[TIPC]: Enhanced & cleaned up system messages; fixed 2 obscure memory leaks.
[linux-3.10.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, 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 #define MAX_PKT_DEFAULT_MCAST 1500      /* bcast link max packet size (fixed) */
53
54 #define BCLINK_WIN_DEFAULT 20           /* bcast link window size (default) */
55
56 #define BCLINK_LOG_BUF_SIZE 0
57
58 /*
59  * Loss rate for incoming broadcast frames; used to test retransmission code.
60  * Set to N to cause every N'th frame to be discarded; 0 => don't discard any.
61  */
62  
63 #define TIPC_BCAST_LOSS_RATE 0
64
65 /**
66  * struct bcbearer_pair - a pair of bearers used by broadcast link
67  * @primary: pointer to primary bearer
68  * @secondary: pointer to secondary bearer
69  * 
70  * Bearers must have same priority and same set of reachable destinations 
71  * to be paired.
72  */
73
74 struct bcbearer_pair {
75         struct bearer *primary;
76         struct bearer *secondary;
77 };
78
79 /**
80  * struct bcbearer - bearer used by broadcast link
81  * @bearer: (non-standard) broadcast bearer structure
82  * @media: (non-standard) broadcast media structure
83  * @bpairs: array of bearer pairs
84  * @bpairs_temp: array of bearer pairs used during creation of "bpairs"
85  */
86
87 struct bcbearer {
88         struct bearer bearer;
89         struct media media;
90         struct bcbearer_pair bpairs[MAX_BEARERS];
91         struct bcbearer_pair bpairs_temp[TIPC_MAX_LINK_PRI + 1];
92 };
93
94 /**
95  * struct bclink - link used for broadcast messages
96  * @link: (non-standard) broadcast link structure
97  * @node: (non-standard) node structure representing b'cast link's peer node
98  * 
99  * Handles sequence numbering, fragmentation, bundling, etc.
100  */
101
102 struct bclink {
103         struct link link;
104         struct node node;
105 };
106
107
108 static struct bcbearer *bcbearer = NULL;
109 static struct bclink *bclink = NULL;
110 static struct link *bcl = NULL;
111 static spinlock_t bc_lock = SPIN_LOCK_UNLOCKED;
112
113 char tipc_bclink_name[] = "multicast-link";
114
115
116 static u32 buf_seqno(struct sk_buff *buf)
117 {
118         return msg_seqno(buf_msg(buf));
119
120
121 static u32 bcbuf_acks(struct sk_buff *buf)
122 {
123         return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
124 }
125
126 static void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
127 {
128         TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks;
129 }
130
131 static void bcbuf_decr_acks(struct sk_buff *buf)
132 {
133         bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
134 }
135
136
137 /** 
138  * bclink_set_gap - set gap according to contents of current deferred pkt queue
139  * 
140  * Called with 'node' locked, bc_lock unlocked
141  */
142
143 static void bclink_set_gap(struct node *n_ptr)
144 {
145         struct sk_buff *buf = n_ptr->bclink.deferred_head;
146
147         n_ptr->bclink.gap_after = n_ptr->bclink.gap_to =
148                 mod(n_ptr->bclink.last_in);
149         if (unlikely(buf != NULL))
150                 n_ptr->bclink.gap_to = mod(buf_seqno(buf) - 1);
151 }
152
153 /** 
154  * bclink_ack_allowed - test if ACK or NACK message can be sent at this moment
155  * 
156  * This mechanism endeavours to prevent all nodes in network from trying
157  * to ACK or NACK at the same time.
158  * 
159  * Note: TIPC uses a different trigger to distribute ACKs than it does to
160  *       distribute NACKs, but tries to use the same spacing (divide by 16). 
161  */
162
163 static int bclink_ack_allowed(u32 n)
164 {
165         return((n % TIPC_MIN_LINK_WIN) == tipc_own_tag);
166 }
167
168
169 /** 
170  * bclink_retransmit_pkt - retransmit broadcast packets
171  * @after: sequence number of last packet to *not* retransmit
172  * @to: sequence number of last packet to retransmit
173  * 
174  * Called with bc_lock locked
175  */
176
177 static void bclink_retransmit_pkt(u32 after, u32 to)
178 {
179         struct sk_buff *buf;
180
181         buf = bcl->first_out;
182         while (buf && less_eq(buf_seqno(buf), after)) {
183                 buf = buf->next;                
184         }
185         tipc_link_retransmit(bcl, buf, mod(to - after));
186 }
187
188 /** 
189  * tipc_bclink_acknowledge - handle acknowledgement of broadcast packets
190  * @n_ptr: node that sent acknowledgement info
191  * @acked: broadcast sequence # that has been acknowledged
192  * 
193  * Node is locked, bc_lock unlocked.
194  */
195
196 void tipc_bclink_acknowledge(struct node *n_ptr, u32 acked)
197 {
198         struct sk_buff *crs;
199         struct sk_buff *next;
200         unsigned int released = 0;
201
202         if (less_eq(acked, n_ptr->bclink.acked))
203                 return;
204
205         spin_lock_bh(&bc_lock);
206
207         /* Skip over packets that node has previously acknowledged */
208
209         crs = bcl->first_out;
210         while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked)) {
211                 crs = crs->next;
212         }
213
214         /* Update packets that node is now acknowledging */
215
216         while (crs && less_eq(buf_seqno(crs), acked)) {
217                 next = crs->next;
218                 bcbuf_decr_acks(crs);
219                 if (bcbuf_acks(crs) == 0) {
220                         bcl->first_out = next;
221                         bcl->out_queue_size--;
222                         buf_discard(crs);
223                         released = 1;
224                 }
225                 crs = next;
226         }
227         n_ptr->bclink.acked = acked;
228
229         /* Try resolving broadcast link congestion, if necessary */
230
231         if (unlikely(bcl->next_out))
232                 tipc_link_push_queue(bcl);
233         if (unlikely(released && !list_empty(&bcl->waiting_ports)))
234                 tipc_link_wakeup_ports(bcl, 0);
235         spin_unlock_bh(&bc_lock);
236 }
237
238 /** 
239  * bclink_send_ack - unicast an ACK msg
240  * 
241  * tipc_net_lock and node lock set
242  */
243
244 static void bclink_send_ack(struct node *n_ptr)
245 {
246         struct link *l_ptr = n_ptr->active_links[n_ptr->addr & 1];
247
248         if (l_ptr != NULL)
249                 tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
250 }
251
252 /** 
253  * bclink_send_nack- broadcast a NACK msg
254  * 
255  * tipc_net_lock and node lock set
256  */
257
258 static void bclink_send_nack(struct node *n_ptr)
259 {
260         struct sk_buff *buf;
261         struct tipc_msg *msg;
262
263         if (!less(n_ptr->bclink.gap_after, n_ptr->bclink.gap_to))
264                 return;
265
266         buf = buf_acquire(INT_H_SIZE);
267         if (buf) {
268                 msg = buf_msg(buf);
269                 msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
270                          TIPC_OK, INT_H_SIZE, n_ptr->addr);
271                 msg_set_mc_netid(msg, tipc_net_id);
272                 msg_set_bcast_ack(msg, mod(n_ptr->bclink.last_in)); 
273                 msg_set_bcgap_after(msg, n_ptr->bclink.gap_after);
274                 msg_set_bcgap_to(msg, n_ptr->bclink.gap_to);
275                 msg_set_bcast_tag(msg, tipc_own_tag);
276
277                 if (tipc_bearer_send(&bcbearer->bearer, buf, NULL)) {
278                         bcl->stats.sent_nacks++;
279                         buf_discard(buf);
280                 } else {
281                         tipc_bearer_schedule(bcl->b_ptr, bcl);
282                         bcl->proto_msg_queue = buf;
283                         bcl->stats.bearer_congs++;
284                 }
285
286                 /* 
287                  * Ensure we doesn't send another NACK msg to the node
288                  * until 16 more deferred messages arrive from it
289                  * (i.e. helps prevent all nodes from NACK'ing at same time)
290                  */
291                 
292                 n_ptr->bclink.nack_sync = tipc_own_tag;
293         }
294 }
295
296 /** 
297  * tipc_bclink_check_gap - send a NACK if a sequence gap exists
298  *
299  * tipc_net_lock and node lock set
300  */
301
302 void tipc_bclink_check_gap(struct node *n_ptr, u32 last_sent)
303 {
304         if (!n_ptr->bclink.supported ||
305             less_eq(last_sent, mod(n_ptr->bclink.last_in)))
306                 return;
307
308         bclink_set_gap(n_ptr);
309         if (n_ptr->bclink.gap_after == n_ptr->bclink.gap_to)
310                 n_ptr->bclink.gap_to = last_sent;
311         bclink_send_nack(n_ptr);
312 }
313
314 /** 
315  * tipc_bclink_peek_nack - process a NACK msg meant for another node
316  * 
317  * Only tipc_net_lock set.
318  */
319
320 static void tipc_bclink_peek_nack(u32 dest, u32 sender_tag, u32 gap_after, u32 gap_to)
321 {
322         struct node *n_ptr = tipc_node_find(dest);
323         u32 my_after, my_to;
324
325         if (unlikely(!n_ptr || !tipc_node_is_up(n_ptr)))
326                 return;
327         tipc_node_lock(n_ptr);
328         /*
329          * Modify gap to suppress unnecessary NACKs from this node
330          */
331         my_after = n_ptr->bclink.gap_after;
332         my_to = n_ptr->bclink.gap_to;
333
334         if (less_eq(gap_after, my_after)) {
335                 if (less(my_after, gap_to) && less(gap_to, my_to))
336                         n_ptr->bclink.gap_after = gap_to;
337                 else if (less_eq(my_to, gap_to))
338                         n_ptr->bclink.gap_to = n_ptr->bclink.gap_after;
339         } else if (less_eq(gap_after, my_to)) {
340                 if (less_eq(my_to, gap_to))
341                         n_ptr->bclink.gap_to = gap_after;
342         } else {
343                 /* 
344                  * Expand gap if missing bufs not in deferred queue:
345                  */
346                 struct sk_buff *buf = n_ptr->bclink.deferred_head;
347                 u32 prev = n_ptr->bclink.gap_to;
348
349                 for (; buf; buf = buf->next) {
350                         u32 seqno = buf_seqno(buf);
351
352                         if (mod(seqno - prev) != 1) {
353                                 buf = NULL;
354                                 break;
355                         }
356                         if (seqno == gap_after)
357                                 break;
358                         prev = seqno;
359                 }
360                 if (buf == NULL)
361                         n_ptr->bclink.gap_to = gap_after;
362         }
363         /*
364          * Some nodes may send a complementary NACK now:
365          */ 
366         if (bclink_ack_allowed(sender_tag + 1)) {
367                 if (n_ptr->bclink.gap_to != n_ptr->bclink.gap_after) {
368                         bclink_send_nack(n_ptr);
369                         bclink_set_gap(n_ptr);
370                 }
371         }
372         tipc_node_unlock(n_ptr);
373 }
374
375 /**
376  * tipc_bclink_send_msg - broadcast a packet to all nodes in cluster
377  */
378
379 int tipc_bclink_send_msg(struct sk_buff *buf)
380 {
381         int res;
382
383         spin_lock_bh(&bc_lock);
384
385         res = tipc_link_send_buf(bcl, buf);
386         if (unlikely(res == -ELINKCONG))
387                 buf_discard(buf);
388         else
389                 bcl->stats.sent_info++;
390
391         if (bcl->out_queue_size > bcl->stats.max_queue_sz)
392                 bcl->stats.max_queue_sz = bcl->out_queue_size;
393         bcl->stats.queue_sz_counts++;
394         bcl->stats.accu_queue_sz += bcl->out_queue_size;
395
396         spin_unlock_bh(&bc_lock);
397         return res;
398 }
399
400 /**
401  * tipc_bclink_recv_pkt - receive a broadcast packet, and deliver upwards
402  * 
403  * tipc_net_lock is read_locked, no other locks set
404  */
405
406 void tipc_bclink_recv_pkt(struct sk_buff *buf)
407 {
408 #if (TIPC_BCAST_LOSS_RATE)
409         static int rx_count = 0;
410 #endif
411         struct tipc_msg *msg = buf_msg(buf);
412         struct node* node = tipc_node_find(msg_prevnode(msg));
413         u32 next_in;
414         u32 seqno;
415         struct sk_buff *deferred;
416
417         msg_dbg(msg, "<BC<<<");
418
419         if (unlikely(!node || !tipc_node_is_up(node) || !node->bclink.supported || 
420                      (msg_mc_netid(msg) != tipc_net_id))) {
421                 buf_discard(buf);
422                 return;
423         }
424
425         if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
426                 msg_dbg(msg, "<BCNACK<<<");
427                 if (msg_destnode(msg) == tipc_own_addr) {
428                         tipc_node_lock(node);
429                         tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
430                         tipc_node_unlock(node);
431                         spin_lock_bh(&bc_lock);
432                         bcl->stats.recv_nacks++;
433                         bcl->owner->next = node;   /* remember requestor */
434                         bclink_retransmit_pkt(msg_bcgap_after(msg),
435                                               msg_bcgap_to(msg));
436                         bcl->owner->next = NULL;
437                         spin_unlock_bh(&bc_lock);              
438                 } else {
439                         tipc_bclink_peek_nack(msg_destnode(msg),
440                                               msg_bcast_tag(msg),
441                                               msg_bcgap_after(msg),
442                                               msg_bcgap_to(msg));
443                 }
444                 buf_discard(buf);
445                 return;
446         }
447
448 #if (TIPC_BCAST_LOSS_RATE)
449         if (++rx_count == TIPC_BCAST_LOSS_RATE) {
450                 rx_count = 0;
451                 buf_discard(buf);
452                 return;
453         }
454 #endif
455
456         tipc_node_lock(node);
457 receive:
458         deferred = node->bclink.deferred_head;
459         next_in = mod(node->bclink.last_in + 1);
460         seqno = msg_seqno(msg);
461
462         if (likely(seqno == next_in)) {
463                 bcl->stats.recv_info++;
464                 node->bclink.last_in++;
465                 bclink_set_gap(node);
466                 if (unlikely(bclink_ack_allowed(seqno))) {
467                         bclink_send_ack(node);
468                         bcl->stats.sent_acks++;
469                 }
470                 if (likely(msg_isdata(msg))) {
471                         tipc_node_unlock(node);
472                         tipc_port_recv_mcast(buf, NULL);
473                 } else if (msg_user(msg) == MSG_BUNDLER) {
474                         bcl->stats.recv_bundles++;
475                         bcl->stats.recv_bundled += msg_msgcnt(msg);
476                         tipc_node_unlock(node);
477                         tipc_link_recv_bundle(buf);
478                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
479                         bcl->stats.recv_fragments++;
480                         if (tipc_link_recv_fragment(&node->bclink.defragm,
481                                                     &buf, &msg))
482                                 bcl->stats.recv_fragmented++;
483                         tipc_node_unlock(node);
484                         tipc_net_route_msg(buf);
485                 } else {
486                         tipc_node_unlock(node);
487                         tipc_net_route_msg(buf);
488                 }
489                 if (deferred && (buf_seqno(deferred) == mod(next_in + 1))) {
490                         tipc_node_lock(node);
491                         buf = deferred;
492                         msg = buf_msg(buf);
493                         node->bclink.deferred_head = deferred->next;
494                         goto receive;
495                 }
496                 return;
497         } else if (less(next_in, seqno)) {
498                 u32 gap_after = node->bclink.gap_after;
499                 u32 gap_to = node->bclink.gap_to;
500
501                 if (tipc_link_defer_pkt(&node->bclink.deferred_head,
502                                         &node->bclink.deferred_tail,
503                                         buf)) {
504                         node->bclink.nack_sync++;
505                         bcl->stats.deferred_recv++;
506                         if (seqno == mod(gap_after + 1))
507                                 node->bclink.gap_after = seqno;
508                         else if (less(gap_after, seqno) && less(seqno, gap_to))
509                                 node->bclink.gap_to = seqno;
510                 }
511                 if (bclink_ack_allowed(node->bclink.nack_sync)) {
512                         if (gap_to != gap_after)
513                                 bclink_send_nack(node);
514                         bclink_set_gap(node);
515                 }
516         } else {
517                 bcl->stats.duplicates++;
518                 buf_discard(buf);
519         }
520         tipc_node_unlock(node);
521 }
522
523 u32 tipc_bclink_get_last_sent(void)
524 {
525         u32 last_sent = mod(bcl->next_out_no - 1);
526
527         if (bcl->next_out)
528                 last_sent = mod(buf_seqno(bcl->next_out) - 1);
529         return last_sent;
530 }
531
532 u32 tipc_bclink_acks_missing(struct node *n_ptr)
533 {
534         return (n_ptr->bclink.supported &&
535                 (tipc_bclink_get_last_sent() != n_ptr->bclink.acked));
536 }
537
538
539 /**
540  * tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer
541  * 
542  * Send through as many bearers as necessary to reach all nodes
543  * that support TIPC multicasting.
544  * 
545  * Returns 0 if packet sent successfully, non-zero if not
546  */
547
548 static int tipc_bcbearer_send(struct sk_buff *buf,
549                               struct tipc_bearer *unused1,
550                               struct tipc_media_addr *unused2)
551 {
552         static int send_count = 0;
553
554         struct node_map *remains;
555         struct node_map *remains_new;
556         struct node_map *remains_tmp;
557         int bp_index;
558         int swap_time;
559         int err;
560
561         /* Prepare buffer for broadcasting (if first time trying to send it) */
562
563         if (likely(!msg_non_seq(buf_msg(buf)))) {
564                 struct tipc_msg *msg;
565
566                 assert(tipc_cltr_bcast_nodes.count != 0);
567                 bcbuf_set_acks(buf, tipc_cltr_bcast_nodes.count);
568                 msg = buf_msg(buf);
569                 msg_set_non_seq(msg);
570                 msg_set_mc_netid(msg, tipc_net_id);
571         }
572
573         /* Determine if bearer pairs should be swapped following this attempt */
574
575         if ((swap_time = (++send_count >= 10)))
576                 send_count = 0;
577
578         /* Send buffer over bearers until all targets reached */
579         
580         remains = kmalloc(sizeof(struct node_map), GFP_ATOMIC);
581         remains_new = kmalloc(sizeof(struct node_map), GFP_ATOMIC);
582         *remains = tipc_cltr_bcast_nodes;
583
584         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
585                 struct bearer *p = bcbearer->bpairs[bp_index].primary;
586                 struct bearer *s = bcbearer->bpairs[bp_index].secondary;
587
588                 if (!p)
589                         break;  /* no more bearers to try */
590
591                 tipc_nmap_diff(remains, &p->nodes, remains_new);
592                 if (remains_new->count == remains->count)
593                         continue;       /* bearer pair doesn't add anything */
594
595                 if (!p->publ.blocked &&
596                     !p->media->send_msg(buf, &p->publ, &p->media->bcast_addr)) {
597                         if (swap_time && s && !s->publ.blocked)
598                                 goto swap;
599                         else
600                                 goto update;
601                 }
602
603                 if (!s || s->publ.blocked ||
604                     s->media->send_msg(buf, &s->publ, &s->media->bcast_addr))
605                         continue;       /* unable to send using bearer pair */
606 swap:
607                 bcbearer->bpairs[bp_index].primary = s;
608                 bcbearer->bpairs[bp_index].secondary = p;
609 update:
610                 if (remains_new->count == 0) {
611                         err = TIPC_OK;
612                         goto out;
613                 }
614
615                 /* swap map */
616                 remains_tmp = remains;
617                 remains = remains_new;
618                 remains_new = remains_tmp;
619         }
620         
621         /* Unable to reach all targets */
622
623         bcbearer->bearer.publ.blocked = 1;
624         bcl->stats.bearer_congs++;
625         err = ~TIPC_OK;
626
627  out:
628         kfree(remains_new);
629         kfree(remains);
630         return err;
631 }
632
633 /**
634  * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer
635  */
636
637 void tipc_bcbearer_sort(void)
638 {
639         struct bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
640         struct bcbearer_pair *bp_curr;
641         int b_index;
642         int pri;
643
644         spin_lock_bh(&bc_lock);
645
646         /* Group bearers by priority (can assume max of two per priority) */
647
648         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
649
650         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
651                 struct bearer *b = &tipc_bearers[b_index];
652
653                 if (!b->active || !b->nodes.count)
654                         continue;
655
656                 if (!bp_temp[b->priority].primary)
657                         bp_temp[b->priority].primary = b;
658                 else
659                         bp_temp[b->priority].secondary = b;
660         }
661
662         /* Create array of bearer pairs for broadcasting */
663
664         bp_curr = bcbearer->bpairs;
665         memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
666
667         for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) {
668
669                 if (!bp_temp[pri].primary)
670                         continue;
671
672                 bp_curr->primary = bp_temp[pri].primary;
673
674                 if (bp_temp[pri].secondary) {
675                         if (tipc_nmap_equal(&bp_temp[pri].primary->nodes,
676                                             &bp_temp[pri].secondary->nodes)) {
677                                 bp_curr->secondary = bp_temp[pri].secondary;
678                         } else {
679                                 bp_curr++;
680                                 bp_curr->primary = bp_temp[pri].secondary;
681                         }
682                 }
683
684                 bp_curr++;
685         }
686
687         spin_unlock_bh(&bc_lock);
688 }
689
690 /**
691  * tipc_bcbearer_push - resolve bearer congestion
692  * 
693  * Forces bclink to push out any unsent packets, until all packets are gone
694  * or congestion reoccurs.
695  * No locks set when function called
696  */
697
698 void tipc_bcbearer_push(void)
699 {
700         struct bearer *b_ptr;
701
702         spin_lock_bh(&bc_lock);
703         b_ptr = &bcbearer->bearer;
704         if (b_ptr->publ.blocked) {
705                 b_ptr->publ.blocked = 0;
706                 tipc_bearer_lock_push(b_ptr);
707         }
708         spin_unlock_bh(&bc_lock);
709 }
710
711
712 int tipc_bclink_stats(char *buf, const u32 buf_size)
713 {
714         struct print_buf pb;
715
716         if (!bcl)
717                 return 0;
718
719         tipc_printbuf_init(&pb, buf, buf_size);
720
721         spin_lock_bh(&bc_lock);
722
723         tipc_printf(&pb, "Link <%s>\n"
724                          "  Window:%u packets\n", 
725                     bcl->name, bcl->queue_limit[0]);
726         tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n", 
727                     bcl->stats.recv_info,
728                     bcl->stats.recv_fragments,
729                     bcl->stats.recv_fragmented,
730                     bcl->stats.recv_bundles,
731                     bcl->stats.recv_bundled);
732         tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n", 
733                     bcl->stats.sent_info,
734                     bcl->stats.sent_fragments,
735                     bcl->stats.sent_fragmented, 
736                     bcl->stats.sent_bundles,
737                     bcl->stats.sent_bundled);
738         tipc_printf(&pb, "  RX naks:%u defs:%u dups:%u\n", 
739                     bcl->stats.recv_nacks,
740                     bcl->stats.deferred_recv, 
741                     bcl->stats.duplicates);
742         tipc_printf(&pb, "  TX naks:%u acks:%u dups:%u\n", 
743                     bcl->stats.sent_nacks, 
744                     bcl->stats.sent_acks, 
745                     bcl->stats.retransmitted);
746         tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
747                     bcl->stats.bearer_congs,
748                     bcl->stats.link_congs,
749                     bcl->stats.max_queue_sz,
750                     bcl->stats.queue_sz_counts
751                     ? (bcl->stats.accu_queue_sz / bcl->stats.queue_sz_counts)
752                     : 0);
753
754         spin_unlock_bh(&bc_lock);
755         return tipc_printbuf_validate(&pb);
756 }
757
758 int tipc_bclink_reset_stats(void)
759 {
760         if (!bcl)
761                 return -ENOPROTOOPT;
762
763         spin_lock_bh(&bc_lock);
764         memset(&bcl->stats, 0, sizeof(bcl->stats));
765         spin_unlock_bh(&bc_lock);
766         return TIPC_OK;
767 }
768
769 int tipc_bclink_set_queue_limits(u32 limit)
770 {
771         if (!bcl)
772                 return -ENOPROTOOPT;
773         if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
774                 return -EINVAL;
775
776         spin_lock_bh(&bc_lock);
777         tipc_link_set_queue_limits(bcl, limit);
778         spin_unlock_bh(&bc_lock);
779         return TIPC_OK;
780 }
781
782 int tipc_bclink_init(void)
783 {
784         bcbearer = kmalloc(sizeof(*bcbearer), GFP_ATOMIC);
785         bclink = kmalloc(sizeof(*bclink), GFP_ATOMIC);
786         if (!bcbearer || !bclink) {
787  nomem:
788                 warn("Multicast link creation failed, no memory\n");
789                 kfree(bcbearer);
790                 bcbearer = NULL;
791                 kfree(bclink);
792                 bclink = NULL;
793                 return -ENOMEM;
794         }
795
796         memset(bcbearer, 0, sizeof(struct bcbearer));
797         INIT_LIST_HEAD(&bcbearer->bearer.cong_links);
798         bcbearer->bearer.media = &bcbearer->media;
799         bcbearer->media.send_msg = tipc_bcbearer_send;
800         sprintf(bcbearer->media.name, "tipc-multicast");
801
802         bcl = &bclink->link;
803         memset(bclink, 0, sizeof(struct bclink));
804         INIT_LIST_HEAD(&bcl->waiting_ports);
805         bcl->next_out_no = 1;
806         bclink->node.lock =  SPIN_LOCK_UNLOCKED;        
807         bcl->owner = &bclink->node;
808         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
809         tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
810         bcl->b_ptr = &bcbearer->bearer;
811         bcl->state = WORKING_WORKING;
812         sprintf(bcl->name, tipc_bclink_name);
813
814         if (BCLINK_LOG_BUF_SIZE) {
815                 char *pb = kmalloc(BCLINK_LOG_BUF_SIZE, GFP_ATOMIC);
816
817                 if (!pb)
818                         goto nomem;
819                 tipc_printbuf_init(&bcl->print_buf, pb, BCLINK_LOG_BUF_SIZE);
820         }
821
822         return TIPC_OK;
823 }
824
825 void tipc_bclink_stop(void)
826 {
827         spin_lock_bh(&bc_lock);
828         if (bcbearer) {
829                 tipc_link_stop(bcl);
830                 if (BCLINK_LOG_BUF_SIZE)
831                         kfree(bcl->print_buf.buf);
832                 bcl = NULL;
833                 kfree(bclink);
834                 bclink = NULL;
835                 kfree(bcbearer);
836                 bcbearer = NULL;
837         }
838         spin_unlock_bh(&bc_lock);
839 }
840