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