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