net/tipc/bcast.c

   1 /*
   2  * net/tipc/bcast.c: TIPC broadcast code
   3  *
   4  * Copyright (c) 2004-2006, 2014, 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 "socket.h"
  41 #include "msg.h"
  42 #include "bcast.h"
  43 #include "name_distr.h"
  44
  45 #define MAX_PKT_DEFAULT_MCAST   1500    /* bcast link max packet size (fixed) */
  46 #define BCLINK_WIN_DEFAULT      20      /* bcast link window size (default) */
  47 #define BCBEARER                MAX_BEARERS
  48
  49 /**
  50  * struct tipc_bcbearer_pair - a pair of bearers used by broadcast link
  51  * @primary: pointer to primary bearer
  52  * @secondary: pointer to secondary bearer
  53  *
  54  * Bearers must have same priority and same set of reachable destinations
  55  * to be paired.
  56  */
  57
  58 struct tipc_bcbearer_pair {
  59         struct tipc_bearer *primary;
  60         struct tipc_bearer *secondary;
  61 };
  62
  63 /**
  64  * struct tipc_bcbearer - bearer used by broadcast link
  65  * @bearer: (non-standard) broadcast bearer structure
  66  * @media: (non-standard) broadcast media structure
  67  * @bpairs: array of bearer pairs
  68  * @bpairs_temp: temporary array of bearer pairs used by tipc_bcbearer_sort()
  69  * @remains: temporary node map used by tipc_bcbearer_send()
  70  * @remains_new: temporary node map used tipc_bcbearer_send()
  71  *
  72  * Note: The fields labelled "temporary" are incorporated into the bearer
  73  * to avoid consuming potentially limited stack space through the use of
  74  * large local variables within multicast routines.  Concurrent access is
  75  * prevented through use of the spinlock "bclink_lock".
  76  */
  77 struct tipc_bcbearer {
  78         struct tipc_bearer bearer;
  79         struct tipc_media media;
  80         struct tipc_bcbearer_pair bpairs[MAX_BEARERS];
  81         struct tipc_bcbearer_pair bpairs_temp[TIPC_MAX_LINK_PRI + 1];
  82         struct tipc_node_map remains;
  83         struct tipc_node_map remains_new;
  84 };
  85
  86 /**
  87  * struct tipc_bclink - link used for broadcast messages
  88  * @lock: spinlock governing access to structure
  89  * @link: (non-standard) broadcast link structure
  90  * @node: (non-standard) node structure representing b'cast link's peer node
  91  * @flags: represent bclink states
  92  * @bcast_nodes: map of broadcast-capable nodes
  93  * @retransmit_to: node that most recently requested a retransmit
  94  *
  95  * Handles sequence numbering, fragmentation, bundling, etc.
  96  */
  97 struct tipc_bclink {
  98         spinlock_t lock;
  99         struct tipc_link link;
 100         struct tipc_node node;
 101         unsigned int flags;
 102         struct tipc_node_map bcast_nodes;
 103         struct tipc_node *retransmit_to;
 104 };
 105
 106 static struct tipc_bcbearer *bcbearer;
 107 static struct tipc_bclink *bclink;
 108 static struct tipc_link *bcl;
 109
 110 const char tipc_bclink_name[] = "broadcast-link";
 111
 112 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
 113                            struct tipc_node_map *nm_b,
 114                            struct tipc_node_map *nm_diff);
 115 static void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node);
 116 static void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node);
 117
 118 static void tipc_bclink_lock(void)
 119 {
 120         spin_lock_bh(&bclink->lock);
 121 }
 122
 123 static void tipc_bclink_unlock(void)
 124 {
 125         struct tipc_node *node = NULL;
 126
 127         if (likely(!bclink->flags)) {
 128                 spin_unlock_bh(&bclink->lock);
 129                 return;
 130         }
 131
 132         if (bclink->flags & TIPC_BCLINK_RESET) {
 133                 bclink->flags &= ~TIPC_BCLINK_RESET;
 134                 node = tipc_bclink_retransmit_to();
 135         }
 136         spin_unlock_bh(&bclink->lock);
 137
 138         if (node)
 139                 tipc_link_reset_all(node);
 140 }
 141
 142 uint  tipc_bclink_get_mtu(void)
 143 {
 144         return MAX_PKT_DEFAULT_MCAST;
 145 }
 146
 147 void tipc_bclink_set_flags(unsigned int flags)
 148 {
 149         bclink->flags |= flags;
 150 }
 151
 152 static u32 bcbuf_acks(struct sk_buff *buf)
 153 {
 154         return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
 155 }
 156
 157 static void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
 158 {
 159         TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks;
 160 }
 161
 162 static void bcbuf_decr_acks(struct sk_buff *buf)
 163 {
 164         bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
 165 }
 166
 167 void tipc_bclink_add_node(u32 addr)
 168 {
 169         tipc_bclink_lock();
 170         tipc_nmap_add(&bclink->bcast_nodes, addr);
 171         tipc_bclink_unlock();
 172 }
 173
 174 void tipc_bclink_remove_node(u32 addr)
 175 {
 176         tipc_bclink_lock();
 177         tipc_nmap_remove(&bclink->bcast_nodes, addr);
 178         tipc_bclink_unlock();
 179 }
 180
 181 static void bclink_set_last_sent(void)
 182 {
 183         if (bcl->next_out)
 184                 bcl->fsm_msg_cnt = mod(buf_seqno(bcl->next_out) - 1);
 185         else
 186                 bcl->fsm_msg_cnt = mod(bcl->next_out_no - 1);
 187 }
 188
 189 u32 tipc_bclink_get_last_sent(void)
 190 {
 191         return bcl->fsm_msg_cnt;
 192 }
 193
 194 static void bclink_update_last_sent(struct tipc_node *node, u32 seqno)
 195 {
 196         node->bclink.last_sent = less_eq(node->bclink.last_sent, seqno) ?
 197                                                 seqno : node->bclink.last_sent;
 198 }
 199
 200
 201 /**
 202  * tipc_bclink_retransmit_to - get most recent node to request retransmission
 203  *
 204  * Called with bclink_lock locked
 205  */
 206 struct tipc_node *tipc_bclink_retransmit_to(void)
 207 {
 208         return bclink->retransmit_to;
 209 }
 210
 211 /**
 212  * bclink_retransmit_pkt - retransmit broadcast packets
 213  * @after: sequence number of last packet to *not* retransmit
 214  * @to: sequence number of last packet to retransmit
 215  *
 216  * Called with bclink_lock locked
 217  */
 218 static void bclink_retransmit_pkt(u32 after, u32 to)
 219 {
 220         struct sk_buff *skb;
 221
 222         skb_queue_walk(&bcl->outqueue, skb) {
 223                 if (more(buf_seqno(skb), after)) {
 224                         tipc_link_retransmit(bcl, skb, mod(to - after));
 225                         break;
 226                 }
 227         }
 228 }
 229
 230 /**
 231  * tipc_bclink_wakeup_users - wake up pending users
 232  *
 233  * Called with no locks taken
 234  */
 235 void tipc_bclink_wakeup_users(void)
 236 {
 237         struct sk_buff *skb;
 238
 239         while ((skb = skb_dequeue(&bclink->link.waiting_sks)))
 240                 tipc_sk_rcv(skb);
 241
 242 }
 243
 244 /**
 245  * tipc_bclink_acknowledge - handle acknowledgement of broadcast packets
 246  * @n_ptr: node that sent acknowledgement info
 247  * @acked: broadcast sequence # that has been acknowledged
 248  *
 249  * Node is locked, bclink_lock unlocked.
 250  */
 251 void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
 252 {
 253         struct sk_buff *skb, *tmp;
 254         struct sk_buff *next;
 255         unsigned int released = 0;
 256
 257         tipc_bclink_lock();
 258         /* Bail out if tx queue is empty (no clean up is required) */
 259         skb = skb_peek(&bcl->outqueue);
 260         if (!skb)
 261                 goto exit;
 262
 263         /* Determine which messages need to be acknowledged */
 264         if (acked == INVALID_LINK_SEQ) {
 265                 /*
 266                  * Contact with specified node has been lost, so need to
 267                  * acknowledge sent messages only (if other nodes still exist)
 268                  * or both sent and unsent messages (otherwise)
 269                  */
 270                 if (bclink->bcast_nodes.count)
 271                         acked = bcl->fsm_msg_cnt;
 272                 else
 273                         acked = bcl->next_out_no;
 274         } else {
 275                 /*
 276                  * Bail out if specified sequence number does not correspond
 277                  * to a message that has been sent and not yet acknowledged
 278                  */
 279                 if (less(acked, buf_seqno(skb)) ||
 280                     less(bcl->fsm_msg_cnt, acked) ||
 281                     less_eq(acked, n_ptr->bclink.acked))
 282                         goto exit;
 283         }
 284
 285         /* Skip over packets that node has previously acknowledged */
 286         skb_queue_walk(&bcl->outqueue, skb) {
 287                 if (more(buf_seqno(skb), n_ptr->bclink.acked))
 288                         break;
 289         }
 290
 291         /* Update packets that node is now acknowledging */
 292         skb_queue_walk_from_safe(&bcl->outqueue, skb, tmp) {
 293                 if (more(buf_seqno(skb), acked))
 294                         break;
 295
 296                 next = tipc_skb_queue_next(&bcl->outqueue, skb);
 297                 if (skb != bcl->next_out) {
 298                         bcbuf_decr_acks(skb);
 299                 } else {
 300                         bcbuf_set_acks(skb, 0);
 301                         bcl->next_out = next;
 302                         bclink_set_last_sent();
 303                 }
 304
 305                 if (bcbuf_acks(skb) == 0) {
 306                         __skb_unlink(skb, &bcl->outqueue);
 307                         kfree_skb(skb);
 308                         released = 1;
 309                 }
 310         }
 311         n_ptr->bclink.acked = acked;
 312
 313         /* Try resolving broadcast link congestion, if necessary */
 314         if (unlikely(bcl->next_out)) {
 315                 tipc_link_push_packets(bcl);
 316                 bclink_set_last_sent();
 317         }
 318         if (unlikely(released && !skb_queue_empty(&bcl->waiting_sks)))
 319                 n_ptr->action_flags |= TIPC_WAKEUP_BCAST_USERS;
 320
 321 exit:
 322         tipc_bclink_unlock();
 323 }
 324
 325 /**
 326  * tipc_bclink_update_link_state - update broadcast link state
 327  *
 328  * RCU and node lock set
 329  */
 330 void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
 331 {
 332         struct sk_buff *buf;
 333
 334         /* Ignore "stale" link state info */
 335         if (less_eq(last_sent, n_ptr->bclink.last_in))
 336                 return;
 337
 338         /* Update link synchronization state; quit if in sync */
 339         bclink_update_last_sent(n_ptr, last_sent);
 340
 341         if (n_ptr->bclink.last_sent == n_ptr->bclink.last_in)
 342                 return;
 343
 344         /* Update out-of-sync state; quit if loss is still unconfirmed */
 345         if ((++n_ptr->bclink.oos_state) == 1) {
 346                 if (n_ptr->bclink.deferred_size < (TIPC_MIN_LINK_WIN / 2))
 347                         return;
 348                 n_ptr->bclink.oos_state++;
 349         }
 350
 351         /* Don't NACK if one has been recently sent (or seen) */
 352         if (n_ptr->bclink.oos_state & 0x1)
 353                 return;
 354
 355         /* Send NACK */
 356         buf = tipc_buf_acquire(INT_H_SIZE);
 357         if (buf) {
 358                 struct tipc_msg *msg = buf_msg(buf);
 359                 struct sk_buff *skb = skb_peek(&n_ptr->bclink.deferred_queue);
 360                 u32 to = skb ? buf_seqno(skb) - 1 : n_ptr->bclink.last_sent;
 361
 362                 tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
 363                               INT_H_SIZE, n_ptr->addr);
 364                 msg_set_non_seq(msg, 1);
 365                 msg_set_mc_netid(msg, tipc_net_id);
 366                 msg_set_bcast_ack(msg, n_ptr->bclink.last_in);
 367                 msg_set_bcgap_after(msg, n_ptr->bclink.last_in);
 368                 msg_set_bcgap_to(msg, to);
 369
 370                 tipc_bclink_lock();
 371                 tipc_bearer_send(MAX_BEARERS, buf, NULL);
 372                 bcl->stats.sent_nacks++;
 373                 tipc_bclink_unlock();
 374                 kfree_skb(buf);
 375
 376                 n_ptr->bclink.oos_state++;
 377         }
 378 }
 379
 380 /**
 381  * bclink_peek_nack - monitor retransmission requests sent by other nodes
 382  *
 383  * Delay any upcoming NACK by this node if another node has already
 384  * requested the first message this node is going to ask for.
 385  */
 386 static void bclink_peek_nack(struct tipc_msg *msg)
 387 {
 388         struct tipc_node *n_ptr = tipc_node_find(msg_destnode(msg));
 389
 390         if (unlikely(!n_ptr))
 391                 return;
 392
 393         tipc_node_lock(n_ptr);
 394
 395         if (n_ptr->bclink.recv_permitted &&
 396             (n_ptr->bclink.last_in != n_ptr->bclink.last_sent) &&
 397             (n_ptr->bclink.last_in == msg_bcgap_after(msg)))
 398                 n_ptr->bclink.oos_state = 2;
 399
 400         tipc_node_unlock(n_ptr);
 401 }
 402
 403 /* tipc_bclink_xmit - broadcast buffer chain to all nodes in cluster
 404  *                    and to identified node local sockets
 405  * @list: chain of buffers containing message
 406  * Consumes the buffer chain, except when returning -ELINKCONG
 407  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 408  */
 409 int tipc_bclink_xmit(struct sk_buff_head *list)
 410 {
 411         int rc = 0;
 412         int bc = 0;
 413         struct sk_buff *skb;
 414
 415         /* Prepare clone of message for local node */
 416         skb = tipc_msg_reassemble(list);
 417         if (unlikely(!skb)) {
 418                 __skb_queue_purge(list);
 419                 return -EHOSTUNREACH;
 420         }
 421
 422         /* Broadcast to all other nodes */
 423         if (likely(bclink)) {
 424                 tipc_bclink_lock();
 425                 if (likely(bclink->bcast_nodes.count)) {
 426                         rc = __tipc_link_xmit(bcl, list);
 427                         if (likely(!rc)) {
 428                                 u32 len = skb_queue_len(&bcl->outqueue);
 429
 430                                 bclink_set_last_sent();
 431                                 bcl->stats.queue_sz_counts++;
 432                                 bcl->stats.accu_queue_sz += len;
 433                         }
 434                         bc = 1;
 435                 }
 436                 tipc_bclink_unlock();
 437         }
 438
 439         if (unlikely(!bc))
 440                 __skb_queue_purge(list);
 441
 442         /* Deliver message clone */
 443         if (likely(!rc))
 444                 tipc_sk_mcast_rcv(skb);
 445         else
 446                 kfree_skb(skb);
 447
 448         return rc;
 449 }
 450
 451 /**
 452  * bclink_accept_pkt - accept an incoming, in-sequence broadcast packet
 453  *
 454  * Called with both sending node's lock and bclink_lock taken.
 455  */
 456 static void bclink_accept_pkt(struct tipc_node *node, u32 seqno)
 457 {
 458         bclink_update_last_sent(node, seqno);
 459         node->bclink.last_in = seqno;
 460         node->bclink.oos_state = 0;
 461         bcl->stats.recv_info++;
 462
 463         /*
 464          * Unicast an ACK periodically, ensuring that
 465          * all nodes in the cluster don't ACK at the same time
 466          */
 467         if (((seqno - tipc_own_addr) % TIPC_MIN_LINK_WIN) == 0) {
 468                 tipc_link_proto_xmit(node->active_links[node->addr & 1],
 469                                      STATE_MSG, 0, 0, 0, 0, 0);
 470                 bcl->stats.sent_acks++;
 471         }
 472 }
 473
 474 /**
 475  * tipc_bclink_rcv - receive a broadcast packet, and deliver upwards
 476  *
 477  * RCU is locked, no other locks set
 478  */
 479 void tipc_bclink_rcv(struct sk_buff *buf)
 480 {
 481         struct tipc_msg *msg = buf_msg(buf);
 482         struct tipc_node *node;
 483         u32 next_in;
 484         u32 seqno;
 485         int deferred = 0;
 486
 487         /* Screen out unwanted broadcast messages */
 488         if (msg_mc_netid(msg) != tipc_net_id)
 489                 goto exit;
 490
 491         node = tipc_node_find(msg_prevnode(msg));
 492         if (unlikely(!node))
 493                 goto exit;
 494
 495         tipc_node_lock(node);
 496         if (unlikely(!node->bclink.recv_permitted))
 497                 goto unlock;
 498
 499         /* Handle broadcast protocol message */
 500         if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
 501                 if (msg_type(msg) != STATE_MSG)
 502                         goto unlock;
 503                 if (msg_destnode(msg) == tipc_own_addr) {
 504                         tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
 505                         tipc_node_unlock(node);
 506                         tipc_bclink_lock();
 507                         bcl->stats.recv_nacks++;
 508                         bclink->retransmit_to = node;
 509                         bclink_retransmit_pkt(msg_bcgap_after(msg),
 510                                               msg_bcgap_to(msg));
 511                         tipc_bclink_unlock();
 512                 } else {
 513                         tipc_node_unlock(node);
 514                         bclink_peek_nack(msg);
 515                 }
 516                 goto exit;
 517         }
 518
 519         /* Handle in-sequence broadcast message */
 520         seqno = msg_seqno(msg);
 521         next_in = mod(node->bclink.last_in + 1);
 522
 523         if (likely(seqno == next_in)) {
 524 receive:
 525                 /* Deliver message to destination */
 526                 if (likely(msg_isdata(msg))) {
 527                         tipc_bclink_lock();
 528                         bclink_accept_pkt(node, seqno);
 529                         tipc_bclink_unlock();
 530                         tipc_node_unlock(node);
 531                         if (likely(msg_mcast(msg)))
 532                                 tipc_sk_mcast_rcv(buf);
 533                         else
 534                                 kfree_skb(buf);
 535                 } else if (msg_user(msg) == MSG_BUNDLER) {
 536                         tipc_bclink_lock();
 537                         bclink_accept_pkt(node, seqno);
 538                         bcl->stats.recv_bundles++;
 539                         bcl->stats.recv_bundled += msg_msgcnt(msg);
 540                         tipc_bclink_unlock();
 541                         tipc_node_unlock(node);
 542                         tipc_link_bundle_rcv(buf);
 543                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
 544                         tipc_buf_append(&node->bclink.reasm_buf, &buf);
 545                         if (unlikely(!buf && !node->bclink.reasm_buf))
 546                                 goto unlock;
 547                         tipc_bclink_lock();
 548                         bclink_accept_pkt(node, seqno);
 549                         bcl->stats.recv_fragments++;
 550                         if (buf) {
 551                                 bcl->stats.recv_fragmented++;
 552                                 msg = buf_msg(buf);
 553                                 tipc_bclink_unlock();
 554                                 goto receive;
 555                         }
 556                         tipc_bclink_unlock();
 557                         tipc_node_unlock(node);
 558                 } else if (msg_user(msg) == NAME_DISTRIBUTOR) {
 559                         tipc_bclink_lock();
 560                         bclink_accept_pkt(node, seqno);
 561                         tipc_bclink_unlock();
 562                         tipc_node_unlock(node);
 563                         tipc_named_rcv(buf);
 564                 } else {
 565                         tipc_bclink_lock();
 566                         bclink_accept_pkt(node, seqno);
 567                         tipc_bclink_unlock();
 568                         tipc_node_unlock(node);
 569                         kfree_skb(buf);
 570                 }
 571                 buf = NULL;
 572
 573                 /* Determine new synchronization state */
 574                 tipc_node_lock(node);
 575                 if (unlikely(!tipc_node_is_up(node)))
 576                         goto unlock;
 577
 578                 if (node->bclink.last_in == node->bclink.last_sent)
 579                         goto unlock;
 580
 581                 if (skb_queue_empty(&node->bclink.deferred_queue)) {
 582                         node->bclink.oos_state = 1;
 583                         goto unlock;
 584                 }
 585
 586                 msg = buf_msg(skb_peek(&node->bclink.deferred_queue));
 587                 seqno = msg_seqno(msg);
 588                 next_in = mod(next_in + 1);
 589                 if (seqno != next_in)
 590                         goto unlock;
 591
 592                 /* Take in-sequence message from deferred queue & deliver it */
 593                 buf = __skb_dequeue(&node->bclink.deferred_queue);
 594                 goto receive;
 595         }
 596
 597         /* Handle out-of-sequence broadcast message */
 598         if (less(next_in, seqno)) {
 599                 deferred = tipc_link_defer_pkt(&node->bclink.deferred_queue,
 600                                                buf);
 601                 bclink_update_last_sent(node, seqno);
 602                 buf = NULL;
 603         }
 604
 605         tipc_bclink_lock();
 606
 607         if (deferred)
 608                 bcl->stats.deferred_recv++;
 609         else
 610                 bcl->stats.duplicates++;
 611
 612         tipc_bclink_unlock();
 613
 614 unlock:
 615         tipc_node_unlock(node);
 616 exit:
 617         kfree_skb(buf);
 618 }
 619
 620 u32 tipc_bclink_acks_missing(struct tipc_node *n_ptr)
 621 {
 622         return (n_ptr->bclink.recv_permitted &&
 623                 (tipc_bclink_get_last_sent() != n_ptr->bclink.acked));
 624 }
 625
 626
 627 /**
 628  * tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer
 629  *
 630  * Send packet over as many bearers as necessary to reach all nodes
 631  * that have joined the broadcast link.
 632  *
 633  * Returns 0 (packet sent successfully) under all circumstances,
 634  * since the broadcast link's pseudo-bearer never blocks
 635  */
 636 static int tipc_bcbearer_send(struct sk_buff *buf, struct tipc_bearer *unused1,
 637                               struct tipc_media_addr *unused2)
 638 {
 639         int bp_index;
 640         struct tipc_msg *msg = buf_msg(buf);
 641
 642         /* Prepare broadcast link message for reliable transmission,
 643          * if first time trying to send it;
 644          * preparation is skipped for broadcast link protocol messages
 645          * since they are sent in an unreliable manner and don't need it
 646          */
 647         if (likely(!msg_non_seq(buf_msg(buf)))) {
 648                 bcbuf_set_acks(buf, bclink->bcast_nodes.count);
 649                 msg_set_non_seq(msg, 1);
 650                 msg_set_mc_netid(msg, tipc_net_id);
 651                 bcl->stats.sent_info++;
 652
 653                 if (WARN_ON(!bclink->bcast_nodes.count)) {
 654                         dump_stack();
 655                         return 0;
 656                 }
 657         }
 658
 659         /* Send buffer over bearers until all targets reached */
 660         bcbearer->remains = bclink->bcast_nodes;
 661
 662         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
 663                 struct tipc_bearer *p = bcbearer->bpairs[bp_index].primary;
 664                 struct tipc_bearer *s = bcbearer->bpairs[bp_index].secondary;
 665                 struct tipc_bearer *bp[2] = {p, s};
 666                 struct tipc_bearer *b = bp[msg_link_selector(msg)];
 667                 struct sk_buff *tbuf;
 668
 669                 if (!p)
 670                         break; /* No more bearers to try */
 671                 if (!b)
 672                         b = p;
 673                 tipc_nmap_diff(&bcbearer->remains, &b->nodes,
 674                                &bcbearer->remains_new);
 675                 if (bcbearer->remains_new.count == bcbearer->remains.count)
 676                         continue; /* Nothing added by bearer pair */
 677
 678                 if (bp_index == 0) {
 679                         /* Use original buffer for first bearer */
 680                         tipc_bearer_send(b->identity, buf, &b->bcast_addr);
 681                 } else {
 682                         /* Avoid concurrent buffer access */
 683                         tbuf = pskb_copy_for_clone(buf, GFP_ATOMIC);
 684                         if (!tbuf)
 685                                 break;
 686                         tipc_bearer_send(b->identity, tbuf, &b->bcast_addr);
 687                         kfree_skb(tbuf); /* Bearer keeps a clone */
 688                 }
 689                 if (bcbearer->remains_new.count == 0)
 690                         break; /* All targets reached */
 691
 692                 bcbearer->remains = bcbearer->remains_new;
 693         }
 694
 695         return 0;
 696 }
 697
 698 /**
 699  * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer
 700  */
 701 void tipc_bcbearer_sort(struct tipc_node_map *nm_ptr, u32 node, bool action)
 702 {
 703         struct tipc_bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
 704         struct tipc_bcbearer_pair *bp_curr;
 705         struct tipc_bearer *b;
 706         int b_index;
 707         int pri;
 708
 709         tipc_bclink_lock();
 710
 711         if (action)
 712                 tipc_nmap_add(nm_ptr, node);
 713         else
 714                 tipc_nmap_remove(nm_ptr, node);
 715
 716         /* Group bearers by priority (can assume max of two per priority) */
 717         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
 718
 719         rcu_read_lock();
 720         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
 721                 b = rcu_dereference_rtnl(bearer_list[b_index]);
 722                 if (!b || !b->nodes.count)
 723                         continue;
 724
 725                 if (!bp_temp[b->priority].primary)
 726                         bp_temp[b->priority].primary = b;
 727                 else
 728                         bp_temp[b->priority].secondary = b;
 729         }
 730         rcu_read_unlock();
 731
 732         /* Create array of bearer pairs for broadcasting */
 733         bp_curr = bcbearer->bpairs;
 734         memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
 735
 736         for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) {
 737
 738                 if (!bp_temp[pri].primary)
 739                         continue;
 740
 741                 bp_curr->primary = bp_temp[pri].primary;
 742
 743                 if (bp_temp[pri].secondary) {
 744                         if (tipc_nmap_equal(&bp_temp[pri].primary->nodes,
 745                                             &bp_temp[pri].secondary->nodes)) {
 746                                 bp_curr->secondary = bp_temp[pri].secondary;
 747                         } else {
 748                                 bp_curr++;
 749                                 bp_curr->primary = bp_temp[pri].secondary;
 750                         }
 751                 }
 752
 753                 bp_curr++;
 754         }
 755
 756         tipc_bclink_unlock();
 757 }
 758
 759 static int __tipc_nl_add_bc_link_stat(struct sk_buff *skb,
 760                                       struct tipc_stats *stats)
 761 {
 762         int i;
 763         struct nlattr *nest;
 764
 765         struct nla_map {
 766                 __u32 key;
 767                 __u32 val;
 768         };
 769
 770         struct nla_map map[] = {
 771                 {TIPC_NLA_STATS_RX_INFO, stats->recv_info},
 772                 {TIPC_NLA_STATS_RX_FRAGMENTS, stats->recv_fragments},
 773                 {TIPC_NLA_STATS_RX_FRAGMENTED, stats->recv_fragmented},
 774                 {TIPC_NLA_STATS_RX_BUNDLES, stats->recv_bundles},
 775                 {TIPC_NLA_STATS_RX_BUNDLED, stats->recv_bundled},
 776                 {TIPC_NLA_STATS_TX_INFO, stats->sent_info},
 777                 {TIPC_NLA_STATS_TX_FRAGMENTS, stats->sent_fragments},
 778                 {TIPC_NLA_STATS_TX_FRAGMENTED, stats->sent_fragmented},
 779                 {TIPC_NLA_STATS_TX_BUNDLES, stats->sent_bundles},
 780                 {TIPC_NLA_STATS_TX_BUNDLED, stats->sent_bundled},
 781                 {TIPC_NLA_STATS_RX_NACKS, stats->recv_nacks},
 782                 {TIPC_NLA_STATS_RX_DEFERRED, stats->deferred_recv},
 783                 {TIPC_NLA_STATS_TX_NACKS, stats->sent_nacks},
 784                 {TIPC_NLA_STATS_TX_ACKS, stats->sent_acks},
 785                 {TIPC_NLA_STATS_RETRANSMITTED, stats->retransmitted},
 786                 {TIPC_NLA_STATS_DUPLICATES, stats->duplicates},
 787                 {TIPC_NLA_STATS_LINK_CONGS, stats->link_congs},
 788                 {TIPC_NLA_STATS_MAX_QUEUE, stats->max_queue_sz},
 789                 {TIPC_NLA_STATS_AVG_QUEUE, stats->queue_sz_counts ?
 790                         (stats->accu_queue_sz / stats->queue_sz_counts) : 0}
 791         };
 792
 793         nest = nla_nest_start(skb, TIPC_NLA_LINK_STATS);
 794         if (!nest)
 795                 return -EMSGSIZE;
 796
 797         for (i = 0; i <  ARRAY_SIZE(map); i++)
 798                 if (nla_put_u32(skb, map[i].key, map[i].val))
 799                         goto msg_full;
 800
 801         nla_nest_end(skb, nest);
 802
 803         return 0;
 804 msg_full:
 805         nla_nest_cancel(skb, nest);
 806
 807         return -EMSGSIZE;
 808 }
 809
 810 int tipc_nl_add_bc_link(struct tipc_nl_msg *msg)
 811 {
 812         int err;
 813         void *hdr;
 814         struct nlattr *attrs;
 815         struct nlattr *prop;
 816
 817         if (!bcl)
 818                 return 0;
 819
 820         tipc_bclink_lock();
 821
 822         hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_v2_family,
 823                           NLM_F_MULTI, TIPC_NL_LINK_GET);
 824         if (!hdr)
 825                 return -EMSGSIZE;
 826
 827         attrs = nla_nest_start(msg->skb, TIPC_NLA_LINK);
 828         if (!attrs)
 829                 goto msg_full;
 830
 831         /* The broadcast link is always up */
 832         if (nla_put_flag(msg->skb, TIPC_NLA_LINK_UP))
 833                 goto attr_msg_full;
 834
 835         if (nla_put_flag(msg->skb, TIPC_NLA_LINK_BROADCAST))
 836                 goto attr_msg_full;
 837         if (nla_put_string(msg->skb, TIPC_NLA_LINK_NAME, bcl->name))
 838                 goto attr_msg_full;
 839         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_RX, bcl->next_in_no))
 840                 goto attr_msg_full;
 841         if (nla_put_u32(msg->skb, TIPC_NLA_LINK_TX, bcl->next_out_no))
 842                 goto attr_msg_full;
 843
 844         prop = nla_nest_start(msg->skb, TIPC_NLA_LINK_PROP);
 845         if (!prop)
 846                 goto attr_msg_full;
 847         if (nla_put_u32(msg->skb, TIPC_NLA_PROP_WIN, bcl->queue_limit[0]))
 848                 goto prop_msg_full;
 849         nla_nest_end(msg->skb, prop);
 850
 851         err = __tipc_nl_add_bc_link_stat(msg->skb, &bcl->stats);
 852         if (err)
 853                 goto attr_msg_full;
 854
 855         tipc_bclink_unlock();
 856         nla_nest_end(msg->skb, attrs);
 857         genlmsg_end(msg->skb, hdr);
 858
 859         return 0;
 860
 861 prop_msg_full:
 862         nla_nest_cancel(msg->skb, prop);
 863 attr_msg_full:
 864         nla_nest_cancel(msg->skb, attrs);
 865 msg_full:
 866         tipc_bclink_unlock();
 867         genlmsg_cancel(msg->skb, hdr);
 868
 869         return -EMSGSIZE;
 870 }
 871
 872 int tipc_bclink_stats(char *buf, const u32 buf_size)
 873 {
 874         int ret;
 875         struct tipc_stats *s;
 876
 877         if (!bcl)
 878                 return 0;
 879
 880         tipc_bclink_lock();
 881
 882         s = &bcl->stats;
 883
 884         ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
 885                             "  Window:%u packets\n",
 886                             bcl->name, bcl->queue_limit[0]);
 887         ret += tipc_snprintf(buf + ret, buf_size - ret,
 888                              "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
 889                              s->recv_info, s->recv_fragments,
 890                              s->recv_fragmented, s->recv_bundles,
 891                              s->recv_bundled);
 892         ret += tipc_snprintf(buf + ret, buf_size - ret,
 893                              "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
 894                              s->sent_info, s->sent_fragments,
 895                              s->sent_fragmented, s->sent_bundles,
 896                              s->sent_bundled);
 897         ret += tipc_snprintf(buf + ret, buf_size - ret,
 898                              "  RX naks:%u defs:%u dups:%u\n",
 899                              s->recv_nacks, s->deferred_recv, s->duplicates);
 900         ret += tipc_snprintf(buf + ret, buf_size - ret,
 901                              "  TX naks:%u acks:%u dups:%u\n",
 902                              s->sent_nacks, s->sent_acks, s->retransmitted);
 903         ret += tipc_snprintf(buf + ret, buf_size - ret,
 904                              "  Congestion link:%u  Send queue max:%u avg:%u\n",
 905                              s->link_congs, s->max_queue_sz,
 906                              s->queue_sz_counts ?
 907                              (s->accu_queue_sz / s->queue_sz_counts) : 0);
 908
 909         tipc_bclink_unlock();
 910         return ret;
 911 }
 912
 913 int tipc_bclink_reset_stats(void)
 914 {
 915         if (!bcl)
 916                 return -ENOPROTOOPT;
 917
 918         tipc_bclink_lock();
 919         memset(&bcl->stats, 0, sizeof(bcl->stats));
 920         tipc_bclink_unlock();
 921         return 0;
 922 }
 923
 924 int tipc_bclink_set_queue_limits(u32 limit)
 925 {
 926         if (!bcl)
 927                 return -ENOPROTOOPT;
 928         if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
 929                 return -EINVAL;
 930
 931         tipc_bclink_lock();
 932         tipc_link_set_queue_limits(bcl, limit);
 933         tipc_bclink_unlock();
 934         return 0;
 935 }
 936
 937 int tipc_bclink_init(void)
 938 {
 939         bcbearer = kzalloc(sizeof(*bcbearer), GFP_ATOMIC);
 940         if (!bcbearer)
 941                 return -ENOMEM;
 942
 943         bclink = kzalloc(sizeof(*bclink), GFP_ATOMIC);
 944         if (!bclink) {
 945                 kfree(bcbearer);
 946                 return -ENOMEM;
 947         }
 948
 949         bcl = &bclink->link;
 950         bcbearer->bearer.media = &bcbearer->media;
 951         bcbearer->media.send_msg = tipc_bcbearer_send;
 952         sprintf(bcbearer->media.name, "tipc-broadcast");
 953
 954         spin_lock_init(&bclink->lock);
 955         __skb_queue_head_init(&bcl->outqueue);
 956         __skb_queue_head_init(&bcl->deferred_queue);
 957         skb_queue_head_init(&bcl->waiting_sks);
 958         bcl->next_out_no = 1;
 959         spin_lock_init(&bclink->node.lock);
 960         __skb_queue_head_init(&bclink->node.waiting_sks);
 961         bcl->owner = &bclink->node;
 962         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
 963         tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
 964         bcl->bearer_id = MAX_BEARERS;
 965         rcu_assign_pointer(bearer_list[MAX_BEARERS], &bcbearer->bearer);
 966         bcl->state = WORKING_WORKING;
 967         strlcpy(bcl->name, tipc_bclink_name, TIPC_MAX_LINK_NAME);
 968         return 0;
 969 }
 970
 971 void tipc_bclink_stop(void)
 972 {
 973         tipc_bclink_lock();
 974         tipc_link_purge_queues(bcl);
 975         tipc_bclink_unlock();
 976
 977         RCU_INIT_POINTER(bearer_list[BCBEARER], NULL);
 978         synchronize_net();
 979         kfree(bcbearer);
 980         kfree(bclink);
 981 }
 982
 983 /**
 984  * tipc_nmap_add - add a node to a node map
 985  */
 986 static void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node)
 987 {
 988         int n = tipc_node(node);
 989         int w = n / WSIZE;
 990         u32 mask = (1 << (n % WSIZE));
 991
 992         if ((nm_ptr->map[w] & mask) == 0) {
 993                 nm_ptr->count++;
 994                 nm_ptr->map[w] |= mask;
 995         }
 996 }
 997
 998 /**
 999  * tipc_nmap_remove - remove a node from a node map
1000  */
1001 static void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node)
1002 {
1003         int n = tipc_node(node);
1004         int w = n / WSIZE;
1005         u32 mask = (1 << (n % WSIZE));
1006
1007         if ((nm_ptr->map[w] & mask) != 0) {
1008                 nm_ptr->map[w] &= ~mask;
1009                 nm_ptr->count--;
1010         }
1011 }
1012
1013 /**
1014  * tipc_nmap_diff - find differences between node maps
1015  * @nm_a: input node map A
1016  * @nm_b: input node map B
1017  * @nm_diff: output node map A-B (i.e. nodes of A that are not in B)
1018  */
1019 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
1020                            struct tipc_node_map *nm_b,
1021                            struct tipc_node_map *nm_diff)
1022 {
1023         int stop = ARRAY_SIZE(nm_a->map);
1024         int w;
1025         int b;
1026         u32 map;
1027
1028         memset(nm_diff, 0, sizeof(*nm_diff));
1029         for (w = 0; w < stop; w++) {
1030                 map = nm_a->map[w] ^ (nm_a->map[w] & nm_b->map[w]);
1031                 nm_diff->map[w] = map;
1032                 if (map != 0) {
1033                         for (b = 0 ; b < WSIZE; b++) {
1034                                 if (map & (1 << b))
1035                                         nm_diff->count++;
1036                         }
1037                 }
1038         }
1039 }
1040
1041 /**
1042  * tipc_port_list_add - add a port to a port list, ensuring no duplicates
1043  */
1044 void tipc_port_list_add(struct tipc_port_list *pl_ptr, u32 port)
1045 {
1046         struct tipc_port_list *item = pl_ptr;
1047         int i;
1048         int item_sz = PLSIZE;
1049         int cnt = pl_ptr->count;
1050
1051         for (; ; cnt -= item_sz, item = item->next) {
1052                 if (cnt < PLSIZE)
1053                         item_sz = cnt;
1054                 for (i = 0; i < item_sz; i++)
1055                         if (item->ports[i] == port)
1056                                 return;
1057                 if (i < PLSIZE) {
1058                         item->ports[i] = port;
1059                         pl_ptr->count++;
1060                         return;
1061                 }
1062                 if (!item->next) {
1063                         item->next = kmalloc(sizeof(*item), GFP_ATOMIC);
1064                         if (!item->next) {
1065                                 pr_warn("Incomplete multicast delivery, no memory\n");
1066                                 return;
1067                         }
1068                         item->next->next = NULL;
1069                 }
1070         }
1071 }
1072
1073 /**
1074  * tipc_port_list_free - free dynamically created entries in port_list chain
1075  *
1076  */
1077 void tipc_port_list_free(struct tipc_port_list *pl_ptr)
1078 {
1079         struct tipc_port_list *item;
1080         struct tipc_port_list *next;
1081
1082         for (item = pl_ptr->next; item; item = next) {
1083                 next = item->next;
1084                 kfree(item);
1085         }
1086 }