net/tipc/bcast.c

   1 /*
   2  * net/tipc/bcast.c: TIPC broadcast code
   3  *
   4  * Copyright (c) 2003-2005, Ericsson Research Canada
   5  * Copyright (c) 2004, Intel Corporation.
   6  * Copyright (c) 2005, Wind River Systems
   7  * Copyright (c) 2005-2006, Ericsson AB
   8  * All rights reserved.
   9  *
  10  * Redistribution and use in source and binary forms, with or without
  11  * modification, are permitted provided that the following conditions are met:
  12  *
  13  * Redistributions of source code must retain the above copyright notice, this
  14  * list of conditions and the following disclaimer.
  15  * Redistributions in binary form must reproduce the above copyright notice,
  16  * this list of conditions and the following disclaimer in the documentation
  17  * and/or other materials provided with the distribution.
  18  * Neither the names of the copyright holders nor the names of its
  19  * contributors may be used to endorse or promote products derived from this
  20  * software without specific prior written permission.
  21  *
  22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  23  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  32  * POSSIBILITY OF SUCH DAMAGE.
  33  */
  34
  35 #include "core.h"
  36 #include "msg.h"
  37 #include "dbg.h"
  38 #include "link.h"
  39 #include "net.h"
  40 #include "node.h"
  41 #include "port.h"
  42 #include "addr.h"
  43 #include "node_subscr.h"
  44 #include "name_distr.h"
  45 #include "bearer.h"
  46 #include "name_table.h"
  47 #include "bcast.h"
  48
  49
  50 #define MAX_PKT_DEFAULT_MCAST 1500      /* bcast link max packet size (fixed) */
  51
  52 #define BCLINK_WIN_DEFAULT 20           /* bcast link window size (default) */
  53
  54 #define BCLINK_LOG_BUF_SIZE 0
  55
  56 /**
  57  * struct bcbearer_pair - a pair of bearers used by broadcast link
  58  * @primary: pointer to primary bearer
  59  * @secondary: pointer to secondary bearer
  60  *
  61  * Bearers must have same priority and same set of reachable destinations
  62  * to be paired.
  63  */
  64
  65 struct bcbearer_pair {
  66         struct bearer *primary;
  67         struct bearer *secondary;
  68 };
  69
  70 /**
  71  * struct bcbearer - bearer used by broadcast link
  72  * @bearer: (non-standard) broadcast bearer structure
  73  * @media: (non-standard) broadcast media structure
  74  * @bpairs: array of bearer pairs
  75  * @bpairs_temp: array of bearer pairs used during creation of "bpairs"
  76  */
  77
  78 struct bcbearer {
  79         struct bearer bearer;
  80         struct media media;
  81         struct bcbearer_pair bpairs[MAX_BEARERS];
  82         struct bcbearer_pair bpairs_temp[TIPC_NUM_LINK_PRI];
  83 };
  84
  85 /**
  86  * struct bclink - link used for broadcast messages
  87  * @link: (non-standard) broadcast link structure
  88  * @node: (non-standard) node structure representing b'cast link's peer node
  89  *
  90  * Handles sequence numbering, fragmentation, bundling, etc.
  91  */
  92
  93 struct bclink {
  94         struct link link;
  95         struct node node;
  96 };
  97
  98
  99 static struct bcbearer *bcbearer = NULL;
 100 static struct bclink *bclink = NULL;
 101 static struct link *bcl = NULL;
 102 static spinlock_t bc_lock = SPIN_LOCK_UNLOCKED;
 103
 104 char bc_link_name[] = "multicast-link";
 105
 106
 107 static inline u32 buf_seqno(struct sk_buff *buf)
 108 {
 109         return msg_seqno(buf_msg(buf));
 110 }
 111
 112 static inline u32 bcbuf_acks(struct sk_buff *buf)
 113 {
 114         return (u32)TIPC_SKB_CB(buf)->handle;
 115 }
 116
 117 static inline void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
 118 {
 119         TIPC_SKB_CB(buf)->handle = (void *)acks;
 120 }
 121
 122 static inline void bcbuf_decr_acks(struct sk_buff *buf)
 123 {
 124         bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
 125 }
 126
 127
 128 /**
 129  * bclink_set_gap - set gap according to contents of current deferred pkt queue
 130  *
 131  * Called with 'node' locked, bc_lock unlocked
 132  */
 133
 134 static inline void bclink_set_gap(struct node *n_ptr)
 135 {
 136         struct sk_buff *buf = n_ptr->bclink.deferred_head;
 137
 138         n_ptr->bclink.gap_after = n_ptr->bclink.gap_to =
 139                 mod(n_ptr->bclink.last_in);
 140         if (unlikely(buf != NULL))
 141                 n_ptr->bclink.gap_to = mod(buf_seqno(buf) - 1);
 142 }
 143
 144 /**
 145  * bclink_ack_allowed - test if ACK or NACK message can be sent at this moment
 146  *
 147  * This mechanism endeavours to prevent all nodes in network from trying
 148  * to ACK or NACK at the same time.
 149  *
 150  * Note: TIPC uses a different trigger to distribute ACKs than it does to
 151  *       distribute NACKs, but tries to use the same spacing (divide by 16).
 152  */
 153
 154 static inline int bclink_ack_allowed(u32 n)
 155 {
 156         return((n % TIPC_MIN_LINK_WIN) == tipc_own_tag);
 157 }
 158
 159
 160 /**
 161  * bclink_retransmit_pkt - retransmit broadcast packets
 162  * @after: sequence number of last packet to *not* retransmit
 163  * @to: sequence number of last packet to retransmit
 164  *
 165  * Called with 'node' locked, bc_lock unlocked
 166  */
 167
 168 static void bclink_retransmit_pkt(u32 after, u32 to)
 169 {
 170         struct sk_buff *buf;
 171
 172         spin_lock_bh(&bc_lock);
 173         buf = bcl->first_out;
 174         while (buf && less_eq(buf_seqno(buf), after)) {
 175                 buf = buf->next;
 176         }
 177         if (buf != NULL)
 178                 link_retransmit(bcl, buf, mod(to - after));
 179         spin_unlock_bh(&bc_lock);
 180 }
 181
 182 /**
 183  * bclink_acknowledge - handle acknowledgement of broadcast packets
 184  * @n_ptr: node that sent acknowledgement info
 185  * @acked: broadcast sequence # that has been acknowledged
 186  *
 187  * Node is locked, bc_lock unlocked.
 188  */
 189
 190 void bclink_acknowledge(struct node *n_ptr, u32 acked)
 191 {
 192         struct sk_buff *crs;
 193         struct sk_buff *next;
 194         unsigned int released = 0;
 195
 196         if (less_eq(acked, n_ptr->bclink.acked))
 197                 return;
 198
 199         spin_lock_bh(&bc_lock);
 200
 201         /* Skip over packets that node has previously acknowledged */
 202
 203         crs = bcl->first_out;
 204         while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked)) {
 205                 crs = crs->next;
 206         }
 207
 208         /* Update packets that node is now acknowledging */
 209
 210         while (crs && less_eq(buf_seqno(crs), acked)) {
 211                 next = crs->next;
 212                 bcbuf_decr_acks(crs);
 213                 if (bcbuf_acks(crs) == 0) {
 214                         bcl->first_out = next;
 215                         bcl->out_queue_size--;
 216                         buf_discard(crs);
 217                         released = 1;
 218                 }
 219                 crs = next;
 220         }
 221         n_ptr->bclink.acked = acked;
 222
 223         /* Try resolving broadcast link congestion, if necessary */
 224
 225         if (unlikely(bcl->next_out))
 226                 link_push_queue(bcl);
 227         if (unlikely(released && !list_empty(&bcl->waiting_ports)))
 228                 link_wakeup_ports(bcl, 0);
 229         spin_unlock_bh(&bc_lock);
 230 }
 231
 232 /**
 233  * bclink_send_ack - unicast an ACK msg
 234  *
 235  * net_lock and node lock set
 236  */
 237
 238 static void bclink_send_ack(struct node *n_ptr)
 239 {
 240         struct link *l_ptr = n_ptr->active_links[n_ptr->addr & 1];
 241
 242         if (l_ptr != NULL)
 243                 link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
 244 }
 245
 246 /**
 247  * bclink_send_nack- broadcast a NACK msg
 248  *
 249  * net_lock and node lock set
 250  */
 251
 252 static void bclink_send_nack(struct node *n_ptr)
 253 {
 254         struct sk_buff *buf;
 255         struct tipc_msg *msg;
 256
 257         if (!less(n_ptr->bclink.gap_after, n_ptr->bclink.gap_to))
 258                 return;
 259
 260         buf = buf_acquire(INT_H_SIZE);
 261         if (buf) {
 262                 msg = buf_msg(buf);
 263                 msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
 264                          TIPC_OK, INT_H_SIZE, n_ptr->addr);
 265                 msg_set_mc_netid(msg, tipc_net_id);
 266                 msg_set_bcast_ack(msg, mod(n_ptr->bclink.last_in));
 267                 msg_set_bcgap_after(msg, n_ptr->bclink.gap_after);
 268                 msg_set_bcgap_to(msg, n_ptr->bclink.gap_to);
 269                 msg_set_bcast_tag(msg, tipc_own_tag);
 270
 271                 if (bearer_send(&bcbearer->bearer, buf, 0)) {
 272                         bcl->stats.sent_nacks++;
 273                         buf_discard(buf);
 274                 } else {
 275                         bearer_schedule(bcl->b_ptr, bcl);
 276                         bcl->proto_msg_queue = buf;
 277                         bcl->stats.bearer_congs++;
 278                 }
 279
 280                 /*
 281                  * Ensure we doesn't send another NACK msg to the node
 282                  * until 16 more deferred messages arrive from it
 283                  * (i.e. helps prevent all nodes from NACK'ing at same time)
 284                  */
 285
 286                 n_ptr->bclink.nack_sync = tipc_own_tag;
 287         }
 288 }
 289
 290 /**
 291  * bclink_check_gap - send a NACK if a sequence gap exists
 292  *
 293  * net_lock and node lock set
 294  */
 295
 296 void bclink_check_gap(struct node *n_ptr, u32 last_sent)
 297 {
 298         if (!n_ptr->bclink.supported ||
 299             less_eq(last_sent, mod(n_ptr->bclink.last_in)))
 300                 return;
 301
 302         bclink_set_gap(n_ptr);
 303         if (n_ptr->bclink.gap_after == n_ptr->bclink.gap_to)
 304                 n_ptr->bclink.gap_to = last_sent;
 305         bclink_send_nack(n_ptr);
 306 }
 307
 308 /**
 309  * bclink_peek_nack - process a NACK msg meant for another node
 310  *
 311  * Only net_lock set.
 312  */
 313
 314 void bclink_peek_nack(u32 dest, u32 sender_tag, u32 gap_after, u32 gap_to)
 315 {
 316         struct node *n_ptr = node_find(dest);
 317         u32 my_after, my_to;
 318
 319         if (unlikely(!n_ptr || !node_is_up(n_ptr)))
 320                 return;
 321         node_lock(n_ptr);
 322         /*
 323          * Modify gap to suppress unnecessary NACKs from this node
 324          */
 325         my_after = n_ptr->bclink.gap_after;
 326         my_to = n_ptr->bclink.gap_to;
 327
 328         if (less_eq(gap_after, my_after)) {
 329                 if (less(my_after, gap_to) && less(gap_to, my_to))
 330                         n_ptr->bclink.gap_after = gap_to;
 331                 else if (less_eq(my_to, gap_to))
 332                         n_ptr->bclink.gap_to = n_ptr->bclink.gap_after;
 333         } else if (less_eq(gap_after, my_to)) {
 334                 if (less_eq(my_to, gap_to))
 335                         n_ptr->bclink.gap_to = gap_after;
 336         } else {
 337                 /*
 338                  * Expand gap if missing bufs not in deferred queue:
 339                  */
 340                 struct sk_buff *buf = n_ptr->bclink.deferred_head;
 341                 u32 prev = n_ptr->bclink.gap_to;
 342
 343                 for (; buf; buf = buf->next) {
 344                         u32 seqno = buf_seqno(buf);
 345
 346                         if (mod(seqno - prev) != 1)
 347                                 buf = NULL;
 348                         if (seqno == gap_after)
 349                                 break;
 350                         prev = seqno;
 351                 }
 352                 if (buf == NULL)
 353                         n_ptr->bclink.gap_to = gap_after;
 354         }
 355         /*
 356          * Some nodes may send a complementary NACK now:
 357          */
 358         if (bclink_ack_allowed(sender_tag + 1)) {
 359                 if (n_ptr->bclink.gap_to != n_ptr->bclink.gap_after) {
 360                         bclink_send_nack(n_ptr);
 361                         bclink_set_gap(n_ptr);
 362                 }
 363         }
 364         node_unlock(n_ptr);
 365 }
 366
 367 /**
 368  * bclink_send_msg - broadcast a packet to all nodes in cluster
 369  */
 370
 371 int bclink_send_msg(struct sk_buff *buf)
 372 {
 373         int res;
 374
 375         spin_lock_bh(&bc_lock);
 376
 377         res = link_send_buf(bcl, buf);
 378         if (unlikely(res == -ELINKCONG))
 379                 buf_discard(buf);
 380         else
 381                 bcl->stats.sent_info++;
 382
 383         if (bcl->out_queue_size > bcl->stats.max_queue_sz)
 384                 bcl->stats.max_queue_sz = bcl->out_queue_size;
 385         bcl->stats.queue_sz_counts++;
 386         bcl->stats.accu_queue_sz += bcl->out_queue_size;
 387
 388         spin_unlock_bh(&bc_lock);
 389         return res;
 390 }
 391
 392 /**
 393  * bclink_recv_pkt - receive a broadcast packet, and deliver upwards
 394  *
 395  * net_lock is read_locked, no other locks set
 396  */
 397
 398 void bclink_recv_pkt(struct sk_buff *buf)
 399 {
 400         struct tipc_msg *msg = buf_msg(buf);
 401         struct node* node = node_find(msg_prevnode(msg));
 402         u32 next_in;
 403         u32 seqno;
 404         struct sk_buff *deferred;
 405
 406         msg_dbg(msg, "<BC<<<");
 407
 408         if (unlikely(!node || !node_is_up(node) || !node->bclink.supported ||
 409                      (msg_mc_netid(msg) != tipc_net_id))) {
 410                 buf_discard(buf);
 411                 return;
 412         }
 413
 414         if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
 415                 msg_dbg(msg, "<BCNACK<<<");
 416                 if (msg_destnode(msg) == tipc_own_addr) {
 417                         node_lock(node);
 418                         bclink_acknowledge(node, msg_bcast_ack(msg));
 419                         node_unlock(node);
 420                         bcl->stats.recv_nacks++;
 421                         bclink_retransmit_pkt(msg_bcgap_after(msg),
 422                                               msg_bcgap_to(msg));
 423                 } else {
 424                         bclink_peek_nack(msg_destnode(msg),
 425                                          msg_bcast_tag(msg),
 426                                          msg_bcgap_after(msg),
 427                                          msg_bcgap_to(msg));
 428                 }
 429                 buf_discard(buf);
 430                 return;
 431         }
 432
 433         node_lock(node);
 434 receive:
 435         deferred = node->bclink.deferred_head;
 436         next_in = mod(node->bclink.last_in + 1);
 437         seqno = msg_seqno(msg);
 438
 439         if (likely(seqno == next_in)) {
 440                 bcl->stats.recv_info++;
 441                 node->bclink.last_in++;
 442                 bclink_set_gap(node);
 443                 if (unlikely(bclink_ack_allowed(seqno))) {
 444                         bclink_send_ack(node);
 445                         bcl->stats.sent_acks++;
 446                 }
 447                 if (likely(msg_isdata(msg))) {
 448                         node_unlock(node);
 449                         port_recv_mcast(buf, NULL);
 450                 } else if (msg_user(msg) == MSG_BUNDLER) {
 451                         bcl->stats.recv_bundles++;
 452                         bcl->stats.recv_bundled += msg_msgcnt(msg);
 453                         node_unlock(node);
 454                         link_recv_bundle(buf);
 455                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
 456                         bcl->stats.recv_fragments++;
 457                         if (link_recv_fragment(&node->bclink.defragm,
 458                                                &buf, &msg))
 459                                 bcl->stats.recv_fragmented++;
 460                         node_unlock(node);
 461                         net_route_msg(buf);
 462                 } else {
 463                         node_unlock(node);
 464                         net_route_msg(buf);
 465                 }
 466                 if (deferred && (buf_seqno(deferred) == mod(next_in + 1))) {
 467                         node_lock(node);
 468                         buf = deferred;
 469                         msg = buf_msg(buf);
 470                         node->bclink.deferred_head = deferred->next;
 471                         goto receive;
 472                 }
 473                 return;
 474         } else if (less(next_in, seqno)) {
 475                 u32 gap_after = node->bclink.gap_after;
 476                 u32 gap_to = node->bclink.gap_to;
 477
 478                 if (link_defer_pkt(&node->bclink.deferred_head,
 479                                    &node->bclink.deferred_tail,
 480                                    buf)) {
 481                         node->bclink.nack_sync++;
 482                         bcl->stats.deferred_recv++;
 483                         if (seqno == mod(gap_after + 1))
 484                                 node->bclink.gap_after = seqno;
 485                         else if (less(gap_after, seqno) && less(seqno, gap_to))
 486                                 node->bclink.gap_to = seqno;
 487                 }
 488                 if (bclink_ack_allowed(node->bclink.nack_sync)) {
 489                         if (gap_to != gap_after)
 490                                 bclink_send_nack(node);
 491                         bclink_set_gap(node);
 492                 }
 493         } else {
 494                 bcl->stats.duplicates++;
 495                 buf_discard(buf);
 496         }
 497         node_unlock(node);
 498 }
 499
 500 u32 bclink_get_last_sent(void)
 501 {
 502         u32 last_sent = mod(bcl->next_out_no - 1);
 503
 504         if (bcl->next_out)
 505                 last_sent = mod(buf_seqno(bcl->next_out) - 1);
 506         return last_sent;
 507 }
 508
 509 u32 bclink_acks_missing(struct node *n_ptr)
 510 {
 511         return (n_ptr->bclink.supported &&
 512                 (bclink_get_last_sent() != n_ptr->bclink.acked));
 513 }
 514
 515
 516 /**
 517  * bcbearer_send - send a packet through the broadcast pseudo-bearer
 518  *
 519  * Send through as many bearers as necessary to reach all nodes
 520  * that support TIPC multicasting.
 521  *
 522  * Returns 0 if packet sent successfully, non-zero if not
 523  */
 524
 525 int bcbearer_send(struct sk_buff *buf,
 526                   struct tipc_bearer *unused1,
 527                   struct tipc_media_addr *unused2)
 528 {
 529         static int send_count = 0;
 530
 531         struct node_map remains;
 532         struct node_map remains_new;
 533         int bp_index;
 534         int swap_time;
 535
 536         /* Prepare buffer for broadcasting (if first time trying to send it) */
 537
 538         if (likely(!msg_non_seq(buf_msg(buf)))) {
 539                 struct tipc_msg *msg;
 540
 541                 assert(cluster_bcast_nodes.count != 0);
 542                 bcbuf_set_acks(buf, cluster_bcast_nodes.count);
 543                 msg = buf_msg(buf);
 544                 msg_set_non_seq(msg);
 545                 msg_set_mc_netid(msg, tipc_net_id);
 546         }
 547
 548         /* Determine if bearer pairs should be swapped following this attempt */
 549
 550         if ((swap_time = (++send_count >= 10)))
 551                 send_count = 0;
 552
 553         /* Send buffer over bearers until all targets reached */
 554
 555         remains = cluster_bcast_nodes;
 556
 557         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
 558                 struct bearer *p = bcbearer->bpairs[bp_index].primary;
 559                 struct bearer *s = bcbearer->bpairs[bp_index].secondary;
 560
 561                 if (!p)
 562                         break;  /* no more bearers to try */
 563
 564                 nmap_diff(&remains, &p->nodes, &remains_new);
 565                 if (remains_new.count == remains.count)
 566                         continue;       /* bearer pair doesn't add anything */
 567
 568                 if (!p->publ.blocked &&
 569                     !p->media->send_msg(buf, &p->publ, &p->media->bcast_addr)) {
 570                         if (swap_time && s && !s->publ.blocked)
 571                                 goto swap;
 572                         else
 573                                 goto update;
 574                 }
 575
 576                 if (!s || s->publ.blocked ||
 577                     s->media->send_msg(buf, &s->publ, &s->media->bcast_addr))
 578                         continue;       /* unable to send using bearer pair */
 579 swap:
 580                 bcbearer->bpairs[bp_index].primary = s;
 581                 bcbearer->bpairs[bp_index].secondary = p;
 582 update:
 583                 if (remains_new.count == 0)
 584                         return TIPC_OK;
 585
 586                 remains = remains_new;
 587         }
 588
 589         /* Unable to reach all targets */
 590
 591         bcbearer->bearer.publ.blocked = 1;
 592         bcl->stats.bearer_congs++;
 593         return ~TIPC_OK;
 594 }
 595
 596 /**
 597  * bcbearer_sort - create sets of bearer pairs used by broadcast bearer
 598  */
 599
 600 void bcbearer_sort(void)
 601 {
 602         struct bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
 603         struct bcbearer_pair *bp_curr;
 604         int b_index;
 605         int pri;
 606
 607         spin_lock_bh(&bc_lock);
 608
 609         /* Group bearers by priority (can assume max of two per priority) */
 610
 611         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
 612
 613         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
 614                 struct bearer *b = &bearers[b_index];
 615
 616                 if (!b->active || !b->nodes.count)
 617                         continue;
 618
 619                 if (!bp_temp[b->priority].primary)
 620                         bp_temp[b->priority].primary = b;
 621                 else
 622                         bp_temp[b->priority].secondary = b;
 623         }
 624
 625         /* Create array of bearer pairs for broadcasting */
 626
 627         bp_curr = bcbearer->bpairs;
 628         memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
 629
 630         for (pri = (TIPC_NUM_LINK_PRI - 1); pri >= 0; pri--) {
 631
 632                 if (!bp_temp[pri].primary)
 633                         continue;
 634
 635                 bp_curr->primary = bp_temp[pri].primary;
 636
 637                 if (bp_temp[pri].secondary) {
 638                         if (nmap_equal(&bp_temp[pri].primary->nodes,
 639                                        &bp_temp[pri].secondary->nodes)) {
 640                                 bp_curr->secondary = bp_temp[pri].secondary;
 641                         } else {
 642                                 bp_curr++;
 643                                 bp_curr->primary = bp_temp[pri].secondary;
 644                         }
 645                 }
 646
 647                 bp_curr++;
 648         }
 649
 650         spin_unlock_bh(&bc_lock);
 651 }
 652
 653 /**
 654  * bcbearer_push - resolve bearer congestion
 655  *
 656  * Forces bclink to push out any unsent packets, until all packets are gone
 657  * or congestion reoccurs.
 658  * No locks set when function called
 659  */
 660
 661 void bcbearer_push(void)
 662 {
 663         struct bearer *b_ptr;
 664
 665         spin_lock_bh(&bc_lock);
 666         b_ptr = &bcbearer->bearer;
 667         if (b_ptr->publ.blocked) {
 668                 b_ptr->publ.blocked = 0;
 669                 bearer_lock_push(b_ptr);
 670         }
 671         spin_unlock_bh(&bc_lock);
 672 }
 673
 674
 675 int bclink_stats(char *buf, const u32 buf_size)
 676 {
 677         struct print_buf pb;
 678
 679         if (!bcl)
 680                 return 0;
 681
 682         printbuf_init(&pb, buf, buf_size);
 683
 684         spin_lock_bh(&bc_lock);
 685
 686         tipc_printf(&pb, "Link <%s>\n"
 687                          "  Window:%u packets\n",
 688                     bcl->name, bcl->queue_limit[0]);
 689         tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
 690                     bcl->stats.recv_info,
 691                     bcl->stats.recv_fragments,
 692                     bcl->stats.recv_fragmented,
 693                     bcl->stats.recv_bundles,
 694                     bcl->stats.recv_bundled);
 695         tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
 696                     bcl->stats.sent_info,
 697                     bcl->stats.sent_fragments,
 698                     bcl->stats.sent_fragmented,
 699                     bcl->stats.sent_bundles,
 700                     bcl->stats.sent_bundled);
 701         tipc_printf(&pb, "  RX naks:%u defs:%u dups:%u\n",
 702                     bcl->stats.recv_nacks,
 703                     bcl->stats.deferred_recv,
 704                     bcl->stats.duplicates);
 705         tipc_printf(&pb, "  TX naks:%u acks:%u dups:%u\n",
 706                     bcl->stats.sent_nacks,
 707                     bcl->stats.sent_acks,
 708                     bcl->stats.retransmitted);
 709         tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
 710                     bcl->stats.bearer_congs,
 711                     bcl->stats.link_congs,
 712                     bcl->stats.max_queue_sz,
 713                     bcl->stats.queue_sz_counts
 714                     ? (bcl->stats.accu_queue_sz / bcl->stats.queue_sz_counts)
 715                     : 0);
 716
 717         spin_unlock_bh(&bc_lock);
 718         return printbuf_validate(&pb);
 719 }
 720
 721 int bclink_reset_stats(void)
 722 {
 723         if (!bcl)
 724                 return -ENOPROTOOPT;
 725
 726         spin_lock_bh(&bc_lock);
 727         memset(&bcl->stats, 0, sizeof(bcl->stats));
 728         spin_unlock_bh(&bc_lock);
 729         return TIPC_OK;
 730 }
 731
 732 int bclink_set_queue_limits(u32 limit)
 733 {
 734         if (!bcl)
 735                 return -ENOPROTOOPT;
 736         if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
 737                 return -EINVAL;
 738
 739         spin_lock_bh(&bc_lock);
 740         link_set_queue_limits(bcl, limit);
 741         spin_unlock_bh(&bc_lock);
 742         return TIPC_OK;
 743 }
 744
 745 int bclink_init(void)
 746 {
 747         bcbearer = kmalloc(sizeof(*bcbearer), GFP_ATOMIC);
 748         bclink = kmalloc(sizeof(*bclink), GFP_ATOMIC);
 749         if (!bcbearer || !bclink) {
 750  nomem:
 751                 warn("Memory squeeze; Failed to create multicast link\n");
 752                 kfree(bcbearer);
 753                 bcbearer = NULL;
 754                 kfree(bclink);
 755                 bclink = NULL;
 756                 return -ENOMEM;
 757         }
 758
 759         memset(bcbearer, 0, sizeof(struct bcbearer));
 760         INIT_LIST_HEAD(&bcbearer->bearer.cong_links);
 761         bcbearer->bearer.media = &bcbearer->media;
 762         bcbearer->media.send_msg = bcbearer_send;
 763         sprintf(bcbearer->media.name, "tipc-multicast");
 764
 765         bcl = &bclink->link;
 766         memset(bclink, 0, sizeof(struct bclink));
 767         INIT_LIST_HEAD(&bcl->waiting_ports);
 768         bcl->next_out_no = 1;
 769         bclink->node.lock =  SPIN_LOCK_UNLOCKED;
 770         bcl->owner = &bclink->node;
 771         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
 772         link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
 773         bcl->b_ptr = &bcbearer->bearer;
 774         bcl->state = WORKING_WORKING;
 775         sprintf(bcl->name, bc_link_name);
 776
 777         if (BCLINK_LOG_BUF_SIZE) {
 778                 char *pb = kmalloc(BCLINK_LOG_BUF_SIZE, GFP_ATOMIC);
 779
 780                 if (!pb)
 781                         goto nomem;
 782                 printbuf_init(&bcl->print_buf, pb, BCLINK_LOG_BUF_SIZE);
 783         }
 784
 785         return TIPC_OK;
 786 }
 787
 788 void bclink_stop(void)
 789 {
 790         spin_lock_bh(&bc_lock);
 791         if (bcbearer) {
 792                 link_stop(bcl);
 793                 if (BCLINK_LOG_BUF_SIZE)
 794                         kfree(bcl->print_buf.buf);
 795                 bcl = NULL;
 796                 kfree(bclink);
 797                 bclink = NULL;
 798                 kfree(bcbearer);
 799                 bcbearer = NULL;
 800         }
 801         spin_unlock_bh(&bc_lock);
 802 }
 803