net/tipc/bcast.c

   1 /*
   2  * net/tipc/bcast.c: TIPC broadcast code
   3  *
   4  * Copyright (c) 2004-2006, Ericsson AB
   5  * Copyright (c) 2004, Intel Corporation.
   6  * Copyright (c) 2005, 2010-2011, Wind River Systems
   7  * All rights reserved.
   8  *
   9  * Redistribution and use in source and binary forms, with or without
  10  * modification, are permitted provided that the following conditions are met:
  11  *
  12  * 1. Redistributions of source code must retain the above copyright
  13  *    notice, this list of conditions and the following disclaimer.
  14  * 2. Redistributions in binary form must reproduce the above copyright
  15  *    notice, this list of conditions and the following disclaimer in the
  16  *    documentation and/or other materials provided with the distribution.
  17  * 3. Neither the names of the copyright holders nor the names of its
  18  *    contributors may be used to endorse or promote products derived from
  19  *    this software without specific prior written permission.
  20  *
  21  * Alternatively, this software may be distributed under the terms of the
  22  * GNU General Public License ("GPL") version 2 as published by the Free
  23  * Software Foundation.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  26  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  28  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  29  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  30  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  31  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  32  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  33  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  34  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  35  * POSSIBILITY OF SUCH DAMAGE.
  36  */
  37
  38 #include "core.h"
  39 #include "link.h"
  40 #include "port.h"
  41 #include "bcast.h"
  42 #include "name_distr.h"
  43
  44 #define MAX_PKT_DEFAULT_MCAST   1500    /* bcast link max packet size (fixed) */
  45 #define BCLINK_WIN_DEFAULT      20      /* bcast link window size (default) */
  46 #define BCBEARER                MAX_BEARERS
  47
  48 /**
  49  * struct tipc_bcbearer_pair - a pair of bearers used by broadcast link
  50  * @primary: pointer to primary bearer
  51  * @secondary: pointer to secondary bearer
  52  *
  53  * Bearers must have same priority and same set of reachable destinations
  54  * to be paired.
  55  */
  56
  57 struct tipc_bcbearer_pair {
  58         struct tipc_bearer *primary;
  59         struct tipc_bearer *secondary;
  60 };
  61
  62 /**
  63  * struct tipc_bcbearer - bearer used by broadcast link
  64  * @bearer: (non-standard) broadcast bearer structure
  65  * @media: (non-standard) broadcast media structure
  66  * @bpairs: array of bearer pairs
  67  * @bpairs_temp: temporary array of bearer pairs used by tipc_bcbearer_sort()
  68  * @remains: temporary node map used by tipc_bcbearer_send()
  69  * @remains_new: temporary node map used tipc_bcbearer_send()
  70  *
  71  * Note: The fields labelled "temporary" are incorporated into the bearer
  72  * to avoid consuming potentially limited stack space through the use of
  73  * large local variables within multicast routines.  Concurrent access is
  74  * prevented through use of the spinlock "bclink_lock".
  75  */
  76 struct tipc_bcbearer {
  77         struct tipc_bearer bearer;
  78         struct tipc_media media;
  79         struct tipc_bcbearer_pair bpairs[MAX_BEARERS];
  80         struct tipc_bcbearer_pair bpairs_temp[TIPC_MAX_LINK_PRI + 1];
  81         struct tipc_node_map remains;
  82         struct tipc_node_map remains_new;
  83 };
  84
  85 /**
  86  * struct tipc_bclink - link used for broadcast messages
  87  * @lock: spinlock governing access to structure
  88  * @link: (non-standard) broadcast link structure
  89  * @node: (non-standard) node structure representing b'cast link's peer node
  90  * @flags: represent bclink states
  91  * @bcast_nodes: map of broadcast-capable nodes
  92  * @retransmit_to: node that most recently requested a retransmit
  93  *
  94  * Handles sequence numbering, fragmentation, bundling, etc.
  95  */
  96 struct tipc_bclink {
  97         spinlock_t lock;
  98         struct tipc_link link;
  99         struct tipc_node node;
 100         unsigned int flags;
 101         struct tipc_node_map bcast_nodes;
 102         struct tipc_node *retransmit_to;
 103 };
 104
 105 static struct tipc_bcbearer *bcbearer;
 106 static struct tipc_bclink *bclink;
 107 static struct tipc_link *bcl;
 108
 109 const char tipc_bclink_name[] = "broadcast-link";
 110
 111 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
 112                            struct tipc_node_map *nm_b,
 113                            struct tipc_node_map *nm_diff);
 114 static void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node);
 115 static void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node);
 116
 117 static void tipc_bclink_lock(void)
 118 {
 119         spin_lock_bh(&bclink->lock);
 120 }
 121
 122 static void tipc_bclink_unlock(void)
 123 {
 124         struct tipc_node *node = NULL;
 125
 126         if (likely(!bclink->flags)) {
 127                 spin_unlock_bh(&bclink->lock);
 128                 return;
 129         }
 130
 131         if (bclink->flags & TIPC_BCLINK_RESET) {
 132                 bclink->flags &= ~TIPC_BCLINK_RESET;
 133                 node = tipc_bclink_retransmit_to();
 134         }
 135         spin_unlock_bh(&bclink->lock);
 136
 137         if (node)
 138                 tipc_link_reset_all(node);
 139 }
 140
 141 void tipc_bclink_set_flags(unsigned int flags)
 142 {
 143         bclink->flags |= flags;
 144 }
 145
 146 static u32 bcbuf_acks(struct sk_buff *buf)
 147 {
 148         return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
 149 }
 150
 151 static void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
 152 {
 153         TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks;
 154 }
 155
 156 static void bcbuf_decr_acks(struct sk_buff *buf)
 157 {
 158         bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
 159 }
 160
 161 void tipc_bclink_add_node(u32 addr)
 162 {
 163         tipc_bclink_lock();
 164         tipc_nmap_add(&bclink->bcast_nodes, addr);
 165         tipc_bclink_unlock();
 166 }
 167
 168 void tipc_bclink_remove_node(u32 addr)
 169 {
 170         tipc_bclink_lock();
 171         tipc_nmap_remove(&bclink->bcast_nodes, addr);
 172         tipc_bclink_unlock();
 173 }
 174
 175 static void bclink_set_last_sent(void)
 176 {
 177         if (bcl->next_out)
 178                 bcl->fsm_msg_cnt = mod(buf_seqno(bcl->next_out) - 1);
 179         else
 180                 bcl->fsm_msg_cnt = mod(bcl->next_out_no - 1);
 181 }
 182
 183 u32 tipc_bclink_get_last_sent(void)
 184 {
 185         return bcl->fsm_msg_cnt;
 186 }
 187
 188 static void bclink_update_last_sent(struct tipc_node *node, u32 seqno)
 189 {
 190         node->bclink.last_sent = less_eq(node->bclink.last_sent, seqno) ?
 191                                                 seqno : node->bclink.last_sent;
 192 }
 193
 194
 195 /**
 196  * tipc_bclink_retransmit_to - get most recent node to request retransmission
 197  *
 198  * Called with bclink_lock locked
 199  */
 200 struct tipc_node *tipc_bclink_retransmit_to(void)
 201 {
 202         return bclink->retransmit_to;
 203 }
 204
 205 /**
 206  * bclink_retransmit_pkt - retransmit broadcast packets
 207  * @after: sequence number of last packet to *not* retransmit
 208  * @to: sequence number of last packet to retransmit
 209  *
 210  * Called with bclink_lock locked
 211  */
 212 static void bclink_retransmit_pkt(u32 after, u32 to)
 213 {
 214         struct sk_buff *buf;
 215
 216         buf = bcl->first_out;
 217         while (buf && less_eq(buf_seqno(buf), after))
 218                 buf = buf->next;
 219         tipc_link_retransmit(bcl, buf, mod(to - after));
 220 }
 221
 222 /**
 223  * tipc_bclink_acknowledge - handle acknowledgement of broadcast packets
 224  * @n_ptr: node that sent acknowledgement info
 225  * @acked: broadcast sequence # that has been acknowledged
 226  *
 227  * Node is locked, bclink_lock unlocked.
 228  */
 229 void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
 230 {
 231         struct sk_buff *crs;
 232         struct sk_buff *next;
 233         unsigned int released = 0;
 234
 235         tipc_bclink_lock();
 236         /* Bail out if tx queue is empty (no clean up is required) */
 237         crs = bcl->first_out;
 238         if (!crs)
 239                 goto exit;
 240
 241         /* Determine which messages need to be acknowledged */
 242         if (acked == INVALID_LINK_SEQ) {
 243                 /*
 244                  * Contact with specified node has been lost, so need to
 245                  * acknowledge sent messages only (if other nodes still exist)
 246                  * or both sent and unsent messages (otherwise)
 247                  */
 248                 if (bclink->bcast_nodes.count)
 249                         acked = bcl->fsm_msg_cnt;
 250                 else
 251                         acked = bcl->next_out_no;
 252         } else {
 253                 /*
 254                  * Bail out if specified sequence number does not correspond
 255                  * to a message that has been sent and not yet acknowledged
 256                  */
 257                 if (less(acked, buf_seqno(crs)) ||
 258                     less(bcl->fsm_msg_cnt, acked) ||
 259                     less_eq(acked, n_ptr->bclink.acked))
 260                         goto exit;
 261         }
 262
 263         /* Skip over packets that node has previously acknowledged */
 264         while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked))
 265                 crs = crs->next;
 266
 267         /* Update packets that node is now acknowledging */
 268
 269         while (crs && less_eq(buf_seqno(crs), acked)) {
 270                 next = crs->next;
 271
 272                 if (crs != bcl->next_out)
 273                         bcbuf_decr_acks(crs);
 274                 else {
 275                         bcbuf_set_acks(crs, 0);
 276                         bcl->next_out = next;
 277                         bclink_set_last_sent();
 278                 }
 279
 280                 if (bcbuf_acks(crs) == 0) {
 281                         bcl->first_out = next;
 282                         bcl->out_queue_size--;
 283                         kfree_skb(crs);
 284                         released = 1;
 285                 }
 286                 crs = next;
 287         }
 288         n_ptr->bclink.acked = acked;
 289
 290         /* Try resolving broadcast link congestion, if necessary */
 291
 292         if (unlikely(bcl->next_out)) {
 293                 tipc_link_push_queue(bcl);
 294                 bclink_set_last_sent();
 295         }
 296         if (unlikely(released && !list_empty(&bcl->waiting_ports)))
 297                 tipc_link_wakeup_ports(bcl, 0);
 298 exit:
 299         tipc_bclink_unlock();
 300 }
 301
 302 /**
 303  * tipc_bclink_update_link_state - update broadcast link state
 304  *
 305  * RCU and node lock set
 306  */
 307 void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
 308 {
 309         struct sk_buff *buf;
 310
 311         /* Ignore "stale" link state info */
 312
 313         if (less_eq(last_sent, n_ptr->bclink.last_in))
 314                 return;
 315
 316         /* Update link synchronization state; quit if in sync */
 317
 318         bclink_update_last_sent(n_ptr, last_sent);
 319
 320         if (n_ptr->bclink.last_sent == n_ptr->bclink.last_in)
 321                 return;
 322
 323         /* Update out-of-sync state; quit if loss is still unconfirmed */
 324
 325         if ((++n_ptr->bclink.oos_state) == 1) {
 326                 if (n_ptr->bclink.deferred_size < (TIPC_MIN_LINK_WIN / 2))
 327                         return;
 328                 n_ptr->bclink.oos_state++;
 329         }
 330
 331         /* Don't NACK if one has been recently sent (or seen) */
 332
 333         if (n_ptr->bclink.oos_state & 0x1)
 334                 return;
 335
 336         /* Send NACK */
 337
 338         buf = tipc_buf_acquire(INT_H_SIZE);
 339         if (buf) {
 340                 struct tipc_msg *msg = buf_msg(buf);
 341
 342                 tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
 343                               INT_H_SIZE, n_ptr->addr);
 344                 msg_set_non_seq(msg, 1);
 345                 msg_set_mc_netid(msg, tipc_net_id);
 346                 msg_set_bcast_ack(msg, n_ptr->bclink.last_in);
 347                 msg_set_bcgap_after(msg, n_ptr->bclink.last_in);
 348                 msg_set_bcgap_to(msg, n_ptr->bclink.deferred_head
 349                                  ? buf_seqno(n_ptr->bclink.deferred_head) - 1
 350                                  : n_ptr->bclink.last_sent);
 351
 352                 tipc_bclink_lock();
 353                 tipc_bearer_send(MAX_BEARERS, buf, NULL);
 354                 bcl->stats.sent_nacks++;
 355                 tipc_bclink_unlock();
 356                 kfree_skb(buf);
 357
 358                 n_ptr->bclink.oos_state++;
 359         }
 360 }
 361
 362 /**
 363  * bclink_peek_nack - monitor retransmission requests sent by other nodes
 364  *
 365  * Delay any upcoming NACK by this node if another node has already
 366  * requested the first message this node is going to ask for.
 367  */
 368 static void bclink_peek_nack(struct tipc_msg *msg)
 369 {
 370         struct tipc_node *n_ptr = tipc_node_find(msg_destnode(msg));
 371
 372         if (unlikely(!n_ptr))
 373                 return;
 374
 375         tipc_node_lock(n_ptr);
 376
 377         if (n_ptr->bclink.recv_permitted &&
 378             (n_ptr->bclink.last_in != n_ptr->bclink.last_sent) &&
 379             (n_ptr->bclink.last_in == msg_bcgap_after(msg)))
 380                 n_ptr->bclink.oos_state = 2;
 381
 382         tipc_node_unlock(n_ptr);
 383 }
 384
 385 /*
 386  * tipc_bclink_xmit - broadcast a packet to all nodes in cluster
 387  */
 388 int tipc_bclink_xmit(struct sk_buff *buf)
 389 {
 390         int res;
 391
 392         tipc_bclink_lock();
 393
 394         if (!bclink->bcast_nodes.count) {
 395                 res = msg_data_sz(buf_msg(buf));
 396                 kfree_skb(buf);
 397                 goto exit;
 398         }
 399
 400         res = __tipc_link_xmit(bcl, buf);
 401         if (likely(res >= 0)) {
 402                 bclink_set_last_sent();
 403                 bcl->stats.queue_sz_counts++;
 404                 bcl->stats.accu_queue_sz += bcl->out_queue_size;
 405         }
 406 exit:
 407         tipc_bclink_unlock();
 408         return res;
 409 }
 410
 411 /**
 412  * bclink_accept_pkt - accept an incoming, in-sequence broadcast packet
 413  *
 414  * Called with both sending node's lock and bclink_lock taken.
 415  */
 416 static void bclink_accept_pkt(struct tipc_node *node, u32 seqno)
 417 {
 418         bclink_update_last_sent(node, seqno);
 419         node->bclink.last_in = seqno;
 420         node->bclink.oos_state = 0;
 421         bcl->stats.recv_info++;
 422
 423         /*
 424          * Unicast an ACK periodically, ensuring that
 425          * all nodes in the cluster don't ACK at the same time
 426          */
 427
 428         if (((seqno - tipc_own_addr) % TIPC_MIN_LINK_WIN) == 0) {
 429                 tipc_link_proto_xmit(node->active_links[node->addr & 1],
 430                                      STATE_MSG, 0, 0, 0, 0, 0);
 431                 bcl->stats.sent_acks++;
 432         }
 433 }
 434
 435 /**
 436  * tipc_bclink_rcv - receive a broadcast packet, and deliver upwards
 437  *
 438  * RCU is locked, no other locks set
 439  */
 440 void tipc_bclink_rcv(struct sk_buff *buf)
 441 {
 442         struct tipc_msg *msg = buf_msg(buf);
 443         struct tipc_node *node;
 444         u32 next_in;
 445         u32 seqno;
 446         int deferred;
 447
 448         /* Screen out unwanted broadcast messages */
 449
 450         if (msg_mc_netid(msg) != tipc_net_id)
 451                 goto exit;
 452
 453         node = tipc_node_find(msg_prevnode(msg));
 454         if (unlikely(!node))
 455                 goto exit;
 456
 457         tipc_node_lock(node);
 458         if (unlikely(!node->bclink.recv_permitted))
 459                 goto unlock;
 460
 461         /* Handle broadcast protocol message */
 462
 463         if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
 464                 if (msg_type(msg) != STATE_MSG)
 465                         goto unlock;
 466                 if (msg_destnode(msg) == tipc_own_addr) {
 467                         tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
 468                         tipc_node_unlock(node);
 469                         tipc_bclink_lock();
 470                         bcl->stats.recv_nacks++;
 471                         bclink->retransmit_to = node;
 472                         bclink_retransmit_pkt(msg_bcgap_after(msg),
 473                                               msg_bcgap_to(msg));
 474                         tipc_bclink_unlock();
 475                 } else {
 476                         tipc_node_unlock(node);
 477                         bclink_peek_nack(msg);
 478                 }
 479                 goto exit;
 480         }
 481
 482         /* Handle in-sequence broadcast message */
 483
 484         seqno = msg_seqno(msg);
 485         next_in = mod(node->bclink.last_in + 1);
 486
 487         if (likely(seqno == next_in)) {
 488 receive:
 489                 /* Deliver message to destination */
 490
 491                 if (likely(msg_isdata(msg))) {
 492                         tipc_bclink_lock();
 493                         bclink_accept_pkt(node, seqno);
 494                         tipc_bclink_unlock();
 495                         tipc_node_unlock(node);
 496                         if (likely(msg_mcast(msg)))
 497                                 tipc_port_mcast_rcv(buf, NULL);
 498                         else
 499                                 kfree_skb(buf);
 500                 } else if (msg_user(msg) == MSG_BUNDLER) {
 501                         tipc_bclink_lock();
 502                         bclink_accept_pkt(node, seqno);
 503                         bcl->stats.recv_bundles++;
 504                         bcl->stats.recv_bundled += msg_msgcnt(msg);
 505                         tipc_bclink_unlock();
 506                         tipc_node_unlock(node);
 507                         tipc_link_bundle_rcv(buf);
 508                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
 509                         tipc_buf_append(&node->bclink.reasm_buf, &buf);
 510                         if (unlikely(!buf && !node->bclink.reasm_buf))
 511                                 goto unlock;
 512                         tipc_bclink_lock();
 513                         bclink_accept_pkt(node, seqno);
 514                         bcl->stats.recv_fragments++;
 515                         if (buf) {
 516                                 bcl->stats.recv_fragmented++;
 517                                 msg = buf_msg(buf);
 518                                 tipc_bclink_unlock();
 519                                 goto receive;
 520                         }
 521                         tipc_bclink_unlock();
 522                         tipc_node_unlock(node);
 523                 } else if (msg_user(msg) == NAME_DISTRIBUTOR) {
 524                         tipc_bclink_lock();
 525                         bclink_accept_pkt(node, seqno);
 526                         tipc_bclink_unlock();
 527                         tipc_node_unlock(node);
 528                         tipc_named_rcv(buf);
 529                 } else {
 530                         tipc_bclink_lock();
 531                         bclink_accept_pkt(node, seqno);
 532                         tipc_bclink_unlock();
 533                         tipc_node_unlock(node);
 534                         kfree_skb(buf);
 535                 }
 536                 buf = NULL;
 537
 538                 /* Determine new synchronization state */
 539
 540                 tipc_node_lock(node);
 541                 if (unlikely(!tipc_node_is_up(node)))
 542                         goto unlock;
 543
 544                 if (node->bclink.last_in == node->bclink.last_sent)
 545                         goto unlock;
 546
 547                 if (!node->bclink.deferred_head) {
 548                         node->bclink.oos_state = 1;
 549                         goto unlock;
 550                 }
 551
 552                 msg = buf_msg(node->bclink.deferred_head);
 553                 seqno = msg_seqno(msg);
 554                 next_in = mod(next_in + 1);
 555                 if (seqno != next_in)
 556                         goto unlock;
 557
 558                 /* Take in-sequence message from deferred queue & deliver it */
 559
 560                 buf = node->bclink.deferred_head;
 561                 node->bclink.deferred_head = buf->next;
 562                 buf->next = NULL;
 563                 node->bclink.deferred_size--;
 564                 goto receive;
 565         }
 566
 567         /* Handle out-of-sequence broadcast message */
 568
 569         if (less(next_in, seqno)) {
 570                 deferred = tipc_link_defer_pkt(&node->bclink.deferred_head,
 571                                                &node->bclink.deferred_tail,
 572                                                buf);
 573                 node->bclink.deferred_size += deferred;
 574                 bclink_update_last_sent(node, seqno);
 575                 buf = NULL;
 576         } else
 577                 deferred = 0;
 578
 579         tipc_bclink_lock();
 580
 581         if (deferred)
 582                 bcl->stats.deferred_recv++;
 583         else
 584                 bcl->stats.duplicates++;
 585
 586         tipc_bclink_unlock();
 587
 588 unlock:
 589         tipc_node_unlock(node);
 590 exit:
 591         kfree_skb(buf);
 592 }
 593
 594 u32 tipc_bclink_acks_missing(struct tipc_node *n_ptr)
 595 {
 596         return (n_ptr->bclink.recv_permitted &&
 597                 (tipc_bclink_get_last_sent() != n_ptr->bclink.acked));
 598 }
 599
 600
 601 /**
 602  * tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer
 603  *
 604  * Send packet over as many bearers as necessary to reach all nodes
 605  * that have joined the broadcast link.
 606  *
 607  * Returns 0 (packet sent successfully) under all circumstances,
 608  * since the broadcast link's pseudo-bearer never blocks
 609  */
 610 static int tipc_bcbearer_send(struct sk_buff *buf, struct tipc_bearer *unused1,
 611                               struct tipc_media_addr *unused2)
 612 {
 613         int bp_index;
 614
 615         /* Prepare broadcast link message for reliable transmission,
 616          * if first time trying to send it;
 617          * preparation is skipped for broadcast link protocol messages
 618          * since they are sent in an unreliable manner and don't need it
 619          */
 620         if (likely(!msg_non_seq(buf_msg(buf)))) {
 621                 struct tipc_msg *msg;
 622
 623                 bcbuf_set_acks(buf, bclink->bcast_nodes.count);
 624                 msg = buf_msg(buf);
 625                 msg_set_non_seq(msg, 1);
 626                 msg_set_mc_netid(msg, tipc_net_id);
 627                 bcl->stats.sent_info++;
 628
 629                 if (WARN_ON(!bclink->bcast_nodes.count)) {
 630                         dump_stack();
 631                         return 0;
 632                 }
 633         }
 634
 635         /* Send buffer over bearers until all targets reached */
 636         bcbearer->remains = bclink->bcast_nodes;
 637
 638         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
 639                 struct tipc_bearer *p = bcbearer->bpairs[bp_index].primary;
 640                 struct tipc_bearer *s = bcbearer->bpairs[bp_index].secondary;
 641                 struct tipc_bearer *b = p;
 642                 struct sk_buff *tbuf;
 643
 644                 if (!p)
 645                         break; /* No more bearers to try */
 646
 647                 tipc_nmap_diff(&bcbearer->remains, &b->nodes,
 648                                &bcbearer->remains_new);
 649                 if (bcbearer->remains_new.count == bcbearer->remains.count)
 650                         continue; /* Nothing added by bearer pair */
 651
 652                 if (bp_index == 0) {
 653                         /* Use original buffer for first bearer */
 654                         tipc_bearer_send(b->identity, buf, &b->bcast_addr);
 655                 } else {
 656                         /* Avoid concurrent buffer access */
 657                         tbuf = pskb_copy_for_clone(buf, GFP_ATOMIC);
 658                         if (!tbuf)
 659                                 break;
 660                         tipc_bearer_send(b->identity, tbuf, &b->bcast_addr);
 661                         kfree_skb(tbuf); /* Bearer keeps a clone */
 662                 }
 663
 664                 /* Swap bearers for next packet */
 665                 if (s) {
 666                         bcbearer->bpairs[bp_index].primary = s;
 667                         bcbearer->bpairs[bp_index].secondary = p;
 668                 }
 669
 670                 if (bcbearer->remains_new.count == 0)
 671                         break; /* All targets reached */
 672
 673                 bcbearer->remains = bcbearer->remains_new;
 674         }
 675
 676         return 0;
 677 }
 678
 679 /**
 680  * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer
 681  */
 682 void tipc_bcbearer_sort(struct tipc_node_map *nm_ptr, u32 node, bool action)
 683 {
 684         struct tipc_bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
 685         struct tipc_bcbearer_pair *bp_curr;
 686         struct tipc_bearer *b;
 687         int b_index;
 688         int pri;
 689
 690         tipc_bclink_lock();
 691
 692         if (action)
 693                 tipc_nmap_add(nm_ptr, node);
 694         else
 695                 tipc_nmap_remove(nm_ptr, node);
 696
 697         /* Group bearers by priority (can assume max of two per priority) */
 698         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
 699
 700         rcu_read_lock();
 701         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
 702                 b = rcu_dereference_rtnl(bearer_list[b_index]);
 703                 if (!b || !b->nodes.count)
 704                         continue;
 705
 706                 if (!bp_temp[b->priority].primary)
 707                         bp_temp[b->priority].primary = b;
 708                 else
 709                         bp_temp[b->priority].secondary = b;
 710         }
 711         rcu_read_unlock();
 712
 713         /* Create array of bearer pairs for broadcasting */
 714         bp_curr = bcbearer->bpairs;
 715         memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
 716
 717         for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) {
 718
 719                 if (!bp_temp[pri].primary)
 720                         continue;
 721
 722                 bp_curr->primary = bp_temp[pri].primary;
 723
 724                 if (bp_temp[pri].secondary) {
 725                         if (tipc_nmap_equal(&bp_temp[pri].primary->nodes,
 726                                             &bp_temp[pri].secondary->nodes)) {
 727                                 bp_curr->secondary = bp_temp[pri].secondary;
 728                         } else {
 729                                 bp_curr++;
 730                                 bp_curr->primary = bp_temp[pri].secondary;
 731                         }
 732                 }
 733
 734                 bp_curr++;
 735         }
 736
 737         tipc_bclink_unlock();
 738 }
 739
 740
 741 int tipc_bclink_stats(char *buf, const u32 buf_size)
 742 {
 743         int ret;
 744         struct tipc_stats *s;
 745
 746         if (!bcl)
 747                 return 0;
 748
 749         tipc_bclink_lock();
 750
 751         s = &bcl->stats;
 752
 753         ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
 754                             "  Window:%u packets\n",
 755                             bcl->name, bcl->queue_limit[0]);
 756         ret += tipc_snprintf(buf + ret, buf_size - ret,
 757                              "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
 758                              s->recv_info, s->recv_fragments,
 759                              s->recv_fragmented, s->recv_bundles,
 760                              s->recv_bundled);
 761         ret += tipc_snprintf(buf + ret, buf_size - ret,
 762                              "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
 763                              s->sent_info, s->sent_fragments,
 764                              s->sent_fragmented, s->sent_bundles,
 765                              s->sent_bundled);
 766         ret += tipc_snprintf(buf + ret, buf_size - ret,
 767                              "  RX naks:%u defs:%u dups:%u\n",
 768                              s->recv_nacks, s->deferred_recv, s->duplicates);
 769         ret += tipc_snprintf(buf + ret, buf_size - ret,
 770                              "  TX naks:%u acks:%u dups:%u\n",
 771                              s->sent_nacks, s->sent_acks, s->retransmitted);
 772         ret += tipc_snprintf(buf + ret, buf_size - ret,
 773                              "  Congestion link:%u  Send queue max:%u avg:%u\n",
 774                              s->link_congs, s->max_queue_sz,
 775                              s->queue_sz_counts ?
 776                              (s->accu_queue_sz / s->queue_sz_counts) : 0);
 777
 778         tipc_bclink_unlock();
 779         return ret;
 780 }
 781
 782 int tipc_bclink_reset_stats(void)
 783 {
 784         if (!bcl)
 785                 return -ENOPROTOOPT;
 786
 787         tipc_bclink_lock();
 788         memset(&bcl->stats, 0, sizeof(bcl->stats));
 789         tipc_bclink_unlock();
 790         return 0;
 791 }
 792
 793 int tipc_bclink_set_queue_limits(u32 limit)
 794 {
 795         if (!bcl)
 796                 return -ENOPROTOOPT;
 797         if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
 798                 return -EINVAL;
 799
 800         tipc_bclink_lock();
 801         tipc_link_set_queue_limits(bcl, limit);
 802         tipc_bclink_unlock();
 803         return 0;
 804 }
 805
 806 int tipc_bclink_init(void)
 807 {
 808         bcbearer = kzalloc(sizeof(*bcbearer), GFP_ATOMIC);
 809         if (!bcbearer)
 810                 return -ENOMEM;
 811
 812         bclink = kzalloc(sizeof(*bclink), GFP_ATOMIC);
 813         if (!bclink) {
 814                 kfree(bcbearer);
 815                 return -ENOMEM;
 816         }
 817
 818         bcl = &bclink->link;
 819         bcbearer->bearer.media = &bcbearer->media;
 820         bcbearer->media.send_msg = tipc_bcbearer_send;
 821         sprintf(bcbearer->media.name, "tipc-broadcast");
 822
 823         spin_lock_init(&bclink->lock);
 824         INIT_LIST_HEAD(&bcl->waiting_ports);
 825         bcl->next_out_no = 1;
 826         spin_lock_init(&bclink->node.lock);
 827         bcl->owner = &bclink->node;
 828         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
 829         tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
 830         bcl->bearer_id = MAX_BEARERS;
 831         rcu_assign_pointer(bearer_list[MAX_BEARERS], &bcbearer->bearer);
 832         bcl->state = WORKING_WORKING;
 833         strlcpy(bcl->name, tipc_bclink_name, TIPC_MAX_LINK_NAME);
 834         return 0;
 835 }
 836
 837 void tipc_bclink_stop(void)
 838 {
 839         tipc_bclink_lock();
 840         tipc_link_purge_queues(bcl);
 841         tipc_bclink_unlock();
 842
 843         RCU_INIT_POINTER(bearer_list[BCBEARER], NULL);
 844         synchronize_net();
 845         kfree(bcbearer);
 846         kfree(bclink);
 847 }
 848
 849 /**
 850  * tipc_nmap_add - add a node to a node map
 851  */
 852 static void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node)
 853 {
 854         int n = tipc_node(node);
 855         int w = n / WSIZE;
 856         u32 mask = (1 << (n % WSIZE));
 857
 858         if ((nm_ptr->map[w] & mask) == 0) {
 859                 nm_ptr->count++;
 860                 nm_ptr->map[w] |= mask;
 861         }
 862 }
 863
 864 /**
 865  * tipc_nmap_remove - remove a node from a node map
 866  */
 867 static void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node)
 868 {
 869         int n = tipc_node(node);
 870         int w = n / WSIZE;
 871         u32 mask = (1 << (n % WSIZE));
 872
 873         if ((nm_ptr->map[w] & mask) != 0) {
 874                 nm_ptr->map[w] &= ~mask;
 875                 nm_ptr->count--;
 876         }
 877 }
 878
 879 /**
 880  * tipc_nmap_diff - find differences between node maps
 881  * @nm_a: input node map A
 882  * @nm_b: input node map B
 883  * @nm_diff: output node map A-B (i.e. nodes of A that are not in B)
 884  */
 885 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
 886                            struct tipc_node_map *nm_b,
 887                            struct tipc_node_map *nm_diff)
 888 {
 889         int stop = ARRAY_SIZE(nm_a->map);
 890         int w;
 891         int b;
 892         u32 map;
 893
 894         memset(nm_diff, 0, sizeof(*nm_diff));
 895         for (w = 0; w < stop; w++) {
 896                 map = nm_a->map[w] ^ (nm_a->map[w] & nm_b->map[w]);
 897                 nm_diff->map[w] = map;
 898                 if (map != 0) {
 899                         for (b = 0 ; b < WSIZE; b++) {
 900                                 if (map & (1 << b))
 901                                         nm_diff->count++;
 902                         }
 903                 }
 904         }
 905 }
 906
 907 /**
 908  * tipc_port_list_add - add a port to a port list, ensuring no duplicates
 909  */
 910 void tipc_port_list_add(struct tipc_port_list *pl_ptr, u32 port)
 911 {
 912         struct tipc_port_list *item = pl_ptr;
 913         int i;
 914         int item_sz = PLSIZE;
 915         int cnt = pl_ptr->count;
 916
 917         for (; ; cnt -= item_sz, item = item->next) {
 918                 if (cnt < PLSIZE)
 919                         item_sz = cnt;
 920                 for (i = 0; i < item_sz; i++)
 921                         if (item->ports[i] == port)
 922                                 return;
 923                 if (i < PLSIZE) {
 924                         item->ports[i] = port;
 925                         pl_ptr->count++;
 926                         return;
 927                 }
 928                 if (!item->next) {
 929                         item->next = kmalloc(sizeof(*item), GFP_ATOMIC);
 930                         if (!item->next) {
 931                                 pr_warn("Incomplete multicast delivery, no memory\n");
 932                                 return;
 933                         }
 934                         item->next->next = NULL;
 935                 }
 936         }
 937 }
 938
 939 /**
 940  * tipc_port_list_free - free dynamically created entries in port_list chain
 941  *
 942  */
 943 void tipc_port_list_free(struct tipc_port_list *pl_ptr)
 944 {
 945         struct tipc_port_list *item;
 946         struct tipc_port_list *next;
 947
 948         for (item = pl_ptr->next; item; item = next) {
 949                 next = item->next;
 950                 kfree(item);
 951         }
 952 }