[TIPC]: Fix 64-bit build warnings.
[linux-2.6] / 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, 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 "msg.h"
40 #include "dbg.h"
41 #include "link.h"
42 #include "net.h"
43 #include "node.h"
44 #include "port.h"
45 #include "addr.h"
46 #include "node_subscr.h"
47 #include "name_distr.h"
48 #include "bearer.h"
49 #include "name_table.h"
50 #include "bcast.h"
51
52
53 #define MAX_PKT_DEFAULT_MCAST 1500      /* bcast link max packet size (fixed) */
54
55 #define BCLINK_WIN_DEFAULT 20           /* bcast link window size (default) */
56
57 #define BCLINK_LOG_BUF_SIZE 0
58
59 /**
60  * struct bcbearer_pair - a pair of bearers used by broadcast link
61  * @primary: pointer to primary bearer
62  * @secondary: pointer to secondary bearer
63  * 
64  * Bearers must have same priority and same set of reachable destinations 
65  * to be paired.
66  */
67
68 struct bcbearer_pair {
69         struct bearer *primary;
70         struct bearer *secondary;
71 };
72
73 /**
74  * struct bcbearer - bearer used by broadcast link
75  * @bearer: (non-standard) broadcast bearer structure
76  * @media: (non-standard) broadcast media structure
77  * @bpairs: array of bearer pairs
78  * @bpairs_temp: array of bearer pairs used during creation of "bpairs"
79  */
80
81 struct bcbearer {
82         struct bearer bearer;
83         struct media media;
84         struct bcbearer_pair bpairs[MAX_BEARERS];
85         struct bcbearer_pair bpairs_temp[TIPC_NUM_LINK_PRI];
86 };
87
88 /**
89  * struct bclink - link used for broadcast messages
90  * @link: (non-standard) broadcast link structure
91  * @node: (non-standard) node structure representing b'cast link's peer node
92  * 
93  * Handles sequence numbering, fragmentation, bundling, etc.
94  */
95
96 struct bclink {
97         struct link link;
98         struct node node;
99 };
100
101
102 static struct bcbearer *bcbearer = NULL;
103 static struct bclink *bclink = NULL;
104 static struct link *bcl = NULL;
105 static spinlock_t bc_lock = SPIN_LOCK_UNLOCKED;
106
107 char bc_link_name[] = "multicast-link";
108
109
110 static inline u32 buf_seqno(struct sk_buff *buf)
111 {
112         return msg_seqno(buf_msg(buf));
113
114
115 static inline u32 bcbuf_acks(struct sk_buff *buf)
116 {
117         return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
118 }
119
120 static inline void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
121 {
122         TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks;
123 }
124
125 static inline void bcbuf_decr_acks(struct sk_buff *buf)
126 {
127         bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
128 }
129
130
131 /** 
132  * bclink_set_gap - set gap according to contents of current deferred pkt queue
133  * 
134  * Called with 'node' locked, bc_lock unlocked
135  */
136
137 static inline void bclink_set_gap(struct node *n_ptr)
138 {
139         struct sk_buff *buf = n_ptr->bclink.deferred_head;
140
141         n_ptr->bclink.gap_after = n_ptr->bclink.gap_to =
142                 mod(n_ptr->bclink.last_in);
143         if (unlikely(buf != NULL))
144                 n_ptr->bclink.gap_to = mod(buf_seqno(buf) - 1);
145 }
146
147 /** 
148  * bclink_ack_allowed - test if ACK or NACK message can be sent at this moment
149  * 
150  * This mechanism endeavours to prevent all nodes in network from trying
151  * to ACK or NACK at the same time.
152  * 
153  * Note: TIPC uses a different trigger to distribute ACKs than it does to
154  *       distribute NACKs, but tries to use the same spacing (divide by 16). 
155  */
156
157 static inline int bclink_ack_allowed(u32 n)
158 {
159         return((n % TIPC_MIN_LINK_WIN) == tipc_own_tag);
160 }
161
162
163 /** 
164  * bclink_retransmit_pkt - retransmit broadcast packets
165  * @after: sequence number of last packet to *not* retransmit
166  * @to: sequence number of last packet to retransmit
167  * 
168  * Called with 'node' locked, bc_lock unlocked
169  */
170
171 static void bclink_retransmit_pkt(u32 after, u32 to)
172 {
173         struct sk_buff *buf;
174
175         spin_lock_bh(&bc_lock);
176         buf = bcl->first_out;
177         while (buf && less_eq(buf_seqno(buf), after)) {
178                 buf = buf->next;                
179         }
180         if (buf != NULL)
181                 link_retransmit(bcl, buf, mod(to - after));
182         spin_unlock_bh(&bc_lock);              
183 }
184
185 /** 
186  * bclink_acknowledge - handle acknowledgement of broadcast packets
187  * @n_ptr: node that sent acknowledgement info
188  * @acked: broadcast sequence # that has been acknowledged
189  * 
190  * Node is locked, bc_lock unlocked.
191  */
192
193 void bclink_acknowledge(struct node *n_ptr, u32 acked)
194 {
195         struct sk_buff *crs;
196         struct sk_buff *next;
197         unsigned int released = 0;
198
199         if (less_eq(acked, n_ptr->bclink.acked))
200                 return;
201
202         spin_lock_bh(&bc_lock);
203
204         /* Skip over packets that node has previously acknowledged */
205
206         crs = bcl->first_out;
207         while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked)) {
208                 crs = crs->next;
209         }
210
211         /* Update packets that node is now acknowledging */
212
213         while (crs && less_eq(buf_seqno(crs), acked)) {
214                 next = crs->next;
215                 bcbuf_decr_acks(crs);
216                 if (bcbuf_acks(crs) == 0) {
217                         bcl->first_out = next;
218                         bcl->out_queue_size--;
219                         buf_discard(crs);
220                         released = 1;
221                 }
222                 crs = next;
223         }
224         n_ptr->bclink.acked = acked;
225
226         /* Try resolving broadcast link congestion, if necessary */
227
228         if (unlikely(bcl->next_out))
229                 link_push_queue(bcl);
230         if (unlikely(released && !list_empty(&bcl->waiting_ports)))
231                 link_wakeup_ports(bcl, 0);
232         spin_unlock_bh(&bc_lock);
233 }
234
235 /** 
236  * bclink_send_ack - unicast an ACK msg
237  * 
238  * net_lock and node lock set
239  */
240
241 static void bclink_send_ack(struct node *n_ptr)
242 {
243         struct link *l_ptr = n_ptr->active_links[n_ptr->addr & 1];
244
245         if (l_ptr != NULL)
246                 link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
247 }
248
249 /** 
250  * bclink_send_nack- broadcast a NACK msg
251  * 
252  * net_lock and node lock set
253  */
254
255 static void bclink_send_nack(struct node *n_ptr)
256 {
257         struct sk_buff *buf;
258         struct tipc_msg *msg;
259
260         if (!less(n_ptr->bclink.gap_after, n_ptr->bclink.gap_to))
261                 return;
262
263         buf = buf_acquire(INT_H_SIZE);
264         if (buf) {
265                 msg = buf_msg(buf);
266                 msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
267                          TIPC_OK, INT_H_SIZE, n_ptr->addr);
268                 msg_set_mc_netid(msg, tipc_net_id);
269                 msg_set_bcast_ack(msg, mod(n_ptr->bclink.last_in)); 
270                 msg_set_bcgap_after(msg, n_ptr->bclink.gap_after);
271                 msg_set_bcgap_to(msg, n_ptr->bclink.gap_to);
272                 msg_set_bcast_tag(msg, tipc_own_tag);
273
274                 if (bearer_send(&bcbearer->bearer, buf, 0)) {
275                         bcl->stats.sent_nacks++;
276                         buf_discard(buf);
277                 } else {
278                         bearer_schedule(bcl->b_ptr, bcl);
279                         bcl->proto_msg_queue = buf;
280                         bcl->stats.bearer_congs++;
281                 }
282
283                 /* 
284                  * Ensure we doesn't send another NACK msg to the node
285                  * until 16 more deferred messages arrive from it
286                  * (i.e. helps prevent all nodes from NACK'ing at same time)
287                  */
288                 
289                 n_ptr->bclink.nack_sync = tipc_own_tag;
290         }
291 }
292
293 /** 
294  * bclink_check_gap - send a NACK if a sequence gap exists
295  *
296  * net_lock and node lock set
297  */
298
299 void bclink_check_gap(struct node *n_ptr, u32 last_sent)
300 {
301         if (!n_ptr->bclink.supported ||
302             less_eq(last_sent, mod(n_ptr->bclink.last_in)))
303                 return;
304
305         bclink_set_gap(n_ptr);
306         if (n_ptr->bclink.gap_after == n_ptr->bclink.gap_to)
307                 n_ptr->bclink.gap_to = last_sent;
308         bclink_send_nack(n_ptr);
309 }
310
311 /** 
312  * bclink_peek_nack - process a NACK msg meant for another node
313  * 
314  * Only net_lock set.
315  */
316
317 void bclink_peek_nack(u32 dest, u32 sender_tag, u32 gap_after, u32 gap_to)
318 {
319         struct node *n_ptr = node_find(dest);
320         u32 my_after, my_to;
321
322         if (unlikely(!n_ptr || !node_is_up(n_ptr)))
323                 return;
324         node_lock(n_ptr);
325         /*
326          * Modify gap to suppress unnecessary NACKs from this node
327          */
328         my_after = n_ptr->bclink.gap_after;
329         my_to = n_ptr->bclink.gap_to;
330
331         if (less_eq(gap_after, my_after)) {
332                 if (less(my_after, gap_to) && less(gap_to, my_to))
333                         n_ptr->bclink.gap_after = gap_to;
334                 else if (less_eq(my_to, gap_to))
335                         n_ptr->bclink.gap_to = n_ptr->bclink.gap_after;
336         } else if (less_eq(gap_after, my_to)) {
337                 if (less_eq(my_to, gap_to))
338                         n_ptr->bclink.gap_to = gap_after;
339         } else {
340                 /* 
341                  * Expand gap if missing bufs not in deferred queue:
342                  */
343                 struct sk_buff *buf = n_ptr->bclink.deferred_head;
344                 u32 prev = n_ptr->bclink.gap_to;
345
346                 for (; buf; buf = buf->next) {
347                         u32 seqno = buf_seqno(buf);
348
349                         if (mod(seqno - prev) != 1)
350                                 buf = NULL;
351                         if (seqno == gap_after)
352                                 break;
353                         prev = seqno;
354                 }
355                 if (buf == NULL)
356                         n_ptr->bclink.gap_to = gap_after;
357         }
358         /*
359          * Some nodes may send a complementary NACK now:
360          */ 
361         if (bclink_ack_allowed(sender_tag + 1)) {
362                 if (n_ptr->bclink.gap_to != n_ptr->bclink.gap_after) {
363                         bclink_send_nack(n_ptr);
364                         bclink_set_gap(n_ptr);
365                 }
366         }
367         node_unlock(n_ptr);
368 }
369
370 /**
371  * bclink_send_msg - broadcast a packet to all nodes in cluster
372  */
373
374 int bclink_send_msg(struct sk_buff *buf)
375 {
376         int res;
377
378         spin_lock_bh(&bc_lock);
379
380         res = link_send_buf(bcl, buf);
381         if (unlikely(res == -ELINKCONG))
382                 buf_discard(buf);
383         else
384                 bcl->stats.sent_info++;
385
386         if (bcl->out_queue_size > bcl->stats.max_queue_sz)
387                 bcl->stats.max_queue_sz = bcl->out_queue_size;
388         bcl->stats.queue_sz_counts++;
389         bcl->stats.accu_queue_sz += bcl->out_queue_size;
390
391         spin_unlock_bh(&bc_lock);
392         return res;
393 }
394
395 /**
396  * bclink_recv_pkt - receive a broadcast packet, and deliver upwards
397  * 
398  * net_lock is read_locked, no other locks set
399  */
400
401 void bclink_recv_pkt(struct sk_buff *buf)
402 {        
403         struct tipc_msg *msg = buf_msg(buf);
404         struct node* node = node_find(msg_prevnode(msg));
405         u32 next_in;
406         u32 seqno;
407         struct sk_buff *deferred;
408
409         msg_dbg(msg, "<BC<<<");
410
411         if (unlikely(!node || !node_is_up(node) || !node->bclink.supported || 
412                      (msg_mc_netid(msg) != tipc_net_id))) {
413                 buf_discard(buf);
414                 return;
415         }
416
417         if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
418                 msg_dbg(msg, "<BCNACK<<<");
419                 if (msg_destnode(msg) == tipc_own_addr) {
420                         node_lock(node);
421                         bclink_acknowledge(node, msg_bcast_ack(msg));
422                         node_unlock(node);
423                         bcl->stats.recv_nacks++;
424                         bclink_retransmit_pkt(msg_bcgap_after(msg),
425                                               msg_bcgap_to(msg));
426                 } else {
427                         bclink_peek_nack(msg_destnode(msg),
428                                          msg_bcast_tag(msg),
429                                          msg_bcgap_after(msg),
430                                          msg_bcgap_to(msg));
431                 }
432                 buf_discard(buf);
433                 return;
434         }
435
436         node_lock(node);
437 receive:
438         deferred = node->bclink.deferred_head;
439         next_in = mod(node->bclink.last_in + 1);
440         seqno = msg_seqno(msg);
441
442         if (likely(seqno == next_in)) {
443                 bcl->stats.recv_info++;
444                 node->bclink.last_in++;
445                 bclink_set_gap(node);
446                 if (unlikely(bclink_ack_allowed(seqno))) {
447                         bclink_send_ack(node);
448                         bcl->stats.sent_acks++;
449                 }
450                 if (likely(msg_isdata(msg))) {
451                         node_unlock(node);
452                         port_recv_mcast(buf, NULL);
453                 } else if (msg_user(msg) == MSG_BUNDLER) {
454                         bcl->stats.recv_bundles++;
455                         bcl->stats.recv_bundled += msg_msgcnt(msg);
456                         node_unlock(node);
457                         link_recv_bundle(buf);
458                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
459                         bcl->stats.recv_fragments++;
460                         if (link_recv_fragment(&node->bclink.defragm,
461                                                &buf, &msg))
462                                 bcl->stats.recv_fragmented++;
463                         node_unlock(node);
464                         net_route_msg(buf);
465                 } else {
466                         node_unlock(node);
467                         net_route_msg(buf);
468                 }
469                 if (deferred && (buf_seqno(deferred) == mod(next_in + 1))) {
470                         node_lock(node);
471                         buf = deferred;
472                         msg = buf_msg(buf);
473                         node->bclink.deferred_head = deferred->next;
474                         goto receive;
475                 }
476                 return;
477         } else if (less(next_in, seqno)) {
478                 u32 gap_after = node->bclink.gap_after;
479                 u32 gap_to = node->bclink.gap_to;
480
481                 if (link_defer_pkt(&node->bclink.deferred_head,
482                                    &node->bclink.deferred_tail,
483                                    buf)) {
484                         node->bclink.nack_sync++;
485                         bcl->stats.deferred_recv++;
486                         if (seqno == mod(gap_after + 1))
487                                 node->bclink.gap_after = seqno;
488                         else if (less(gap_after, seqno) && less(seqno, gap_to))
489                                 node->bclink.gap_to = seqno;
490                 }
491                 if (bclink_ack_allowed(node->bclink.nack_sync)) {
492                         if (gap_to != gap_after)
493                                 bclink_send_nack(node);
494                         bclink_set_gap(node);
495                 }
496         } else {
497                 bcl->stats.duplicates++;
498                 buf_discard(buf);
499         }
500         node_unlock(node);
501 }
502
503 u32 bclink_get_last_sent(void)
504 {
505         u32 last_sent = mod(bcl->next_out_no - 1);
506
507         if (bcl->next_out)
508                 last_sent = mod(buf_seqno(bcl->next_out) - 1);
509         return last_sent;
510 }
511
512 u32 bclink_acks_missing(struct node *n_ptr)
513 {
514         return (n_ptr->bclink.supported &&
515                 (bclink_get_last_sent() != n_ptr->bclink.acked));
516 }
517
518
519 /**
520  * bcbearer_send - send a packet through the broadcast pseudo-bearer
521  * 
522  * Send through as many bearers as necessary to reach all nodes
523  * that support TIPC multicasting.
524  * 
525  * Returns 0 if packet sent successfully, non-zero if not
526  */
527
528 int bcbearer_send(struct sk_buff *buf,
529                   struct tipc_bearer *unused1,
530                   struct tipc_media_addr *unused2)
531 {
532         static int send_count = 0;
533
534         struct node_map remains;
535         struct node_map remains_new;
536         int bp_index;
537         int swap_time;
538
539         /* Prepare buffer for broadcasting (if first time trying to send it) */
540
541         if (likely(!msg_non_seq(buf_msg(buf)))) {
542                 struct tipc_msg *msg;
543
544                 assert(cluster_bcast_nodes.count != 0);
545                 bcbuf_set_acks(buf, cluster_bcast_nodes.count);
546                 msg = buf_msg(buf);
547                 msg_set_non_seq(msg);
548                 msg_set_mc_netid(msg, tipc_net_id);
549         }
550
551         /* Determine if bearer pairs should be swapped following this attempt */
552
553         if ((swap_time = (++send_count >= 10)))
554                 send_count = 0;
555
556         /* Send buffer over bearers until all targets reached */
557         
558         remains = cluster_bcast_nodes;
559
560         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
561                 struct bearer *p = bcbearer->bpairs[bp_index].primary;
562                 struct bearer *s = bcbearer->bpairs[bp_index].secondary;
563
564                 if (!p)
565                         break;  /* no more bearers to try */
566
567                 nmap_diff(&remains, &p->nodes, &remains_new);
568                 if (remains_new.count == remains.count)
569                         continue;       /* bearer pair doesn't add anything */
570
571                 if (!p->publ.blocked &&
572                     !p->media->send_msg(buf, &p->publ, &p->media->bcast_addr)) {
573                         if (swap_time && s && !s->publ.blocked)
574                                 goto swap;
575                         else
576                                 goto update;
577                 }
578
579                 if (!s || s->publ.blocked ||
580                     s->media->send_msg(buf, &s->publ, &s->media->bcast_addr))
581                         continue;       /* unable to send using bearer pair */
582 swap:
583                 bcbearer->bpairs[bp_index].primary = s;
584                 bcbearer->bpairs[bp_index].secondary = p;
585 update:
586                 if (remains_new.count == 0)
587                         return TIPC_OK;
588
589                 remains = remains_new;
590         }
591         
592         /* Unable to reach all targets */
593
594         bcbearer->bearer.publ.blocked = 1;
595         bcl->stats.bearer_congs++;
596         return ~TIPC_OK;
597 }
598
599 /**
600  * bcbearer_sort - create sets of bearer pairs used by broadcast bearer
601  */
602
603 void bcbearer_sort(void)
604 {
605         struct bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
606         struct bcbearer_pair *bp_curr;
607         int b_index;
608         int pri;
609
610         spin_lock_bh(&bc_lock);
611
612         /* Group bearers by priority (can assume max of two per priority) */
613
614         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
615
616         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
617                 struct bearer *b = &bearers[b_index];
618
619                 if (!b->active || !b->nodes.count)
620                         continue;
621
622                 if (!bp_temp[b->priority].primary)
623                         bp_temp[b->priority].primary = b;
624                 else
625                         bp_temp[b->priority].secondary = b;
626         }
627
628         /* Create array of bearer pairs for broadcasting */
629
630         bp_curr = bcbearer->bpairs;
631         memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
632
633         for (pri = (TIPC_NUM_LINK_PRI - 1); pri >= 0; pri--) {
634
635                 if (!bp_temp[pri].primary)
636                         continue;
637
638                 bp_curr->primary = bp_temp[pri].primary;
639
640                 if (bp_temp[pri].secondary) {
641                         if (nmap_equal(&bp_temp[pri].primary->nodes,
642                                        &bp_temp[pri].secondary->nodes)) {
643                                 bp_curr->secondary = bp_temp[pri].secondary;
644                         } else {
645                                 bp_curr++;
646                                 bp_curr->primary = bp_temp[pri].secondary;
647                         }
648                 }
649
650                 bp_curr++;
651         }
652
653         spin_unlock_bh(&bc_lock);
654 }
655
656 /**
657  * bcbearer_push - resolve bearer congestion
658  * 
659  * Forces bclink to push out any unsent packets, until all packets are gone
660  * or congestion reoccurs.
661  * No locks set when function called
662  */
663
664 void bcbearer_push(void)
665 {
666         struct bearer *b_ptr;
667
668         spin_lock_bh(&bc_lock);
669         b_ptr = &bcbearer->bearer;
670         if (b_ptr->publ.blocked) {
671                 b_ptr->publ.blocked = 0;
672                 bearer_lock_push(b_ptr);
673         }
674         spin_unlock_bh(&bc_lock);
675 }
676
677
678 int bclink_stats(char *buf, const u32 buf_size)
679 {
680         struct print_buf pb;
681
682         if (!bcl)
683                 return 0;
684
685         printbuf_init(&pb, buf, buf_size);
686
687         spin_lock_bh(&bc_lock);
688
689         tipc_printf(&pb, "Link <%s>\n"
690                          "  Window:%u packets\n", 
691                     bcl->name, bcl->queue_limit[0]);
692         tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n", 
693                     bcl->stats.recv_info,
694                     bcl->stats.recv_fragments,
695                     bcl->stats.recv_fragmented,
696                     bcl->stats.recv_bundles,
697                     bcl->stats.recv_bundled);
698         tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n", 
699                     bcl->stats.sent_info,
700                     bcl->stats.sent_fragments,
701                     bcl->stats.sent_fragmented, 
702                     bcl->stats.sent_bundles,
703                     bcl->stats.sent_bundled);
704         tipc_printf(&pb, "  RX naks:%u defs:%u dups:%u\n", 
705                     bcl->stats.recv_nacks,
706                     bcl->stats.deferred_recv, 
707                     bcl->stats.duplicates);
708         tipc_printf(&pb, "  TX naks:%u acks:%u dups:%u\n", 
709                     bcl->stats.sent_nacks, 
710                     bcl->stats.sent_acks, 
711                     bcl->stats.retransmitted);
712         tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
713                     bcl->stats.bearer_congs,
714                     bcl->stats.link_congs,
715                     bcl->stats.max_queue_sz,
716                     bcl->stats.queue_sz_counts
717                     ? (bcl->stats.accu_queue_sz / bcl->stats.queue_sz_counts)
718                     : 0);
719
720         spin_unlock_bh(&bc_lock);
721         return printbuf_validate(&pb);
722 }
723
724 int bclink_reset_stats(void)
725 {
726         if (!bcl)
727                 return -ENOPROTOOPT;
728
729         spin_lock_bh(&bc_lock);
730         memset(&bcl->stats, 0, sizeof(bcl->stats));
731         spin_unlock_bh(&bc_lock);
732         return TIPC_OK;
733 }
734
735 int bclink_set_queue_limits(u32 limit)
736 {
737         if (!bcl)
738                 return -ENOPROTOOPT;
739         if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
740                 return -EINVAL;
741
742         spin_lock_bh(&bc_lock);
743         link_set_queue_limits(bcl, limit);
744         spin_unlock_bh(&bc_lock);
745         return TIPC_OK;
746 }
747
748 int bclink_init(void)
749 {
750         bcbearer = kmalloc(sizeof(*bcbearer), GFP_ATOMIC);
751         bclink = kmalloc(sizeof(*bclink), GFP_ATOMIC);
752         if (!bcbearer || !bclink) {
753  nomem:
754                 warn("Memory squeeze; Failed to create multicast link\n");
755                 kfree(bcbearer);
756                 bcbearer = NULL;
757                 kfree(bclink);
758                 bclink = NULL;
759                 return -ENOMEM;
760         }
761
762         memset(bcbearer, 0, sizeof(struct bcbearer));
763         INIT_LIST_HEAD(&bcbearer->bearer.cong_links);
764         bcbearer->bearer.media = &bcbearer->media;
765         bcbearer->media.send_msg = bcbearer_send;
766         sprintf(bcbearer->media.name, "tipc-multicast");
767
768         bcl = &bclink->link;
769         memset(bclink, 0, sizeof(struct bclink));
770         INIT_LIST_HEAD(&bcl->waiting_ports);
771         bcl->next_out_no = 1;
772         bclink->node.lock =  SPIN_LOCK_UNLOCKED;        
773         bcl->owner = &bclink->node;
774         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
775         link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
776         bcl->b_ptr = &bcbearer->bearer;
777         bcl->state = WORKING_WORKING;
778         sprintf(bcl->name, bc_link_name);
779
780         if (BCLINK_LOG_BUF_SIZE) {
781                 char *pb = kmalloc(BCLINK_LOG_BUF_SIZE, GFP_ATOMIC);
782
783                 if (!pb)
784                         goto nomem;
785                 printbuf_init(&bcl->print_buf, pb, BCLINK_LOG_BUF_SIZE);
786         }
787
788         return TIPC_OK;
789 }
790
791 void bclink_stop(void)
792 {
793         spin_lock_bh(&bc_lock);
794         if (bcbearer) {
795                 link_stop(bcl);
796                 if (BCLINK_LOG_BUF_SIZE)
797                         kfree(bcl->print_buf.buf);
798                 bcl = NULL;
799                 kfree(bclink);
800                 bclink = NULL;
801                 kfree(bcbearer);
802                 bcbearer = NULL;
803         }
804         spin_unlock_bh(&bc_lock);
805 }
806