Merge branch 'upstream'
[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_MAX_LINK_PRI + 1];
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 tipc_bclink_name[] = "multicast-link";
108
109
110 static u32 buf_seqno(struct sk_buff *buf)
111 {
112         return msg_seqno(buf_msg(buf));
113
114
115 static u32 bcbuf_acks(struct sk_buff *buf)
116 {
117         return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
118 }
119
120 static 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 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 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 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                 tipc_link_retransmit(bcl, buf, mod(to - after));
182         spin_unlock_bh(&bc_lock);              
183 }
184
185 /** 
186  * tipc_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 tipc_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                 tipc_link_push_queue(bcl);
230         if (unlikely(released && !list_empty(&bcl->waiting_ports)))
231                 tipc_link_wakeup_ports(bcl, 0);
232         spin_unlock_bh(&bc_lock);
233 }
234
235 /** 
236  * bclink_send_ack - unicast an ACK msg
237  * 
238  * tipc_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                 tipc_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  * tipc_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 (tipc_bearer_send(&bcbearer->bearer, buf, NULL)) {
275                         bcl->stats.sent_nacks++;
276                         buf_discard(buf);
277                 } else {
278                         tipc_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  * tipc_bclink_check_gap - send a NACK if a sequence gap exists
295  *
296  * tipc_net_lock and node lock set
297  */
298
299 void tipc_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  * tipc_bclink_peek_nack - process a NACK msg meant for another node
313  * 
314  * Only tipc_net_lock set.
315  */
316
317 static void tipc_bclink_peek_nack(u32 dest, u32 sender_tag, u32 gap_after, u32 gap_to)
318 {
319         struct node *n_ptr = tipc_node_find(dest);
320         u32 my_after, my_to;
321
322         if (unlikely(!n_ptr || !tipc_node_is_up(n_ptr)))
323                 return;
324         tipc_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         tipc_node_unlock(n_ptr);
368 }
369
370 /**
371  * tipc_bclink_send_msg - broadcast a packet to all nodes in cluster
372  */
373
374 int tipc_bclink_send_msg(struct sk_buff *buf)
375 {
376         int res;
377
378         spin_lock_bh(&bc_lock);
379
380         res = tipc_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  * tipc_bclink_recv_pkt - receive a broadcast packet, and deliver upwards
397  * 
398  * tipc_net_lock is read_locked, no other locks set
399  */
400
401 void tipc_bclink_recv_pkt(struct sk_buff *buf)
402 {        
403         struct tipc_msg *msg = buf_msg(buf);
404         struct node* node = tipc_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 || !tipc_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                         tipc_node_lock(node);
421                         tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
422                         tipc_node_unlock(node);
423                         bcl->stats.recv_nacks++;
424                         bclink_retransmit_pkt(msg_bcgap_after(msg),
425                                               msg_bcgap_to(msg));
426                 } else {
427                         tipc_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         tipc_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                         tipc_node_unlock(node);
452                         tipc_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                         tipc_node_unlock(node);
457                         tipc_link_recv_bundle(buf);
458                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
459                         bcl->stats.recv_fragments++;
460                         if (tipc_link_recv_fragment(&node->bclink.defragm,
461                                                     &buf, &msg))
462                                 bcl->stats.recv_fragmented++;
463                         tipc_node_unlock(node);
464                         tipc_net_route_msg(buf);
465                 } else {
466                         tipc_node_unlock(node);
467                         tipc_net_route_msg(buf);
468                 }
469                 if (deferred && (buf_seqno(deferred) == mod(next_in + 1))) {
470                         tipc_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 (tipc_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         tipc_node_unlock(node);
501 }
502
503 u32 tipc_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 tipc_bclink_acks_missing(struct node *n_ptr)
513 {
514         return (n_ptr->bclink.supported &&
515                 (tipc_bclink_get_last_sent() != n_ptr->bclink.acked));
516 }
517
518
519 /**
520  * tipc_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 static int tipc_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         struct node_map *remains_tmp;
537         int bp_index;
538         int swap_time;
539         int err;
540
541         /* Prepare buffer for broadcasting (if first time trying to send it) */
542
543         if (likely(!msg_non_seq(buf_msg(buf)))) {
544                 struct tipc_msg *msg;
545
546                 assert(tipc_cltr_bcast_nodes.count != 0);
547                 bcbuf_set_acks(buf, tipc_cltr_bcast_nodes.count);
548                 msg = buf_msg(buf);
549                 msg_set_non_seq(msg);
550                 msg_set_mc_netid(msg, tipc_net_id);
551         }
552
553         /* Determine if bearer pairs should be swapped following this attempt */
554
555         if ((swap_time = (++send_count >= 10)))
556                 send_count = 0;
557
558         /* Send buffer over bearers until all targets reached */
559         
560         remains = kmalloc(sizeof(struct node_map), GFP_ATOMIC);
561         remains_new = kmalloc(sizeof(struct node_map), GFP_ATOMIC);
562         *remains = tipc_cltr_bcast_nodes;
563
564         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
565                 struct bearer *p = bcbearer->bpairs[bp_index].primary;
566                 struct bearer *s = bcbearer->bpairs[bp_index].secondary;
567
568                 if (!p)
569                         break;  /* no more bearers to try */
570
571                 tipc_nmap_diff(remains, &p->nodes, remains_new);
572                 if (remains_new->count == remains->count)
573                         continue;       /* bearer pair doesn't add anything */
574
575                 if (!p->publ.blocked &&
576                     !p->media->send_msg(buf, &p->publ, &p->media->bcast_addr)) {
577                         if (swap_time && s && !s->publ.blocked)
578                                 goto swap;
579                         else
580                                 goto update;
581                 }
582
583                 if (!s || s->publ.blocked ||
584                     s->media->send_msg(buf, &s->publ, &s->media->bcast_addr))
585                         continue;       /* unable to send using bearer pair */
586 swap:
587                 bcbearer->bpairs[bp_index].primary = s;
588                 bcbearer->bpairs[bp_index].secondary = p;
589 update:
590                 if (remains_new->count == 0) {
591                         err = TIPC_OK;
592                         goto out;
593                 }
594
595                 /* swap map */
596                 remains_tmp = remains;
597                 remains = remains_new;
598                 remains_new = remains_tmp;
599         }
600         
601         /* Unable to reach all targets */
602
603         bcbearer->bearer.publ.blocked = 1;
604         bcl->stats.bearer_congs++;
605         err = ~TIPC_OK;
606
607  out:
608         kfree(remains_new);
609         kfree(remains);
610         return err;
611 }
612
613 /**
614  * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer
615  */
616
617 void tipc_bcbearer_sort(void)
618 {
619         struct bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
620         struct bcbearer_pair *bp_curr;
621         int b_index;
622         int pri;
623
624         spin_lock_bh(&bc_lock);
625
626         /* Group bearers by priority (can assume max of two per priority) */
627
628         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
629
630         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
631                 struct bearer *b = &tipc_bearers[b_index];
632
633                 if (!b->active || !b->nodes.count)
634                         continue;
635
636                 if (!bp_temp[b->priority].primary)
637                         bp_temp[b->priority].primary = b;
638                 else
639                         bp_temp[b->priority].secondary = b;
640         }
641
642         /* Create array of bearer pairs for broadcasting */
643
644         bp_curr = bcbearer->bpairs;
645         memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
646
647         for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) {
648
649                 if (!bp_temp[pri].primary)
650                         continue;
651
652                 bp_curr->primary = bp_temp[pri].primary;
653
654                 if (bp_temp[pri].secondary) {
655                         if (tipc_nmap_equal(&bp_temp[pri].primary->nodes,
656                                             &bp_temp[pri].secondary->nodes)) {
657                                 bp_curr->secondary = bp_temp[pri].secondary;
658                         } else {
659                                 bp_curr++;
660                                 bp_curr->primary = bp_temp[pri].secondary;
661                         }
662                 }
663
664                 bp_curr++;
665         }
666
667         spin_unlock_bh(&bc_lock);
668 }
669
670 /**
671  * tipc_bcbearer_push - resolve bearer congestion
672  * 
673  * Forces bclink to push out any unsent packets, until all packets are gone
674  * or congestion reoccurs.
675  * No locks set when function called
676  */
677
678 void tipc_bcbearer_push(void)
679 {
680         struct bearer *b_ptr;
681
682         spin_lock_bh(&bc_lock);
683         b_ptr = &bcbearer->bearer;
684         if (b_ptr->publ.blocked) {
685                 b_ptr->publ.blocked = 0;
686                 tipc_bearer_lock_push(b_ptr);
687         }
688         spin_unlock_bh(&bc_lock);
689 }
690
691
692 int tipc_bclink_stats(char *buf, const u32 buf_size)
693 {
694         struct print_buf pb;
695
696         if (!bcl)
697                 return 0;
698
699         tipc_printbuf_init(&pb, buf, buf_size);
700
701         spin_lock_bh(&bc_lock);
702
703         tipc_printf(&pb, "Link <%s>\n"
704                          "  Window:%u packets\n", 
705                     bcl->name, bcl->queue_limit[0]);
706         tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n", 
707                     bcl->stats.recv_info,
708                     bcl->stats.recv_fragments,
709                     bcl->stats.recv_fragmented,
710                     bcl->stats.recv_bundles,
711                     bcl->stats.recv_bundled);
712         tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n", 
713                     bcl->stats.sent_info,
714                     bcl->stats.sent_fragments,
715                     bcl->stats.sent_fragmented, 
716                     bcl->stats.sent_bundles,
717                     bcl->stats.sent_bundled);
718         tipc_printf(&pb, "  RX naks:%u defs:%u dups:%u\n", 
719                     bcl->stats.recv_nacks,
720                     bcl->stats.deferred_recv, 
721                     bcl->stats.duplicates);
722         tipc_printf(&pb, "  TX naks:%u acks:%u dups:%u\n", 
723                     bcl->stats.sent_nacks, 
724                     bcl->stats.sent_acks, 
725                     bcl->stats.retransmitted);
726         tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
727                     bcl->stats.bearer_congs,
728                     bcl->stats.link_congs,
729                     bcl->stats.max_queue_sz,
730                     bcl->stats.queue_sz_counts
731                     ? (bcl->stats.accu_queue_sz / bcl->stats.queue_sz_counts)
732                     : 0);
733
734         spin_unlock_bh(&bc_lock);
735         return tipc_printbuf_validate(&pb);
736 }
737
738 int tipc_bclink_reset_stats(void)
739 {
740         if (!bcl)
741                 return -ENOPROTOOPT;
742
743         spin_lock_bh(&bc_lock);
744         memset(&bcl->stats, 0, sizeof(bcl->stats));
745         spin_unlock_bh(&bc_lock);
746         return TIPC_OK;
747 }
748
749 int tipc_bclink_set_queue_limits(u32 limit)
750 {
751         if (!bcl)
752                 return -ENOPROTOOPT;
753         if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
754                 return -EINVAL;
755
756         spin_lock_bh(&bc_lock);
757         tipc_link_set_queue_limits(bcl, limit);
758         spin_unlock_bh(&bc_lock);
759         return TIPC_OK;
760 }
761
762 int tipc_bclink_init(void)
763 {
764         bcbearer = kmalloc(sizeof(*bcbearer), GFP_ATOMIC);
765         bclink = kmalloc(sizeof(*bclink), GFP_ATOMIC);
766         if (!bcbearer || !bclink) {
767  nomem:
768                 warn("Memory squeeze; Failed to create multicast link\n");
769                 kfree(bcbearer);
770                 bcbearer = NULL;
771                 kfree(bclink);
772                 bclink = NULL;
773                 return -ENOMEM;
774         }
775
776         memset(bcbearer, 0, sizeof(struct bcbearer));
777         INIT_LIST_HEAD(&bcbearer->bearer.cong_links);
778         bcbearer->bearer.media = &bcbearer->media;
779         bcbearer->media.send_msg = tipc_bcbearer_send;
780         sprintf(bcbearer->media.name, "tipc-multicast");
781
782         bcl = &bclink->link;
783         memset(bclink, 0, sizeof(struct bclink));
784         INIT_LIST_HEAD(&bcl->waiting_ports);
785         bcl->next_out_no = 1;
786         bclink->node.lock =  SPIN_LOCK_UNLOCKED;        
787         bcl->owner = &bclink->node;
788         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
789         tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
790         bcl->b_ptr = &bcbearer->bearer;
791         bcl->state = WORKING_WORKING;
792         sprintf(bcl->name, tipc_bclink_name);
793
794         if (BCLINK_LOG_BUF_SIZE) {
795                 char *pb = kmalloc(BCLINK_LOG_BUF_SIZE, GFP_ATOMIC);
796
797                 if (!pb)
798                         goto nomem;
799                 tipc_printbuf_init(&bcl->print_buf, pb, BCLINK_LOG_BUF_SIZE);
800         }
801
802         return TIPC_OK;
803 }
804
805 void tipc_bclink_stop(void)
806 {
807         spin_lock_bh(&bc_lock);
808         if (bcbearer) {
809                 tipc_link_stop(bcl);
810                 if (BCLINK_LOG_BUF_SIZE)
811                         kfree(bcl->print_buf.buf);
812                 bcl = NULL;
813                 kfree(bclink);
814                 bclink = NULL;
815                 kfree(bcbearer);
816                 bcbearer = NULL;
817         }
818         spin_unlock_bh(&bc_lock);
819 }
820