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 net *net,
 105                                        struct tipc_link *l_ptr,
 106                                        struct sk_buff *buf);
 107 static void tipc_link_proto_rcv(struct net *net, struct tipc_link *l_ptr,
 108                                 struct sk_buff *buf);
 109 static int  tipc_link_tunnel_rcv(struct net *net, struct tipc_node *n_ptr,
 110                                  struct sk_buff **buf);
 111 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol);
 112 static void link_state_event(struct tipc_link *l_ptr, u32 event);
 113 static void link_reset_statistics(struct tipc_link *l_ptr);
 114 static void link_print(struct tipc_link *l_ptr, const char *str);
 115 static void tipc_link_sync_xmit(struct tipc_link *l);
 116 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 117 static int tipc_link_input(struct net *net, struct tipc_link *l,
 118                            struct sk_buff *buf);
 119 static int tipc_link_prepare_input(struct net *net, struct tipc_link *l,
 120                                    struct sk_buff **buf);
 121
 122 /*
 123  *  Simple link routines
 124  */
 125 static unsigned int align(unsigned int i)
 126 {
 127         return (i + 3) & ~3u;
 128 }
 129
 130 static void tipc_link_release(struct kref *kref)
 131 {
 132         kfree(container_of(kref, struct tipc_link, ref));
 133 }
 134
 135 static void tipc_link_get(struct tipc_link *l_ptr)
 136 {
 137         kref_get(&l_ptr->ref);
 138 }
 139
 140 static void tipc_link_put(struct tipc_link *l_ptr)
 141 {
 142         kref_put(&l_ptr->ref, tipc_link_release);
 143 }
 144
 145 static void link_init_max_pkt(struct tipc_link *l_ptr)
 146 {
 147         struct tipc_node *node = l_ptr->owner;
 148         struct tipc_net *tn = net_generic(node->net, tipc_net_id);
 149         struct tipc_bearer *b_ptr;
 150         u32 max_pkt;
 151
 152         rcu_read_lock();
 153         b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]);
 154         if (!b_ptr) {
 155                 rcu_read_unlock();
 156                 return;
 157         }
 158         max_pkt = (b_ptr->mtu & ~3);
 159         rcu_read_unlock();
 160
 161         if (max_pkt > MAX_MSG_SIZE)
 162                 max_pkt = MAX_MSG_SIZE;
 163
 164         l_ptr->max_pkt_target = max_pkt;
 165         if (l_ptr->max_pkt_target < MAX_PKT_DEFAULT)
 166                 l_ptr->max_pkt = l_ptr->max_pkt_target;
 167         else
 168                 l_ptr->max_pkt = MAX_PKT_DEFAULT;
 169
 170         l_ptr->max_pkt_probes = 0;
 171 }
 172
 173 /*
 174  *  Simple non-static link routines (i.e. referenced outside this file)
 175  */
 176 int tipc_link_is_up(struct tipc_link *l_ptr)
 177 {
 178         if (!l_ptr)
 179                 return 0;
 180         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 181 }
 182
 183 int tipc_link_is_active(struct tipc_link *l_ptr)
 184 {
 185         return  (l_ptr->owner->active_links[0] == l_ptr) ||
 186                 (l_ptr->owner->active_links[1] == l_ptr);
 187 }
 188
 189 /**
 190  * link_timeout - handle expiration of link timer
 191  * @l_ptr: pointer to link
 192  */
 193 static void link_timeout(unsigned long data)
 194 {
 195         struct tipc_link *l_ptr = (struct tipc_link *)data;
 196         struct sk_buff *skb;
 197
 198         tipc_node_lock(l_ptr->owner);
 199
 200         /* update counters used in statistical profiling of send traffic */
 201         l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->outqueue);
 202         l_ptr->stats.queue_sz_counts++;
 203
 204         skb = skb_peek(&l_ptr->outqueue);
 205         if (skb) {
 206                 struct tipc_msg *msg = buf_msg(skb);
 207                 u32 length = msg_size(msg);
 208
 209                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 210                     (msg_type(msg) == FIRST_FRAGMENT)) {
 211                         length = msg_size(msg_get_wrapped(msg));
 212                 }
 213                 if (length) {
 214                         l_ptr->stats.msg_lengths_total += length;
 215                         l_ptr->stats.msg_length_counts++;
 216                         if (length <= 64)
 217                                 l_ptr->stats.msg_length_profile[0]++;
 218                         else if (length <= 256)
 219                                 l_ptr->stats.msg_length_profile[1]++;
 220                         else if (length <= 1024)
 221                                 l_ptr->stats.msg_length_profile[2]++;
 222                         else if (length <= 4096)
 223                                 l_ptr->stats.msg_length_profile[3]++;
 224                         else if (length <= 16384)
 225                                 l_ptr->stats.msg_length_profile[4]++;
 226                         else if (length <= 32768)
 227                                 l_ptr->stats.msg_length_profile[5]++;
 228                         else
 229                                 l_ptr->stats.msg_length_profile[6]++;
 230                 }
 231         }
 232
 233         /* do all other link processing performed on a periodic basis */
 234         link_state_event(l_ptr, TIMEOUT_EVT);
 235
 236         if (l_ptr->next_out)
 237                 tipc_link_push_packets(l_ptr);
 238
 239         tipc_node_unlock(l_ptr->owner);
 240         tipc_link_put(l_ptr);
 241 }
 242
 243 static void link_set_timer(struct tipc_link *link, unsigned long time)
 244 {
 245         if (!mod_timer(&link->timer, jiffies + time))
 246                 tipc_link_get(link);
 247 }
 248
 249 /**
 250  * tipc_link_create - create a new link
 251  * @n_ptr: pointer to associated node
 252  * @b_ptr: pointer to associated bearer
 253  * @media_addr: media address to use when sending messages over link
 254  *
 255  * Returns pointer to link.
 256  */
 257 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 258                                    struct tipc_bearer *b_ptr,
 259                                    const struct tipc_media_addr *media_addr)
 260 {
 261         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 262         struct tipc_link *l_ptr;
 263         struct tipc_msg *msg;
 264         char *if_name;
 265         char addr_string[16];
 266         u32 peer = n_ptr->addr;
 267
 268         if (n_ptr->link_cnt >= MAX_BEARERS) {
 269                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 270                 pr_err("Attempt to establish %uth link to %s. Max %u allowed.\n",
 271                         n_ptr->link_cnt, addr_string, MAX_BEARERS);
 272                 return NULL;
 273         }
 274
 275         if (n_ptr->links[b_ptr->identity]) {
 276                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 277                 pr_err("Attempt to establish second link on <%s> to %s\n",
 278                        b_ptr->name, addr_string);
 279                 return NULL;
 280         }
 281
 282         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 283         if (!l_ptr) {
 284                 pr_warn("Link creation failed, no memory\n");
 285                 return NULL;
 286         }
 287         kref_init(&l_ptr->ref);
 288         l_ptr->addr = peer;
 289         if_name = strchr(b_ptr->name, ':') + 1;
 290         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 291                 tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
 292                 tipc_node(tn->own_addr),
 293                 if_name,
 294                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 295                 /* note: peer i/f name is updated by reset/activate message */
 296         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 297         l_ptr->owner = n_ptr;
 298         l_ptr->checkpoint = 1;
 299         l_ptr->peer_session = INVALID_SESSION;
 300         l_ptr->bearer_id = b_ptr->identity;
 301         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 302         l_ptr->state = RESET_UNKNOWN;
 303
 304         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 305         msg = l_ptr->pmsg;
 306         tipc_msg_init(n_ptr->net, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
 307                       l_ptr->addr);
 308         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 309         msg_set_session(msg, (tn->random & 0xffff));
 310         msg_set_bearer_id(msg, b_ptr->identity);
 311         strcpy((char *)msg_data(msg), if_name);
 312
 313         l_ptr->priority = b_ptr->priority;
 314         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 315
 316         l_ptr->net_plane = b_ptr->net_plane;
 317         link_init_max_pkt(l_ptr);
 318
 319         l_ptr->next_out_no = 1;
 320         __skb_queue_head_init(&l_ptr->outqueue);
 321         __skb_queue_head_init(&l_ptr->deferred_queue);
 322         skb_queue_head_init(&l_ptr->waiting_sks);
 323
 324         link_reset_statistics(l_ptr);
 325         tipc_node_attach_link(n_ptr, l_ptr);
 326         setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr);
 327         link_state_event(l_ptr, STARTING_EVT);
 328
 329         return l_ptr;
 330 }
 331
 332 /**
 333  * link_delete - Conditional deletion of link.
 334  *               If timer still running, real delete is done when it expires
 335  * @link: link to be deleted
 336  */
 337 void tipc_link_delete(struct tipc_link *link)
 338 {
 339         tipc_link_reset_fragments(link);
 340         tipc_node_detach_link(link->owner, link);
 341         tipc_link_put(link);
 342 }
 343
 344 void tipc_link_delete_list(struct net *net, unsigned int bearer_id,
 345                            bool shutting_down)
 346 {
 347         struct tipc_net *tn = net_generic(net, tipc_net_id);
 348         struct tipc_link *link;
 349         struct tipc_node *node;
 350
 351         rcu_read_lock();
 352         list_for_each_entry_rcu(node, &tn->node_list, list) {
 353                 tipc_node_lock(node);
 354                 link = node->links[bearer_id];
 355                 if (!link) {
 356                         tipc_node_unlock(node);
 357                         continue;
 358                 }
 359                 tipc_link_reset(link);
 360                 if (del_timer(&link->timer))
 361                         tipc_link_put(link);
 362                 link->flags |= LINK_STOPPED;
 363                 /* Delete link now, or when failover is finished: */
 364                 if (shutting_down || !tipc_node_is_up(node))
 365                         tipc_link_delete(link);
 366                 tipc_node_unlock(node);
 367         }
 368         rcu_read_unlock();
 369 }
 370
 371 /**
 372  * link_schedule_user - schedule user for wakeup after congestion
 373  * @link: congested link
 374  * @oport: sending port
 375  * @chain_sz: size of buffer chain that was attempted sent
 376  * @imp: importance of message attempted sent
 377  * Create pseudo msg to send back to user when congestion abates
 378  */
 379 static bool link_schedule_user(struct tipc_link *link, u32 oport,
 380                                uint chain_sz, uint imp)
 381 {
 382         struct net *net = link->owner->net;
 383         struct tipc_net *tn = net_generic(net, tipc_net_id);
 384         struct sk_buff *buf;
 385
 386         buf = tipc_msg_create(net, SOCK_WAKEUP, 0, INT_H_SIZE, 0, tn->own_addr,
 387                               tn->own_addr, oport, 0, 0);
 388         if (!buf)
 389                 return false;
 390         TIPC_SKB_CB(buf)->chain_sz = chain_sz;
 391         TIPC_SKB_CB(buf)->chain_imp = imp;
 392         skb_queue_tail(&link->waiting_sks, buf);
 393         link->stats.link_congs++;
 394         return true;
 395 }
 396
 397 /**
 398  * link_prepare_wakeup - prepare users for wakeup after congestion
 399  * @link: congested link
 400  * Move a number of waiting users, as permitted by available space in
 401  * the send queue, from link wait queue to node wait queue for wakeup
 402  */
 403 static void link_prepare_wakeup(struct tipc_link *link)
 404 {
 405         uint pend_qsz = skb_queue_len(&link->outqueue);
 406         struct sk_buff *skb, *tmp;
 407
 408         skb_queue_walk_safe(&link->waiting_sks, skb, tmp) {
 409                 if (pend_qsz >= link->queue_limit[TIPC_SKB_CB(skb)->chain_imp])
 410                         break;
 411                 pend_qsz += TIPC_SKB_CB(skb)->chain_sz;
 412                 skb_unlink(skb, &link->waiting_sks);
 413                 skb_queue_tail(&link->owner->waiting_sks, skb);
 414         }
 415 }
 416
 417 /**
 418  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 419  * @l_ptr: pointer to link
 420  */
 421 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 422 {
 423         kfree_skb(l_ptr->reasm_buf);
 424         l_ptr->reasm_buf = NULL;
 425 }
 426
 427 /**
 428  * tipc_link_purge_queues - purge all pkt queues associated with link
 429  * @l_ptr: pointer to link
 430  */
 431 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 432 {
 433         __skb_queue_purge(&l_ptr->deferred_queue);
 434         __skb_queue_purge(&l_ptr->outqueue);
 435         tipc_link_reset_fragments(l_ptr);
 436 }
 437
 438 void tipc_link_reset(struct tipc_link *l_ptr)
 439 {
 440         u32 prev_state = l_ptr->state;
 441         u32 checkpoint = l_ptr->next_in_no;
 442         int was_active_link = tipc_link_is_active(l_ptr);
 443         struct tipc_node *owner = l_ptr->owner;
 444
 445         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 446
 447         /* Link is down, accept any session */
 448         l_ptr->peer_session = INVALID_SESSION;
 449
 450         /* Prepare for max packet size negotiation */
 451         link_init_max_pkt(l_ptr);
 452
 453         l_ptr->state = RESET_UNKNOWN;
 454
 455         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 456                 return;
 457
 458         tipc_node_link_down(l_ptr->owner, l_ptr);
 459         tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 460
 461         if (was_active_link && tipc_node_active_links(l_ptr->owner)) {
 462                 l_ptr->reset_checkpoint = checkpoint;
 463                 l_ptr->exp_msg_count = START_CHANGEOVER;
 464         }
 465
 466         /* Clean up all queues: */
 467         __skb_queue_purge(&l_ptr->outqueue);
 468         __skb_queue_purge(&l_ptr->deferred_queue);
 469         if (!skb_queue_empty(&l_ptr->waiting_sks)) {
 470                 skb_queue_splice_init(&l_ptr->waiting_sks, &owner->waiting_sks);
 471                 owner->action_flags |= TIPC_WAKEUP_USERS;
 472         }
 473         l_ptr->next_out = NULL;
 474         l_ptr->unacked_window = 0;
 475         l_ptr->checkpoint = 1;
 476         l_ptr->next_out_no = 1;
 477         l_ptr->fsm_msg_cnt = 0;
 478         l_ptr->stale_count = 0;
 479         link_reset_statistics(l_ptr);
 480 }
 481
 482 void tipc_link_reset_list(struct net *net, unsigned int bearer_id)
 483 {
 484         struct tipc_net *tn = net_generic(net, tipc_net_id);
 485         struct tipc_link *l_ptr;
 486         struct tipc_node *n_ptr;
 487
 488         rcu_read_lock();
 489         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
 490                 tipc_node_lock(n_ptr);
 491                 l_ptr = n_ptr->links[bearer_id];
 492                 if (l_ptr)
 493                         tipc_link_reset(l_ptr);
 494                 tipc_node_unlock(n_ptr);
 495         }
 496         rcu_read_unlock();
 497 }
 498
 499 static void link_activate(struct tipc_link *link)
 500 {
 501         struct tipc_node *node = link->owner;
 502
 503         link->next_in_no = 1;
 504         link->stats.recv_info = 1;
 505         tipc_node_link_up(node, link);
 506         tipc_bearer_add_dest(node->net, link->bearer_id, link->addr);
 507 }
 508
 509 /**
 510  * link_state_event - link finite state machine
 511  * @l_ptr: pointer to link
 512  * @event: state machine event to process
 513  */
 514 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 515 {
 516         struct tipc_link *other;
 517         unsigned long cont_intv = l_ptr->cont_intv;
 518
 519         if (l_ptr->flags & LINK_STOPPED)
 520                 return;
 521
 522         if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 523                 return;         /* Not yet. */
 524
 525         /* Check whether changeover is going on */
 526         if (l_ptr->exp_msg_count) {
 527                 if (event == TIMEOUT_EVT)
 528                         link_set_timer(l_ptr, cont_intv);
 529                 return;
 530         }
 531
 532         switch (l_ptr->state) {
 533         case WORKING_WORKING:
 534                 switch (event) {
 535                 case TRAFFIC_MSG_EVT:
 536                 case ACTIVATE_MSG:
 537                         break;
 538                 case TIMEOUT_EVT:
 539                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 540                                 l_ptr->checkpoint = l_ptr->next_in_no;
 541                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 542                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 543                                                              0, 0, 0, 0, 0);
 544                                         l_ptr->fsm_msg_cnt++;
 545                                 } else if (l_ptr->max_pkt < l_ptr->max_pkt_target) {
 546                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 547                                                              1, 0, 0, 0, 0);
 548                                         l_ptr->fsm_msg_cnt++;
 549                                 }
 550                                 link_set_timer(l_ptr, cont_intv);
 551                                 break;
 552                         }
 553                         l_ptr->state = WORKING_UNKNOWN;
 554                         l_ptr->fsm_msg_cnt = 0;
 555                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 556                         l_ptr->fsm_msg_cnt++;
 557                         link_set_timer(l_ptr, cont_intv / 4);
 558                         break;
 559                 case RESET_MSG:
 560                         pr_debug("%s<%s>, requested by peer\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                 default:
 571                         pr_debug("%s%u in WW state\n", link_unk_evt, event);
 572                 }
 573                 break;
 574         case WORKING_UNKNOWN:
 575                 switch (event) {
 576                 case TRAFFIC_MSG_EVT:
 577                 case ACTIVATE_MSG:
 578                         l_ptr->state = WORKING_WORKING;
 579                         l_ptr->fsm_msg_cnt = 0;
 580                         link_set_timer(l_ptr, cont_intv);
 581                         break;
 582                 case RESET_MSG:
 583                         pr_debug("%s<%s>, requested by peer while probing\n",
 584                                  link_rst_msg, l_ptr->name);
 585                         tipc_link_reset(l_ptr);
 586                         l_ptr->state = RESET_RESET;
 587                         l_ptr->fsm_msg_cnt = 0;
 588                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 589                                              0, 0, 0, 0, 0);
 590                         l_ptr->fsm_msg_cnt++;
 591                         link_set_timer(l_ptr, cont_intv);
 592                         break;
 593                 case TIMEOUT_EVT:
 594                         if (l_ptr->next_in_no != l_ptr->checkpoint) {
 595                                 l_ptr->state = WORKING_WORKING;
 596                                 l_ptr->fsm_msg_cnt = 0;
 597                                 l_ptr->checkpoint = l_ptr->next_in_no;
 598                                 if (tipc_bclink_acks_missing(l_ptr->owner)) {
 599                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 600                                                              0, 0, 0, 0, 0);
 601                                         l_ptr->fsm_msg_cnt++;
 602                                 }
 603                                 link_set_timer(l_ptr, cont_intv);
 604                         } else if (l_ptr->fsm_msg_cnt < l_ptr->abort_limit) {
 605                                 tipc_link_proto_xmit(l_ptr, STATE_MSG,
 606                                                      1, 0, 0, 0, 0);
 607                                 l_ptr->fsm_msg_cnt++;
 608                                 link_set_timer(l_ptr, cont_intv / 4);
 609                         } else {        /* Link has failed */
 610                                 pr_debug("%s<%s>, peer not responding\n",
 611                                          link_rst_msg, l_ptr->name);
 612                                 tipc_link_reset(l_ptr);
 613                                 l_ptr->state = RESET_UNKNOWN;
 614                                 l_ptr->fsm_msg_cnt = 0;
 615                                 tipc_link_proto_xmit(l_ptr, RESET_MSG,
 616                                                      0, 0, 0, 0, 0);
 617                                 l_ptr->fsm_msg_cnt++;
 618                                 link_set_timer(l_ptr, cont_intv);
 619                         }
 620                         break;
 621                 default:
 622                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 623                 }
 624                 break;
 625         case RESET_UNKNOWN:
 626                 switch (event) {
 627                 case TRAFFIC_MSG_EVT:
 628                         break;
 629                 case ACTIVATE_MSG:
 630                         other = l_ptr->owner->active_links[0];
 631                         if (other && link_working_unknown(other))
 632                                 break;
 633                         l_ptr->state = WORKING_WORKING;
 634                         l_ptr->fsm_msg_cnt = 0;
 635                         link_activate(l_ptr);
 636                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 637                         l_ptr->fsm_msg_cnt++;
 638                         if (l_ptr->owner->working_links == 1)
 639                                 tipc_link_sync_xmit(l_ptr);
 640                         link_set_timer(l_ptr, cont_intv);
 641                         break;
 642                 case RESET_MSG:
 643                         l_ptr->state = RESET_RESET;
 644                         l_ptr->fsm_msg_cnt = 0;
 645                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 646                                              1, 0, 0, 0, 0);
 647                         l_ptr->fsm_msg_cnt++;
 648                         link_set_timer(l_ptr, cont_intv);
 649                         break;
 650                 case STARTING_EVT:
 651                         l_ptr->flags |= LINK_STARTED;
 652                         l_ptr->fsm_msg_cnt++;
 653                         link_set_timer(l_ptr, cont_intv);
 654                         break;
 655                 case TIMEOUT_EVT:
 656                         tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0, 0);
 657                         l_ptr->fsm_msg_cnt++;
 658                         link_set_timer(l_ptr, cont_intv);
 659                         break;
 660                 default:
 661                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 662                 }
 663                 break;
 664         case RESET_RESET:
 665                 switch (event) {
 666                 case TRAFFIC_MSG_EVT:
 667                 case ACTIVATE_MSG:
 668                         other = l_ptr->owner->active_links[0];
 669                         if (other && link_working_unknown(other))
 670                                 break;
 671                         l_ptr->state = WORKING_WORKING;
 672                         l_ptr->fsm_msg_cnt = 0;
 673                         link_activate(l_ptr);
 674                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0, 0);
 675                         l_ptr->fsm_msg_cnt++;
 676                         if (l_ptr->owner->working_links == 1)
 677                                 tipc_link_sync_xmit(l_ptr);
 678                         link_set_timer(l_ptr, cont_intv);
 679                         break;
 680                 case RESET_MSG:
 681                         break;
 682                 case TIMEOUT_EVT:
 683                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 684                                              0, 0, 0, 0, 0);
 685                         l_ptr->fsm_msg_cnt++;
 686                         link_set_timer(l_ptr, cont_intv);
 687                         break;
 688                 default:
 689                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 690                 }
 691                 break;
 692         default:
 693                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 694         }
 695 }
 696
 697 /* tipc_link_cong: determine return value and how to treat the
 698  * sent buffer during link congestion.
 699  * - For plain, errorless user data messages we keep the buffer and
 700  *   return -ELINKONG.
 701  * - For all other messages we discard the buffer and return -EHOSTUNREACH
 702  * - For TIPC internal messages we also reset the link
 703  */
 704 static int tipc_link_cong(struct tipc_link *link, struct sk_buff_head *list)
 705 {
 706         struct sk_buff *skb = skb_peek(list);
 707         struct tipc_msg *msg = buf_msg(skb);
 708         uint imp = tipc_msg_tot_importance(msg);
 709         u32 oport = msg_tot_origport(msg);
 710
 711         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 712                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 713                 tipc_link_reset(link);
 714                 goto drop;
 715         }
 716         if (unlikely(msg_errcode(msg)))
 717                 goto drop;
 718         if (unlikely(msg_reroute_cnt(msg)))
 719                 goto drop;
 720         if (TIPC_SKB_CB(skb)->wakeup_pending)
 721                 return -ELINKCONG;
 722         if (link_schedule_user(link, oport, skb_queue_len(list), imp))
 723                 return -ELINKCONG;
 724 drop:
 725         __skb_queue_purge(list);
 726         return -EHOSTUNREACH;
 727 }
 728
 729 /**
 730  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 731  * @link: link to use
 732  * @list: chain of buffers containing message
 733  *
 734  * Consumes the buffer chain, except when returning -ELINKCONG
 735  * Returns 0 if success, otherwise errno: -ELINKCONG, -EMSGSIZE (plain socket
 736  * user data messages) or -EHOSTUNREACH (all other messages/senders)
 737  * Only the socket functions tipc_send_stream() and tipc_send_packet() need
 738  * to act on the return value, since they may need to do more send attempts.
 739  */
 740 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 741                      struct sk_buff_head *list)
 742 {
 743         struct tipc_msg *msg = buf_msg(skb_peek(list));
 744         uint psz = msg_size(msg);
 745         uint sndlim = link->queue_limit[0];
 746         uint imp = tipc_msg_tot_importance(msg);
 747         uint mtu = link->max_pkt;
 748         uint ack = mod(link->next_in_no - 1);
 749         uint seqno = link->next_out_no;
 750         uint bc_last_in = link->owner->bclink.last_in;
 751         struct tipc_media_addr *addr = &link->media_addr;
 752         struct sk_buff_head *outqueue = &link->outqueue;
 753         struct sk_buff *skb, *tmp;
 754
 755         /* Match queue limits against msg importance: */
 756         if (unlikely(skb_queue_len(outqueue) >= link->queue_limit[imp]))
 757                 return tipc_link_cong(link, list);
 758
 759         /* Has valid packet limit been used ? */
 760         if (unlikely(psz > mtu)) {
 761                 __skb_queue_purge(list);
 762                 return -EMSGSIZE;
 763         }
 764
 765         /* Prepare each packet for sending, and add to outqueue: */
 766         skb_queue_walk_safe(list, skb, tmp) {
 767                 __skb_unlink(skb, list);
 768                 msg = buf_msg(skb);
 769                 msg_set_word(msg, 2, ((ack << 16) | mod(seqno)));
 770                 msg_set_bcast_ack(msg, bc_last_in);
 771
 772                 if (skb_queue_len(outqueue) < sndlim) {
 773                         __skb_queue_tail(outqueue, skb);
 774                         tipc_bearer_send(net, link->bearer_id,
 775                                          skb, addr);
 776                         link->next_out = NULL;
 777                         link->unacked_window = 0;
 778                 } else if (tipc_msg_bundle(outqueue, skb, mtu)) {
 779                         link->stats.sent_bundled++;
 780                         continue;
 781                 } else if (tipc_msg_make_bundle(net, outqueue, skb, mtu,
 782                                                 link->addr)) {
 783                         link->stats.sent_bundled++;
 784                         link->stats.sent_bundles++;
 785                         if (!link->next_out)
 786                                 link->next_out = skb_peek_tail(outqueue);
 787                 } else {
 788                         __skb_queue_tail(outqueue, skb);
 789                         if (!link->next_out)
 790                                 link->next_out = skb;
 791                 }
 792                 seqno++;
 793         }
 794         link->next_out_no = seqno;
 795         return 0;
 796 }
 797
 798 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
 799 {
 800         __skb_queue_head_init(list);
 801         __skb_queue_tail(list, skb);
 802 }
 803
 804 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 805 {
 806         struct sk_buff_head head;
 807
 808         skb2list(skb, &head);
 809         return __tipc_link_xmit(link->owner->net, link, &head);
 810 }
 811
 812 int tipc_link_xmit_skb(struct net *net, struct sk_buff *skb, u32 dnode,
 813                        u32 selector)
 814 {
 815         struct sk_buff_head head;
 816
 817         skb2list(skb, &head);
 818         return tipc_link_xmit(net, &head, dnode, selector);
 819 }
 820
 821 /**
 822  * tipc_link_xmit() is the general link level function for message sending
 823  * @net: the applicable net namespace
 824  * @list: chain of buffers containing message
 825  * @dsz: amount of user data to be sent
 826  * @dnode: address of destination node
 827  * @selector: a number used for deterministic link selection
 828  * Consumes the buffer chain, except when returning -ELINKCONG
 829  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 830  */
 831 int tipc_link_xmit(struct net *net, struct sk_buff_head *list, u32 dnode,
 832                    u32 selector)
 833 {
 834         struct tipc_link *link = NULL;
 835         struct tipc_node *node;
 836         int rc = -EHOSTUNREACH;
 837
 838         node = tipc_node_find(net, dnode);
 839         if (node) {
 840                 tipc_node_lock(node);
 841                 link = node->active_links[selector & 1];
 842                 if (link)
 843                         rc = __tipc_link_xmit(net, link, list);
 844                 tipc_node_unlock(node);
 845         }
 846
 847         if (link)
 848                 return rc;
 849
 850         if (likely(in_own_node(net, dnode))) {
 851                 /* As a node local message chain never contains more than one
 852                  * buffer, we just need to dequeue one SKB buffer from the
 853                  * head list.
 854                  */
 855                 return tipc_sk_rcv(net, __skb_dequeue(list));
 856         }
 857         __skb_queue_purge(list);
 858
 859         return rc;
 860 }
 861
 862 /*
 863  * tipc_link_sync_xmit - synchronize broadcast link endpoints.
 864  *
 865  * Give a newly added peer node the sequence number where it should
 866  * start receiving and acking broadcast packets.
 867  *
 868  * Called with node locked
 869  */
 870 static void tipc_link_sync_xmit(struct tipc_link *link)
 871 {
 872         struct sk_buff *skb;
 873         struct tipc_msg *msg;
 874
 875         skb = tipc_buf_acquire(INT_H_SIZE);
 876         if (!skb)
 877                 return;
 878
 879         msg = buf_msg(skb);
 880         tipc_msg_init(link->owner->net, msg, BCAST_PROTOCOL, STATE_MSG,
 881                       INT_H_SIZE, link->addr);
 882         msg_set_last_bcast(msg, link->owner->bclink.acked);
 883         __tipc_link_xmit_skb(link, skb);
 884 }
 885
 886 /*
 887  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 888  * Receive the sequence number where we should start receiving and
 889  * acking broadcast packets from a newly added peer node, and open
 890  * up for reception of such packets.
 891  *
 892  * Called with node locked
 893  */
 894 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 895 {
 896         struct tipc_msg *msg = buf_msg(buf);
 897
 898         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 899         n->bclink.recv_permitted = true;
 900         kfree_skb(buf);
 901 }
 902
 903 struct sk_buff *tipc_skb_queue_next(const struct sk_buff_head *list,
 904                                     const struct sk_buff *skb)
 905 {
 906         if (skb_queue_is_last(list, skb))
 907                 return NULL;
 908         return skb->next;
 909 }
 910
 911 /*
 912  * tipc_link_push_packets - push unsent packets to bearer
 913  *
 914  * Push out the unsent messages of a link where congestion
 915  * has abated. Node is locked.
 916  *
 917  * Called with node locked
 918  */
 919 void tipc_link_push_packets(struct tipc_link *l_ptr)
 920 {
 921         struct sk_buff_head *outqueue = &l_ptr->outqueue;
 922         struct sk_buff *skb = l_ptr->next_out;
 923         struct tipc_msg *msg;
 924         u32 next, first;
 925
 926         skb_queue_walk_from(outqueue, skb) {
 927                 msg = buf_msg(skb);
 928                 next = msg_seqno(msg);
 929                 first = buf_seqno(skb_peek(outqueue));
 930
 931                 if (mod(next - first) < l_ptr->queue_limit[0]) {
 932                         msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
 933                         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 934                         if (msg_user(msg) == MSG_BUNDLER)
 935                                 TIPC_SKB_CB(skb)->bundling = false;
 936                         tipc_bearer_send(l_ptr->owner->net,
 937                                          l_ptr->bearer_id, skb,
 938                                          &l_ptr->media_addr);
 939                         l_ptr->next_out = tipc_skb_queue_next(outqueue, skb);
 940                 } else {
 941                         break;
 942                 }
 943         }
 944 }
 945
 946 void tipc_link_reset_all(struct tipc_node *node)
 947 {
 948         char addr_string[16];
 949         u32 i;
 950
 951         tipc_node_lock(node);
 952
 953         pr_warn("Resetting all links to %s\n",
 954                 tipc_addr_string_fill(addr_string, node->addr));
 955
 956         for (i = 0; i < MAX_BEARERS; i++) {
 957                 if (node->links[i]) {
 958                         link_print(node->links[i], "Resetting link\n");
 959                         tipc_link_reset(node->links[i]);
 960                 }
 961         }
 962
 963         tipc_node_unlock(node);
 964 }
 965
 966 static void link_retransmit_failure(struct tipc_link *l_ptr,
 967                                     struct sk_buff *buf)
 968 {
 969         struct tipc_msg *msg = buf_msg(buf);
 970         struct net *net = l_ptr->owner->net;
 971
 972         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 973
 974         if (l_ptr->addr) {
 975                 /* Handle failure on standard link */
 976                 link_print(l_ptr, "Resetting link\n");
 977                 tipc_link_reset(l_ptr);
 978
 979         } else {
 980                 /* Handle failure on broadcast link */
 981                 struct tipc_node *n_ptr;
 982                 char addr_string[16];
 983
 984                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 985                 pr_cont("Outstanding acks: %lu\n",
 986                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 987
 988                 n_ptr = tipc_bclink_retransmit_to(net);
 989                 tipc_node_lock(n_ptr);
 990
 991                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 992                 pr_info("Broadcast link info for %s\n", addr_string);
 993                 pr_info("Reception permitted: %d,  Acked: %u\n",
 994                         n_ptr->bclink.recv_permitted,
 995                         n_ptr->bclink.acked);
 996                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 997                         n_ptr->bclink.last_in,
 998                         n_ptr->bclink.oos_state,
 999                         n_ptr->bclink.last_sent);
1000
1001                 tipc_node_unlock(n_ptr);
1002
1003                 tipc_bclink_set_flags(net, TIPC_BCLINK_RESET);
1004                 l_ptr->stale_count = 0;
1005         }
1006 }
1007
1008 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
1009                           u32 retransmits)
1010 {
1011         struct tipc_msg *msg;
1012
1013         if (!skb)
1014                 return;
1015
1016         msg = buf_msg(skb);
1017
1018         /* Detect repeated retransmit failures */
1019         if (l_ptr->last_retransmitted == msg_seqno(msg)) {
1020                 if (++l_ptr->stale_count > 100) {
1021                         link_retransmit_failure(l_ptr, skb);
1022                         return;
1023                 }
1024         } else {
1025                 l_ptr->last_retransmitted = msg_seqno(msg);
1026                 l_ptr->stale_count = 1;
1027         }
1028
1029         skb_queue_walk_from(&l_ptr->outqueue, skb) {
1030                 if (!retransmits || skb == l_ptr->next_out)
1031                         break;
1032                 msg = buf_msg(skb);
1033                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1034                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1035                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
1036                                  &l_ptr->media_addr);
1037                 retransmits--;
1038                 l_ptr->stats.retransmitted++;
1039         }
1040 }
1041
1042 static void link_retrieve_defq(struct tipc_link *link,
1043                                struct sk_buff_head *list)
1044 {
1045         u32 seq_no;
1046
1047         if (skb_queue_empty(&link->deferred_queue))
1048                 return;
1049
1050         seq_no = buf_seqno(skb_peek(&link->deferred_queue));
1051         if (seq_no == mod(link->next_in_no))
1052                 skb_queue_splice_tail_init(&link->deferred_queue, list);
1053 }
1054
1055 /**
1056  * link_recv_buf_validate - validate basic format of received message
1057  *
1058  * This routine ensures a TIPC message has an acceptable header, and at least
1059  * as much data as the header indicates it should.  The routine also ensures
1060  * that the entire message header is stored in the main fragment of the message
1061  * buffer, to simplify future access to message header fields.
1062  *
1063  * Note: Having extra info present in the message header or data areas is OK.
1064  * TIPC will ignore the excess, under the assumption that it is optional info
1065  * introduced by a later release of the protocol.
1066  */
1067 static int link_recv_buf_validate(struct sk_buff *buf)
1068 {
1069         static u32 min_data_hdr_size[8] = {
1070                 SHORT_H_SIZE, MCAST_H_SIZE, NAMED_H_SIZE, BASIC_H_SIZE,
1071                 MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE, MAX_H_SIZE
1072                 };
1073
1074         struct tipc_msg *msg;
1075         u32 tipc_hdr[2];
1076         u32 size;
1077         u32 hdr_size;
1078         u32 min_hdr_size;
1079
1080         /* If this packet comes from the defer queue, the skb has already
1081          * been validated
1082          */
1083         if (unlikely(TIPC_SKB_CB(buf)->deferred))
1084                 return 1;
1085
1086         if (unlikely(buf->len < MIN_H_SIZE))
1087                 return 0;
1088
1089         msg = skb_header_pointer(buf, 0, sizeof(tipc_hdr), tipc_hdr);
1090         if (msg == NULL)
1091                 return 0;
1092
1093         if (unlikely(msg_version(msg) != TIPC_VERSION))
1094                 return 0;
1095
1096         size = msg_size(msg);
1097         hdr_size = msg_hdr_sz(msg);
1098         min_hdr_size = msg_isdata(msg) ?
1099                 min_data_hdr_size[msg_type(msg)] : INT_H_SIZE;
1100
1101         if (unlikely((hdr_size < min_hdr_size) ||
1102                      (size < hdr_size) ||
1103                      (buf->len < size) ||
1104                      (size - hdr_size > TIPC_MAX_USER_MSG_SIZE)))
1105                 return 0;
1106
1107         return pskb_may_pull(buf, hdr_size);
1108 }
1109
1110 /**
1111  * tipc_rcv - process TIPC packets/messages arriving from off-node
1112  * @net: the applicable net namespace
1113  * @skb: TIPC packet
1114  * @b_ptr: pointer to bearer message arrived on
1115  *
1116  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1117  * structure (i.e. cannot be NULL), but bearer can be inactive.
1118  */
1119 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
1120 {
1121         struct tipc_net *tn = net_generic(net, tipc_net_id);
1122         struct sk_buff_head head;
1123         struct tipc_node *n_ptr;
1124         struct tipc_link *l_ptr;
1125         struct sk_buff *skb1, *tmp;
1126         struct tipc_msg *msg;
1127         u32 seq_no;
1128         u32 ackd;
1129         u32 released;
1130
1131         skb2list(skb, &head);
1132
1133         while ((skb = __skb_dequeue(&head))) {
1134                 /* Ensure message is well-formed */
1135                 if (unlikely(!link_recv_buf_validate(skb)))
1136                         goto discard;
1137
1138                 /* Ensure message data is a single contiguous unit */
1139                 if (unlikely(skb_linearize(skb)))
1140                         goto discard;
1141
1142                 /* Handle arrival of a non-unicast link message */
1143                 msg = buf_msg(skb);
1144
1145                 if (unlikely(msg_non_seq(msg))) {
1146                         if (msg_user(msg) ==  LINK_CONFIG)
1147                                 tipc_disc_rcv(net, skb, b_ptr);
1148                         else
1149                                 tipc_bclink_rcv(net, skb);
1150                         continue;
1151                 }
1152
1153                 /* Discard unicast link messages destined for another node */
1154                 if (unlikely(!msg_short(msg) &&
1155                              (msg_destnode(msg) != tn->own_addr)))
1156                         goto discard;
1157
1158                 /* Locate neighboring node that sent message */
1159                 n_ptr = tipc_node_find(net, msg_prevnode(msg));
1160                 if (unlikely(!n_ptr))
1161                         goto discard;
1162                 tipc_node_lock(n_ptr);
1163
1164                 /* Locate unicast link endpoint that should handle message */
1165                 l_ptr = n_ptr->links[b_ptr->identity];
1166                 if (unlikely(!l_ptr))
1167                         goto unlock_discard;
1168
1169                 /* Verify that communication with node is currently allowed */
1170                 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
1171                     msg_user(msg) == LINK_PROTOCOL &&
1172                     (msg_type(msg) == RESET_MSG ||
1173                     msg_type(msg) == ACTIVATE_MSG) &&
1174                     !msg_redundant_link(msg))
1175                         n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
1176
1177                 if (tipc_node_blocked(n_ptr))
1178                         goto unlock_discard;
1179
1180                 /* Validate message sequence number info */
1181                 seq_no = msg_seqno(msg);
1182                 ackd = msg_ack(msg);
1183
1184                 /* Release acked messages */
1185                 if (n_ptr->bclink.recv_permitted)
1186                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1187
1188                 released = 0;
1189                 skb_queue_walk_safe(&l_ptr->outqueue, skb1, tmp) {
1190                         if (skb1 == l_ptr->next_out ||
1191                             more(buf_seqno(skb1), ackd))
1192                                 break;
1193                          __skb_unlink(skb1, &l_ptr->outqueue);
1194                          kfree_skb(skb1);
1195                          released = 1;
1196                 }
1197
1198                 /* Try sending any messages link endpoint has pending */
1199                 if (unlikely(l_ptr->next_out))
1200                         tipc_link_push_packets(l_ptr);
1201
1202                 if (released && !skb_queue_empty(&l_ptr->waiting_sks)) {
1203                         link_prepare_wakeup(l_ptr);
1204                         l_ptr->owner->action_flags |= TIPC_WAKEUP_USERS;
1205                 }
1206
1207                 /* Process the incoming packet */
1208                 if (unlikely(!link_working_working(l_ptr))) {
1209                         if (msg_user(msg) == LINK_PROTOCOL) {
1210                                 tipc_link_proto_rcv(net, l_ptr, skb);
1211                                 link_retrieve_defq(l_ptr, &head);
1212                                 tipc_node_unlock(n_ptr);
1213                                 continue;
1214                         }
1215
1216                         /* Traffic message. Conditionally activate link */
1217                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1218
1219                         if (link_working_working(l_ptr)) {
1220                                 /* Re-insert buffer in front of queue */
1221                                 __skb_queue_head(&head, skb);
1222                                 tipc_node_unlock(n_ptr);
1223                                 continue;
1224                         }
1225                         goto unlock_discard;
1226                 }
1227
1228                 /* Link is now in state WORKING_WORKING */
1229                 if (unlikely(seq_no != mod(l_ptr->next_in_no))) {
1230                         link_handle_out_of_seq_msg(net, l_ptr, skb);
1231                         link_retrieve_defq(l_ptr, &head);
1232                         tipc_node_unlock(n_ptr);
1233                         continue;
1234                 }
1235                 l_ptr->next_in_no++;
1236                 if (unlikely(!skb_queue_empty(&l_ptr->deferred_queue)))
1237                         link_retrieve_defq(l_ptr, &head);
1238
1239                 if (unlikely(++l_ptr->unacked_window >= TIPC_MIN_LINK_WIN)) {
1240                         l_ptr->stats.sent_acks++;
1241                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1242                 }
1243
1244                 if (tipc_link_prepare_input(net, l_ptr, &skb)) {
1245                         tipc_node_unlock(n_ptr);
1246                         continue;
1247                 }
1248                 tipc_node_unlock(n_ptr);
1249
1250                 if (tipc_link_input(net, l_ptr, skb) != 0)
1251                         goto discard;
1252                 continue;
1253 unlock_discard:
1254                 tipc_node_unlock(n_ptr);
1255 discard:
1256                 kfree_skb(skb);
1257         }
1258 }
1259
1260 /**
1261  * tipc_link_prepare_input - process TIPC link messages
1262  *
1263  * returns nonzero if the message was consumed
1264  *
1265  * Node lock must be held
1266  */
1267 static int tipc_link_prepare_input(struct net *net, struct tipc_link *l,
1268                                    struct sk_buff **buf)
1269 {
1270         struct tipc_node *n;
1271         struct tipc_msg *msg;
1272         int res = -EINVAL;
1273
1274         n = l->owner;
1275         msg = buf_msg(*buf);
1276         switch (msg_user(msg)) {
1277         case CHANGEOVER_PROTOCOL:
1278                 if (tipc_link_tunnel_rcv(net, n, buf))
1279                         res = 0;
1280                 break;
1281         case MSG_FRAGMENTER:
1282                 l->stats.recv_fragments++;
1283                 if (tipc_buf_append(&l->reasm_buf, buf)) {
1284                         l->stats.recv_fragmented++;
1285                         res = 0;
1286                 } else if (!l->reasm_buf) {
1287                         tipc_link_reset(l);
1288                 }
1289                 break;
1290         case MSG_BUNDLER:
1291                 l->stats.recv_bundles++;
1292                 l->stats.recv_bundled += msg_msgcnt(msg);
1293                 res = 0;
1294                 break;
1295         case NAME_DISTRIBUTOR:
1296                 n->bclink.recv_permitted = true;
1297                 res = 0;
1298                 break;
1299         case BCAST_PROTOCOL:
1300                 tipc_link_sync_rcv(n, *buf);
1301                 break;
1302         default:
1303                 res = 0;
1304         }
1305         return res;
1306 }
1307 /**
1308  * tipc_link_input - Deliver message too higher layers
1309  */
1310 static int tipc_link_input(struct net *net, struct tipc_link *l,
1311                            struct sk_buff *buf)
1312 {
1313         struct tipc_msg *msg = buf_msg(buf);
1314         int res = 0;
1315
1316         switch (msg_user(msg)) {
1317         case TIPC_LOW_IMPORTANCE:
1318         case TIPC_MEDIUM_IMPORTANCE:
1319         case TIPC_HIGH_IMPORTANCE:
1320         case TIPC_CRITICAL_IMPORTANCE:
1321         case CONN_MANAGER:
1322                 tipc_sk_rcv(net, buf);
1323                 break;
1324         case NAME_DISTRIBUTOR:
1325                 tipc_named_rcv(net, buf);
1326                 break;
1327         case MSG_BUNDLER:
1328                 tipc_link_bundle_rcv(net, buf);
1329                 break;
1330         default:
1331                 res = -EINVAL;
1332         }
1333         return res;
1334 }
1335
1336 /**
1337  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1338  *
1339  * Returns increase in queue length (i.e. 0 or 1)
1340  */
1341 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1342 {
1343         struct sk_buff *skb1;
1344         u32 seq_no = buf_seqno(skb);
1345
1346         /* Empty queue ? */
1347         if (skb_queue_empty(list)) {
1348                 __skb_queue_tail(list, skb);
1349                 return 1;
1350         }
1351
1352         /* Last ? */
1353         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1354                 __skb_queue_tail(list, skb);
1355                 return 1;
1356         }
1357
1358         /* Locate insertion point in queue, then insert; discard if duplicate */
1359         skb_queue_walk(list, skb1) {
1360                 u32 curr_seqno = buf_seqno(skb1);
1361
1362                 if (seq_no == curr_seqno) {
1363                         kfree_skb(skb);
1364                         return 0;
1365                 }
1366
1367                 if (less(seq_no, curr_seqno))
1368                         break;
1369         }
1370
1371         __skb_queue_before(list, skb1, skb);
1372         return 1;
1373 }
1374
1375 /*
1376  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1377  */
1378 static void link_handle_out_of_seq_msg(struct net *net,
1379                                        struct tipc_link *l_ptr,
1380                                        struct sk_buff *buf)
1381 {
1382         u32 seq_no = buf_seqno(buf);
1383
1384         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1385                 tipc_link_proto_rcv(net, l_ptr, buf);
1386                 return;
1387         }
1388
1389         /* Record OOS packet arrival (force mismatch on next timeout) */
1390         l_ptr->checkpoint--;
1391
1392         /*
1393          * Discard packet if a duplicate; otherwise add it to deferred queue
1394          * and notify peer of gap as per protocol specification
1395          */
1396         if (less(seq_no, mod(l_ptr->next_in_no))) {
1397                 l_ptr->stats.duplicates++;
1398                 kfree_skb(buf);
1399                 return;
1400         }
1401
1402         if (tipc_link_defer_pkt(&l_ptr->deferred_queue, buf)) {
1403                 l_ptr->stats.deferred_recv++;
1404                 TIPC_SKB_CB(buf)->deferred = true;
1405                 if ((skb_queue_len(&l_ptr->deferred_queue) % 16) == 1)
1406                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
1407         } else {
1408                 l_ptr->stats.duplicates++;
1409         }
1410 }
1411
1412 /*
1413  * Send protocol message to the other endpoint.
1414  */
1415 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1416                           u32 gap, u32 tolerance, u32 priority, u32 ack_mtu)
1417 {
1418         struct sk_buff *buf = NULL;
1419         struct tipc_msg *msg = l_ptr->pmsg;
1420         u32 msg_size = sizeof(l_ptr->proto_msg);
1421         int r_flag;
1422
1423         /* Don't send protocol message during link changeover */
1424         if (l_ptr->exp_msg_count)
1425                 return;
1426
1427         /* Abort non-RESET send if communication with node is prohibited */
1428         if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG))
1429                 return;
1430
1431         /* Create protocol message with "out-of-sequence" sequence number */
1432         msg_set_type(msg, msg_typ);
1433         msg_set_net_plane(msg, l_ptr->net_plane);
1434         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1435         msg_set_last_bcast(msg, tipc_bclink_get_last_sent(l_ptr->owner->net));
1436
1437         if (msg_typ == STATE_MSG) {
1438                 u32 next_sent = mod(l_ptr->next_out_no);
1439
1440                 if (!tipc_link_is_up(l_ptr))
1441                         return;
1442                 if (l_ptr->next_out)
1443                         next_sent = buf_seqno(l_ptr->next_out);
1444                 msg_set_next_sent(msg, next_sent);
1445                 if (!skb_queue_empty(&l_ptr->deferred_queue)) {
1446                         u32 rec = buf_seqno(skb_peek(&l_ptr->deferred_queue));
1447                         gap = mod(rec - mod(l_ptr->next_in_no));
1448                 }
1449                 msg_set_seq_gap(msg, gap);
1450                 if (gap)
1451                         l_ptr->stats.sent_nacks++;
1452                 msg_set_link_tolerance(msg, tolerance);
1453                 msg_set_linkprio(msg, priority);
1454                 msg_set_max_pkt(msg, ack_mtu);
1455                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));
1456                 msg_set_probe(msg, probe_msg != 0);
1457                 if (probe_msg) {
1458                         u32 mtu = l_ptr->max_pkt;
1459
1460                         if ((mtu < l_ptr->max_pkt_target) &&
1461                             link_working_working(l_ptr) &&
1462                             l_ptr->fsm_msg_cnt) {
1463                                 msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1464                                 if (l_ptr->max_pkt_probes == 10) {
1465                                         l_ptr->max_pkt_target = (msg_size - 4);
1466                                         l_ptr->max_pkt_probes = 0;
1467                                         msg_size = (mtu + (l_ptr->max_pkt_target - mtu)/2 + 2) & ~3;
1468                                 }
1469                                 l_ptr->max_pkt_probes++;
1470                         }
1471
1472                         l_ptr->stats.sent_probes++;
1473                 }
1474                 l_ptr->stats.sent_states++;
1475         } else {                /* RESET_MSG or ACTIVATE_MSG */
1476                 msg_set_ack(msg, mod(l_ptr->reset_checkpoint - 1));
1477                 msg_set_seq_gap(msg, 0);
1478                 msg_set_next_sent(msg, 1);
1479                 msg_set_probe(msg, 0);
1480                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1481                 msg_set_linkprio(msg, l_ptr->priority);
1482                 msg_set_max_pkt(msg, l_ptr->max_pkt_target);
1483         }
1484
1485         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1486         msg_set_redundant_link(msg, r_flag);
1487         msg_set_linkprio(msg, l_ptr->priority);
1488         msg_set_size(msg, msg_size);
1489
1490         msg_set_seqno(msg, mod(l_ptr->next_out_no + (0xffff/2)));
1491
1492         buf = tipc_buf_acquire(msg_size);
1493         if (!buf)
1494                 return;
1495
1496         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1497         buf->priority = TC_PRIO_CONTROL;
1498
1499         tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, buf,
1500                          &l_ptr->media_addr);
1501         l_ptr->unacked_window = 0;
1502         kfree_skb(buf);
1503 }
1504
1505 /*
1506  * Receive protocol message :
1507  * Note that network plane id propagates through the network, and may
1508  * change at any time. The node with lowest address rules
1509  */
1510 static void tipc_link_proto_rcv(struct net *net, struct tipc_link *l_ptr,
1511                                 struct sk_buff *buf)
1512 {
1513         struct tipc_net *tn = net_generic(net, tipc_net_id);
1514         u32 rec_gap = 0;
1515         u32 max_pkt_info;
1516         u32 max_pkt_ack;
1517         u32 msg_tol;
1518         struct tipc_msg *msg = buf_msg(buf);
1519
1520         /* Discard protocol message during link changeover */
1521         if (l_ptr->exp_msg_count)
1522                 goto exit;
1523
1524         if (l_ptr->net_plane != msg_net_plane(msg))
1525                 if (tn->own_addr > msg_prevnode(msg))
1526                         l_ptr->net_plane = msg_net_plane(msg);
1527
1528         switch (msg_type(msg)) {
1529
1530         case RESET_MSG:
1531                 if (!link_working_unknown(l_ptr) &&
1532                     (l_ptr->peer_session != INVALID_SESSION)) {
1533                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1534                                 break; /* duplicate or old reset: ignore */
1535                 }
1536
1537                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1538                                 link_working_unknown(l_ptr))) {
1539                         /*
1540                          * peer has lost contact -- don't allow peer's links
1541                          * to reactivate before we recognize loss & clean up
1542                          */
1543                         l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
1544                 }
1545
1546                 link_state_event(l_ptr, RESET_MSG);
1547
1548                 /* fall thru' */
1549         case ACTIVATE_MSG:
1550                 /* Update link settings according other endpoint's values */
1551                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1552
1553                 msg_tol = msg_link_tolerance(msg);
1554                 if (msg_tol > l_ptr->tolerance)
1555                         link_set_supervision_props(l_ptr, msg_tol);
1556
1557                 if (msg_linkprio(msg) > l_ptr->priority)
1558                         l_ptr->priority = msg_linkprio(msg);
1559
1560                 max_pkt_info = msg_max_pkt(msg);
1561                 if (max_pkt_info) {
1562                         if (max_pkt_info < l_ptr->max_pkt_target)
1563                                 l_ptr->max_pkt_target = max_pkt_info;
1564                         if (l_ptr->max_pkt > l_ptr->max_pkt_target)
1565                                 l_ptr->max_pkt = l_ptr->max_pkt_target;
1566                 } else {
1567                         l_ptr->max_pkt = l_ptr->max_pkt_target;
1568                 }
1569
1570                 /* Synchronize broadcast link info, if not done previously */
1571                 if (!tipc_node_is_up(l_ptr->owner)) {
1572                         l_ptr->owner->bclink.last_sent =
1573                                 l_ptr->owner->bclink.last_in =
1574                                 msg_last_bcast(msg);
1575                         l_ptr->owner->bclink.oos_state = 0;
1576                 }
1577
1578                 l_ptr->peer_session = msg_session(msg);
1579                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1580
1581                 if (msg_type(msg) == ACTIVATE_MSG)
1582                         link_state_event(l_ptr, ACTIVATE_MSG);
1583                 break;
1584         case STATE_MSG:
1585
1586                 msg_tol = msg_link_tolerance(msg);
1587                 if (msg_tol)
1588                         link_set_supervision_props(l_ptr, msg_tol);
1589
1590                 if (msg_linkprio(msg) &&
1591                     (msg_linkprio(msg) != l_ptr->priority)) {
1592                         pr_debug("%s<%s>, priority change %u->%u\n",
1593                                  link_rst_msg, l_ptr->name,
1594                                  l_ptr->priority, msg_linkprio(msg));
1595                         l_ptr->priority = msg_linkprio(msg);
1596                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1597                         break;
1598                 }
1599
1600                 /* Record reception; force mismatch at next timeout: */
1601                 l_ptr->checkpoint--;
1602
1603                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1604                 l_ptr->stats.recv_states++;
1605                 if (link_reset_unknown(l_ptr))
1606                         break;
1607
1608                 if (less_eq(mod(l_ptr->next_in_no), msg_next_sent(msg))) {
1609                         rec_gap = mod(msg_next_sent(msg) -
1610                                       mod(l_ptr->next_in_no));
1611                 }
1612
1613                 max_pkt_ack = msg_max_pkt(msg);
1614                 if (max_pkt_ack > l_ptr->max_pkt) {
1615                         l_ptr->max_pkt = max_pkt_ack;
1616                         l_ptr->max_pkt_probes = 0;
1617                 }
1618
1619                 max_pkt_ack = 0;
1620                 if (msg_probe(msg)) {
1621                         l_ptr->stats.recv_probes++;
1622                         if (msg_size(msg) > sizeof(l_ptr->proto_msg))
1623                                 max_pkt_ack = msg_size(msg);
1624                 }
1625
1626                 /* Protocol message before retransmits, reduce loss risk */
1627                 if (l_ptr->owner->bclink.recv_permitted)
1628                         tipc_bclink_update_link_state(net, l_ptr->owner,
1629                                                       msg_last_bcast(msg));
1630
1631                 if (rec_gap || (msg_probe(msg))) {
1632                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, rec_gap, 0,
1633                                              0, max_pkt_ack);
1634                 }
1635                 if (msg_seq_gap(msg)) {
1636                         l_ptr->stats.recv_nacks++;
1637                         tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->outqueue),
1638                                              msg_seq_gap(msg));
1639                 }
1640                 break;
1641         }
1642 exit:
1643         kfree_skb(buf);
1644 }
1645
1646
1647 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1648  * a different bearer. Owner node is locked.
1649  */
1650 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1651                                   struct tipc_msg *tunnel_hdr,
1652                                   struct tipc_msg *msg,
1653                                   u32 selector)
1654 {
1655         struct tipc_link *tunnel;
1656         struct sk_buff *skb;
1657         u32 length = msg_size(msg);
1658
1659         tunnel = l_ptr->owner->active_links[selector & 1];
1660         if (!tipc_link_is_up(tunnel)) {
1661                 pr_warn("%stunnel link no longer available\n", link_co_err);
1662                 return;
1663         }
1664         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1665         skb = tipc_buf_acquire(length + INT_H_SIZE);
1666         if (!skb) {
1667                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1668                 return;
1669         }
1670         skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
1671         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
1672         __tipc_link_xmit_skb(tunnel, skb);
1673 }
1674
1675
1676 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1677  * link is still active. We can do failover. Tunnel the failing link's
1678  * whole send queue via the remaining link. This way, we don't lose
1679  * any packets, and sequence order is preserved for subsequent traffic
1680  * sent over the remaining link. Owner node is locked.
1681  */
1682 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1683 {
1684         u32 msgcount = skb_queue_len(&l_ptr->outqueue);
1685         struct tipc_link *tunnel = l_ptr->owner->active_links[0];
1686         struct tipc_msg tunnel_hdr;
1687         struct sk_buff *skb;
1688         int split_bundles;
1689
1690         if (!tunnel)
1691                 return;
1692
1693         tipc_msg_init(l_ptr->owner->net, &tunnel_hdr, CHANGEOVER_PROTOCOL,
1694                       ORIGINAL_MSG, INT_H_SIZE, l_ptr->addr);
1695         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1696         msg_set_msgcnt(&tunnel_hdr, msgcount);
1697
1698         if (skb_queue_empty(&l_ptr->outqueue)) {
1699                 skb = tipc_buf_acquire(INT_H_SIZE);
1700                 if (skb) {
1701                         skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
1702                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1703                         __tipc_link_xmit_skb(tunnel, skb);
1704                 } else {
1705                         pr_warn("%sunable to send changeover msg\n",
1706                                 link_co_err);
1707                 }
1708                 return;
1709         }
1710
1711         split_bundles = (l_ptr->owner->active_links[0] !=
1712                          l_ptr->owner->active_links[1]);
1713
1714         skb_queue_walk(&l_ptr->outqueue, skb) {
1715                 struct tipc_msg *msg = buf_msg(skb);
1716
1717                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1718                         struct tipc_msg *m = msg_get_wrapped(msg);
1719                         unchar *pos = (unchar *)m;
1720
1721                         msgcount = msg_msgcnt(msg);
1722                         while (msgcount--) {
1723                                 msg_set_seqno(m, msg_seqno(msg));
1724                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1725                                                       msg_link_selector(m));
1726                                 pos += align(msg_size(m));
1727                                 m = (struct tipc_msg *)pos;
1728                         }
1729                 } else {
1730                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1731                                               msg_link_selector(msg));
1732                 }
1733         }
1734 }
1735
1736 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1737  * duplicate of the first link's send queue via the new link. This way, we
1738  * are guaranteed that currently queued packets from a socket are delivered
1739  * before future traffic from the same socket, even if this is using the
1740  * new link. The last arriving copy of each duplicate packet is dropped at
1741  * the receiving end by the regular protocol check, so packet cardinality
1742  * and sequence order is preserved per sender/receiver socket pair.
1743  * Owner node is locked.
1744  */
1745 void tipc_link_dup_queue_xmit(struct tipc_link *l_ptr,
1746                               struct tipc_link *tunnel)
1747 {
1748         struct sk_buff *skb;
1749         struct tipc_msg tunnel_hdr;
1750
1751         tipc_msg_init(l_ptr->owner->net, &tunnel_hdr, CHANGEOVER_PROTOCOL,
1752                       DUPLICATE_MSG, INT_H_SIZE, l_ptr->addr);
1753         msg_set_msgcnt(&tunnel_hdr, skb_queue_len(&l_ptr->outqueue));
1754         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1755         skb_queue_walk(&l_ptr->outqueue, skb) {
1756                 struct sk_buff *outskb;
1757                 struct tipc_msg *msg = buf_msg(skb);
1758                 u32 length = msg_size(msg);
1759
1760                 if (msg_user(msg) == MSG_BUNDLER)
1761                         msg_set_type(msg, CLOSED_MSG);
1762                 msg_set_ack(msg, mod(l_ptr->next_in_no - 1));   /* Update */
1763                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1764                 msg_set_size(&tunnel_hdr, length + INT_H_SIZE);
1765                 outskb = tipc_buf_acquire(length + INT_H_SIZE);
1766                 if (outskb == NULL) {
1767                         pr_warn("%sunable to send duplicate msg\n",
1768                                 link_co_err);
1769                         return;
1770                 }
1771                 skb_copy_to_linear_data(outskb, &tunnel_hdr, INT_H_SIZE);
1772                 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE, skb->data,
1773                                                length);
1774                 __tipc_link_xmit_skb(tunnel, outskb);
1775                 if (!tipc_link_is_up(l_ptr))
1776                         return;
1777         }
1778 }
1779
1780 /**
1781  * buf_extract - extracts embedded TIPC message from another message
1782  * @skb: encapsulating message buffer
1783  * @from_pos: offset to extract from
1784  *
1785  * Returns a new message buffer containing an embedded message.  The
1786  * encapsulating message itself is left unchanged.
1787  */
1788 static struct sk_buff *buf_extract(struct sk_buff *skb, u32 from_pos)
1789 {
1790         struct tipc_msg *msg = (struct tipc_msg *)(skb->data + from_pos);
1791         u32 size = msg_size(msg);
1792         struct sk_buff *eb;
1793
1794         eb = tipc_buf_acquire(size);
1795         if (eb)
1796                 skb_copy_to_linear_data(eb, msg, size);
1797         return eb;
1798 }
1799
1800
1801
1802 /* tipc_link_dup_rcv(): Receive a tunnelled DUPLICATE_MSG packet.
1803  * Owner node is locked.
1804  */
1805 static void tipc_link_dup_rcv(struct net *net, struct tipc_link *l_ptr,
1806                               struct sk_buff *t_buf)
1807 {
1808         struct sk_buff *buf;
1809
1810         if (!tipc_link_is_up(l_ptr))
1811                 return;
1812
1813         buf = buf_extract(t_buf, INT_H_SIZE);
1814         if (buf == NULL) {
1815                 pr_warn("%sfailed to extract inner dup pkt\n", link_co_err);
1816                 return;
1817         }
1818
1819         /* Add buffer to deferred queue, if applicable: */
1820         link_handle_out_of_seq_msg(net, l_ptr, buf);
1821 }
1822
1823 /*  tipc_link_failover_rcv(): Receive a tunnelled ORIGINAL_MSG packet
1824  *  Owner node is locked.
1825  */
1826 static struct sk_buff *tipc_link_failover_rcv(struct tipc_link *l_ptr,
1827                                               struct sk_buff *t_buf)
1828 {
1829         struct tipc_msg *t_msg = buf_msg(t_buf);
1830         struct sk_buff *buf = NULL;
1831         struct tipc_msg *msg;
1832
1833         if (tipc_link_is_up(l_ptr))
1834                 tipc_link_reset(l_ptr);
1835
1836         /* First failover packet? */
1837         if (l_ptr->exp_msg_count == START_CHANGEOVER)
1838                 l_ptr->exp_msg_count = msg_msgcnt(t_msg);
1839
1840         /* Should there be an inner packet? */
1841         if (l_ptr->exp_msg_count) {
1842                 l_ptr->exp_msg_count--;
1843                 buf = buf_extract(t_buf, INT_H_SIZE);
1844                 if (buf == NULL) {
1845                         pr_warn("%sno inner failover pkt\n", link_co_err);
1846                         goto exit;
1847                 }
1848                 msg = buf_msg(buf);
1849
1850                 if (less(msg_seqno(msg), l_ptr->reset_checkpoint)) {
1851                         kfree_skb(buf);
1852                         buf = NULL;
1853                         goto exit;
1854                 }
1855                 if (msg_user(msg) == MSG_FRAGMENTER) {
1856                         l_ptr->stats.recv_fragments++;
1857                         tipc_buf_append(&l_ptr->reasm_buf, &buf);
1858                 }
1859         }
1860 exit:
1861         if ((!l_ptr->exp_msg_count) && (l_ptr->flags & LINK_STOPPED))
1862                 tipc_link_delete(l_ptr);
1863         return buf;
1864 }
1865
1866 /*  tipc_link_tunnel_rcv(): Receive a tunnelled packet, sent
1867  *  via other link as result of a failover (ORIGINAL_MSG) or
1868  *  a new active link (DUPLICATE_MSG). Failover packets are
1869  *  returned to the active link for delivery upwards.
1870  *  Owner node is locked.
1871  */
1872 static int tipc_link_tunnel_rcv(struct net *net, struct tipc_node *n_ptr,
1873                                 struct sk_buff **buf)
1874 {
1875         struct sk_buff *t_buf = *buf;
1876         struct tipc_link *l_ptr;
1877         struct tipc_msg *t_msg = buf_msg(t_buf);
1878         u32 bearer_id = msg_bearer_id(t_msg);
1879
1880         *buf = NULL;
1881
1882         if (bearer_id >= MAX_BEARERS)
1883                 goto exit;
1884
1885         l_ptr = n_ptr->links[bearer_id];
1886         if (!l_ptr)
1887                 goto exit;
1888
1889         if (msg_type(t_msg) == DUPLICATE_MSG)
1890                 tipc_link_dup_rcv(net, l_ptr, t_buf);
1891         else if (msg_type(t_msg) == ORIGINAL_MSG)
1892                 *buf = tipc_link_failover_rcv(l_ptr, t_buf);
1893         else
1894                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1895 exit:
1896         kfree_skb(t_buf);
1897         return *buf != NULL;
1898 }
1899
1900 /*
1901  *  Bundler functionality:
1902  */
1903 void tipc_link_bundle_rcv(struct net *net, struct sk_buff *buf)
1904 {
1905         u32 msgcount = msg_msgcnt(buf_msg(buf));
1906         u32 pos = INT_H_SIZE;
1907         struct sk_buff *obuf;
1908         struct tipc_msg *omsg;
1909
1910         while (msgcount--) {
1911                 obuf = buf_extract(buf, pos);
1912                 if (obuf == NULL) {
1913                         pr_warn("Link unable to unbundle message(s)\n");
1914                         break;
1915                 }
1916                 omsg = buf_msg(obuf);
1917                 pos += align(msg_size(omsg));
1918                 if (msg_isdata(omsg)) {
1919                         if (unlikely(msg_type(omsg) == TIPC_MCAST_MSG))
1920                                 tipc_sk_mcast_rcv(net, obuf);
1921                         else
1922                                 tipc_sk_rcv(net, obuf);
1923                 } else if (msg_user(omsg) == CONN_MANAGER) {
1924                         tipc_sk_rcv(net, obuf);
1925                 } else if (msg_user(omsg) == NAME_DISTRIBUTOR) {
1926                         tipc_named_rcv(net, obuf);
1927                 } else {
1928                         pr_warn("Illegal bundled msg: %u\n", msg_user(omsg));
1929                         kfree_skb(obuf);
1930                 }
1931         }
1932         kfree_skb(buf);
1933 }
1934
1935 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol)
1936 {
1937         unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
1938
1939         if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1940                 return;
1941
1942         l_ptr->tolerance = tol;
1943         l_ptr->cont_intv = msecs_to_jiffies(intv);
1944         l_ptr->abort_limit = tol / (jiffies_to_msecs(l_ptr->cont_intv) / 4);
1945 }
1946
1947 void tipc_link_set_queue_limits(struct tipc_link *l_ptr, u32 window)
1948 {
1949         /* Data messages from this node, inclusive FIRST_FRAGM */
1950         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE] = window;
1951         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE] = (window / 3) * 4;
1952         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE] = (window / 3) * 5;
1953         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE] = (window / 3) * 6;
1954         /* Transiting data messages,inclusive FIRST_FRAGM */
1955         l_ptr->queue_limit[TIPC_LOW_IMPORTANCE + 4] = 300;
1956         l_ptr->queue_limit[TIPC_MEDIUM_IMPORTANCE + 4] = 600;
1957         l_ptr->queue_limit[TIPC_HIGH_IMPORTANCE + 4] = 900;
1958         l_ptr->queue_limit[TIPC_CRITICAL_IMPORTANCE + 4] = 1200;
1959         l_ptr->queue_limit[CONN_MANAGER] = 1200;
1960         l_ptr->queue_limit[CHANGEOVER_PROTOCOL] = 2500;
1961         l_ptr->queue_limit[NAME_DISTRIBUTOR] = 3000;
1962         /* FRAGMENT and LAST_FRAGMENT packets */
1963         l_ptr->queue_limit[MSG_FRAGMENTER] = 4000;
1964 }
1965
1966 /* tipc_link_find_owner - locate owner node of link by link's name
1967  * @net: the applicable net namespace
1968  * @name: pointer to link name string
1969  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1970  *
1971  * Returns pointer to node owning the link, or 0 if no matching link is found.
1972  */
1973 static struct tipc_node *tipc_link_find_owner(struct net *net,
1974                                               const char *link_name,
1975                                               unsigned int *bearer_id)
1976 {
1977         struct tipc_net *tn = net_generic(net, tipc_net_id);
1978         struct tipc_link *l_ptr;
1979         struct tipc_node *n_ptr;
1980         struct tipc_node *found_node = NULL;
1981         int i;
1982
1983         *bearer_id = 0;
1984         rcu_read_lock();
1985         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1986                 tipc_node_lock(n_ptr);
1987                 for (i = 0; i < MAX_BEARERS; i++) {
1988                         l_ptr = n_ptr->links[i];
1989                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1990                                 *bearer_id = i;
1991                                 found_node = n_ptr;
1992                                 break;
1993                         }
1994                 }
1995                 tipc_node_unlock(n_ptr);
1996                 if (found_node)
1997                         break;
1998         }
1999         rcu_read_unlock();
2000
2001         return found_node;
2002 }
2003
2004 /**
2005  * link_value_is_valid -- validate proposed link tolerance/priority/window
2006  *
2007  * @cmd: value type (TIPC_CMD_SET_LINK_*)
2008  * @new_value: the new value
2009  *
2010  * Returns 1 if value is within range, 0 if not.
2011  */
2012 static int link_value_is_valid(u16 cmd, u32 new_value)
2013 {
2014         switch (cmd) {
2015         case TIPC_CMD_SET_LINK_TOL:
2016                 return (new_value >= TIPC_MIN_LINK_TOL) &&
2017                         (new_value <= TIPC_MAX_LINK_TOL);
2018         case TIPC_CMD_SET_LINK_PRI:
2019                 return (new_value <= TIPC_MAX_LINK_PRI);
2020         case TIPC_CMD_SET_LINK_WINDOW:
2021                 return (new_value >= TIPC_MIN_LINK_WIN) &&
2022                         (new_value <= TIPC_MAX_LINK_WIN);
2023         }
2024         return 0;
2025 }
2026
2027 /**
2028  * link_cmd_set_value - change priority/tolerance/window for link/bearer/media
2029  * @net: the applicable net namespace
2030  * @name: ptr to link, bearer, or media name
2031  * @new_value: new value of link, bearer, or media setting
2032  * @cmd: which link, bearer, or media attribute to set (TIPC_CMD_SET_LINK_*)
2033  *
2034  * Caller must hold RTNL lock to ensure link/bearer/media is not deleted.
2035  *
2036  * Returns 0 if value updated and negative value on error.
2037  */
2038 static int link_cmd_set_value(struct net *net, const char *name, u32 new_value,
2039                               u16 cmd)
2040 {
2041         struct tipc_node *node;
2042         struct tipc_link *l_ptr;
2043         struct tipc_bearer *b_ptr;
2044         struct tipc_media *m_ptr;
2045         int bearer_id;
2046         int res = 0;
2047
2048         node = tipc_link_find_owner(net, name, &bearer_id);
2049         if (node) {
2050                 tipc_node_lock(node);
2051                 l_ptr = node->links[bearer_id];
2052
2053                 if (l_ptr) {
2054                         switch (cmd) {
2055                         case TIPC_CMD_SET_LINK_TOL:
2056                                 link_set_supervision_props(l_ptr, new_value);
2057                                 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2058                                                      new_value, 0, 0);
2059                                 break;
2060                         case TIPC_CMD_SET_LINK_PRI:
2061                                 l_ptr->priority = new_value;
2062                                 tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0,
2063                                                      0, new_value, 0);
2064                                 break;
2065                         case TIPC_CMD_SET_LINK_WINDOW:
2066                                 tipc_link_set_queue_limits(l_ptr, new_value);
2067                                 break;
2068                         default:
2069                                 res = -EINVAL;
2070                                 break;
2071                         }
2072                 }
2073                 tipc_node_unlock(node);
2074                 return res;
2075         }
2076
2077         b_ptr = tipc_bearer_find(net, name);
2078         if (b_ptr) {
2079                 switch (cmd) {
2080                 case TIPC_CMD_SET_LINK_TOL:
2081                         b_ptr->tolerance = new_value;
2082                         break;
2083                 case TIPC_CMD_SET_LINK_PRI:
2084                         b_ptr->priority = new_value;
2085                         break;
2086                 case TIPC_CMD_SET_LINK_WINDOW:
2087                         b_ptr->window = new_value;
2088                         break;
2089                 default:
2090                         res = -EINVAL;
2091                         break;
2092                 }
2093                 return res;
2094         }
2095
2096         m_ptr = tipc_media_find(name);
2097         if (!m_ptr)
2098                 return -ENODEV;
2099         switch (cmd) {
2100         case TIPC_CMD_SET_LINK_TOL:
2101                 m_ptr->tolerance = new_value;
2102                 break;
2103         case TIPC_CMD_SET_LINK_PRI:
2104                 m_ptr->priority = new_value;
2105                 break;
2106         case TIPC_CMD_SET_LINK_WINDOW:
2107                 m_ptr->window = new_value;
2108                 break;
2109         default:
2110                 res = -EINVAL;
2111                 break;
2112         }
2113         return res;
2114 }
2115
2116 struct sk_buff *tipc_link_cmd_config(struct net *net, const void *req_tlv_area,
2117                                      int req_tlv_space, u16 cmd)
2118 {
2119         struct tipc_link_config *args;
2120         u32 new_value;
2121         int res;
2122
2123         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_CONFIG))
2124                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2125
2126         args = (struct tipc_link_config *)TLV_DATA(req_tlv_area);
2127         new_value = ntohl(args->value);
2128
2129         if (!link_value_is_valid(cmd, new_value))
2130                 return tipc_cfg_reply_error_string(
2131                         "cannot change, value invalid");
2132
2133         if (!strcmp(args->name, tipc_bclink_name)) {
2134                 if ((cmd == TIPC_CMD_SET_LINK_WINDOW) &&
2135                     (tipc_bclink_set_queue_limits(net, new_value) == 0))
2136                         return tipc_cfg_reply_none();
2137                 return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
2138                                                    " (cannot change setting on broadcast link)");
2139         }
2140
2141         res = link_cmd_set_value(net, args->name, new_value, cmd);
2142         if (res)
2143                 return tipc_cfg_reply_error_string("cannot change link setting");
2144
2145         return tipc_cfg_reply_none();
2146 }
2147
2148 /**
2149  * link_reset_statistics - reset link statistics
2150  * @l_ptr: pointer to link
2151  */
2152 static void link_reset_statistics(struct tipc_link *l_ptr)
2153 {
2154         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
2155         l_ptr->stats.sent_info = l_ptr->next_out_no;
2156         l_ptr->stats.recv_info = l_ptr->next_in_no;
2157 }
2158
2159 struct sk_buff *tipc_link_cmd_reset_stats(struct net *net,
2160                                           const void *req_tlv_area,
2161                                           int req_tlv_space)
2162 {
2163         char *link_name;
2164         struct tipc_link *l_ptr;
2165         struct tipc_node *node;
2166         unsigned int bearer_id;
2167
2168         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2169                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2170
2171         link_name = (char *)TLV_DATA(req_tlv_area);
2172         if (!strcmp(link_name, tipc_bclink_name)) {
2173                 if (tipc_bclink_reset_stats(net))
2174                         return tipc_cfg_reply_error_string("link not found");
2175                 return tipc_cfg_reply_none();
2176         }
2177         node = tipc_link_find_owner(net, link_name, &bearer_id);
2178         if (!node)
2179                 return tipc_cfg_reply_error_string("link not found");
2180
2181         tipc_node_lock(node);
2182         l_ptr = node->links[bearer_id];
2183         if (!l_ptr) {
2184                 tipc_node_unlock(node);
2185                 return tipc_cfg_reply_error_string("link not found");
2186         }
2187         link_reset_statistics(l_ptr);
2188         tipc_node_unlock(node);
2189         return tipc_cfg_reply_none();
2190 }
2191
2192 /**
2193  * percent - convert count to a percentage of total (rounding up or down)
2194  */
2195 static u32 percent(u32 count, u32 total)
2196 {
2197         return (count * 100 + (total / 2)) / total;
2198 }
2199
2200 /**
2201  * tipc_link_stats - print link statistics
2202  * @net: the applicable net namespace
2203  * @name: link name
2204  * @buf: print buffer area
2205  * @buf_size: size of print buffer area
2206  *
2207  * Returns length of print buffer data string (or 0 if error)
2208  */
2209 static int tipc_link_stats(struct net *net, const char *name, char *buf,
2210                            const u32 buf_size)
2211 {
2212         struct tipc_link *l;
2213         struct tipc_stats *s;
2214         struct tipc_node *node;
2215         char *status;
2216         u32 profile_total = 0;
2217         unsigned int bearer_id;
2218         int ret;
2219
2220         if (!strcmp(name, tipc_bclink_name))
2221                 return tipc_bclink_stats(net, buf, buf_size);
2222
2223         node = tipc_link_find_owner(net, name, &bearer_id);
2224         if (!node)
2225                 return 0;
2226
2227         tipc_node_lock(node);
2228
2229         l = node->links[bearer_id];
2230         if (!l) {
2231                 tipc_node_unlock(node);
2232                 return 0;
2233         }
2234
2235         s = &l->stats;
2236
2237         if (tipc_link_is_active(l))
2238                 status = "ACTIVE";
2239         else if (tipc_link_is_up(l))
2240                 status = "STANDBY";
2241         else
2242                 status = "DEFUNCT";
2243
2244         ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
2245                             "  %s  MTU:%u  Priority:%u  Tolerance:%u ms"
2246                             "  Window:%u packets\n",
2247                             l->name, status, l->max_pkt, l->priority,
2248                             l->tolerance, l->queue_limit[0]);
2249
2250         ret += tipc_snprintf(buf + ret, buf_size - ret,
2251                              "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
2252                              l->next_in_no - s->recv_info, s->recv_fragments,
2253                              s->recv_fragmented, s->recv_bundles,
2254                              s->recv_bundled);
2255
2256         ret += tipc_snprintf(buf + ret, buf_size - ret,
2257                              "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
2258                              l->next_out_no - s->sent_info, s->sent_fragments,
2259                              s->sent_fragmented, s->sent_bundles,
2260                              s->sent_bundled);
2261
2262         profile_total = s->msg_length_counts;
2263         if (!profile_total)
2264                 profile_total = 1;
2265
2266         ret += tipc_snprintf(buf + ret, buf_size - ret,
2267                              "  TX profile sample:%u packets  average:%u octets\n"
2268                              "  0-64:%u%% -256:%u%% -1024:%u%% -4096:%u%% "
2269                              "-16384:%u%% -32768:%u%% -66000:%u%%\n",
2270                              s->msg_length_counts,
2271                              s->msg_lengths_total / profile_total,
2272                              percent(s->msg_length_profile[0], profile_total),
2273                              percent(s->msg_length_profile[1], profile_total),
2274                              percent(s->msg_length_profile[2], profile_total),
2275                              percent(s->msg_length_profile[3], profile_total),
2276                              percent(s->msg_length_profile[4], profile_total),
2277                              percent(s->msg_length_profile[5], profile_total),
2278                              percent(s->msg_length_profile[6], profile_total));
2279
2280         ret += tipc_snprintf(buf + ret, buf_size - ret,
2281                              "  RX states:%u probes:%u naks:%u defs:%u"
2282                              " dups:%u\n", s->recv_states, s->recv_probes,
2283                              s->recv_nacks, s->deferred_recv, s->duplicates);
2284
2285         ret += tipc_snprintf(buf + ret, buf_size - ret,
2286                              "  TX states:%u probes:%u naks:%u acks:%u"
2287                              " dups:%u\n", s->sent_states, s->sent_probes,
2288                              s->sent_nacks, s->sent_acks, s->retransmitted);
2289
2290         ret += tipc_snprintf(buf + ret, buf_size - ret,
2291                              "  Congestion link:%u  Send queue"
2292                              " max:%u avg:%u\n", s->link_congs,
2293                              s->max_queue_sz, s->queue_sz_counts ?
2294                              (s->accu_queue_sz / s->queue_sz_counts) : 0);
2295
2296         tipc_node_unlock(node);
2297         return ret;
2298 }
2299
2300 struct sk_buff *tipc_link_cmd_show_stats(struct net *net,
2301                                          const void *req_tlv_area,
2302                                          int req_tlv_space)
2303 {
2304         struct sk_buff *buf;
2305         struct tlv_desc *rep_tlv;
2306         int str_len;
2307         int pb_len;
2308         char *pb;
2309
2310         if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_LINK_NAME))
2311                 return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
2312
2313         buf = tipc_cfg_reply_alloc(TLV_SPACE(ULTRA_STRING_MAX_LEN));
2314         if (!buf)
2315                 return NULL;
2316
2317         rep_tlv = (struct tlv_desc *)buf->data;
2318         pb = TLV_DATA(rep_tlv);
2319         pb_len = ULTRA_STRING_MAX_LEN;
2320         str_len = tipc_link_stats(net, (char *)TLV_DATA(req_tlv_area),
2321                                   pb, pb_len);
2322         if (!str_len) {
2323                 kfree_skb(buf);
2324                 return tipc_cfg_reply_error_string("link not found");
2325         }
2326         str_len += 1;   /* for "\0" */
2327         skb_put(buf, TLV_SPACE(str_len));
2328         TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
2329
2330         return buf;
2331 }
2332
2333 static void link_print(struct tipc_link *l_ptr, const char *str)
2334 {
2335         struct tipc_net *tn = net_generic(l_ptr->owner->net, tipc_net_id);
2336         struct tipc_bearer *b_ptr;
2337
2338         rcu_read_lock();
2339         b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]);
2340         if (b_ptr)
2341                 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name);
2342         rcu_read_unlock();
2343
2344         if (link_working_unknown(l_ptr))
2345                 pr_cont(":WU\n");
2346         else if (link_reset_reset(l_ptr))
2347                 pr_cont(":RR\n");
2348         else if (link_reset_unknown(l_ptr))
2349                 pr_cont(":RU\n");
2350         else if (link_working_working(l_ptr))
2351                 pr_cont(":WW\n");
2352         else
2353                 pr_cont("\n");
2354 }
2355
2356 /* Parse and validate nested (link) properties valid for media, bearer and link
2357  */
2358 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
2359 {
2360         int err;
2361
2362         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
2363                                tipc_nl_prop_policy);
2364         if (err)
2365                 return err;
2366
2367         if (props[TIPC_NLA_PROP_PRIO]) {
2368                 u32 prio;
2369
2370                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2371                 if (prio > TIPC_MAX_LINK_PRI)
2372                         return -EINVAL;
2373         }
2374
2375         if (props[TIPC_NLA_PROP_TOL]) {
2376                 u32 tol;
2377
2378                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2379                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
2380                         return -EINVAL;
2381         }
2382
2383         if (props[TIPC_NLA_PROP_WIN]) {
2384                 u32 win;
2385
2386                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2387                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
2388                         return -EINVAL;
2389         }
2390
2391         return 0;
2392 }
2393
2394 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
2395 {
2396         int err;
2397         int res = 0;
2398         int bearer_id;
2399         char *name;
2400         struct tipc_link *link;
2401         struct tipc_node *node;
2402         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2403         struct net *net = genl_info_net(info);
2404
2405         if (!info->attrs[TIPC_NLA_LINK])
2406                 return -EINVAL;
2407
2408         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2409                                info->attrs[TIPC_NLA_LINK],
2410                                tipc_nl_link_policy);
2411         if (err)
2412                 return err;
2413
2414         if (!attrs[TIPC_NLA_LINK_NAME])
2415                 return -EINVAL;
2416
2417         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2418
2419         node = tipc_link_find_owner(net, name, &bearer_id);
2420         if (!node)
2421                 return -EINVAL;
2422
2423         tipc_node_lock(node);
2424
2425         link = node->links[bearer_id];
2426         if (!link) {
2427                 res = -EINVAL;
2428                 goto out;
2429         }
2430
2431         if (attrs[TIPC_NLA_LINK_PROP]) {
2432                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
2433
2434                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
2435                                               props);
2436                 if (err) {
2437                         res = err;
2438                         goto out;
2439                 }
2440
2441                 if (props[TIPC_NLA_PROP_TOL]) {
2442                         u32 tol;
2443
2444                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
2445                         link_set_supervision_props(link, tol);
2446                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0, 0);
2447                 }
2448                 if (props[TIPC_NLA_PROP_PRIO]) {
2449                         u32 prio;
2450
2451                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
2452                         link->priority = prio;
2453                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio, 0);
2454                 }
2455                 if (props[TIPC_NLA_PROP_WIN]) {
2456                         u32 win;
2457
2458                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
2459                         tipc_link_set_queue_limits(link, win);
2460                 }
2461         }
2462
2463 out:
2464         tipc_node_unlock(node);
2465
2466         return res;
2467 }
2468
2469 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
2470 {
2471         int i;
2472         struct nlattr *stats;
2473
2474         struct nla_map {
2475                 u32 key;
2476                 u32 val;
2477         };
2478
2479         struct nla_map map[] = {
2480                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
2481                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
2482                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
2483                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
2484                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
2485                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
2486                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
2487                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
2488                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
2489                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
2490                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
2491                         s->msg_length_counts : 1},
2492                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
2493                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
2494                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
2495                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
2496                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
2497                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
2498                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
2499                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
2500                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
2501                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
2502                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
2503                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
2504                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
2505                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
2506                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
2507                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
2508                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
2509                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
2510                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
2511                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
2512                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
2513                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
2514                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
2515         };
2516
2517         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
2518         if (!stats)
2519                 return -EMSGSIZE;
2520
2521         for (i = 0; i <  ARRAY_SIZE(map); i++)
2522                 if (nla_put_u32(skb, map[i].key, map[i].val))
2523                         goto msg_full;
2524
2525         nla_nest_end(skb, stats);
2526
2527         return 0;
2528 msg_full:
2529         nla_nest_cancel(skb, stats);
2530
2531         return -EMSGSIZE;
2532 }
2533
2534 /* Caller should hold appropriate locks to protect the link */
2535 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
2536                               struct tipc_link *link)
2537 {
2538         int err;
2539         void *hdr;
2540         struct nlattr *attrs;
2541         struct nlattr *prop;
2542         struct tipc_net *tn = net_generic(net, tipc_net_id);
2543
2544         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_v2_family,
2545                           NLM_F_MULTI, TIPC_NL_LINK_GET);
2546         if (!hdr)
2547                 return -EMSGSIZE;
2548
2549         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
2550         if (!attrs)
2551                 goto msg_full;
2552
2553         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2554                 goto attr_msg_full;
2555         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
2556                         tipc_cluster_mask(tn->own_addr)))
2557                 goto attr_msg_full;
2558         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->max_pkt))
2559                 goto attr_msg_full;
2560         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->next_in_no))
2561                 goto attr_msg_full;
2562         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->next_out_no))
2563                 goto attr_msg_full;
2564
2565         if (tipc_link_is_up(link))
2566                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2567                         goto attr_msg_full;
2568         if (tipc_link_is_active(link))
2569                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2570                         goto attr_msg_full;
2571
2572         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2573         if (!prop)
2574                 goto attr_msg_full;
2575         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2576                 goto prop_msg_full;
2577         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2578                 goto prop_msg_full;
2579         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2580                         link->queue_limit[TIPC_LOW_IMPORTANCE]))
2581                 goto prop_msg_full;
2582         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2583                 goto prop_msg_full;
2584         nla_nest_end(msg->skb, prop);
2585
2586         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2587         if (err)
2588                 goto attr_msg_full;
2589
2590         nla_nest_end(msg->skb, attrs);
2591         genlmsg_end(msg->skb, hdr);
2592
2593         return 0;
2594
2595 prop_msg_full:
2596         nla_nest_cancel(msg->skb, prop);
2597 attr_msg_full:
2598         nla_nest_cancel(msg->skb, attrs);
2599 msg_full:
2600         genlmsg_cancel(msg->skb, hdr);
2601
2602         return -EMSGSIZE;
2603 }
2604
2605 /* Caller should hold node lock  */
2606 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2607                                     struct tipc_node *node, u32 *prev_link)
2608 {
2609         u32 i;
2610         int err;
2611
2612         for (i = *prev_link; i < MAX_BEARERS; i++) {
2613                 *prev_link = i;
2614
2615                 if (!node->links[i])
2616                         continue;
2617
2618                 err = __tipc_nl_add_link(net, msg, node->links[i]);
2619                 if (err)
2620                         return err;
2621         }
2622         *prev_link = 0;
2623
2624         return 0;
2625 }
2626
2627 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2628 {
2629         struct net *net = sock_net(skb->sk);
2630         struct tipc_net *tn = net_generic(net, tipc_net_id);
2631         struct tipc_node *node;
2632         struct tipc_nl_msg msg;
2633         u32 prev_node = cb->args[0];
2634         u32 prev_link = cb->args[1];
2635         int done = cb->args[2];
2636         int err;
2637
2638         if (done)
2639                 return 0;
2640
2641         msg.skb = skb;
2642         msg.portid = NETLINK_CB(cb->skb).portid;
2643         msg.seq = cb->nlh->nlmsg_seq;
2644
2645         rcu_read_lock();
2646
2647         if (prev_node) {
2648                 node = tipc_node_find(net, prev_node);
2649                 if (!node) {
2650                         /* We never set seq or call nl_dump_check_consistent()
2651                          * this means that setting prev_seq here will cause the
2652                          * consistence check to fail in the netlink callback
2653                          * handler. Resulting in the last NLMSG_DONE message
2654                          * having the NLM_F_DUMP_INTR flag set.
2655                          */
2656                         cb->prev_seq = 1;
2657                         goto out;
2658                 }
2659
2660                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2661                                                  list) {
2662                         tipc_node_lock(node);
2663                         err = __tipc_nl_add_node_links(net, &msg, node,
2664                                                        &prev_link);
2665                         tipc_node_unlock(node);
2666                         if (err)
2667                                 goto out;
2668
2669                         prev_node = node->addr;
2670                 }
2671         } else {
2672                 err = tipc_nl_add_bc_link(net, &msg);
2673                 if (err)
2674                         goto out;
2675
2676                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2677                         tipc_node_lock(node);
2678                         err = __tipc_nl_add_node_links(net, &msg, node,
2679                                                        &prev_link);
2680                         tipc_node_unlock(node);
2681                         if (err)
2682                                 goto out;
2683
2684                         prev_node = node->addr;
2685                 }
2686         }
2687         done = 1;
2688 out:
2689         rcu_read_unlock();
2690
2691         cb->args[0] = prev_node;
2692         cb->args[1] = prev_link;
2693         cb->args[2] = done;
2694
2695         return skb->len;
2696 }
2697
2698 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2699 {
2700         struct net *net = genl_info_net(info);
2701         struct sk_buff *ans_skb;
2702         struct tipc_nl_msg msg;
2703         struct tipc_link *link;
2704         struct tipc_node *node;
2705         char *name;
2706         int bearer_id;
2707         int err;
2708
2709         if (!info->attrs[TIPC_NLA_LINK_NAME])
2710                 return -EINVAL;
2711
2712         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2713         node = tipc_link_find_owner(net, name, &bearer_id);
2714         if (!node)
2715                 return -EINVAL;
2716
2717         ans_skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2718         if (!ans_skb)
2719                 return -ENOMEM;
2720
2721         msg.skb = ans_skb;
2722         msg.portid = info->snd_portid;
2723         msg.seq = info->snd_seq;
2724
2725         tipc_node_lock(node);
2726         link = node->links[bearer_id];
2727         if (!link) {
2728                 err = -EINVAL;
2729                 goto err_out;
2730         }
2731
2732         err = __tipc_nl_add_link(net, &msg, link);
2733         if (err)
2734                 goto err_out;
2735
2736         tipc_node_unlock(node);
2737
2738         return genlmsg_reply(ans_skb, info);
2739
2740 err_out:
2741         tipc_node_unlock(node);
2742         nlmsg_free(ans_skb);
2743
2744         return err;
2745 }
2746
2747 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2748 {
2749         int err;
2750         char *link_name;
2751         unsigned int bearer_id;
2752         struct tipc_link *link;
2753         struct tipc_node *node;
2754         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2755         struct net *net = genl_info_net(info);
2756
2757         if (!info->attrs[TIPC_NLA_LINK])
2758                 return -EINVAL;
2759
2760         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2761                                info->attrs[TIPC_NLA_LINK],
2762                                tipc_nl_link_policy);
2763         if (err)
2764                 return err;
2765
2766         if (!attrs[TIPC_NLA_LINK_NAME])
2767                 return -EINVAL;
2768
2769         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2770
2771         if (strcmp(link_name, tipc_bclink_name) == 0) {
2772                 err = tipc_bclink_reset_stats(net);
2773                 if (err)
2774                         return err;
2775                 return 0;
2776         }
2777
2778         node = tipc_link_find_owner(net, link_name, &bearer_id);
2779         if (!node)
2780                 return -EINVAL;
2781
2782         tipc_node_lock(node);
2783
2784         link = node->links[bearer_id];
2785         if (!link) {
2786                 tipc_node_unlock(node);
2787                 return -EINVAL;
2788         }
2789
2790         link_reset_statistics(link);
2791
2792         tipc_node_unlock(node);
2793
2794         return 0;
2795 }