv_info = l_ptr->next_in_no;
2187 }
2188
2189 struct sk_buff *tipc_link_cmd_reset_stats(const void *req_tlv_area, int req_tlv_space)
2190 {
2191         char *link_name;
2192         struct tipc_link *l_ptr;
2193         struct tipc_node *node;
2194         unsigned int bearer_id;
2195
2196         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2197                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2198
2199         link_name = (char *)TLV_DATA(req_tlv_area);
2200         if (!strcmp(link_name, tipc_bclink_name)) {
2201                 if (tipc_bclink_reset_stats())
2202                         return tipc_cfg_reply_error_string("link not found");
2203                 return tipc_cfg_reply_none();
2204         }
2205         node = tipc_link_find_owner(link_name, &bearer_id);
2206         if (!node)
2207                 return tipc_cfg_reply_error_string("link not found");
2208
2209         tipc_node_lock(node);
2210         l_ptr = node->links[bearer_id];
2211         if (!l_ptr) {
2212                 tipc_node_unlock(node);
2213                 return tipc_cfg_reply_error_string("link not found");
2214         }
2215         link_reset_statistics(l_ptr);
2216         tipc_node_unlock(node);
2217         return tipc_cfg_reply_none();
2218 }
2219
2220 /**
2221  * percent - convert count to a percentage of total (rounding up or down)
2222  */
2223 static u32 percent(u32 count, u32 total)
2224 {
2225         return (count * 100 + (total / 2)) / total;
2226 }
2227
2228 /**
2229  * tipc_link_stats - print link statistics
2230  * @name: link name
2231  * @buf: print buffer area
2232  * @buf_size: size of print buffer area
2233  *
2234  * Returns length of print buffer data string (or 0 if error)
2235  */
2236 static int tipc_link_stats(const char *name, char *buf, const u32 buf_size)
2237 {
2238         struct tipc_link *l;
2239         struct tipc_stats *s;
2240         struct tipc_node *node;
2241         char *status;
2242         u32 profile_total = 0;
2243         unsigned int bearer_id;
2244         int ret;
2245
2246         if (!strcmp(name, tipc_bclink_name))
2247                 return tipc_bclink_stats(buf, buf_size);
2248
2249         node = tipc_link_find_owner(name, &bearer_id);
2250         if (!node)
2251                 return 0;
2252
2253         tipc_node_lock(node);
2254
2255         l = node->links[bearer_id];
2256         if (!l) {
2257                 tipc_node_unlock(node);
2258                 return 0;
2259         }
2260
2261         s = &l->stats;
2262
2263         if (tipc_link_is_active(l))
2264                 status = "ACTIVE";
2265         else if (tipc_link_is_up(l))
2266                 status = "STANDBY";
2267         else
2268                 status = "DEFUNCT";
2269
2270         ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
2271                             "  %s  MTU:%u  Priority:%u  Tolerance:%u ms"
2272                             "  Window:%u packets\n",
2273                             l->name, status, l->max_pkt, l->priority,
2274                             l->tolerance, l->queue_limit[0]);
2275
2276         ret += tipc_snprintf(buf + ret, buf_size - ret,
2277                              "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2278                              l->next_in_no - s->recv_info, s->recv_fragments,
2279                              s->recv_fragmented, s->recv_bundles,
2280                              s->recv_bundled);
2281
2282         ret += tipc_snprintf(buf + ret, buf_size - ret,
2283                              "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2284                              l->next_out_no - s->sent_info, s->sent_fragments,
2285                              s->sent_fragmented, s->sent_bundles,
2286                              s->sent_bundled);
2287
2288         profile_total = s->msg_length_counts;
2289         if (!profile_total)
2290                 profile_total = 1;
2291
2292         ret += tipc_snprintf(buf + ret, buf_size - ret,
2293                              "  TX profile sample:%u packets  average:%u octets\n"
2294                              "  0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
2295                              "-16384:%u%% -32768:%u%% -66000:%u%%\n",
2296                              s->msg_length_counts,
2297                              s->msg_lengths_total / profile_total,
2298                              percent(s->msg_length_profile[0], profile_total),
2299                              percent(s->msg_length_profile[1], profile_total),
2300                              percent(s->msg_length_profile[2], profile_total),
2301                              percent(s->msg_length_profile[3], profile_total),
2302                              percent(s->msg_length_profile[4], profile_total),
2303                              percent(s->msg_length_profile[5], profile_total),
2304                              percent(s->msg_length_profile[6], profile_total));
2305
2306         ret += tipc_snprintf(buf + ret, buf_size - ret,
2307                              "  RX states:%u probes:%u naks:%u defs:%u"
2308                              " dups:%u\n", s->recv_states, s->recv_probes,
2309                              s->recv_nacks, s->deferred_recv, s->duplicates);
2310
2311         ret += tipc_snprintf(buf + ret, buf_size - ret,
2312                              "  TX states:%u probes:%u naks:%u acks:%u"
2313                              " dups:%u\n", s->sent_states, s->sent_probes,
2314                              s->sent_nacks, s->sent_acks, s->retransmitted);
2315
2316         ret += tipc_snprintf(buf + ret, buf_size - ret,
2317                              "  Congestion link:%u  Send queue"
2318                              " max:%u avg:%u\n", s->link_congs,
2319                              s->max_queue_sz, s->queue_sz_counts ?
2320                              (s->accu_queue_sz / s->queue_sz_counts) : 0);
2321
2322         tipc_node_unlock(node);
2323         return ret;
2324 }
2325
2326 struct sk_buff *tipc_link_cmd_show_stats(const void *req_tlv_area, int req_tlv_space)
2327 {
2328         struct sk_buff *buf;
2329         struct tlv_desc *rep_tlv;
2330         int str_len;
2331         int pb_len;
2332         char *pb;
2333
2334         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2335                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2336
2337         buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
2338         if (!buf)
2339                 return NULL;
2340
2341         rep_tlv = (struct tlv_desc *)buf->data;
2342         pb = TLV_DATA(rep_tlv);
2343         pb_len = ULTRA_STRING_MAX_LEN;
2344         str_len = tipc_link_stats((char *)TLV_DATA(req_tlv_area),
2345                                   pb, pb_len);
2346         if (!str_len) {
2347                 kfree_skb(buf);
2348                 return tipc_cfg_reply_error_string("link not found");
2349         }
2350         str_len += 1;   /* for "\0" */
2351         skb_put(buf, TLV_SPACE(str_len));
2352         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
2353
2354         return buf;
2355 }
2356
2357 /**
2358  * tipc_link_get_max_pkt - get maximum packet size to use when sending to destination
2359  * @dest: network address of destination node
2360  * @selector: used to select from set of active links
2361  *
2362  * If no active link can be found, uses default maximum packet size.
2363  */
2364 u32 tipc_link_get_max_pkt(u32 dest, u32 selector)
2365 {
2366         struct tipc_node *n_ptr;
2367         struct tipc_link *l_ptr;
2368         u32 res = MAX_PKT_DEFAULT;
2369
2370         if (dest == tipc_own_addr)
2371                 return MAX_MSG_SIZE;
2372
2373         n_ptr = tipc_node_find(dest);
2374         if (n_ptr) {
2375                 tipc_node_lock(n_ptr);
2376                 l_ptr = n_ptr->active_links[selector & 1];
2377                 if (l_ptr)
2378                         res = l_ptr->max_pkt;
2379                 tipc_node_unlock(n_ptr);
2380         }
2381         return res;
2382 }
2383
2384 static void link_print(struct tipc_link *l_ptr, const char *str)
2385 {
2386         struct tipc_bearer *b_ptr;
2387
2388         rcu_read_lock();
2389         b_ptr = rcu_dereference_rtnl(bearer_list[l_ptr->bearer_id]);
2390         if (b_ptr)
2391                 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name);
2392         rcu_read_unlock();
2393
2394         if (link_working_unknown(l_ptr))
2395                 pr_cont(":WU\n");
2396         else if (link_reset_reset(l_ptr))
2397                 pr_cont(":RR\n");
2398         else if (link_reset_unknown(l_ptr))
2399                 pr_cont(":RU\n");
2400         else if (link_working_working(l_ptr))
2401                 pr_cont(":WW\n");
2402         else
2403                 pr_cont("\n");
2404 }
2405
2406 /* Parse and validate nested (link) properties valid for media, bearer and link
2407  */
2408 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
2409 {
2410         int err;
2411
2412         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
2413                                tipc_nl_prop_policy);
2414         if (err)
2415                 return err;
2416
2417         if (props[TIPC_NLA_PROP_PRIO]) {
2418                 u32 prio;
2419
2420                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2421                 if (prio > TIPC_MAX_LINK_PRI)
2422                         return -EINVAL;
2423         }
2424
2425         if (props[TIPC_NLA_PROP_TOL]) {
2426                 u32 tol;
2427
2428                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2429                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
2430                         return -EINVAL;
2431         }
2432
2433         if (props[TIPC_NLA_PROP_WIN]) {
2434                 u32 win;
2435
2436                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2437                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
2438                         return -EINVAL;
2439         }
2440
2441         return 0;
2442 }
2443
2444 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
2445 {
2446         int err;
2447         int res = 0;
2448         int bearer_id;
2449         char *name;
2450         struct tipc_link *link;
2451         struct tipc_node *node;
2452         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2453
2454         if (!info->attrs[TIPC_NLA_LINK])
2455                 return -EINVAL;
2456
2457         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2458                                info->attrs[TIPC_NLA_LINK],
2459                                tipc_nl_link_policy);
2460         if (err)
2461                 return err;
2462
2463         if (!attrs[TIPC_NLA_LINK_NAME])
2464                 return -EINVAL;
2465
2466         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2467
2468         node = tipc_link_find_owner(name, &bearer_id);
2469         if (!node)
2470                 return -EINVAL;
2471
2472         tipc_node_lock(node);
2473
2474         link = node->links[bearer_id];
2475         if (!link) {
2476                 res = -EINVAL;
2477                 goto out;
2478         }
2479
2480         if (attrs[TIPC_NLA_LINK_PROP]) {
2481                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2482
2483                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
2484                                               props);
2485                 if (err) {
2486                         res = err;
2487                         goto out;
2488                 }
2489
2490                 if (props[TIPC_NLA_PROP_TOL]) {
2491                         u32 tol;
2492
2493                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2494                         link_set_supervision_props(link, tol);
2495                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0, 0);
2496                 }
2497                 if (props[TIPC_NLA_PROP_PRIO]) {
2498                         u32 prio;
2499
2500                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2501                         link->priority = prio;
2502                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio, 0);
2503                 }
2504                 if (props[TIPC_NLA_PROP_WIN]) {
2505                         u32 win;
2506
2507                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2508                         tipc_link_set_queue_limits(link, win);
2509                 }
2510         }
2511
2512 out:
2513         tipc_node_unlock(node);
2514
2515         return res;
2516 }
2517 int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
2518 {
2519         int i;
2520         struct nlattr *stats;
2521
2522         struct nla_map {
2523                 u32 key;
2524                 u32 val;
2525         };
2526
2527         struct nla_map map[] = {
2528                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
2529                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
2530                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
2531                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
2532                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
2533                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
2534                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
2535                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
2536                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
2537                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
2538                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
2539                         s->msg_length_counts : 1},
2540                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
2541                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
2542                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
2543                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
2544                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
2545                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
2546                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
2547                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
2548                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
2549                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
2550                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
2551                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
2552                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
2553                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
2554                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
2555                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
2556                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
2557                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
2558                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
2559                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
2560                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
2561                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
2562                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
2563         };
2564
2565         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
2566         if (!stats)
2567                 return -EMSGSIZE;
2568
2569         for (i = 0; i <  ARRAY_SIZE(map); i++)
2570                 if (nla_put_u32(skb, map[i].key, map[i].val))
2571                         goto msg_full;
2572
2573         nla_nest_end(skb, stats);
2574
2575         return 0;
2576 msg_full:
2577         nla_nest_cancel(skb, stats);
2578
2579         return -EMSGSIZE;
2580 }
2581
2582 /* Caller should hold appropriate locks to protect the link */
2583 int __tipc_nl_add_link(struct tipc_nl_msg *msg, struct tipc_link *link)
2584 {
2585         int err;
2586         void *hdr;
2587         struct nlattr *attrs;
2588         struct nlattr *prop;
2589
2590         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_v2_family,
2591                           NLM_F_MULTI, TIPC_NL_LINK_GET);
2592         if (!hdr)
2593                 return -EMSGSIZE;
2594
2595         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
2596         if (!attrs)
2597                 goto msg_full;
2598
2599         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2600                 goto attr_msg_full;
2601         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
2602                         tipc_cluster_mask(tipc_own_addr)))
2603                 goto attr_msg_full;
2604         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->max_pkt))
2605                 goto attr_msg_full;
2606         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->next_in_no))
2607                 goto attr_msg_full;
2608         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->next_out_no))
2609                 goto attr_msg_full;
2610
2611         if (tipc_link_is_up(link))
2612                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2613                         goto attr_msg_full;
2614         if (tipc_link_is_active(link))
2615                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2616                         goto attr_msg_full;
2617
2618         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2619         if (!prop)
2620                 goto attr_msg_full;
2621         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2622                 goto prop_msg_full;
2623         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2624                 goto prop_msg_full;
2625         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2626                         link->queue_limit[TIPC_LOW_IMPORTANCE]))
2627                 goto prop_msg_full;
2628         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2629                 goto prop_msg_full;
2630         nla_nest_end(msg->skb, prop);
2631
2632         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2633         if (err)
2634                 goto attr_msg_full;
2635
2636         nla_nest_end(msg->skb, attrs);
2637         genlmsg_end(msg->skb, hdr);
2638
2639         return 0;
2640
2641 prop_msg_full:
2642         nla_nest_cancel(msg->skb, prop);
2643 attr_msg_full:
2644         nla_nest_cancel(msg->skb, attrs);
2645 msg_full:
2646         genlmsg_cancel(msg->skb, hdr);
2647
2648         return -EMSGSIZE;
2649 }
2650
2651 /* Caller should hold node lock  */
2652 int __tipc_nl_add_node_links(struct tipc_nl_msg *msg, struct tipc_node *node,
2653                              u32 *prev_link)
2654 {
2655         u32 i;
2656         int err;
2657
2658         for (i = *prev_link; i < MAX_BEARERS; i++) {
2659                 *prev_link = i;
2660
2661                 if (!node->links[i])
2662                         continue;
2663
2664                 err = __tipc_nl_add_link(msg, node->links[i]);
2665                 if (err)
2666                         return err;
2667         }
2668         *prev_link = 0;
2669
2670         return 0;
2671 }
2672
2673 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2674 {
2675         struct tipc_node *node;
2676         struct tipc_nl_msg msg;
2677         u32 prev_node = cb->args[0];
2678         u32 prev_link = cb->args[1];
2679         int done = cb->args[2];
2680         int err;
2681
2682         if (done)
2683                 return 0;
2684
2685         msg.skb = skb;
2686         msg.portid = NETLINK_CB(cb->skb).portid;
2687         msg.seq = cb->nlh->nlmsg_seq;
2688
2689         rcu_read_lock();
2690
2691         if (prev_node) {
2692                 node = tipc_node_find(prev_node);
2693                 if (!node) {
2694                         /* We never set seq or call nl_dump_check_consistent()
2695                          * this means that setting prev_seq here will cause the
2696                          * consistence check to fail in the netlink callback
2697                          * handler. Resulting in the last NLMSG_DONE message
2698                          * having the NLM_F_DUMP_INTR flag set.
2699                          */
2700                         cb->prev_seq = 1;
2701                         goto out;
2702                 }
2703
2704                 list_for_each_entry_continue_rcu(node, &tipc_node_list, list) {
2705                         tipc_node_lock(node);
2706                         err = __tipc_nl_add_node_links(&msg, node, &prev_link);
2707                         tipc_node_unlock(node);
2708                         if (err)
2709                                 goto out;
2710
2711                         prev_node = node->addr;
2712                 }
2713         } else {
2714                 err = tipc_nl_add_bc_link(&msg);
2715                 if (err)
2716                         goto out;
2717
2718                 list_for_each_entry_rcu(node, &tipc_node_list, list) {
2719                         tipc_node_lock(node);
2720                         err = __tipc_nl_add_node_links(&msg, node, &prev_link);
2721                         tipc_node_unlock(node);
2722                         if (err)
2723                                 goto out;
2724
2725                         prev_node = node->addr;
2726                 }
2727         }
2728         done = 1;
2729 out:
2730         rcu_read_unlock();
2731
2732         cb->args[0] = prev_node;
2733         cb->args[1] = prev_link;
2734         cb->args[2] = done;
2735
2736         return skb->len;
2737 }
2738
2739 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2740 {
2741         struct sk_buff *ans_skb;
2742         struct tipc_nl_msg msg;
2743         struct tipc_link *link;
2744         struct tipc_node *node;
2745         char *name;
2746         int bearer_id;
2747         int err;
2748
2749         if (!info->attrs[TIPC_NLA_LINK_NAME])
2750                 return -EINVAL;
2751
2752         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2753         node = tipc_link_find_owner(name, &bearer_id);
2754         if (!node)
2755                 return -EINVAL;
2756
2757         ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2758         if (!ans_skb)
2759                 return -ENOMEM;
2760
2761         msg.skb = ans_skb;
2762         msg.portid = info->snd_portid;
2763         msg.seq = info->snd_seq;
2764
2765         tipc_node_lock(node);
2766         link = node->links[bearer_id];
2767         if (!link) {
2768                 err = -EINVAL;
2769                 goto err_out;
2770         }
2771
2772         err = __tipc_nl_add_link(&msg, link);
2773         if (err)
2774                 goto err_out;
2775
2776         tipc_node_unlock(node);
2777
2778         return genlmsg_reply(ans_skb, info);
2779
2780 err_out:
2781         tipc_node_unlock(node);
2782         nlmsg_free(ans_skb);
2783
2784         return err;
2785 }
2786
2787 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2788 {
2789         int err;
2790         char *link_name;
2791         unsigned int bearer_id;
2792         struct tipc_link *link;
2793         struct tipc_node *node;
2794         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2795
2796         if (!info->attrs[TIPC_NLA_LINK])
2797                 return -EINVAL;
2798
2799         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2800                                info->attrs[TIPC_NLA_LINK],
2801                                tipc_nl_link_policy);
2802         if (err)
2803                 return err;
2804
2805         if (!attrs[TIPC_NLA_LINK_NAME])
2806                 return -EINVAL;
2807
2808         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2809
2810         if (strcmp(link_name, tipc_bclink_name) == 0) {
2811                 err = tipc_bclink_reset_stats();
2812                 if (err)
2813                         return err;
2814                 return 0;
2815         }
2816
2817         node = tipc_link_find_owner(link_name, &bearer_id);
2818         if (!node)
2819                 return -EINVAL;
2820
2821         tipc_node_lock(node);
2822
2823         link = node->links[bearer_id];
2824         if (!link) {
2825                 tipc_node_unlock(node);
2826                 return -EINVAL;
2827         }
2828
2829         link_reset_statistics(link);
2830
2831         tipc_node_unlock(node);
2832
2833         return 0;
2834 }