net/tipc/link.c

   1 /*
   2  * net/tipc/link.c: TIPC link code
   3  *
   4  * Copyright (c) 1996-2007, 2012-2015, Ericsson AB
   5  * Copyright (c) 2004-2007, 2010-2013, Wind River Systems
   6  * All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions are met:
  10  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the names of the copyright holders nor the names of its
  17  *    contributors may be used to endorse or promote products derived from
  18  *    this software without specific prior written permission.
  19  *
  20  * Alternatively, this software may be distributed under the terms of the
  21  * GNU General Public License ("GPL") version 2 as published by the Free
  22  * Software Foundation.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34  * POSSIBILITY OF SUCH DAMAGE.
  35  */
  36
  37 #include "core.h"
  38 #include "subscr.h"
  39 #include "link.h"
  40 #include "bcast.h"
  41 #include "socket.h"
  42 #include "name_distr.h"
  43 #include "discover.h"
  44 #include "netlink.h"
  45
  46 #include <linux/pkt_sched.h>
  47
  48 /*
  49  * Error message prefixes
  50  */
  51 static const char *link_co_err = "Link changeover error, ";
  52 static const char *link_rst_msg = "Resetting link ";
  53 static const char *link_unk_evt = "Unknown link event ";
  54
  55 static const struct nla_policy tipc_nl_link_policy[TIPC_NLA_LINK_MAX + 1] = {
  56         [TIPC_NLA_LINK_UNSPEC]          = { .type = NLA_UNSPEC },
  57         [TIPC_NLA_LINK_NAME] = {
  58                 .type = NLA_STRING,
  59                 .len = TIPC_MAX_LINK_NAME
  60         },
  61         [TIPC_NLA_LINK_MTU]             = { .type = NLA_U32 },
  62         [TIPC_NLA_LINK_BROADCAST]       = { .type = NLA_FLAG },
  63         [TIPC_NLA_LINK_UP]              = { .type = NLA_FLAG },
  64         [TIPC_NLA_LINK_ACTIVE]          = { .type = NLA_FLAG },
  65         [TIPC_NLA_LINK_PROP]            = { .type = NLA_NESTED },
  66         [TIPC_NLA_LINK_STATS]           = { .type = NLA_NESTED },
  67         [TIPC_NLA_LINK_RX]              = { .type = NLA_U32 },
  68         [TIPC_NLA_LINK_TX]              = { .type = NLA_U32 }
  69 };
  70
  71 /* Properties valid for media, bearar and link */
  72 static const struct nla_policy tipc_nl_prop_policy[TIPC_NLA_PROP_MAX + 1] = {
  73         [TIPC_NLA_PROP_UNSPEC]          = { .type = NLA_UNSPEC },
  74         [TIPC_NLA_PROP_PRIO]            = { .type = NLA_U32 },
  75         [TIPC_NLA_PROP_TOL]             = { .type = NLA_U32 },
  76         [TIPC_NLA_PROP_WIN]             = { .type = NLA_U32 }
  77 };
  78
  79 /*
  80  * Out-of-range value for link session numbers
  81  */
  82 #define INVALID_SESSION 0x10000
  83
  84 /*
  85  * Link state events:
  86  */
  87 #define  STARTING_EVT    856384768      /* link processing trigger */
  88 #define  TRAFFIC_MSG_EVT 560815u        /* rx'd ??? */
  89 #define  SILENCE_EVT     560817u        /* timer dicovered silence from peer */
  90
  91 /*
  92  * State value stored in 'failover_pkts'
  93  */
  94 #define FIRST_FAILOVER 0xffffu
  95
  96 static void link_handle_out_of_seq_msg(struct tipc_link *link,
  97                                        struct sk_buff *skb);
  98 static void tipc_link_proto_rcv(struct tipc_link *link,
  99                                 struct sk_buff *skb);
 100 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol);
 101 static void link_state_event(struct tipc_link *l_ptr, u32 event);
 102 static void link_reset_statistics(struct tipc_link *l_ptr);
 103 static void link_print(struct tipc_link *l_ptr, const char *str);
 104 static void tipc_link_sync_xmit(struct tipc_link *l);
 105 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf);
 106 static void tipc_link_input(struct tipc_link *l, struct sk_buff *skb);
 107 static bool tipc_data_input(struct tipc_link *l, struct sk_buff *skb);
 108 static bool tipc_link_failover_rcv(struct tipc_link *l, struct sk_buff **skb);
 109 static void link_set_timer(struct tipc_link *link, unsigned long time);
 110 /*
 111  *  Simple link routines
 112  */
 113 static unsigned int align(unsigned int i)
 114 {
 115         return (i + 3) & ~3u;
 116 }
 117
 118 static void tipc_link_release(struct kref *kref)
 119 {
 120         kfree(container_of(kref, struct tipc_link, ref));
 121 }
 122
 123 static void tipc_link_get(struct tipc_link *l_ptr)
 124 {
 125         kref_get(&l_ptr->ref);
 126 }
 127
 128 static void tipc_link_put(struct tipc_link *l_ptr)
 129 {
 130         kref_put(&l_ptr->ref, tipc_link_release);
 131 }
 132
 133 static struct tipc_link *tipc_parallel_link(struct tipc_link *l)
 134 {
 135         struct tipc_node *n = l->owner;
 136
 137         if (node_active_link(n, 0) != l)
 138                 return node_active_link(n, 0);
 139         return node_active_link(n, 1);
 140 }
 141
 142 /*
 143  *  Simple non-static link routines (i.e. referenced outside this file)
 144  */
 145 int tipc_link_is_up(struct tipc_link *l_ptr)
 146 {
 147         if (!l_ptr)
 148                 return 0;
 149         return link_working_working(l_ptr) || link_working_unknown(l_ptr);
 150 }
 151
 152 int tipc_link_is_active(struct tipc_link *l)
 153 {
 154         struct tipc_node *n = l->owner;
 155
 156         return (node_active_link(n, 0) == l) || (node_active_link(n, 1) == l);
 157 }
 158
 159 /**
 160  * link_timeout - handle expiration of link timer
 161  * @l_ptr: pointer to link
 162  */
 163 static void link_timeout(unsigned long data)
 164 {
 165         struct tipc_link *l_ptr = (struct tipc_link *)data;
 166         struct sk_buff *skb;
 167
 168         tipc_node_lock(l_ptr->owner);
 169
 170         /* update counters used in statistical profiling of send traffic */
 171         l_ptr->stats.accu_queue_sz += skb_queue_len(&l_ptr->transmq);
 172         l_ptr->stats.queue_sz_counts++;
 173
 174         skb = skb_peek(&l_ptr->transmq);
 175         if (skb) {
 176                 struct tipc_msg *msg = buf_msg(skb);
 177                 u32 length = msg_size(msg);
 178
 179                 if ((msg_user(msg) == MSG_FRAGMENTER) &&
 180                     (msg_type(msg) == FIRST_FRAGMENT)) {
 181                         length = msg_size(msg_get_wrapped(msg));
 182                 }
 183                 if (length) {
 184                         l_ptr->stats.msg_lengths_total += length;
 185                         l_ptr->stats.msg_length_counts++;
 186                         if (length <= 64)
 187                                 l_ptr->stats.msg_length_profile[0]++;
 188                         else if (length <= 256)
 189                                 l_ptr->stats.msg_length_profile[1]++;
 190                         else if (length <= 1024)
 191                                 l_ptr->stats.msg_length_profile[2]++;
 192                         else if (length <= 4096)
 193                                 l_ptr->stats.msg_length_profile[3]++;
 194                         else if (length <= 16384)
 195                                 l_ptr->stats.msg_length_profile[4]++;
 196                         else if (length <= 32768)
 197                                 l_ptr->stats.msg_length_profile[5]++;
 198                         else
 199                                 l_ptr->stats.msg_length_profile[6]++;
 200                 }
 201         }
 202
 203         /* do all other link processing performed on a periodic basis */
 204         if (l_ptr->silent_intv_cnt || tipc_bclink_acks_missing(l_ptr->owner))
 205                 link_state_event(l_ptr, SILENCE_EVT);
 206         l_ptr->silent_intv_cnt++;
 207         if (skb_queue_len(&l_ptr->backlogq))
 208                 tipc_link_push_packets(l_ptr);
 209         link_set_timer(l_ptr, l_ptr->keepalive_intv);
 210         tipc_node_unlock(l_ptr->owner);
 211         tipc_link_put(l_ptr);
 212 }
 213
 214 static void link_set_timer(struct tipc_link *link, unsigned long time)
 215 {
 216         if (!mod_timer(&link->timer, jiffies + time))
 217                 tipc_link_get(link);
 218 }
 219
 220 /**
 221  * tipc_link_create - create a new link
 222  * @n_ptr: pointer to associated node
 223  * @b_ptr: pointer to associated bearer
 224  * @media_addr: media address to use when sending messages over link
 225  *
 226  * Returns pointer to link.
 227  */
 228 struct tipc_link *tipc_link_create(struct tipc_node *n_ptr,
 229                                    struct tipc_bearer *b_ptr,
 230                                    const struct tipc_media_addr *media_addr,
 231                                    struct sk_buff_head *inputq,
 232                                    struct sk_buff_head *namedq)
 233 {
 234         struct tipc_net *tn = net_generic(n_ptr->net, tipc_net_id);
 235         struct tipc_link *l_ptr;
 236         struct tipc_msg *msg;
 237         char *if_name;
 238         char addr_string[16];
 239         u32 peer = n_ptr->addr;
 240
 241         if (n_ptr->link_cnt >= MAX_BEARERS) {
 242                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 243                 pr_err("Cannot establish %uth link to %s. Max %u allowed.\n",
 244                        n_ptr->link_cnt, addr_string, MAX_BEARERS);
 245                 return NULL;
 246         }
 247
 248         if (n_ptr->links[b_ptr->identity].link) {
 249                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 250                 pr_err("Attempt to establish second link on <%s> to %s\n",
 251                        b_ptr->name, addr_string);
 252                 return NULL;
 253         }
 254
 255         l_ptr = kzalloc(sizeof(*l_ptr), GFP_ATOMIC);
 256         if (!l_ptr) {
 257                 pr_warn("Link creation failed, no memory\n");
 258                 return NULL;
 259         }
 260         kref_init(&l_ptr->ref);
 261         l_ptr->addr = peer;
 262         if_name = strchr(b_ptr->name, ':') + 1;
 263         sprintf(l_ptr->name, "%u.%u.%u:%s-%u.%u.%u:unknown",
 264                 tipc_zone(tn->own_addr), tipc_cluster(tn->own_addr),
 265                 tipc_node(tn->own_addr),
 266                 if_name,
 267                 tipc_zone(peer), tipc_cluster(peer), tipc_node(peer));
 268                 /* note: peer i/f name is updated by reset/activate message */
 269         memcpy(&l_ptr->media_addr, media_addr, sizeof(*media_addr));
 270         l_ptr->owner = n_ptr;
 271         l_ptr->peer_session = INVALID_SESSION;
 272         l_ptr->bearer_id = b_ptr->identity;
 273         link_set_supervision_props(l_ptr, b_ptr->tolerance);
 274         l_ptr->state = RESET_UNKNOWN;
 275
 276         l_ptr->pmsg = (struct tipc_msg *)&l_ptr->proto_msg;
 277         msg = l_ptr->pmsg;
 278         tipc_msg_init(tn->own_addr, msg, LINK_PROTOCOL, RESET_MSG, INT_H_SIZE,
 279                       l_ptr->addr);
 280         msg_set_size(msg, sizeof(l_ptr->proto_msg));
 281         msg_set_session(msg, (tn->random & 0xffff));
 282         msg_set_bearer_id(msg, b_ptr->identity);
 283         strcpy((char *)msg_data(msg), if_name);
 284         l_ptr->net_plane = b_ptr->net_plane;
 285         l_ptr->advertised_mtu = b_ptr->mtu;
 286         l_ptr->mtu = l_ptr->advertised_mtu;
 287         l_ptr->priority = b_ptr->priority;
 288         tipc_link_set_queue_limits(l_ptr, b_ptr->window);
 289         l_ptr->snd_nxt = 1;
 290         __skb_queue_head_init(&l_ptr->transmq);
 291         __skb_queue_head_init(&l_ptr->backlogq);
 292         __skb_queue_head_init(&l_ptr->deferdq);
 293         skb_queue_head_init(&l_ptr->wakeupq);
 294         l_ptr->inputq = inputq;
 295         l_ptr->namedq = namedq;
 296         skb_queue_head_init(l_ptr->inputq);
 297         link_reset_statistics(l_ptr);
 298         tipc_node_attach_link(n_ptr, l_ptr);
 299         setup_timer(&l_ptr->timer, link_timeout, (unsigned long)l_ptr);
 300         link_state_event(l_ptr, STARTING_EVT);
 301
 302         return l_ptr;
 303 }
 304
 305 /**
 306  * tipc_link_delete - Delete a link
 307  * @l: link to be deleted
 308  */
 309 void tipc_link_delete(struct tipc_link *l)
 310 {
 311         tipc_link_reset(l);
 312         if (del_timer(&l->timer))
 313                 tipc_link_put(l);
 314         l->flags |= LINK_STOPPED;
 315         /* Delete link now, or when timer is finished: */
 316         tipc_link_reset_fragments(l);
 317         tipc_node_detach_link(l->owner, l);
 318         tipc_link_put(l);
 319 }
 320
 321 void tipc_link_delete_list(struct net *net, unsigned int bearer_id)
 322 {
 323         struct tipc_net *tn = net_generic(net, tipc_net_id);
 324         struct tipc_link *link;
 325         struct tipc_node *node;
 326
 327         rcu_read_lock();
 328         list_for_each_entry_rcu(node, &tn->node_list, list) {
 329                 tipc_node_lock(node);
 330                 link = node->links[bearer_id].link;
 331                 if (link)
 332                         tipc_link_delete(link);
 333                 tipc_node_unlock(node);
 334         }
 335         rcu_read_unlock();
 336 }
 337
 338 /**
 339  * link_schedule_user - schedule a message sender for wakeup after congestion
 340  * @link: congested link
 341  * @list: message that was attempted sent
 342  * Create pseudo msg to send back to user when congestion abates
 343  * Does not consume buffer list
 344  */
 345 static int link_schedule_user(struct tipc_link *link, struct sk_buff_head *list)
 346 {
 347         struct tipc_msg *msg = buf_msg(skb_peek(list));
 348         int imp = msg_importance(msg);
 349         u32 oport = msg_origport(msg);
 350         u32 addr = link_own_addr(link);
 351         struct sk_buff *skb;
 352
 353         /* This really cannot happen...  */
 354         if (unlikely(imp > TIPC_CRITICAL_IMPORTANCE)) {
 355                 pr_warn("%s<%s>, send queue full", link_rst_msg, link->name);
 356                 return -ENOBUFS;
 357         }
 358         /* Non-blocking sender: */
 359         if (TIPC_SKB_CB(skb_peek(list))->wakeup_pending)
 360                 return -ELINKCONG;
 361
 362         /* Create and schedule wakeup pseudo message */
 363         skb = tipc_msg_create(SOCK_WAKEUP, 0, INT_H_SIZE, 0,
 364                               addr, addr, oport, 0, 0);
 365         if (!skb)
 366                 return -ENOBUFS;
 367         TIPC_SKB_CB(skb)->chain_sz = skb_queue_len(list);
 368         TIPC_SKB_CB(skb)->chain_imp = imp;
 369         skb_queue_tail(&link->wakeupq, skb);
 370         link->stats.link_congs++;
 371         return -ELINKCONG;
 372 }
 373
 374 /**
 375  * link_prepare_wakeup - prepare users for wakeup after congestion
 376  * @link: congested link
 377  * Move a number of waiting users, as permitted by available space in
 378  * the send queue, from link wait queue to node wait queue for wakeup
 379  */
 380 void link_prepare_wakeup(struct tipc_link *l)
 381 {
 382         int pnd[TIPC_SYSTEM_IMPORTANCE + 1] = {0,};
 383         int imp, lim;
 384         struct sk_buff *skb, *tmp;
 385
 386         skb_queue_walk_safe(&l->wakeupq, skb, tmp) {
 387                 imp = TIPC_SKB_CB(skb)->chain_imp;
 388                 lim = l->window + l->backlog[imp].limit;
 389                 pnd[imp] += TIPC_SKB_CB(skb)->chain_sz;
 390                 if ((pnd[imp] + l->backlog[imp].len) >= lim)
 391                         break;
 392                 skb_unlink(skb, &l->wakeupq);
 393                 skb_queue_tail(l->inputq, skb);
 394                 l->owner->inputq = l->inputq;
 395                 l->owner->action_flags |= TIPC_MSG_EVT;
 396         }
 397 }
 398
 399 /**
 400  * tipc_link_reset_fragments - purge link's inbound message fragments queue
 401  * @l_ptr: pointer to link
 402  */
 403 void tipc_link_reset_fragments(struct tipc_link *l_ptr)
 404 {
 405         kfree_skb(l_ptr->reasm_buf);
 406         l_ptr->reasm_buf = NULL;
 407 }
 408
 409 void tipc_link_purge_backlog(struct tipc_link *l)
 410 {
 411         __skb_queue_purge(&l->backlogq);
 412         l->backlog[TIPC_LOW_IMPORTANCE].len = 0;
 413         l->backlog[TIPC_MEDIUM_IMPORTANCE].len = 0;
 414         l->backlog[TIPC_HIGH_IMPORTANCE].len = 0;
 415         l->backlog[TIPC_CRITICAL_IMPORTANCE].len = 0;
 416         l->backlog[TIPC_SYSTEM_IMPORTANCE].len = 0;
 417 }
 418
 419 /**
 420  * tipc_link_purge_queues - purge all pkt queues associated with link
 421  * @l_ptr: pointer to link
 422  */
 423 void tipc_link_purge_queues(struct tipc_link *l_ptr)
 424 {
 425         __skb_queue_purge(&l_ptr->deferdq);
 426         __skb_queue_purge(&l_ptr->transmq);
 427         tipc_link_purge_backlog(l_ptr);
 428         tipc_link_reset_fragments(l_ptr);
 429 }
 430
 431 void tipc_link_reset(struct tipc_link *l_ptr)
 432 {
 433         u32 prev_state = l_ptr->state;
 434         int was_active_link = tipc_link_is_active(l_ptr);
 435         struct tipc_node *owner = l_ptr->owner;
 436         struct tipc_link *pl = tipc_parallel_link(l_ptr);
 437
 438         msg_set_session(l_ptr->pmsg, ((msg_session(l_ptr->pmsg) + 1) & 0xffff));
 439
 440         /* Link is down, accept any session */
 441         l_ptr->peer_session = INVALID_SESSION;
 442
 443         /* Prepare for renewed mtu size negotiation */
 444         l_ptr->mtu = l_ptr->advertised_mtu;
 445
 446         l_ptr->state = RESET_UNKNOWN;
 447
 448         if ((prev_state == RESET_UNKNOWN) || (prev_state == RESET_RESET))
 449                 return;
 450
 451         tipc_node_link_down(l_ptr->owner, l_ptr->bearer_id);
 452         tipc_bearer_remove_dest(owner->net, l_ptr->bearer_id, l_ptr->addr);
 453
 454         if (was_active_link && tipc_node_is_up(l_ptr->owner) && (pl != l_ptr)) {
 455                 l_ptr->flags |= LINK_FAILINGOVER;
 456                 l_ptr->failover_checkpt = l_ptr->rcv_nxt;
 457                 pl->failover_pkts = FIRST_FAILOVER;
 458                 pl->failover_checkpt = l_ptr->rcv_nxt;
 459                 pl->failover_skb = l_ptr->reasm_buf;
 460         } else {
 461                 kfree_skb(l_ptr->reasm_buf);
 462         }
 463         /* Clean up all queues, except inputq: */
 464         __skb_queue_purge(&l_ptr->transmq);
 465         __skb_queue_purge(&l_ptr->deferdq);
 466         if (!owner->inputq)
 467                 owner->inputq = l_ptr->inputq;
 468         skb_queue_splice_init(&l_ptr->wakeupq, owner->inputq);
 469         if (!skb_queue_empty(owner->inputq))
 470                 owner->action_flags |= TIPC_MSG_EVT;
 471         tipc_link_purge_backlog(l_ptr);
 472         l_ptr->reasm_buf = NULL;
 473         l_ptr->rcv_unacked = 0;
 474         l_ptr->snd_nxt = 1;
 475         l_ptr->silent_intv_cnt = 0;
 476         l_ptr->stale_count = 0;
 477         link_reset_statistics(l_ptr);
 478 }
 479
 480 static void link_activate(struct tipc_link *link)
 481 {
 482         struct tipc_node *node = link->owner;
 483
 484         link->rcv_nxt = 1;
 485         link->stats.recv_info = 1;
 486         link->silent_intv_cnt = 0;
 487         tipc_node_link_up(node, link->bearer_id);
 488         tipc_bearer_add_dest(node->net, link->bearer_id, link->addr);
 489 }
 490
 491 /**
 492  * link_state_event - link finite state machine
 493  * @l_ptr: pointer to link
 494  * @event: state machine event to process
 495  */
 496 static void link_state_event(struct tipc_link *l_ptr, unsigned int event)
 497 {
 498         struct tipc_link *other;
 499         unsigned long timer_intv = l_ptr->keepalive_intv;
 500
 501         if (l_ptr->flags & LINK_STOPPED)
 502                 return;
 503
 504         if (!(l_ptr->flags & LINK_STARTED) && (event != STARTING_EVT))
 505                 return;         /* Not yet. */
 506
 507         if (l_ptr->flags & LINK_FAILINGOVER)
 508                 return;
 509
 510         switch (l_ptr->state) {
 511         case WORKING_WORKING:
 512                 switch (event) {
 513                 case TRAFFIC_MSG_EVT:
 514                 case ACTIVATE_MSG:
 515                         l_ptr->silent_intv_cnt = 0;
 516                         break;
 517                 case SILENCE_EVT:
 518                         if (!l_ptr->silent_intv_cnt) {
 519                                 if (tipc_bclink_acks_missing(l_ptr->owner))
 520                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 521                                                              0, 0, 0, 0);
 522                                 break;
 523                         }
 524                         l_ptr->state = WORKING_UNKNOWN;
 525                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 526                         break;
 527                 case RESET_MSG:
 528                         pr_debug("%s<%s>, requested by peer\n",
 529                                  link_rst_msg, l_ptr->name);
 530                         tipc_link_reset(l_ptr);
 531                         l_ptr->state = RESET_RESET;
 532                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 533                                              0, 0, 0, 0);
 534                         break;
 535                 default:
 536                         pr_debug("%s%u in WW state\n", link_unk_evt, event);
 537                 }
 538                 break;
 539         case WORKING_UNKNOWN:
 540                 switch (event) {
 541                 case TRAFFIC_MSG_EVT:
 542                 case ACTIVATE_MSG:
 543                         l_ptr->state = WORKING_WORKING;
 544                         l_ptr->silent_intv_cnt = 0;
 545                         break;
 546                 case RESET_MSG:
 547                         pr_debug("%s<%s>, requested by peer while probing\n",
 548                                  link_rst_msg, l_ptr->name);
 549                         tipc_link_reset(l_ptr);
 550                         l_ptr->state = RESET_RESET;
 551                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 552                                              0, 0, 0, 0);
 553                         break;
 554                 case SILENCE_EVT:
 555                         if (!l_ptr->silent_intv_cnt) {
 556                                 l_ptr->state = WORKING_WORKING;
 557                                 if (tipc_bclink_acks_missing(l_ptr->owner))
 558                                         tipc_link_proto_xmit(l_ptr, STATE_MSG,
 559                                                              0, 0, 0, 0);
 560                         } else if (l_ptr->silent_intv_cnt <
 561                                    l_ptr->abort_limit) {
 562                                 tipc_link_proto_xmit(l_ptr, STATE_MSG,
 563                                                      1, 0, 0, 0);
 564                         } else {        /* Link has failed */
 565                                 pr_debug("%s<%s>, peer not responding\n",
 566                                          link_rst_msg, l_ptr->name);
 567                                 tipc_link_reset(l_ptr);
 568                                 l_ptr->state = RESET_UNKNOWN;
 569                                 tipc_link_proto_xmit(l_ptr, RESET_MSG,
 570                                                      0, 0, 0, 0);
 571                         }
 572                         break;
 573                 default:
 574                         pr_err("%s%u in WU state\n", link_unk_evt, event);
 575                 }
 576                 break;
 577         case RESET_UNKNOWN:
 578                 switch (event) {
 579                 case TRAFFIC_MSG_EVT:
 580                         break;
 581                 case ACTIVATE_MSG:
 582                         other = node_active_link(l_ptr->owner, 0);
 583                         if (other && link_working_unknown(other))
 584                                 break;
 585                         l_ptr->state = WORKING_WORKING;
 586                         link_activate(l_ptr);
 587                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 588                         if (l_ptr->owner->working_links == 1)
 589                                 tipc_link_sync_xmit(l_ptr);
 590                         break;
 591                 case RESET_MSG:
 592                         l_ptr->state = RESET_RESET;
 593                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 594                                              1, 0, 0, 0);
 595                         break;
 596                 case STARTING_EVT:
 597                         l_ptr->flags |= LINK_STARTED;
 598                         link_set_timer(l_ptr, timer_intv);
 599                         break;
 600                 case SILENCE_EVT:
 601                         tipc_link_proto_xmit(l_ptr, RESET_MSG, 0, 0, 0, 0);
 602                         break;
 603                 default:
 604                         pr_err("%s%u in RU state\n", link_unk_evt, event);
 605                 }
 606                 break;
 607         case RESET_RESET:
 608                 switch (event) {
 609                 case TRAFFIC_MSG_EVT:
 610                 case ACTIVATE_MSG:
 611                         other = node_active_link(l_ptr->owner, 0);
 612                         if (other && link_working_unknown(other))
 613                                 break;
 614                         l_ptr->state = WORKING_WORKING;
 615                         link_activate(l_ptr);
 616                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 1, 0, 0, 0);
 617                         if (l_ptr->owner->working_links == 1)
 618                                 tipc_link_sync_xmit(l_ptr);
 619                         break;
 620                 case RESET_MSG:
 621                         break;
 622                 case SILENCE_EVT:
 623                         tipc_link_proto_xmit(l_ptr, ACTIVATE_MSG,
 624                                              0, 0, 0, 0);
 625                         break;
 626                 default:
 627                         pr_err("%s%u in RR state\n", link_unk_evt, event);
 628                 }
 629                 break;
 630         default:
 631                 pr_err("Unknown link state %u/%u\n", l_ptr->state, event);
 632         }
 633 }
 634
 635 /**
 636  * __tipc_link_xmit(): same as tipc_link_xmit, but destlink is known & locked
 637  * @link: link to use
 638  * @list: chain of buffers containing message
 639  *
 640  * Consumes the buffer chain, except when returning an error code,
 641  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 642  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 643  */
 644 int __tipc_link_xmit(struct net *net, struct tipc_link *link,
 645                      struct sk_buff_head *list)
 646 {
 647         struct tipc_msg *msg = buf_msg(skb_peek(list));
 648         unsigned int maxwin = link->window;
 649         unsigned int i, imp = msg_importance(msg);
 650         uint mtu = link->mtu;
 651         u16 ack = mod(link->rcv_nxt - 1);
 652         u16 seqno = link->snd_nxt;
 653         u16 bc_last_in = link->owner->bclink.last_in;
 654         struct tipc_media_addr *addr = &link->media_addr;
 655         struct sk_buff_head *transmq = &link->transmq;
 656         struct sk_buff_head *backlogq = &link->backlogq;
 657         struct sk_buff *skb, *bskb;
 658
 659         /* Match msg importance against this and all higher backlog limits: */
 660         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 661                 if (unlikely(link->backlog[i].len >= link->backlog[i].limit))
 662                         return link_schedule_user(link, list);
 663         }
 664         if (unlikely(msg_size(msg) > mtu))
 665                 return -EMSGSIZE;
 666
 667         /* Prepare each packet for sending, and add to relevant queue: */
 668         while (skb_queue_len(list)) {
 669                 skb = skb_peek(list);
 670                 msg = buf_msg(skb);
 671                 msg_set_seqno(msg, seqno);
 672                 msg_set_ack(msg, ack);
 673                 msg_set_bcast_ack(msg, bc_last_in);
 674
 675                 if (likely(skb_queue_len(transmq) < maxwin)) {
 676                         __skb_dequeue(list);
 677                         __skb_queue_tail(transmq, skb);
 678                         tipc_bearer_send(net, link->bearer_id, skb, addr);
 679                         link->rcv_unacked = 0;
 680                         seqno++;
 681                         continue;
 682                 }
 683                 if (tipc_msg_bundle(skb_peek_tail(backlogq), msg, mtu)) {
 684                         kfree_skb(__skb_dequeue(list));
 685                         link->stats.sent_bundled++;
 686                         continue;
 687                 }
 688                 if (tipc_msg_make_bundle(&bskb, msg, mtu, link->addr)) {
 689                         kfree_skb(__skb_dequeue(list));
 690                         __skb_queue_tail(backlogq, bskb);
 691                         link->backlog[msg_importance(buf_msg(bskb))].len++;
 692                         link->stats.sent_bundled++;
 693                         link->stats.sent_bundles++;
 694                         continue;
 695                 }
 696                 link->backlog[imp].len += skb_queue_len(list);
 697                 skb_queue_splice_tail_init(list, backlogq);
 698         }
 699         link->snd_nxt = seqno;
 700         return 0;
 701 }
 702
 703 /**
 704  * tipc_link_xmit(): enqueue buffer list according to queue situation
 705  * @link: link to use
 706  * @list: chain of buffers containing message
 707  * @xmitq: returned list of packets to be sent by caller
 708  *
 709  * Consumes the buffer chain, except when returning -ELINKCONG,
 710  * since the caller then may want to make more send attempts.
 711  * Returns 0 if success, or errno: -ELINKCONG, -EMSGSIZE or -ENOBUFS
 712  * Messages at TIPC_SYSTEM_IMPORTANCE are always accepted
 713  */
 714 int tipc_link_xmit(struct tipc_link *l, struct sk_buff_head *list,
 715                    struct sk_buff_head *xmitq)
 716 {
 717         struct tipc_msg *hdr = buf_msg(skb_peek(list));
 718         unsigned int maxwin = l->window;
 719         unsigned int i, imp = msg_importance(hdr);
 720         unsigned int mtu = l->mtu;
 721         u16 ack = l->rcv_nxt - 1;
 722         u16 seqno = l->snd_nxt;
 723         u16 bc_last_in = l->owner->bclink.last_in;
 724         struct sk_buff_head *transmq = &l->transmq;
 725         struct sk_buff_head *backlogq = &l->backlogq;
 726         struct sk_buff *skb, *_skb, *bskb;
 727
 728         /* Match msg importance against this and all higher backlog limits: */
 729         for (i = imp; i <= TIPC_SYSTEM_IMPORTANCE; i++) {
 730                 if (unlikely(l->backlog[i].len >= l->backlog[i].limit))
 731                         return link_schedule_user(l, list);
 732         }
 733         if (unlikely(msg_size(hdr) > mtu))
 734                 return -EMSGSIZE;
 735
 736         /* Prepare each packet for sending, and add to relevant queue: */
 737         while (skb_queue_len(list)) {
 738                 skb = skb_peek(list);
 739                 hdr = buf_msg(skb);
 740                 msg_set_seqno(hdr, seqno);
 741                 msg_set_ack(hdr, ack);
 742                 msg_set_bcast_ack(hdr, bc_last_in);
 743
 744                 if (likely(skb_queue_len(transmq) < maxwin)) {
 745                         _skb = skb_clone(skb, GFP_ATOMIC);
 746                         if (!_skb)
 747                                 return -ENOBUFS;
 748                         __skb_dequeue(list);
 749                         __skb_queue_tail(transmq, skb);
 750                         __skb_queue_tail(xmitq, _skb);
 751                         l->rcv_unacked = 0;
 752                         seqno++;
 753                         continue;
 754                 }
 755                 if (tipc_msg_bundle(skb_peek_tail(backlogq), hdr, mtu)) {
 756                         kfree_skb(__skb_dequeue(list));
 757                         l->stats.sent_bundled++;
 758                         continue;
 759                 }
 760                 if (tipc_msg_make_bundle(&bskb, hdr, mtu, l->addr)) {
 761                         kfree_skb(__skb_dequeue(list));
 762                         __skb_queue_tail(backlogq, bskb);
 763                         l->backlog[msg_importance(buf_msg(bskb))].len++;
 764                         l->stats.sent_bundled++;
 765                         l->stats.sent_bundles++;
 766                         continue;
 767                 }
 768                 l->backlog[imp].len += skb_queue_len(list);
 769                 skb_queue_splice_tail_init(list, backlogq);
 770         }
 771         l->snd_nxt = seqno;
 772         return 0;
 773 }
 774
 775 static void skb2list(struct sk_buff *skb, struct sk_buff_head *list)
 776 {
 777         skb_queue_head_init(list);
 778         __skb_queue_tail(list, skb);
 779 }
 780
 781 static int __tipc_link_xmit_skb(struct tipc_link *link, struct sk_buff *skb)
 782 {
 783         struct sk_buff_head head;
 784
 785         skb2list(skb, &head);
 786         return __tipc_link_xmit(link->owner->net, link, &head);
 787 }
 788
 789 /*
 790  * tipc_link_sync_xmit - synchronize broadcast link endpoints.
 791  *
 792  * Give a newly added peer node the sequence number where it should
 793  * start receiving and acking broadcast packets.
 794  *
 795  * Called with node locked
 796  */
 797 static void tipc_link_sync_xmit(struct tipc_link *link)
 798 {
 799         struct sk_buff *skb;
 800         struct tipc_msg *msg;
 801
 802         skb = tipc_buf_acquire(INT_H_SIZE);
 803         if (!skb)
 804                 return;
 805
 806         msg = buf_msg(skb);
 807         tipc_msg_init(link_own_addr(link), msg, BCAST_PROTOCOL, STATE_MSG,
 808                       INT_H_SIZE, link->addr);
 809         msg_set_last_bcast(msg, link->owner->bclink.acked);
 810         __tipc_link_xmit_skb(link, skb);
 811 }
 812
 813 /*
 814  * tipc_link_sync_rcv - synchronize broadcast link endpoints.
 815  * Receive the sequence number where we should start receiving and
 816  * acking broadcast packets from a newly added peer node, and open
 817  * up for reception of such packets.
 818  *
 819  * Called with node locked
 820  */
 821 static void tipc_link_sync_rcv(struct tipc_node *n, struct sk_buff *buf)
 822 {
 823         struct tipc_msg *msg = buf_msg(buf);
 824
 825         n->bclink.last_sent = n->bclink.last_in = msg_last_bcast(msg);
 826         n->bclink.recv_permitted = true;
 827         kfree_skb(buf);
 828 }
 829
 830 /*
 831  * tipc_link_push_packets - push unsent packets to bearer
 832  *
 833  * Push out the unsent messages of a link where congestion
 834  * has abated. Node is locked.
 835  *
 836  * Called with node locked
 837  */
 838 void tipc_link_push_packets(struct tipc_link *link)
 839 {
 840         struct sk_buff *skb;
 841         struct tipc_msg *msg;
 842         u16 seqno = link->snd_nxt;
 843         u16 ack = mod(link->rcv_nxt - 1);
 844
 845         while (skb_queue_len(&link->transmq) < link->window) {
 846                 skb = __skb_dequeue(&link->backlogq);
 847                 if (!skb)
 848                         break;
 849                 msg = buf_msg(skb);
 850                 link->backlog[msg_importance(msg)].len--;
 851                 msg_set_ack(msg, ack);
 852                 msg_set_seqno(msg, seqno);
 853                 seqno = mod(seqno + 1);
 854                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
 855                 link->rcv_unacked = 0;
 856                 __skb_queue_tail(&link->transmq, skb);
 857                 tipc_bearer_send(link->owner->net, link->bearer_id,
 858                                  skb, &link->media_addr);
 859         }
 860         link->snd_nxt = seqno;
 861 }
 862
 863 void tipc_link_reset_all(struct tipc_node *node)
 864 {
 865         char addr_string[16];
 866         u32 i;
 867
 868         tipc_node_lock(node);
 869
 870         pr_warn("Resetting all links to %s\n",
 871                 tipc_addr_string_fill(addr_string, node->addr));
 872
 873         for (i = 0; i < MAX_BEARERS; i++) {
 874                 if (node->links[i].link) {
 875                         link_print(node->links[i].link, "Resetting link\n");
 876                         tipc_link_reset(node->links[i].link);
 877                 }
 878         }
 879
 880         tipc_node_unlock(node);
 881 }
 882
 883 static void link_retransmit_failure(struct tipc_link *l_ptr,
 884                                     struct sk_buff *buf)
 885 {
 886         struct tipc_msg *msg = buf_msg(buf);
 887         struct net *net = l_ptr->owner->net;
 888
 889         pr_warn("Retransmission failure on link <%s>\n", l_ptr->name);
 890
 891         if (l_ptr->addr) {
 892                 /* Handle failure on standard link */
 893                 link_print(l_ptr, "Resetting link\n");
 894                 tipc_link_reset(l_ptr);
 895
 896         } else {
 897                 /* Handle failure on broadcast link */
 898                 struct tipc_node *n_ptr;
 899                 char addr_string[16];
 900
 901                 pr_info("Msg seq number: %u,  ", msg_seqno(msg));
 902                 pr_cont("Outstanding acks: %lu\n",
 903                         (unsigned long) TIPC_SKB_CB(buf)->handle);
 904
 905                 n_ptr = tipc_bclink_retransmit_to(net);
 906
 907                 tipc_addr_string_fill(addr_string, n_ptr->addr);
 908                 pr_info("Broadcast link info for %s\n", addr_string);
 909                 pr_info("Reception permitted: %d,  Acked: %u\n",
 910                         n_ptr->bclink.recv_permitted,
 911                         n_ptr->bclink.acked);
 912                 pr_info("Last in: %u,  Oos state: %u,  Last sent: %u\n",
 913                         n_ptr->bclink.last_in,
 914                         n_ptr->bclink.oos_state,
 915                         n_ptr->bclink.last_sent);
 916
 917                 n_ptr->action_flags |= TIPC_BCAST_RESET;
 918                 l_ptr->stale_count = 0;
 919         }
 920 }
 921
 922 void tipc_link_retransmit(struct tipc_link *l_ptr, struct sk_buff *skb,
 923                           u32 retransmits)
 924 {
 925         struct tipc_msg *msg;
 926
 927         if (!skb)
 928                 return;
 929
 930         msg = buf_msg(skb);
 931
 932         /* Detect repeated retransmit failures */
 933         if (l_ptr->last_retransm == msg_seqno(msg)) {
 934                 if (++l_ptr->stale_count > 100) {
 935                         link_retransmit_failure(l_ptr, skb);
 936                         return;
 937                 }
 938         } else {
 939                 l_ptr->last_retransm = msg_seqno(msg);
 940                 l_ptr->stale_count = 1;
 941         }
 942
 943         skb_queue_walk_from(&l_ptr->transmq, skb) {
 944                 if (!retransmits)
 945                         break;
 946                 msg = buf_msg(skb);
 947                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
 948                 msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
 949                 tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, skb,
 950                                  &l_ptr->media_addr);
 951                 retransmits--;
 952                 l_ptr->stats.retransmitted++;
 953         }
 954 }
 955
 956 /* link_synch(): check if all packets arrived before the synch
 957  *               point have been consumed
 958  * Returns true if the parallel links are synched, otherwise false
 959  */
 960 static bool link_synch(struct tipc_link *l)
 961 {
 962         unsigned int post_synch;
 963         struct tipc_link *pl;
 964
 965         pl  = tipc_parallel_link(l);
 966         if (pl == l)
 967                 goto synched;
 968
 969         /* Was last pre-synch packet added to input queue ? */
 970         if (less_eq(pl->rcv_nxt, l->synch_point))
 971                 return false;
 972
 973         /* Is it still in the input queue ? */
 974         post_synch = mod(pl->rcv_nxt - l->synch_point) - 1;
 975         if (skb_queue_len(pl->inputq) > post_synch)
 976                 return false;
 977 synched:
 978         l->flags &= ~LINK_SYNCHING;
 979         return true;
 980 }
 981
 982 static void link_retrieve_defq(struct tipc_link *link,
 983                                struct sk_buff_head *list)
 984 {
 985         u16 seq_no;
 986
 987         if (skb_queue_empty(&link->deferdq))
 988                 return;
 989
 990         seq_no = buf_seqno(skb_peek(&link->deferdq));
 991         if (seq_no == link->rcv_nxt)
 992                 skb_queue_splice_tail_init(&link->deferdq, list);
 993 }
 994
 995 /**
 996  * tipc_rcv - process TIPC packets/messages arriving from off-node
 997  * @net: the applicable net namespace
 998  * @skb: TIPC packet
 999  * @b_ptr: pointer to bearer message arrived on
1000  *
1001  * Invoked with no locks held.  Bearer pointer must point to a valid bearer
1002  * structure (i.e. cannot be NULL), but bearer can be inactive.
1003  */
1004 void tipc_rcv(struct net *net, struct sk_buff *skb, struct tipc_bearer *b_ptr)
1005 {
1006         struct tipc_net *tn = net_generic(net, tipc_net_id);
1007         struct sk_buff_head head;
1008         struct tipc_node *n_ptr;
1009         struct tipc_link *l_ptr;
1010         struct sk_buff *skb1, *tmp;
1011         struct tipc_msg *msg;
1012         u16 seq_no;
1013         u16 ackd;
1014         u32 released;
1015
1016         skb2list(skb, &head);
1017
1018         while ((skb = __skb_dequeue(&head))) {
1019                 /* Ensure message is well-formed */
1020                 if (unlikely(!tipc_msg_validate(skb)))
1021                         goto discard;
1022
1023                 /* Handle arrival of a non-unicast link message */
1024                 msg = buf_msg(skb);
1025                 if (unlikely(msg_non_seq(msg))) {
1026                         if (msg_user(msg) ==  LINK_CONFIG)
1027                                 tipc_disc_rcv(net, skb, b_ptr);
1028                         else
1029                                 tipc_bclink_rcv(net, skb);
1030                         continue;
1031                 }
1032
1033                 /* Discard unicast link messages destined for another node */
1034                 if (unlikely(!msg_short(msg) &&
1035                              (msg_destnode(msg) != tn->own_addr)))
1036                         goto discard;
1037
1038                 /* Locate neighboring node that sent message */
1039                 n_ptr = tipc_node_find(net, msg_prevnode(msg));
1040                 if (unlikely(!n_ptr))
1041                         goto discard;
1042
1043                 tipc_node_lock(n_ptr);
1044                 /* Locate unicast link endpoint that should handle message */
1045                 l_ptr = n_ptr->links[b_ptr->identity].link;
1046                 if (unlikely(!l_ptr))
1047                         goto unlock;
1048
1049                 /* Verify that communication with node is currently allowed */
1050                 if ((n_ptr->action_flags & TIPC_WAIT_PEER_LINKS_DOWN) &&
1051                     msg_user(msg) == LINK_PROTOCOL &&
1052                     (msg_type(msg) == RESET_MSG ||
1053                     msg_type(msg) == ACTIVATE_MSG) &&
1054                     !msg_redundant_link(msg))
1055                         n_ptr->action_flags &= ~TIPC_WAIT_PEER_LINKS_DOWN;
1056
1057                 if (tipc_node_blocked(n_ptr))
1058                         goto unlock;
1059
1060                 /* Validate message sequence number info */
1061                 seq_no = msg_seqno(msg);
1062                 ackd = msg_ack(msg);
1063
1064                 /* Release acked messages */
1065                 if (unlikely(n_ptr->bclink.acked != msg_bcast_ack(msg)))
1066                         tipc_bclink_acknowledge(n_ptr, msg_bcast_ack(msg));
1067
1068                 released = 0;
1069                 skb_queue_walk_safe(&l_ptr->transmq, skb1, tmp) {
1070                         if (more(buf_seqno(skb1), ackd))
1071                                 break;
1072                          __skb_unlink(skb1, &l_ptr->transmq);
1073                          kfree_skb(skb1);
1074                          released = 1;
1075                 }
1076
1077                 /* Try sending any messages link endpoint has pending */
1078                 if (unlikely(skb_queue_len(&l_ptr->backlogq)))
1079                         tipc_link_push_packets(l_ptr);
1080
1081                 if (released && !skb_queue_empty(&l_ptr->wakeupq))
1082                         link_prepare_wakeup(l_ptr);
1083
1084                 /* Process the incoming packet */
1085                 if (unlikely(!link_working_working(l_ptr))) {
1086                         if (msg_user(msg) == LINK_PROTOCOL) {
1087                                 tipc_link_proto_rcv(l_ptr, skb);
1088                                 link_retrieve_defq(l_ptr, &head);
1089                                 skb = NULL;
1090                                 goto unlock;
1091                         }
1092
1093                         /* Traffic message. Conditionally activate link */
1094                         link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1095
1096                         if (link_working_working(l_ptr)) {
1097                                 /* Re-insert buffer in front of queue */
1098                                 __skb_queue_head(&head, skb);
1099                                 skb = NULL;
1100                                 goto unlock;
1101                         }
1102                         goto unlock;
1103                 }
1104
1105                 /* Link is now in state WORKING_WORKING */
1106                 if (unlikely(seq_no != l_ptr->rcv_nxt)) {
1107                         link_handle_out_of_seq_msg(l_ptr, skb);
1108                         link_retrieve_defq(l_ptr, &head);
1109                         skb = NULL;
1110                         goto unlock;
1111                 }
1112                 l_ptr->silent_intv_cnt = 0;
1113
1114                 /* Synchronize with parallel link if applicable */
1115                 if (unlikely((l_ptr->flags & LINK_SYNCHING) && !msg_dup(msg))) {
1116                         if (!link_synch(l_ptr))
1117                                 goto unlock;
1118                 }
1119                 l_ptr->rcv_nxt++;
1120                 if (unlikely(!skb_queue_empty(&l_ptr->deferdq)))
1121                         link_retrieve_defq(l_ptr, &head);
1122                 if (unlikely(++l_ptr->rcv_unacked >= TIPC_MIN_LINK_WIN)) {
1123                         l_ptr->stats.sent_acks++;
1124                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1125                 }
1126                 tipc_link_input(l_ptr, skb);
1127                 skb = NULL;
1128 unlock:
1129                 tipc_node_unlock(n_ptr);
1130                 tipc_node_put(n_ptr);
1131 discard:
1132                 if (unlikely(skb))
1133                         kfree_skb(skb);
1134         }
1135 }
1136
1137 /* tipc_data_input - deliver data and name distr msgs to upper layer
1138  *
1139  * Consumes buffer if message is of right type
1140  * Node lock must be held
1141  */
1142 static bool tipc_data_input(struct tipc_link *link, struct sk_buff *skb)
1143 {
1144         struct tipc_node *node = link->owner;
1145         struct tipc_msg *msg = buf_msg(skb);
1146         u32 dport = msg_destport(msg);
1147
1148         switch (msg_user(msg)) {
1149         case TIPC_LOW_IMPORTANCE:
1150         case TIPC_MEDIUM_IMPORTANCE:
1151         case TIPC_HIGH_IMPORTANCE:
1152         case TIPC_CRITICAL_IMPORTANCE:
1153         case CONN_MANAGER:
1154                 if (tipc_skb_queue_tail(link->inputq, skb, dport)) {
1155                         node->inputq = link->inputq;
1156                         node->action_flags |= TIPC_MSG_EVT;
1157                 }
1158                 return true;
1159         case NAME_DISTRIBUTOR:
1160                 node->bclink.recv_permitted = true;
1161                 node->namedq = link->namedq;
1162                 skb_queue_tail(link->namedq, skb);
1163                 if (skb_queue_len(link->namedq) == 1)
1164                         node->action_flags |= TIPC_NAMED_MSG_EVT;
1165                 return true;
1166         case MSG_BUNDLER:
1167         case TUNNEL_PROTOCOL:
1168         case MSG_FRAGMENTER:
1169         case BCAST_PROTOCOL:
1170                 return false;
1171         default:
1172                 pr_warn("Dropping received illegal msg type\n");
1173                 kfree_skb(skb);
1174                 return false;
1175         };
1176 }
1177
1178 /* tipc_link_input - process packet that has passed link protocol check
1179  *
1180  * Consumes buffer
1181  * Node lock must be held
1182  */
1183 static void tipc_link_input(struct tipc_link *link, struct sk_buff *skb)
1184 {
1185         struct tipc_node *node = link->owner;
1186         struct tipc_msg *msg = buf_msg(skb);
1187         struct sk_buff *iskb;
1188         int pos = 0;
1189
1190         if (likely(tipc_data_input(link, skb)))
1191                 return;
1192
1193         switch (msg_user(msg)) {
1194         case TUNNEL_PROTOCOL:
1195                 if (msg_dup(msg)) {
1196                         link->flags |= LINK_SYNCHING;
1197                         link->synch_point = msg_seqno(msg_get_wrapped(msg));
1198                         kfree_skb(skb);
1199                         break;
1200                 }
1201                 if (!tipc_link_failover_rcv(link, &skb))
1202                         break;
1203                 if (msg_user(buf_msg(skb)) != MSG_BUNDLER) {
1204                         tipc_data_input(link, skb);
1205                         break;
1206                 }
1207         case MSG_BUNDLER:
1208                 link->stats.recv_bundles++;
1209                 link->stats.recv_bundled += msg_msgcnt(msg);
1210
1211                 while (tipc_msg_extract(skb, &iskb, &pos))
1212                         tipc_data_input(link, iskb);
1213                 break;
1214         case MSG_FRAGMENTER:
1215                 link->stats.recv_fragments++;
1216                 if (tipc_buf_append(&link->reasm_buf, &skb)) {
1217                         link->stats.recv_fragmented++;
1218                         tipc_data_input(link, skb);
1219                 } else if (!link->reasm_buf) {
1220                         tipc_link_reset(link);
1221                 }
1222                 break;
1223         case BCAST_PROTOCOL:
1224                 tipc_link_sync_rcv(node, skb);
1225                 break;
1226         default:
1227                 break;
1228         };
1229 }
1230
1231 /**
1232  * tipc_link_defer_pkt - Add out-of-sequence message to deferred reception queue
1233  *
1234  * Returns increase in queue length (i.e. 0 or 1)
1235  */
1236 u32 tipc_link_defer_pkt(struct sk_buff_head *list, struct sk_buff *skb)
1237 {
1238         struct sk_buff *skb1;
1239         u16 seq_no = buf_seqno(skb);
1240
1241         /* Empty queue ? */
1242         if (skb_queue_empty(list)) {
1243                 __skb_queue_tail(list, skb);
1244                 return 1;
1245         }
1246
1247         /* Last ? */
1248         if (less(buf_seqno(skb_peek_tail(list)), seq_no)) {
1249                 __skb_queue_tail(list, skb);
1250                 return 1;
1251         }
1252
1253         /* Locate insertion point in queue, then insert; discard if duplicate */
1254         skb_queue_walk(list, skb1) {
1255                 u16 curr_seqno = buf_seqno(skb1);
1256
1257                 if (seq_no == curr_seqno) {
1258                         kfree_skb(skb);
1259                         return 0;
1260                 }
1261
1262                 if (less(seq_no, curr_seqno))
1263                         break;
1264         }
1265
1266         __skb_queue_before(list, skb1, skb);
1267         return 1;
1268 }
1269
1270 /*
1271  * link_handle_out_of_seq_msg - handle arrival of out-of-sequence packet
1272  */
1273 static void link_handle_out_of_seq_msg(struct tipc_link *l_ptr,
1274                                        struct sk_buff *buf)
1275 {
1276         u32 seq_no = buf_seqno(buf);
1277
1278         if (likely(msg_user(buf_msg(buf)) == LINK_PROTOCOL)) {
1279                 tipc_link_proto_rcv(l_ptr, buf);
1280                 return;
1281         }
1282
1283         /* Record OOS packet arrival */
1284         l_ptr->silent_intv_cnt = 0;
1285
1286         /*
1287          * Discard packet if a duplicate; otherwise add it to deferred queue
1288          * and notify peer of gap as per protocol specification
1289          */
1290         if (less(seq_no, l_ptr->rcv_nxt)) {
1291                 l_ptr->stats.duplicates++;
1292                 kfree_skb(buf);
1293                 return;
1294         }
1295
1296         if (tipc_link_defer_pkt(&l_ptr->deferdq, buf)) {
1297                 l_ptr->stats.deferred_recv++;
1298                 if ((skb_queue_len(&l_ptr->deferdq) % TIPC_MIN_LINK_WIN) == 1)
1299                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0, 0, 0, 0);
1300         } else {
1301                 l_ptr->stats.duplicates++;
1302         }
1303 }
1304
1305 /*
1306  * Send protocol message to the other endpoint.
1307  */
1308 void tipc_link_proto_xmit(struct tipc_link *l_ptr, u32 msg_typ, int probe_msg,
1309                           u32 gap, u32 tolerance, u32 priority)
1310 {
1311         struct sk_buff *buf = NULL;
1312         struct tipc_msg *msg = l_ptr->pmsg;
1313         u32 msg_size = sizeof(l_ptr->proto_msg);
1314         int r_flag;
1315         u16 last_rcv;
1316
1317         /* Don't send protocol message during link failover */
1318         if (l_ptr->flags & LINK_FAILINGOVER)
1319                 return;
1320
1321         /* Abort non-RESET send if communication with node is prohibited */
1322         if ((tipc_node_blocked(l_ptr->owner)) && (msg_typ != RESET_MSG))
1323                 return;
1324
1325         /* Create protocol message with "out-of-sequence" sequence number */
1326         msg_set_type(msg, msg_typ);
1327         msg_set_net_plane(msg, l_ptr->net_plane);
1328         msg_set_bcast_ack(msg, l_ptr->owner->bclink.last_in);
1329         msg_set_last_bcast(msg, tipc_bclink_get_last_sent(l_ptr->owner->net));
1330
1331         if (msg_typ == STATE_MSG) {
1332                 u16 next_sent = l_ptr->snd_nxt;
1333
1334                 if (!tipc_link_is_up(l_ptr))
1335                         return;
1336                 msg_set_next_sent(msg, next_sent);
1337                 if (!skb_queue_empty(&l_ptr->deferdq)) {
1338                         last_rcv = buf_seqno(skb_peek(&l_ptr->deferdq));
1339                         gap = mod(last_rcv - l_ptr->rcv_nxt);
1340                 }
1341                 msg_set_seq_gap(msg, gap);
1342                 if (gap)
1343                         l_ptr->stats.sent_nacks++;
1344                 msg_set_link_tolerance(msg, tolerance);
1345                 msg_set_linkprio(msg, priority);
1346                 msg_set_max_pkt(msg, l_ptr->mtu);
1347                 msg_set_ack(msg, mod(l_ptr->rcv_nxt - 1));
1348                 msg_set_probe(msg, probe_msg != 0);
1349                 if (probe_msg)
1350                         l_ptr->stats.sent_probes++;
1351                 l_ptr->stats.sent_states++;
1352         } else {                /* RESET_MSG or ACTIVATE_MSG */
1353                 msg_set_ack(msg, mod(l_ptr->failover_checkpt - 1));
1354                 msg_set_seq_gap(msg, 0);
1355                 msg_set_next_sent(msg, 1);
1356                 msg_set_probe(msg, 0);
1357                 msg_set_link_tolerance(msg, l_ptr->tolerance);
1358                 msg_set_linkprio(msg, l_ptr->priority);
1359                 msg_set_max_pkt(msg, l_ptr->advertised_mtu);
1360         }
1361
1362         r_flag = (l_ptr->owner->working_links > tipc_link_is_up(l_ptr));
1363         msg_set_redundant_link(msg, r_flag);
1364         msg_set_linkprio(msg, l_ptr->priority);
1365         msg_set_size(msg, msg_size);
1366
1367         msg_set_seqno(msg, mod(l_ptr->snd_nxt + (0xffff / 2)));
1368
1369         buf = tipc_buf_acquire(msg_size);
1370         if (!buf)
1371                 return;
1372
1373         skb_copy_to_linear_data(buf, msg, sizeof(l_ptr->proto_msg));
1374         buf->priority = TC_PRIO_CONTROL;
1375         tipc_bearer_send(l_ptr->owner->net, l_ptr->bearer_id, buf,
1376                          &l_ptr->media_addr);
1377         l_ptr->rcv_unacked = 0;
1378         kfree_skb(buf);
1379 }
1380
1381 /*
1382  * Receive protocol message :
1383  * Note that network plane id propagates through the network, and may
1384  * change at any time. The node with lowest address rules
1385  */
1386 static void tipc_link_proto_rcv(struct tipc_link *l_ptr,
1387                                 struct sk_buff *buf)
1388 {
1389         u32 rec_gap = 0;
1390         u32 msg_tol;
1391         struct tipc_msg *msg = buf_msg(buf);
1392
1393         if (l_ptr->flags & LINK_FAILINGOVER)
1394                 goto exit;
1395
1396         if (l_ptr->net_plane != msg_net_plane(msg))
1397                 if (link_own_addr(l_ptr) > msg_prevnode(msg))
1398                         l_ptr->net_plane = msg_net_plane(msg);
1399
1400         switch (msg_type(msg)) {
1401
1402         case RESET_MSG:
1403                 if (!link_working_unknown(l_ptr) &&
1404                     (l_ptr->peer_session != INVALID_SESSION)) {
1405                         if (less_eq(msg_session(msg), l_ptr->peer_session))
1406                                 break; /* duplicate or old reset: ignore */
1407                 }
1408
1409                 if (!msg_redundant_link(msg) && (link_working_working(l_ptr) ||
1410                                 link_working_unknown(l_ptr))) {
1411                         /*
1412                          * peer has lost contact -- don't allow peer's links
1413                          * to reactivate before we recognize loss & clean up
1414                          */
1415                         l_ptr->owner->action_flags |= TIPC_WAIT_OWN_LINKS_DOWN;
1416                 }
1417
1418                 link_state_event(l_ptr, RESET_MSG);
1419
1420                 /* fall thru' */
1421         case ACTIVATE_MSG:
1422                 /* Update link settings according other endpoint's values */
1423                 strcpy((strrchr(l_ptr->name, ':') + 1), (char *)msg_data(msg));
1424
1425                 msg_tol = msg_link_tolerance(msg);
1426                 if (msg_tol > l_ptr->tolerance)
1427                         link_set_supervision_props(l_ptr, msg_tol);
1428
1429                 if (msg_linkprio(msg) > l_ptr->priority)
1430                         l_ptr->priority = msg_linkprio(msg);
1431
1432                 if (l_ptr->mtu > msg_max_pkt(msg))
1433                         l_ptr->mtu = msg_max_pkt(msg);
1434
1435                 /* Synchronize broadcast link info, if not done previously */
1436                 if (!tipc_node_is_up(l_ptr->owner)) {
1437                         l_ptr->owner->bclink.last_sent =
1438                                 l_ptr->owner->bclink.last_in =
1439                                 msg_last_bcast(msg);
1440                         l_ptr->owner->bclink.oos_state = 0;
1441                 }
1442
1443                 l_ptr->peer_session = msg_session(msg);
1444                 l_ptr->peer_bearer_id = msg_bearer_id(msg);
1445
1446                 if (msg_type(msg) == ACTIVATE_MSG)
1447                         link_state_event(l_ptr, ACTIVATE_MSG);
1448                 break;
1449         case STATE_MSG:
1450
1451                 msg_tol = msg_link_tolerance(msg);
1452                 if (msg_tol)
1453                         link_set_supervision_props(l_ptr, msg_tol);
1454
1455                 if (msg_linkprio(msg) &&
1456                     (msg_linkprio(msg) != l_ptr->priority)) {
1457                         pr_debug("%s<%s>, priority change %u->%u\n",
1458                                  link_rst_msg, l_ptr->name,
1459                                  l_ptr->priority, msg_linkprio(msg));
1460                         l_ptr->priority = msg_linkprio(msg);
1461                         tipc_link_reset(l_ptr); /* Enforce change to take effect */
1462                         break;
1463                 }
1464
1465                 /* Record reception; force mismatch at next timeout: */
1466                 l_ptr->silent_intv_cnt = 0;
1467
1468                 link_state_event(l_ptr, TRAFFIC_MSG_EVT);
1469                 l_ptr->stats.recv_states++;
1470                 if (link_reset_unknown(l_ptr))
1471                         break;
1472
1473                 if (less_eq(l_ptr->rcv_nxt, msg_next_sent(msg)))
1474                         rec_gap = mod(msg_next_sent(msg) - l_ptr->rcv_nxt);
1475
1476                 if (msg_probe(msg))
1477                         l_ptr->stats.recv_probes++;
1478
1479                 /* Protocol message before retransmits, reduce loss risk */
1480                 if (l_ptr->owner->bclink.recv_permitted)
1481                         tipc_bclink_update_link_state(l_ptr->owner,
1482                                                       msg_last_bcast(msg));
1483
1484                 if (rec_gap || (msg_probe(msg))) {
1485                         tipc_link_proto_xmit(l_ptr, STATE_MSG, 0,
1486                                              rec_gap, 0, 0);
1487                 }
1488                 if (msg_seq_gap(msg)) {
1489                         l_ptr->stats.recv_nacks++;
1490                         tipc_link_retransmit(l_ptr, skb_peek(&l_ptr->transmq),
1491                                              msg_seq_gap(msg));
1492                 }
1493                 break;
1494         }
1495 exit:
1496         kfree_skb(buf);
1497 }
1498
1499
1500 /* tipc_link_tunnel_xmit(): Tunnel one packet via a link belonging to
1501  * a different bearer. Owner node is locked.
1502  */
1503 static void tipc_link_tunnel_xmit(struct tipc_link *l_ptr,
1504                                   struct tipc_msg *tunnel_hdr,
1505                                   struct tipc_msg *msg,
1506                                   u32 selector)
1507 {
1508         struct tipc_link *tunnel;
1509         struct sk_buff *skb;
1510         u32 length = msg_size(msg);
1511
1512         tunnel = node_active_link(l_ptr->owner, selector & 1);
1513         if (!tipc_link_is_up(tunnel)) {
1514                 pr_warn("%stunnel link no longer available\n", link_co_err);
1515                 return;
1516         }
1517         msg_set_size(tunnel_hdr, length + INT_H_SIZE);
1518         skb = tipc_buf_acquire(length + INT_H_SIZE);
1519         if (!skb) {
1520                 pr_warn("%sunable to send tunnel msg\n", link_co_err);
1521                 return;
1522         }
1523         skb_copy_to_linear_data(skb, tunnel_hdr, INT_H_SIZE);
1524         skb_copy_to_linear_data_offset(skb, INT_H_SIZE, msg, length);
1525         __tipc_link_xmit_skb(tunnel, skb);
1526 }
1527
1528
1529 /* tipc_link_failover_send_queue(): A link has gone down, but a second
1530  * link is still active. We can do failover. Tunnel the failing link's
1531  * whole send queue via the remaining link. This way, we don't lose
1532  * any packets, and sequence order is preserved for subsequent traffic
1533  * sent over the remaining link. Owner node is locked.
1534  */
1535 void tipc_link_failover_send_queue(struct tipc_link *l_ptr)
1536 {
1537         int msgcount;
1538         struct tipc_link *tunnel = node_active_link(l_ptr->owner, 0);
1539         struct tipc_msg tunnel_hdr;
1540         struct sk_buff *skb;
1541         int split_bundles;
1542
1543         if (!tunnel)
1544                 return;
1545
1546         tipc_msg_init(link_own_addr(l_ptr), &tunnel_hdr, TUNNEL_PROTOCOL,
1547                       FAILOVER_MSG, INT_H_SIZE, l_ptr->addr);
1548
1549         skb_queue_walk(&l_ptr->backlogq, skb) {
1550                 msg_set_seqno(buf_msg(skb), l_ptr->snd_nxt);
1551                 l_ptr->snd_nxt = mod(l_ptr->snd_nxt + 1);
1552         }
1553         skb_queue_splice_tail_init(&l_ptr->backlogq, &l_ptr->transmq);
1554         tipc_link_purge_backlog(l_ptr);
1555         msgcount = skb_queue_len(&l_ptr->transmq);
1556         msg_set_bearer_id(&tunnel_hdr, l_ptr->peer_bearer_id);
1557         msg_set_msgcnt(&tunnel_hdr, msgcount);
1558
1559         if (skb_queue_empty(&l_ptr->transmq)) {
1560                 skb = tipc_buf_acquire(INT_H_SIZE);
1561                 if (skb) {
1562                         skb_copy_to_linear_data(skb, &tunnel_hdr, INT_H_SIZE);
1563                         msg_set_size(&tunnel_hdr, INT_H_SIZE);
1564                         __tipc_link_xmit_skb(tunnel, skb);
1565                 } else {
1566                         pr_warn("%sunable to send changeover msg\n",
1567                                 link_co_err);
1568                 }
1569                 return;
1570         }
1571
1572         split_bundles = (node_active_link(l_ptr->owner, 0) !=
1573                          node_active_link(l_ptr->owner, 0));
1574
1575         skb_queue_walk(&l_ptr->transmq, skb) {
1576                 struct tipc_msg *msg = buf_msg(skb);
1577
1578                 if ((msg_user(msg) == MSG_BUNDLER) && split_bundles) {
1579                         struct tipc_msg *m = msg_get_wrapped(msg);
1580                         unchar *pos = (unchar *)m;
1581
1582                         msgcount = msg_msgcnt(msg);
1583                         while (msgcount--) {
1584                                 msg_set_seqno(m, msg_seqno(msg));
1585                                 tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, m,
1586                                                       msg_link_selector(m));
1587                                 pos += align(msg_size(m));
1588                                 m = (struct tipc_msg *)pos;
1589                         }
1590                 } else {
1591                         tipc_link_tunnel_xmit(l_ptr, &tunnel_hdr, msg,
1592                                               msg_link_selector(msg));
1593                 }
1594         }
1595 }
1596
1597 /* tipc_link_dup_queue_xmit(): A second link has become active. Tunnel a
1598  * duplicate of the first link's send queue via the new link. This way, we
1599  * are guaranteed that currently queued packets from a socket are delivered
1600  * before future traffic from the same socket, even if this is using the
1601  * new link. The last arriving copy of each duplicate packet is dropped at
1602  * the receiving end by the regular protocol check, so packet cardinality
1603  * and sequence order is preserved per sender/receiver socket pair.
1604  * Owner node is locked.
1605  */
1606 void tipc_link_dup_queue_xmit(struct tipc_link *link,
1607                               struct tipc_link *tnl)
1608 {
1609         struct sk_buff *skb;
1610         struct tipc_msg tnl_hdr;
1611         struct sk_buff_head *queue = &link->transmq;
1612         int mcnt;
1613         u16 seqno;
1614
1615         tipc_msg_init(link_own_addr(link), &tnl_hdr, TUNNEL_PROTOCOL,
1616                       SYNCH_MSG, INT_H_SIZE, link->addr);
1617         mcnt = skb_queue_len(&link->transmq) + skb_queue_len(&link->backlogq);
1618         msg_set_msgcnt(&tnl_hdr, mcnt);
1619         msg_set_bearer_id(&tnl_hdr, link->peer_bearer_id);
1620
1621 tunnel_queue:
1622         skb_queue_walk(queue, skb) {
1623                 struct sk_buff *outskb;
1624                 struct tipc_msg *msg = buf_msg(skb);
1625                 u32 len = msg_size(msg);
1626
1627                 msg_set_ack(msg, mod(link->rcv_nxt - 1));
1628                 msg_set_bcast_ack(msg, link->owner->bclink.last_in);
1629                 msg_set_size(&tnl_hdr, len + INT_H_SIZE);
1630                 outskb = tipc_buf_acquire(len + INT_H_SIZE);
1631                 if (outskb == NULL) {
1632                         pr_warn("%sunable to send duplicate msg\n",
1633                                 link_co_err);
1634                         return;
1635                 }
1636                 skb_copy_to_linear_data(outskb, &tnl_hdr, INT_H_SIZE);
1637                 skb_copy_to_linear_data_offset(outskb, INT_H_SIZE,
1638                                                skb->data, len);
1639                 __tipc_link_xmit_skb(tnl, outskb);
1640                 if (!tipc_link_is_up(link))
1641                         return;
1642         }
1643         if (queue == &link->backlogq)
1644                 return;
1645         seqno = link->snd_nxt;
1646         skb_queue_walk(&link->backlogq, skb) {
1647                 msg_set_seqno(buf_msg(skb), seqno);
1648                 seqno = mod(seqno + 1);
1649         }
1650         queue = &link->backlogq;
1651         goto tunnel_queue;
1652 }
1653
1654 /*  tipc_link_failover_rcv(): Receive a tunnelled FAILOVER_MSG packet
1655  *  Owner node is locked.
1656  */
1657 static bool tipc_link_failover_rcv(struct tipc_link *link,
1658                                    struct sk_buff **skb)
1659 {
1660         struct tipc_msg *msg = buf_msg(*skb);
1661         struct sk_buff *iskb = NULL;
1662         struct tipc_link *pl = NULL;
1663         int bearer_id = msg_bearer_id(msg);
1664         int pos = 0;
1665
1666         if (msg_type(msg) != FAILOVER_MSG) {
1667                 pr_warn("%sunknown tunnel pkt received\n", link_co_err);
1668                 goto exit;
1669         }
1670         if (bearer_id >= MAX_BEARERS)
1671                 goto exit;
1672
1673         if (bearer_id == link->bearer_id)
1674                 goto exit;
1675
1676         pl = link->owner->links[bearer_id].link;
1677         if (pl && tipc_link_is_up(pl))
1678                 tipc_link_reset(pl);
1679
1680         if (link->failover_pkts == FIRST_FAILOVER)
1681                 link->failover_pkts = msg_msgcnt(msg);
1682
1683         /* Should we expect an inner packet? */
1684         if (!link->failover_pkts)
1685                 goto exit;
1686
1687         if (!tipc_msg_extract(*skb, &iskb, &pos)) {
1688                 pr_warn("%sno inner failover pkt\n", link_co_err);
1689                 *skb = NULL;
1690                 goto exit;
1691         }
1692         link->failover_pkts--;
1693         *skb = NULL;
1694
1695         /* Was this packet already delivered? */
1696         if (less(buf_seqno(iskb), link->failover_checkpt)) {
1697                 kfree_skb(iskb);
1698                 iskb = NULL;
1699                 goto exit;
1700         }
1701         if (msg_user(buf_msg(iskb)) == MSG_FRAGMENTER) {
1702                 link->stats.recv_fragments++;
1703                 tipc_buf_append(&link->failover_skb, &iskb);
1704         }
1705 exit:
1706         if (!link->failover_pkts && pl)
1707                 pl->flags &= ~LINK_FAILINGOVER;
1708         kfree_skb(*skb);
1709         *skb = iskb;
1710         return *skb;
1711 }
1712
1713 static void link_set_supervision_props(struct tipc_link *l_ptr, u32 tol)
1714 {
1715         unsigned long intv = ((tol / 4) > 500) ? 500 : tol / 4;
1716
1717         if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1718                 return;
1719
1720         l_ptr->tolerance = tol;
1721         l_ptr->keepalive_intv = msecs_to_jiffies(intv);
1722         l_ptr->abort_limit = tol / (jiffies_to_msecs(l_ptr->keepalive_intv));
1723 }
1724
1725 void tipc_link_set_queue_limits(struct tipc_link *l, u32 win)
1726 {
1727         int max_bulk = TIPC_MAX_PUBLICATIONS / (l->mtu / ITEM_SIZE);
1728
1729         l->window = win;
1730         l->backlog[TIPC_LOW_IMPORTANCE].limit      = win / 2;
1731         l->backlog[TIPC_MEDIUM_IMPORTANCE].limit   = win;
1732         l->backlog[TIPC_HIGH_IMPORTANCE].limit     = win / 2 * 3;
1733         l->backlog[TIPC_CRITICAL_IMPORTANCE].limit = win * 2;
1734         l->backlog[TIPC_SYSTEM_IMPORTANCE].limit   = max_bulk;
1735 }
1736
1737 /* tipc_link_find_owner - locate owner node of link by link's name
1738  * @net: the applicable net namespace
1739  * @name: pointer to link name string
1740  * @bearer_id: pointer to index in 'node->links' array where the link was found.
1741  *
1742  * Returns pointer to node owning the link, or 0 if no matching link is found.
1743  */
1744 static struct tipc_node *tipc_link_find_owner(struct net *net,
1745                                               const char *link_name,
1746                                               unsigned int *bearer_id)
1747 {
1748         struct tipc_net *tn = net_generic(net, tipc_net_id);
1749         struct tipc_link *l_ptr;
1750         struct tipc_node *n_ptr;
1751         struct tipc_node *found_node = NULL;
1752         int i;
1753
1754         *bearer_id = 0;
1755         rcu_read_lock();
1756         list_for_each_entry_rcu(n_ptr, &tn->node_list, list) {
1757                 tipc_node_lock(n_ptr);
1758                 for (i = 0; i < MAX_BEARERS; i++) {
1759                         l_ptr = n_ptr->links[i].link;
1760                         if (l_ptr && !strcmp(l_ptr->name, link_name)) {
1761                                 *bearer_id = i;
1762                                 found_node = n_ptr;
1763                                 break;
1764                         }
1765                 }
1766                 tipc_node_unlock(n_ptr);
1767                 if (found_node)
1768                         break;
1769         }
1770         rcu_read_unlock();
1771
1772         return found_node;
1773 }
1774
1775 /**
1776  * link_reset_statistics - reset link statistics
1777  * @l_ptr: pointer to link
1778  */
1779 static void link_reset_statistics(struct tipc_link *l_ptr)
1780 {
1781         memset(&l_ptr->stats, 0, sizeof(l_ptr->stats));
1782         l_ptr->stats.sent_info = l_ptr->snd_nxt;
1783         l_ptr->stats.recv_info = l_ptr->rcv_nxt;
1784 }
1785
1786 static void link_print(struct tipc_link *l_ptr, const char *str)
1787 {
1788         struct tipc_net *tn = net_generic(l_ptr->owner->net, tipc_net_id);
1789         struct tipc_bearer *b_ptr;
1790
1791         rcu_read_lock();
1792         b_ptr = rcu_dereference_rtnl(tn->bearer_list[l_ptr->bearer_id]);
1793         if (b_ptr)
1794                 pr_info("%s Link %x<%s>:", str, l_ptr->addr, b_ptr->name);
1795         rcu_read_unlock();
1796
1797         if (link_working_unknown(l_ptr))
1798                 pr_cont(":WU\n");
1799         else if (link_reset_reset(l_ptr))
1800                 pr_cont(":RR\n");
1801         else if (link_reset_unknown(l_ptr))
1802                 pr_cont(":RU\n");
1803         else if (link_working_working(l_ptr))
1804                 pr_cont(":WW\n");
1805         else
1806                 pr_cont("\n");
1807 }
1808
1809 /* Parse and validate nested (link) properties valid for media, bearer and link
1810  */
1811 int tipc_nl_parse_link_prop(struct nlattr *prop, struct nlattr *props[])
1812 {
1813         int err;
1814
1815         err = nla_parse_nested(props, TIPC_NLA_PROP_MAX, prop,
1816                                tipc_nl_prop_policy);
1817         if (err)
1818                 return err;
1819
1820         if (props[TIPC_NLA_PROP_PRIO]) {
1821                 u32 prio;
1822
1823                 prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1824                 if (prio > TIPC_MAX_LINK_PRI)
1825                         return -EINVAL;
1826         }
1827
1828         if (props[TIPC_NLA_PROP_TOL]) {
1829                 u32 tol;
1830
1831                 tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1832                 if ((tol < TIPC_MIN_LINK_TOL) || (tol > TIPC_MAX_LINK_TOL))
1833                         return -EINVAL;
1834         }
1835
1836         if (props[TIPC_NLA_PROP_WIN]) {
1837                 u32 win;
1838
1839                 win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1840                 if ((win < TIPC_MIN_LINK_WIN) || (win > TIPC_MAX_LINK_WIN))
1841                         return -EINVAL;
1842         }
1843
1844         return 0;
1845 }
1846
1847 int tipc_nl_link_set(struct sk_buff *skb, struct genl_info *info)
1848 {
1849         int err;
1850         int res = 0;
1851         int bearer_id;
1852         char *name;
1853         struct tipc_link *link;
1854         struct tipc_node *node;
1855         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
1856         struct net *net = sock_net(skb->sk);
1857
1858         if (!info->attrs[TIPC_NLA_LINK])
1859                 return -EINVAL;
1860
1861         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
1862                                info->attrs[TIPC_NLA_LINK],
1863                                tipc_nl_link_policy);
1864         if (err)
1865                 return err;
1866
1867         if (!attrs[TIPC_NLA_LINK_NAME])
1868                 return -EINVAL;
1869
1870         name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
1871
1872         if (strcmp(name, tipc_bclink_name) == 0)
1873                 return tipc_nl_bc_link_set(net, attrs);
1874
1875         node = tipc_link_find_owner(net, name, &bearer_id);
1876         if (!node)
1877                 return -EINVAL;
1878
1879         tipc_node_lock(node);
1880
1881         link = node->links[bearer_id].link;
1882         if (!link) {
1883                 res = -EINVAL;
1884                 goto out;
1885         }
1886
1887         if (attrs[TIPC_NLA_LINK_PROP]) {
1888                 struct nlattr *props[TIPC_NLA_PROP_MAX + 1];
1889
1890                 err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP],
1891                                               props);
1892                 if (err) {
1893                         res = err;
1894                         goto out;
1895                 }
1896
1897                 if (props[TIPC_NLA_PROP_TOL]) {
1898                         u32 tol;
1899
1900                         tol = nla_get_u32(props[TIPC_NLA_PROP_TOL]);
1901                         link_set_supervision_props(link, tol);
1902                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, tol, 0);
1903                 }
1904                 if (props[TIPC_NLA_PROP_PRIO]) {
1905                         u32 prio;
1906
1907                         prio = nla_get_u32(props[TIPC_NLA_PROP_PRIO]);
1908                         link->priority = prio;
1909                         tipc_link_proto_xmit(link, STATE_MSG, 0, 0, 0, prio);
1910                 }
1911                 if (props[TIPC_NLA_PROP_WIN]) {
1912                         u32 win;
1913
1914                         win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);
1915                         tipc_link_set_queue_limits(link, win);
1916                 }
1917         }
1918
1919 out:
1920         tipc_node_unlock(node);
1921
1922         return res;
1923 }
1924
1925 static int __tipc_nl_add_stats(struct sk_buff *skb, struct tipc_stats *s)
1926 {
1927         int i;
1928         struct nlattr *stats;
1929
1930         struct nla_map {
1931                 u32 key;
1932                 u32 val;
1933         };
1934
1935         struct nla_map map[] = {
1936                 {TIPC_NLA_STATS_RX_INFO, s->recv_info},
1937                 {TIPC_NLA_STATS_RX_FRAGMENTS, s->recv_fragments},
1938                 {TIPC_NLA_STATS_RX_FRAGMENTED, s->recv_fragmented},
1939                 {TIPC_NLA_STATS_RX_BUNDLES, s->recv_bundles},
1940                 {TIPC_NLA_STATS_RX_BUNDLED, s->recv_bundled},
1941                 {TIPC_NLA_STATS_TX_INFO, s->sent_info},
1942                 {TIPC_NLA_STATS_TX_FRAGMENTS, s->sent_fragments},
1943                 {TIPC_NLA_STATS_TX_FRAGMENTED, s->sent_fragmented},
1944                 {TIPC_NLA_STATS_TX_BUNDLES, s->sent_bundles},
1945                 {TIPC_NLA_STATS_TX_BUNDLED, s->sent_bundled},
1946                 {TIPC_NLA_STATS_MSG_PROF_TOT, (s->msg_length_counts) ?
1947                         s->msg_length_counts : 1},
1948                 {TIPC_NLA_STATS_MSG_LEN_CNT, s->msg_length_counts},
1949                 {TIPC_NLA_STATS_MSG_LEN_TOT, s->msg_lengths_total},
1950                 {TIPC_NLA_STATS_MSG_LEN_P0, s->msg_length_profile[0]},
1951                 {TIPC_NLA_STATS_MSG_LEN_P1, s->msg_length_profile[1]},
1952                 {TIPC_NLA_STATS_MSG_LEN_P2, s->msg_length_profile[2]},
1953                 {TIPC_NLA_STATS_MSG_LEN_P3, s->msg_length_profile[3]},
1954                 {TIPC_NLA_STATS_MSG_LEN_P4, s->msg_length_profile[4]},
1955                 {TIPC_NLA_STATS_MSG_LEN_P5, s->msg_length_profile[5]},
1956                 {TIPC_NLA_STATS_MSG_LEN_P6, s->msg_length_profile[6]},
1957                 {TIPC_NLA_STATS_RX_STATES, s->recv_states},
1958                 {TIPC_NLA_STATS_RX_PROBES, s->recv_probes},
1959                 {TIPC_NLA_STATS_RX_NACKS, s->recv_nacks},
1960                 {TIPC_NLA_STATS_RX_DEFERRED, s->deferred_recv},
1961                 {TIPC_NLA_STATS_TX_STATES, s->sent_states},
1962                 {TIPC_NLA_STATS_TX_PROBES, s->sent_probes},
1963                 {TIPC_NLA_STATS_TX_NACKS, s->sent_nacks},
1964                 {TIPC_NLA_STATS_TX_ACKS, s->sent_acks},
1965                 {TIPC_NLA_STATS_RETRANSMITTED, s->retransmitted},
1966                 {TIPC_NLA_STATS_DUPLICATES, s->duplicates},
1967                 {TIPC_NLA_STATS_LINK_CONGS, s->link_congs},
1968                 {TIPC_NLA_STATS_MAX_QUEUE, s->max_queue_sz},
1969                 {TIPC_NLA_STATS_AVG_QUEUE, s->queue_sz_counts ?
1970                         (s->accu_queue_sz / s->queue_sz_counts) : 0}
1971         };
1972
1973         stats = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
1974         if (!stats)
1975                 return -EMSGSIZE;
1976
1977         for (i = 0; i <  ARRAY_SIZE(map); i++)
1978                 if (nla_put_u32(skb, map[i].key, map[i].val))
1979                         goto msg_full;
1980
1981         nla_nest_end(skb, stats);
1982
1983         return 0;
1984 msg_full:
1985         nla_nest_cancel(skb, stats);
1986
1987         return -EMSGSIZE;
1988 }
1989
1990 /* Caller should hold appropriate locks to protect the link */
1991 static int __tipc_nl_add_link(struct net *net, struct tipc_nl_msg *msg,
1992                               struct tipc_link *link, int nlflags)
1993 {
1994         int err;
1995         void *hdr;
1996         struct nlattr *attrs;
1997         struct nlattr *prop;
1998         struct tipc_net *tn = net_generic(net, tipc_net_id);
1999
2000         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
2001                           nlflags, TIPC_NL_LINK_GET);
2002         if (!hdr)
2003                 return -EMSGSIZE;
2004
2005         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
2006         if (!attrs)
2007                 goto msg_full;
2008
2009         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, link->name))
2010                 goto attr_msg_full;
2011         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_DEST,
2012                         tipc_cluster_mask(tn->own_addr)))
2013                 goto attr_msg_full;
2014         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_MTU, link->mtu))
2015                 goto attr_msg_full;
2016         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, link->rcv_nxt))
2017                 goto attr_msg_full;
2018         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, link->snd_nxt))
2019                 goto attr_msg_full;
2020
2021         if (tipc_link_is_up(link))
2022                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
2023                         goto attr_msg_full;
2024         if (tipc_link_is_active(link))
2025                 if (nla_put_flag(msg->skb, TIPC_NLA_LINK_ACTIVE))
2026                         goto attr_msg_full;
2027
2028         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
2029         if (!prop)
2030                 goto attr_msg_full;
2031         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2032                 goto prop_msg_full;
2033         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_TOL, link->tolerance))
2034                 goto prop_msg_full;
2035         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN,
2036                         link->window))
2037                 goto prop_msg_full;
2038         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_PRIO, link->priority))
2039                 goto prop_msg_full;
2040         nla_nest_end(msg->skb, prop);
2041
2042         err = __tipc_nl_add_stats(msg->skb, &link->stats);
2043         if (err)
2044                 goto attr_msg_full;
2045
2046         nla_nest_end(msg->skb, attrs);
2047         genlmsg_end(msg->skb, hdr);
2048
2049         return 0;
2050
2051 prop_msg_full:
2052         nla_nest_cancel(msg->skb, prop);
2053 attr_msg_full:
2054         nla_nest_cancel(msg->skb, attrs);
2055 msg_full:
2056         genlmsg_cancel(msg->skb, hdr);
2057
2058         return -EMSGSIZE;
2059 }
2060
2061 /* Caller should hold node lock  */
2062 static int __tipc_nl_add_node_links(struct net *net, struct tipc_nl_msg *msg,
2063                                     struct tipc_node *node, u32 *prev_link)
2064 {
2065         u32 i;
2066         int err;
2067
2068         for (i = *prev_link; i < MAX_BEARERS; i++) {
2069                 *prev_link = i;
2070
2071                 if (!node->links[i].link)
2072                         continue;
2073
2074                 err = __tipc_nl_add_link(net, msg,
2075                                          node->links[i].link, NLM_F_MULTI);
2076                 if (err)
2077                         return err;
2078         }
2079         *prev_link = 0;
2080
2081         return 0;
2082 }
2083
2084 int tipc_nl_link_dump(struct sk_buff *skb, struct netlink_callback *cb)
2085 {
2086         struct net *net = sock_net(skb->sk);
2087         struct tipc_net *tn = net_generic(net, tipc_net_id);
2088         struct tipc_node *node;
2089         struct tipc_nl_msg msg;
2090         u32 prev_node = cb->args[0];
2091         u32 prev_link = cb->args[1];
2092         int done = cb->args[2];
2093         int err;
2094
2095         if (done)
2096                 return 0;
2097
2098         msg.skb = skb;
2099         msg.portid = NETLINK_CB(cb->skb).portid;
2100         msg.seq = cb->nlh->nlmsg_seq;
2101
2102         rcu_read_lock();
2103         if (prev_node) {
2104                 node = tipc_node_find(net, prev_node);
2105                 if (!node) {
2106                         /* We never set seq or call nl_dump_check_consistent()
2107                          * this means that setting prev_seq here will cause the
2108                          * consistence check to fail in the netlink callback
2109                          * handler. Resulting in the last NLMSG_DONE message
2110                          * having the NLM_F_DUMP_INTR flag set.
2111                          */
2112                         cb->prev_seq = 1;
2113                         goto out;
2114                 }
2115                 tipc_node_put(node);
2116
2117                 list_for_each_entry_continue_rcu(node, &tn->node_list,
2118                                                  list) {
2119                         tipc_node_lock(node);
2120                         err = __tipc_nl_add_node_links(net, &msg, node,
2121                                                        &prev_link);
2122                         tipc_node_unlock(node);
2123                         if (err)
2124                                 goto out;
2125
2126                         prev_node = node->addr;
2127                 }
2128         } else {
2129                 err = tipc_nl_add_bc_link(net, &msg);
2130                 if (err)
2131                         goto out;
2132
2133                 list_for_each_entry_rcu(node, &tn->node_list, list) {
2134                         tipc_node_lock(node);
2135                         err = __tipc_nl_add_node_links(net, &msg, node,
2136                                                        &prev_link);
2137                         tipc_node_unlock(node);
2138                         if (err)
2139                                 goto out;
2140
2141                         prev_node = node->addr;
2142                 }
2143         }
2144         done = 1;
2145 out:
2146         rcu_read_unlock();
2147
2148         cb->args[0] = prev_node;
2149         cb->args[1] = prev_link;
2150         cb->args[2] = done;
2151
2152         return skb->len;
2153 }
2154
2155 int tipc_nl_link_get(struct sk_buff *skb, struct genl_info *info)
2156 {
2157         struct net *net = genl_info_net(info);
2158         struct tipc_nl_msg msg;
2159         char *name;
2160         int err;
2161
2162         msg.portid = info->snd_portid;
2163         msg.seq = info->snd_seq;
2164
2165         if (!info->attrs[TIPC_NLA_LINK_NAME])
2166                 return -EINVAL;
2167         name = nla_data(info->attrs[TIPC_NLA_LINK_NAME]);
2168
2169         msg.skb = nlmsg_new(NLMSG_GOODSIZE, GFP_KERNEL);
2170         if (!msg.skb)
2171                 return -ENOMEM;
2172
2173         if (strcmp(name, tipc_bclink_name) == 0) {
2174                 err = tipc_nl_add_bc_link(net, &msg);
2175                 if (err) {
2176                         nlmsg_free(msg.skb);
2177                         return err;
2178                 }
2179         } else {
2180                 int bearer_id;
2181                 struct tipc_node *node;
2182                 struct tipc_link *link;
2183
2184                 node = tipc_link_find_owner(net, name, &bearer_id);
2185                 if (!node)
2186                         return -EINVAL;
2187
2188                 tipc_node_lock(node);
2189                 link = node->links[bearer_id].link;
2190                 if (!link) {
2191                         tipc_node_unlock(node);
2192                         nlmsg_free(msg.skb);
2193                         return -EINVAL;
2194                 }
2195
2196                 err = __tipc_nl_add_link(net, &msg, link, 0);
2197                 tipc_node_unlock(node);
2198                 if (err) {
2199                         nlmsg_free(msg.skb);
2200                         return err;
2201                 }
2202         }
2203
2204         return genlmsg_reply(msg.skb, info);
2205 }
2206
2207 int tipc_nl_link_reset_stats(struct sk_buff *skb, struct genl_info *info)
2208 {
2209         int err;
2210         char *link_name;
2211         unsigned int bearer_id;
2212         struct tipc_link *link;
2213         struct tipc_node *node;
2214         struct nlattr *attrs[TIPC_NLA_LINK_MAX + 1];
2215         struct net *net = sock_net(skb->sk);
2216
2217         if (!info->attrs[TIPC_NLA_LINK])
2218                 return -EINVAL;
2219
2220         err = nla_parse_nested(attrs, TIPC_NLA_LINK_MAX,
2221                                info->attrs[TIPC_NLA_LINK],
2222                                tipc_nl_link_policy);
2223         if (err)
2224                 return err;
2225
2226         if (!attrs[TIPC_NLA_LINK_NAME])
2227                 return -EINVAL;
2228
2229         link_name = nla_data(attrs[TIPC_NLA_LINK_NAME]);
2230
2231         if (strcmp(link_name, tipc_bclink_name) == 0) {
2232                 err = tipc_bclink_reset_stats(net);
2233                 if (err)
2234                         return err;
2235                 return 0;
2236         }
2237
2238         node = tipc_link_find_owner(net, link_name, &bearer_id);
2239         if (!node)
2240                 return -EINVAL;
2241
2242         tipc_node_lock(node);
2243
2244         link = node->links[bearer_id].link;
2245         if (!link) {
2246                 tipc_node_unlock(node);
2247                 return -EINVAL;
2248         }
2249
2250         link_reset_statistics(link);
2251
2252         tipc_node_unlock(node);
2253
2254         return 0;
2255 }