tipc: Minor optimization to rejection of connection-based messages
[linux-2.6.git] / 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
46 #define BCLINK_WIN_DEFAULT 20           /* bcast link window size (default) */
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 "bc_lock".
75  */
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  * @link: (non-standard) broadcast link structure
89  * @node: (non-standard) node structure representing b'cast link's peer node
90  * @bcast_nodes: map of broadcast-capable nodes
91  * @retransmit_to: node that most recently requested a retransmit
92  *
93  * Handles sequence numbering, fragmentation, bundling, etc.
94  */
95
96 struct tipc_bclink {
97         struct tipc_link link;
98         struct tipc_node node;
99         struct tipc_node_map bcast_nodes;
100         struct tipc_node *retransmit_to;
101 };
102
103 static struct tipc_bcbearer bcast_bearer;
104 static struct tipc_bclink bcast_link;
105
106 static struct tipc_bcbearer *bcbearer = &bcast_bearer;
107 static struct tipc_bclink *bclink = &bcast_link;
108 static struct tipc_link *bcl = &bcast_link.link;
109
110 static DEFINE_SPINLOCK(bc_lock);
111
112 const char tipc_bclink_name[] = "broadcast-link";
113
114 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
115                            struct tipc_node_map *nm_b,
116                            struct tipc_node_map *nm_diff);
117
118 static u32 bcbuf_acks(struct sk_buff *buf)
119 {
120         return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
121 }
122
123 static void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
124 {
125         TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks;
126 }
127
128 static void bcbuf_decr_acks(struct sk_buff *buf)
129 {
130         bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
131 }
132
133 void tipc_bclink_add_node(u32 addr)
134 {
135         spin_lock_bh(&bc_lock);
136         tipc_nmap_add(&bclink->bcast_nodes, addr);
137         spin_unlock_bh(&bc_lock);
138 }
139
140 void tipc_bclink_remove_node(u32 addr)
141 {
142         spin_lock_bh(&bc_lock);
143         tipc_nmap_remove(&bclink->bcast_nodes, addr);
144         spin_unlock_bh(&bc_lock);
145 }
146
147 static void bclink_set_last_sent(void)
148 {
149         if (bcl->next_out)
150                 bcl->fsm_msg_cnt = mod(buf_seqno(bcl->next_out) - 1);
151         else
152                 bcl->fsm_msg_cnt = mod(bcl->next_out_no - 1);
153 }
154
155 u32 tipc_bclink_get_last_sent(void)
156 {
157         return bcl->fsm_msg_cnt;
158 }
159
160 static void bclink_update_last_sent(struct tipc_node *node, u32 seqno)
161 {
162         node->bclink.last_sent = less_eq(node->bclink.last_sent, seqno) ?
163                                                 seqno : node->bclink.last_sent;
164 }
165
166
167 /*
168  * tipc_bclink_retransmit_to - get most recent node to request retransmission
169  *
170  * Called with bc_lock locked
171  */
172
173 struct tipc_node *tipc_bclink_retransmit_to(void)
174 {
175         return bclink->retransmit_to;
176 }
177
178 /**
179  * bclink_retransmit_pkt - retransmit broadcast packets
180  * @after: sequence number of last packet to *not* retransmit
181  * @to: sequence number of last packet to retransmit
182  *
183  * Called with bc_lock locked
184  */
185
186 static void bclink_retransmit_pkt(u32 after, u32 to)
187 {
188         struct sk_buff *buf;
189
190         buf = bcl->first_out;
191         while (buf && less_eq(buf_seqno(buf), after))
192                 buf = buf->next;
193         tipc_link_retransmit(bcl, buf, mod(to - after));
194 }
195
196 /**
197  * tipc_bclink_acknowledge - handle acknowledgement of broadcast packets
198  * @n_ptr: node that sent acknowledgement info
199  * @acked: broadcast sequence # that has been acknowledged
200  *
201  * Node is locked, bc_lock unlocked.
202  */
203
204 void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
205 {
206         struct sk_buff *crs;
207         struct sk_buff *next;
208         unsigned int released = 0;
209
210         spin_lock_bh(&bc_lock);
211
212         /* Bail out if tx queue is empty (no clean up is required) */
213         crs = bcl->first_out;
214         if (!crs)
215                 goto exit;
216
217         /* Determine which messages need to be acknowledged */
218         if (acked == INVALID_LINK_SEQ) {
219                 /*
220                  * Contact with specified node has been lost, so need to
221                  * acknowledge sent messages only (if other nodes still exist)
222                  * or both sent and unsent messages (otherwise)
223                  */
224                 if (bclink->bcast_nodes.count)
225                         acked = bcl->fsm_msg_cnt;
226                 else
227                         acked = bcl->next_out_no;
228         } else {
229                 /*
230                  * Bail out if specified sequence number does not correspond
231                  * to a message that has been sent and not yet acknowledged
232                  */
233                 if (less(acked, buf_seqno(crs)) ||
234                     less(bcl->fsm_msg_cnt, acked) ||
235                     less_eq(acked, n_ptr->bclink.acked))
236                         goto exit;
237         }
238
239         /* Skip over packets that node has previously acknowledged */
240         while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked))
241                 crs = crs->next;
242
243         /* Update packets that node is now acknowledging */
244
245         while (crs && less_eq(buf_seqno(crs), acked)) {
246                 next = crs->next;
247
248                 if (crs != bcl->next_out)
249                         bcbuf_decr_acks(crs);
250                 else {
251                         bcbuf_set_acks(crs, 0);
252                         bcl->next_out = next;
253                         bclink_set_last_sent();
254                 }
255
256                 if (bcbuf_acks(crs) == 0) {
257                         bcl->first_out = next;
258                         bcl->out_queue_size--;
259                         buf_discard(crs);
260                         released = 1;
261                 }
262                 crs = next;
263         }
264         n_ptr->bclink.acked = acked;
265
266         /* Try resolving broadcast link congestion, if necessary */
267
268         if (unlikely(bcl->next_out)) {
269                 tipc_link_push_queue(bcl);
270                 bclink_set_last_sent();
271         }
272         if (unlikely(released && !list_empty(&bcl->waiting_ports)))
273                 tipc_link_wakeup_ports(bcl, 0);
274 exit:
275         spin_unlock_bh(&bc_lock);
276 }
277
278 /*
279  * tipc_bclink_update_link_state - update broadcast link state
280  *
281  * tipc_net_lock and node lock set
282  */
283
284 void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
285 {
286         struct sk_buff *buf;
287
288         /* Ignore "stale" link state info */
289
290         if (less_eq(last_sent, n_ptr->bclink.last_in))
291                 return;
292
293         /* Update link synchronization state; quit if in sync */
294
295         bclink_update_last_sent(n_ptr, last_sent);
296
297         if (n_ptr->bclink.last_sent == n_ptr->bclink.last_in)
298                 return;
299
300         /* Update out-of-sync state; quit if loss is still unconfirmed */
301
302         if ((++n_ptr->bclink.oos_state) == 1) {
303                 if (n_ptr->bclink.deferred_size < (TIPC_MIN_LINK_WIN / 2))
304                         return;
305                 n_ptr->bclink.oos_state++;
306         }
307
308         /* Don't NACK if one has been recently sent (or seen) */
309
310         if (n_ptr->bclink.oos_state & 0x1)
311                 return;
312
313         /* Send NACK */
314
315         buf = tipc_buf_acquire(INT_H_SIZE);
316         if (buf) {
317                 struct tipc_msg *msg = buf_msg(buf);
318
319                 tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
320                               INT_H_SIZE, n_ptr->addr);
321                 msg_set_non_seq(msg, 1);
322                 msg_set_mc_netid(msg, tipc_net_id);
323                 msg_set_bcast_ack(msg, n_ptr->bclink.last_in);
324                 msg_set_bcgap_after(msg, n_ptr->bclink.last_in);
325                 msg_set_bcgap_to(msg, n_ptr->bclink.deferred_head
326                                  ? buf_seqno(n_ptr->bclink.deferred_head) - 1
327                                  : n_ptr->bclink.last_sent);
328
329                 spin_lock_bh(&bc_lock);
330                 tipc_bearer_send(&bcbearer->bearer, buf, NULL);
331                 bcl->stats.sent_nacks++;
332                 spin_unlock_bh(&bc_lock);
333                 buf_discard(buf);
334
335                 n_ptr->bclink.oos_state++;
336         }
337 }
338
339 /*
340  * bclink_peek_nack - monitor retransmission requests sent by other nodes
341  *
342  * Delay any upcoming NACK by this node if another node has already
343  * requested the first message this node is going to ask for.
344  *
345  * Only tipc_net_lock set.
346  */
347
348 static void bclink_peek_nack(struct tipc_msg *msg)
349 {
350         struct tipc_node *n_ptr = tipc_node_find(msg_destnode(msg));
351
352         if (unlikely(!n_ptr))
353                 return;
354
355         tipc_node_lock(n_ptr);
356
357         if (n_ptr->bclink.supported &&
358             (n_ptr->bclink.last_in != n_ptr->bclink.last_sent) &&
359             (n_ptr->bclink.last_in == msg_bcgap_after(msg)))
360                 n_ptr->bclink.oos_state = 2;
361
362         tipc_node_unlock(n_ptr);
363 }
364
365 /*
366  * tipc_bclink_send_msg - broadcast a packet to all nodes in cluster
367  */
368
369 int tipc_bclink_send_msg(struct sk_buff *buf)
370 {
371         int res;
372
373         spin_lock_bh(&bc_lock);
374
375         if (!bclink->bcast_nodes.count) {
376                 res = msg_data_sz(buf_msg(buf));
377                 buf_discard(buf);
378                 goto exit;
379         }
380
381         res = tipc_link_send_buf(bcl, buf);
382         if (likely(res >= 0)) {
383                 bclink_set_last_sent();
384                 bcl->stats.queue_sz_counts++;
385                 bcl->stats.accu_queue_sz += bcl->out_queue_size;
386         }
387 exit:
388         spin_unlock_bh(&bc_lock);
389         return res;
390 }
391
392 /*
393  * bclink_accept_pkt - accept an incoming, in-sequence broadcast packet
394  *
395  * Called with both sending node's lock and bc_lock taken.
396  */
397
398 static void bclink_accept_pkt(struct tipc_node *node, u32 seqno)
399 {
400         bclink_update_last_sent(node, seqno);
401         node->bclink.last_in = seqno;
402         node->bclink.oos_state = 0;
403         bcl->stats.recv_info++;
404
405         /*
406          * Unicast an ACK periodically, ensuring that
407          * all nodes in the cluster don't ACK at the same time
408          */
409
410         if (((seqno - tipc_own_addr) % TIPC_MIN_LINK_WIN) == 0) {
411                 tipc_link_send_proto_msg(
412                         node->active_links[node->addr & 1],
413                         STATE_MSG, 0, 0, 0, 0, 0);
414                 bcl->stats.sent_acks++;
415         }
416 }
417
418 /*
419  * tipc_bclink_recv_pkt - receive a broadcast packet, and deliver upwards
420  *
421  * tipc_net_lock is read_locked, no other locks set
422  */
423
424 void tipc_bclink_recv_pkt(struct sk_buff *buf)
425 {
426         struct tipc_msg *msg = buf_msg(buf);
427         struct tipc_node *node;
428         u32 next_in;
429         u32 seqno;
430         int deferred;
431
432         /* Screen out unwanted broadcast messages */
433
434         if (msg_mc_netid(msg) != tipc_net_id)
435                 goto exit;
436
437         node = tipc_node_find(msg_prevnode(msg));
438         if (unlikely(!node))
439                 goto exit;
440
441         tipc_node_lock(node);
442         if (unlikely(!node->bclink.supported))
443                 goto unlock;
444
445         /* Handle broadcast protocol message */
446
447         if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
448                 if (msg_type(msg) != STATE_MSG)
449                         goto unlock;
450                 if (msg_destnode(msg) == tipc_own_addr) {
451                         tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
452                         tipc_node_unlock(node);
453                         spin_lock_bh(&bc_lock);
454                         bcl->stats.recv_nacks++;
455                         bclink->retransmit_to = node;
456                         bclink_retransmit_pkt(msg_bcgap_after(msg),
457                                               msg_bcgap_to(msg));
458                         spin_unlock_bh(&bc_lock);
459                 } else {
460                         tipc_node_unlock(node);
461                         bclink_peek_nack(msg);
462                 }
463                 goto exit;
464         }
465
466         /* Handle in-sequence broadcast message */
467
468         seqno = msg_seqno(msg);
469         next_in = mod(node->bclink.last_in + 1);
470
471         if (likely(seqno == next_in)) {
472 receive:
473                 /* Deliver message to destination */
474
475                 if (likely(msg_isdata(msg))) {
476                         spin_lock_bh(&bc_lock);
477                         bclink_accept_pkt(node, seqno);
478                         spin_unlock_bh(&bc_lock);
479                         tipc_node_unlock(node);
480                         if (likely(msg_mcast(msg)))
481                                 tipc_port_recv_mcast(buf, NULL);
482                         else
483                                 buf_discard(buf);
484                 } else if (msg_user(msg) == MSG_BUNDLER) {
485                         spin_lock_bh(&bc_lock);
486                         bclink_accept_pkt(node, seqno);
487                         bcl->stats.recv_bundles++;
488                         bcl->stats.recv_bundled += msg_msgcnt(msg);
489                         spin_unlock_bh(&bc_lock);
490                         tipc_node_unlock(node);
491                         tipc_link_recv_bundle(buf);
492                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
493                         int ret = tipc_link_recv_fragment(&node->bclink.defragm,
494                                                       &buf, &msg);
495                         if (ret < 0)
496                                 goto unlock;
497                         spin_lock_bh(&bc_lock);
498                         bclink_accept_pkt(node, seqno);
499                         bcl->stats.recv_fragments++;
500                         if (ret > 0)
501                                 bcl->stats.recv_fragmented++;
502                         spin_unlock_bh(&bc_lock);
503                         tipc_node_unlock(node);
504                         tipc_net_route_msg(buf);
505                 } else if (msg_user(msg) == NAME_DISTRIBUTOR) {
506                         spin_lock_bh(&bc_lock);
507                         bclink_accept_pkt(node, seqno);
508                         spin_unlock_bh(&bc_lock);
509                         tipc_node_unlock(node);
510                         tipc_named_recv(buf);
511                 } else {
512                         spin_lock_bh(&bc_lock);
513                         bclink_accept_pkt(node, seqno);
514                         spin_unlock_bh(&bc_lock);
515                         tipc_node_unlock(node);
516                         buf_discard(buf);
517                 }
518                 buf = NULL;
519
520                 /* Determine new synchronization state */
521
522                 tipc_node_lock(node);
523                 if (unlikely(!tipc_node_is_up(node)))
524                         goto unlock;
525
526                 if (node->bclink.last_in == node->bclink.last_sent)
527                         goto unlock;
528
529                 if (!node->bclink.deferred_head) {
530                         node->bclink.oos_state = 1;
531                         goto unlock;
532                 }
533
534                 msg = buf_msg(node->bclink.deferred_head);
535                 seqno = msg_seqno(msg);
536                 next_in = mod(next_in + 1);
537                 if (seqno != next_in)
538                         goto unlock;
539
540                 /* Take in-sequence message from deferred queue & deliver it */
541
542                 buf = node->bclink.deferred_head;
543                 node->bclink.deferred_head = buf->next;
544                 node->bclink.deferred_size--;
545                 goto receive;
546         }
547
548         /* Handle out-of-sequence broadcast message */
549
550         if (less(next_in, seqno)) {
551                 deferred = tipc_link_defer_pkt(&node->bclink.deferred_head,
552                                                &node->bclink.deferred_tail,
553                                                buf);
554                 node->bclink.deferred_size += deferred;
555                 bclink_update_last_sent(node, seqno);
556                 buf = NULL;
557         } else
558                 deferred = 0;
559
560         spin_lock_bh(&bc_lock);
561
562         if (deferred)
563                 bcl->stats.deferred_recv++;
564         else
565                 bcl->stats.duplicates++;
566
567         spin_unlock_bh(&bc_lock);
568
569 unlock:
570         tipc_node_unlock(node);
571 exit:
572         buf_discard(buf);
573 }
574
575 u32 tipc_bclink_acks_missing(struct tipc_node *n_ptr)
576 {
577         return (n_ptr->bclink.supported &&
578                 (tipc_bclink_get_last_sent() != n_ptr->bclink.acked));
579 }
580
581
582 /**
583  * tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer
584  *
585  * Send packet over as many bearers as necessary to reach all nodes
586  * that have joined the broadcast link.
587  *
588  * Returns 0 (packet sent successfully) under all circumstances,
589  * since the broadcast link's pseudo-bearer never blocks
590  */
591
592 static int tipc_bcbearer_send(struct sk_buff *buf,
593                               struct tipc_bearer *unused1,
594                               struct tipc_media_addr *unused2)
595 {
596         int bp_index;
597
598         /*
599          * Prepare broadcast link message for reliable transmission,
600          * if first time trying to send it;
601          * preparation is skipped for broadcast link protocol messages
602          * since they are sent in an unreliable manner and don't need it
603          */
604
605         if (likely(!msg_non_seq(buf_msg(buf)))) {
606                 struct tipc_msg *msg;
607
608                 bcbuf_set_acks(buf, bclink->bcast_nodes.count);
609                 msg = buf_msg(buf);
610                 msg_set_non_seq(msg, 1);
611                 msg_set_mc_netid(msg, tipc_net_id);
612                 bcl->stats.sent_info++;
613
614                 if (WARN_ON(!bclink->bcast_nodes.count)) {
615                         dump_stack();
616                         return 0;
617                 }
618         }
619
620         /* Send buffer over bearers until all targets reached */
621
622         bcbearer->remains = bclink->bcast_nodes;
623
624         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
625                 struct tipc_bearer *p = bcbearer->bpairs[bp_index].primary;
626                 struct tipc_bearer *s = bcbearer->bpairs[bp_index].secondary;
627
628                 if (!p)
629                         break;  /* no more bearers to try */
630
631                 tipc_nmap_diff(&bcbearer->remains, &p->nodes, &bcbearer->remains_new);
632                 if (bcbearer->remains_new.count == bcbearer->remains.count)
633                         continue;       /* bearer pair doesn't add anything */
634
635                 if (p->blocked ||
636                     p->media->send_msg(buf, p, &p->media->bcast_addr)) {
637                         /* unable to send on primary bearer */
638                         if (!s || s->blocked ||
639                             s->media->send_msg(buf, s,
640                                                &s->media->bcast_addr)) {
641                                 /* unable to send on either bearer */
642                                 continue;
643                         }
644                 }
645
646                 if (s) {
647                         bcbearer->bpairs[bp_index].primary = s;
648                         bcbearer->bpairs[bp_index].secondary = p;
649                 }
650
651                 if (bcbearer->remains_new.count == 0)
652                         break;  /* all targets reached */
653
654                 bcbearer->remains = bcbearer->remains_new;
655         }
656
657         return 0;
658 }
659
660 /**
661  * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer
662  */
663
664 void tipc_bcbearer_sort(void)
665 {
666         struct tipc_bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
667         struct tipc_bcbearer_pair *bp_curr;
668         int b_index;
669         int pri;
670
671         spin_lock_bh(&bc_lock);
672
673         /* Group bearers by priority (can assume max of two per priority) */
674
675         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
676
677         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
678                 struct tipc_bearer *b = &tipc_bearers[b_index];
679
680                 if (!b->active || !b->nodes.count)
681                         continue;
682
683                 if (!bp_temp[b->priority].primary)
684                         bp_temp[b->priority].primary = b;
685                 else
686                         bp_temp[b->priority].secondary = b;
687         }
688
689         /* Create array of bearer pairs for broadcasting */
690
691         bp_curr = bcbearer->bpairs;
692         memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
693
694         for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) {
695
696                 if (!bp_temp[pri].primary)
697                         continue;
698
699                 bp_curr->primary = bp_temp[pri].primary;
700
701                 if (bp_temp[pri].secondary) {
702                         if (tipc_nmap_equal(&bp_temp[pri].primary->nodes,
703                                             &bp_temp[pri].secondary->nodes)) {
704                                 bp_curr->secondary = bp_temp[pri].secondary;
705                         } else {
706                                 bp_curr++;
707                                 bp_curr->primary = bp_temp[pri].secondary;
708                         }
709                 }
710
711                 bp_curr++;
712         }
713
714         spin_unlock_bh(&bc_lock);
715 }
716
717
718 int tipc_bclink_stats(char *buf, const u32 buf_size)
719 {
720         struct print_buf pb;
721
722         if (!bcl)
723                 return 0;
724
725         tipc_printbuf_init(&pb, buf, buf_size);
726
727         spin_lock_bh(&bc_lock);
728
729         tipc_printf(&pb, "Link <%s>\n"
730                          "  Window:%u packets\n",
731                     bcl->name, bcl->queue_limit[0]);
732         tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
733                     bcl->stats.recv_info,
734                     bcl->stats.recv_fragments,
735                     bcl->stats.recv_fragmented,
736                     bcl->stats.recv_bundles,
737                     bcl->stats.recv_bundled);
738         tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
739                     bcl->stats.sent_info,
740                     bcl->stats.sent_fragments,
741                     bcl->stats.sent_fragmented,
742                     bcl->stats.sent_bundles,
743                     bcl->stats.sent_bundled);
744         tipc_printf(&pb, "  RX naks:%u defs:%u dups:%u\n",
745                     bcl->stats.recv_nacks,
746                     bcl->stats.deferred_recv,
747                     bcl->stats.duplicates);
748         tipc_printf(&pb, "  TX naks:%u acks:%u dups:%u\n",
749                     bcl->stats.sent_nacks,
750                     bcl->stats.sent_acks,
751                     bcl->stats.retransmitted);
752         tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
753                     bcl->stats.bearer_congs,
754                     bcl->stats.link_congs,
755                     bcl->stats.max_queue_sz,
756                     bcl->stats.queue_sz_counts
757                     ? (bcl->stats.accu_queue_sz / bcl->stats.queue_sz_counts)
758                     : 0);
759
760         spin_unlock_bh(&bc_lock);
761         return tipc_printbuf_validate(&pb);
762 }
763
764 int tipc_bclink_reset_stats(void)
765 {
766         if (!bcl)
767                 return -ENOPROTOOPT;
768
769         spin_lock_bh(&bc_lock);
770         memset(&bcl->stats, 0, sizeof(bcl->stats));
771         spin_unlock_bh(&bc_lock);
772         return 0;
773 }
774
775 int tipc_bclink_set_queue_limits(u32 limit)
776 {
777         if (!bcl)
778                 return -ENOPROTOOPT;
779         if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
780                 return -EINVAL;
781
782         spin_lock_bh(&bc_lock);
783         tipc_link_set_queue_limits(bcl, limit);
784         spin_unlock_bh(&bc_lock);
785         return 0;
786 }
787
788 void tipc_bclink_init(void)
789 {
790         INIT_LIST_HEAD(&bcbearer->bearer.cong_links);
791         bcbearer->bearer.media = &bcbearer->media;
792         bcbearer->media.send_msg = tipc_bcbearer_send;
793         sprintf(bcbearer->media.name, "tipc-broadcast");
794
795         INIT_LIST_HEAD(&bcl->waiting_ports);
796         bcl->next_out_no = 1;
797         spin_lock_init(&bclink->node.lock);
798         bcl->owner = &bclink->node;
799         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
800         tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
801         bcl->b_ptr = &bcbearer->bearer;
802         bcl->state = WORKING_WORKING;
803         strlcpy(bcl->name, tipc_bclink_name, TIPC_MAX_LINK_NAME);
804 }
805
806 void tipc_bclink_stop(void)
807 {
808         spin_lock_bh(&bc_lock);
809         tipc_link_stop(bcl);
810         spin_unlock_bh(&bc_lock);
811
812         memset(bclink, 0, sizeof(*bclink));
813         memset(bcbearer, 0, sizeof(*bcbearer));
814 }
815
816
817 /**
818  * tipc_nmap_add - add a node to a node map
819  */
820
821 void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node)
822 {
823         int n = tipc_node(node);
824         int w = n / WSIZE;
825         u32 mask = (1 << (n % WSIZE));
826
827         if ((nm_ptr->map[w] & mask) == 0) {
828                 nm_ptr->count++;
829                 nm_ptr->map[w] |= mask;
830         }
831 }
832
833 /**
834  * tipc_nmap_remove - remove a node from a node map
835  */
836
837 void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node)
838 {
839         int n = tipc_node(node);
840         int w = n / WSIZE;
841         u32 mask = (1 << (n % WSIZE));
842
843         if ((nm_ptr->map[w] & mask) != 0) {
844                 nm_ptr->map[w] &= ~mask;
845                 nm_ptr->count--;
846         }
847 }
848
849 /**
850  * tipc_nmap_diff - find differences between node maps
851  * @nm_a: input node map A
852  * @nm_b: input node map B
853  * @nm_diff: output node map A-B (i.e. nodes of A that are not in B)
854  */
855
856 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
857                            struct tipc_node_map *nm_b,
858                            struct tipc_node_map *nm_diff)
859 {
860         int stop = ARRAY_SIZE(nm_a->map);
861         int w;
862         int b;
863         u32 map;
864
865         memset(nm_diff, 0, sizeof(*nm_diff));
866         for (w = 0; w < stop; w++) {
867                 map = nm_a->map[w] ^ (nm_a->map[w] & nm_b->map[w]);
868                 nm_diff->map[w] = map;
869                 if (map != 0) {
870                         for (b = 0 ; b < WSIZE; b++) {
871                                 if (map & (1 << b))
872                                         nm_diff->count++;
873                         }
874                 }
875         }
876 }
877
878 /**
879  * tipc_port_list_add - add a port to a port list, ensuring no duplicates
880  */
881
882 void tipc_port_list_add(struct tipc_port_list *pl_ptr, u32 port)
883 {
884         struct tipc_port_list *item = pl_ptr;
885         int i;
886         int item_sz = PLSIZE;
887         int cnt = pl_ptr->count;
888
889         for (; ; cnt -= item_sz, item = item->next) {
890                 if (cnt < PLSIZE)
891                         item_sz = cnt;
892                 for (i = 0; i < item_sz; i++)
893                         if (item->ports[i] == port)
894                                 return;
895                 if (i < PLSIZE) {
896                         item->ports[i] = port;
897                         pl_ptr->count++;
898                         return;
899                 }
900                 if (!item->next) {
901                         item->next = kmalloc(sizeof(*item), GFP_ATOMIC);
902                         if (!item->next) {
903                                 warn("Incomplete multicast delivery, no memory\n");
904                                 return;
905                         }
906                         item->next->next = NULL;
907                 }
908         }
909 }
910
911 /**
912  * tipc_port_list_free - free dynamically created entries in port_list chain
913  *
914  */
915
916 void tipc_port_list_free(struct tipc_port_list *pl_ptr)
917 {
918         struct tipc_port_list *item;
919         struct tipc_port_list *next;
920
921         for (item = pl_ptr->next; item; item = next) {
922                 next = item->next;
923                 kfree(item);
924         }
925 }
926