tipc: Eliminate dynamic allocation of broadcast link data structures
[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 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 bcbearer_pair {
58         struct tipc_bearer *primary;
59         struct tipc_bearer *secondary;
60 };
61
62 /**
63  * struct 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 bcbearer {
78         struct tipc_bearer bearer;
79         struct media media;
80         struct bcbearer_pair bpairs[MAX_BEARERS];
81         struct 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 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  * @retransmit_to: node that most recently requested a retransmit
91  *
92  * Handles sequence numbering, fragmentation, bundling, etc.
93  */
94
95 struct bclink {
96         struct link link;
97         struct tipc_node node;
98         struct tipc_node *retransmit_to;
99 };
100
101 static struct bcbearer bcast_bearer;
102 static struct bclink bcast_link;
103
104 static struct bcbearer *bcbearer = &bcast_bearer;
105 static struct bclink *bclink = &bcast_link;
106 static struct link *bcl = &bcast_link.link;
107
108 static DEFINE_SPINLOCK(bc_lock);
109
110 /* broadcast-capable node map */
111 struct tipc_node_map tipc_bcast_nmap;
112
113 const char tipc_bclink_name[] = "broadcast-link";
114
115 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
116                            struct tipc_node_map *nm_b,
117                            struct tipc_node_map *nm_diff);
118
119 static u32 buf_seqno(struct sk_buff *buf)
120 {
121         return msg_seqno(buf_msg(buf));
122 }
123
124 static u32 bcbuf_acks(struct sk_buff *buf)
125 {
126         return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
127 }
128
129 static void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
130 {
131         TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks;
132 }
133
134 static void bcbuf_decr_acks(struct sk_buff *buf)
135 {
136         bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
137 }
138
139
140 static void bclink_set_last_sent(void)
141 {
142         if (bcl->next_out)
143                 bcl->fsm_msg_cnt = mod(buf_seqno(bcl->next_out) - 1);
144         else
145                 bcl->fsm_msg_cnt = mod(bcl->next_out_no - 1);
146 }
147
148 u32 tipc_bclink_get_last_sent(void)
149 {
150         return bcl->fsm_msg_cnt;
151 }
152
153 /**
154  * bclink_set_gap - set gap according to contents of current deferred pkt queue
155  *
156  * Called with 'node' locked, bc_lock unlocked
157  */
158
159 static void bclink_set_gap(struct tipc_node *n_ptr)
160 {
161         struct sk_buff *buf = n_ptr->bclink.deferred_head;
162
163         n_ptr->bclink.gap_after = n_ptr->bclink.gap_to =
164                 mod(n_ptr->bclink.last_in);
165         if (unlikely(buf != NULL))
166                 n_ptr->bclink.gap_to = mod(buf_seqno(buf) - 1);
167 }
168
169 /**
170  * bclink_ack_allowed - test if ACK or NACK message can be sent at this moment
171  *
172  * This mechanism endeavours to prevent all nodes in network from trying
173  * to ACK or NACK at the same time.
174  *
175  * Note: TIPC uses a different trigger to distribute ACKs than it does to
176  *       distribute NACKs, but tries to use the same spacing (divide by 16).
177  */
178
179 static int bclink_ack_allowed(u32 n)
180 {
181         return (n % TIPC_MIN_LINK_WIN) == tipc_own_tag;
182 }
183
184
185 /**
186  * tipc_bclink_retransmit_to - get most recent node to request retransmission
187  *
188  * Called with bc_lock locked
189  */
190
191 struct tipc_node *tipc_bclink_retransmit_to(void)
192 {
193         return bclink->retransmit_to;
194 }
195
196 /**
197  * bclink_retransmit_pkt - retransmit broadcast packets
198  * @after: sequence number of last packet to *not* retransmit
199  * @to: sequence number of last packet to retransmit
200  *
201  * Called with bc_lock locked
202  */
203
204 static void bclink_retransmit_pkt(u32 after, u32 to)
205 {
206         struct sk_buff *buf;
207
208         buf = bcl->first_out;
209         while (buf && less_eq(buf_seqno(buf), after))
210                 buf = buf->next;
211         tipc_link_retransmit(bcl, buf, mod(to - after));
212 }
213
214 /**
215  * tipc_bclink_acknowledge - handle acknowledgement of broadcast packets
216  * @n_ptr: node that sent acknowledgement info
217  * @acked: broadcast sequence # that has been acknowledged
218  *
219  * Node is locked, bc_lock unlocked.
220  */
221
222 void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
223 {
224         struct sk_buff *crs;
225         struct sk_buff *next;
226         unsigned int released = 0;
227
228         if (less_eq(acked, n_ptr->bclink.acked))
229                 return;
230
231         spin_lock_bh(&bc_lock);
232
233         /* Skip over packets that node has previously acknowledged */
234
235         crs = bcl->first_out;
236         while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked))
237                 crs = crs->next;
238
239         /* Update packets that node is now acknowledging */
240
241         while (crs && less_eq(buf_seqno(crs), acked)) {
242                 next = crs->next;
243                 bcbuf_decr_acks(crs);
244                 if (bcbuf_acks(crs) == 0) {
245                         bcl->first_out = next;
246                         bcl->out_queue_size--;
247                         buf_discard(crs);
248                         released = 1;
249                 }
250                 crs = next;
251         }
252         n_ptr->bclink.acked = acked;
253
254         /* Try resolving broadcast link congestion, if necessary */
255
256         if (unlikely(bcl->next_out)) {
257                 tipc_link_push_queue(bcl);
258                 bclink_set_last_sent();
259         }
260         if (unlikely(released && !list_empty(&bcl->waiting_ports)))
261                 tipc_link_wakeup_ports(bcl, 0);
262         spin_unlock_bh(&bc_lock);
263 }
264
265 /**
266  * bclink_send_ack - unicast an ACK msg
267  *
268  * tipc_net_lock and node lock set
269  */
270
271 static void bclink_send_ack(struct tipc_node *n_ptr)
272 {
273         struct link *l_ptr = n_ptr->active_links[n_ptr->addr & 1];
274
275         if (l_ptr != NULL)
276                 tipc_link_send_proto_msg(l_ptr, STATE_MSG, 0, 0, 0, 0, 0);
277 }
278
279 /**
280  * bclink_send_nack- broadcast a NACK msg
281  *
282  * tipc_net_lock and node lock set
283  */
284
285 static void bclink_send_nack(struct tipc_node *n_ptr)
286 {
287         struct sk_buff *buf;
288         struct tipc_msg *msg;
289
290         if (!less(n_ptr->bclink.gap_after, n_ptr->bclink.gap_to))
291                 return;
292
293         buf = tipc_buf_acquire(INT_H_SIZE);
294         if (buf) {
295                 msg = buf_msg(buf);
296                 tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
297                          INT_H_SIZE, n_ptr->addr);
298                 msg_set_non_seq(msg, 1);
299                 msg_set_mc_netid(msg, tipc_net_id);
300                 msg_set_bcast_ack(msg, mod(n_ptr->bclink.last_in));
301                 msg_set_bcgap_after(msg, n_ptr->bclink.gap_after);
302                 msg_set_bcgap_to(msg, n_ptr->bclink.gap_to);
303                 msg_set_bcast_tag(msg, tipc_own_tag);
304
305                 tipc_bearer_send(&bcbearer->bearer, buf, NULL);
306                 bcl->stats.sent_nacks++;
307                 buf_discard(buf);
308
309                 /*
310                  * Ensure we doesn't send another NACK msg to the node
311                  * until 16 more deferred messages arrive from it
312                  * (i.e. helps prevent all nodes from NACK'ing at same time)
313                  */
314
315                 n_ptr->bclink.nack_sync = tipc_own_tag;
316         }
317 }
318
319 /**
320  * tipc_bclink_check_gap - send a NACK if a sequence gap exists
321  *
322  * tipc_net_lock and node lock set
323  */
324
325 void tipc_bclink_check_gap(struct tipc_node *n_ptr, u32 last_sent)
326 {
327         if (!n_ptr->bclink.supported ||
328             less_eq(last_sent, mod(n_ptr->bclink.last_in)))
329                 return;
330
331         bclink_set_gap(n_ptr);
332         if (n_ptr->bclink.gap_after == n_ptr->bclink.gap_to)
333                 n_ptr->bclink.gap_to = last_sent;
334         bclink_send_nack(n_ptr);
335 }
336
337 /**
338  * tipc_bclink_peek_nack - process a NACK msg meant for another node
339  *
340  * Only tipc_net_lock set.
341  */
342
343 static void tipc_bclink_peek_nack(u32 dest, u32 sender_tag, u32 gap_after, u32 gap_to)
344 {
345         struct tipc_node *n_ptr = tipc_node_find(dest);
346         u32 my_after, my_to;
347
348         if (unlikely(!n_ptr || !tipc_node_is_up(n_ptr)))
349                 return;
350         tipc_node_lock(n_ptr);
351         /*
352          * Modify gap to suppress unnecessary NACKs from this node
353          */
354         my_after = n_ptr->bclink.gap_after;
355         my_to = n_ptr->bclink.gap_to;
356
357         if (less_eq(gap_after, my_after)) {
358                 if (less(my_after, gap_to) && less(gap_to, my_to))
359                         n_ptr->bclink.gap_after = gap_to;
360                 else if (less_eq(my_to, gap_to))
361                         n_ptr->bclink.gap_to = n_ptr->bclink.gap_after;
362         } else if (less_eq(gap_after, my_to)) {
363                 if (less_eq(my_to, gap_to))
364                         n_ptr->bclink.gap_to = gap_after;
365         } else {
366                 /*
367                  * Expand gap if missing bufs not in deferred queue:
368                  */
369                 struct sk_buff *buf = n_ptr->bclink.deferred_head;
370                 u32 prev = n_ptr->bclink.gap_to;
371
372                 for (; buf; buf = buf->next) {
373                         u32 seqno = buf_seqno(buf);
374
375                         if (mod(seqno - prev) != 1) {
376                                 buf = NULL;
377                                 break;
378                         }
379                         if (seqno == gap_after)
380                                 break;
381                         prev = seqno;
382                 }
383                 if (buf == NULL)
384                         n_ptr->bclink.gap_to = gap_after;
385         }
386         /*
387          * Some nodes may send a complementary NACK now:
388          */
389         if (bclink_ack_allowed(sender_tag + 1)) {
390                 if (n_ptr->bclink.gap_to != n_ptr->bclink.gap_after) {
391                         bclink_send_nack(n_ptr);
392                         bclink_set_gap(n_ptr);
393                 }
394         }
395         tipc_node_unlock(n_ptr);
396 }
397
398 /**
399  * tipc_bclink_send_msg - broadcast a packet to all nodes in cluster
400  */
401
402 int tipc_bclink_send_msg(struct sk_buff *buf)
403 {
404         int res;
405
406         spin_lock_bh(&bc_lock);
407
408         res = tipc_link_send_buf(bcl, buf);
409         if (likely(res > 0))
410                 bclink_set_last_sent();
411
412         bcl->stats.queue_sz_counts++;
413         bcl->stats.accu_queue_sz += bcl->out_queue_size;
414
415         spin_unlock_bh(&bc_lock);
416         return res;
417 }
418
419 /**
420  * tipc_bclink_recv_pkt - receive a broadcast packet, and deliver upwards
421  *
422  * tipc_net_lock is read_locked, no other locks set
423  */
424
425 void tipc_bclink_recv_pkt(struct sk_buff *buf)
426 {
427         struct tipc_msg *msg = buf_msg(buf);
428         struct tipc_node *node;
429         u32 next_in;
430         u32 seqno;
431         struct sk_buff *deferred;
432
433         /* Screen out unwanted broadcast messages */
434
435         if (msg_mc_netid(msg) != tipc_net_id)
436                 goto exit;
437
438         node = tipc_node_find(msg_prevnode(msg));
439         if (unlikely(!node))
440                 goto exit;
441
442         tipc_node_lock(node);
443         if (unlikely(!node->bclink.supported))
444                 goto unlock;
445
446         if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
447                 if (msg_type(msg) != STATE_MSG)
448                         goto unlock;
449                 if (msg_destnode(msg) == tipc_own_addr) {
450                         tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
451                         tipc_node_unlock(node);
452                         spin_lock_bh(&bc_lock);
453                         bcl->stats.recv_nacks++;
454                         bclink->retransmit_to = node;
455                         bclink_retransmit_pkt(msg_bcgap_after(msg),
456                                               msg_bcgap_to(msg));
457                         spin_unlock_bh(&bc_lock);
458                 } else {
459                         tipc_node_unlock(node);
460                         tipc_bclink_peek_nack(msg_destnode(msg),
461                                               msg_bcast_tag(msg),
462                                               msg_bcgap_after(msg),
463                                               msg_bcgap_to(msg));
464                 }
465                 goto exit;
466         }
467
468         /* Handle in-sequence broadcast message */
469
470 receive:
471         next_in = mod(node->bclink.last_in + 1);
472         seqno = msg_seqno(msg);
473
474         if (likely(seqno == next_in)) {
475                 bcl->stats.recv_info++;
476                 node->bclink.last_in++;
477                 bclink_set_gap(node);
478                 if (unlikely(bclink_ack_allowed(seqno))) {
479                         bclink_send_ack(node);
480                         bcl->stats.sent_acks++;
481                 }
482                 if (likely(msg_isdata(msg))) {
483                         tipc_node_unlock(node);
484                         if (likely(msg_mcast(msg)))
485                                 tipc_port_recv_mcast(buf, NULL);
486                         else
487                                 buf_discard(buf);
488                 } else if (msg_user(msg) == MSG_BUNDLER) {
489                         bcl->stats.recv_bundles++;
490                         bcl->stats.recv_bundled += msg_msgcnt(msg);
491                         tipc_node_unlock(node);
492                         tipc_link_recv_bundle(buf);
493                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
494                         bcl->stats.recv_fragments++;
495                         if (tipc_link_recv_fragment(&node->bclink.defragm,
496                                                     &buf, &msg))
497                                 bcl->stats.recv_fragmented++;
498                         tipc_node_unlock(node);
499                         tipc_net_route_msg(buf);
500                 } else if (msg_user(msg) == NAME_DISTRIBUTOR) {
501                         tipc_node_unlock(node);
502                         tipc_named_recv(buf);
503                 } else {
504                         tipc_node_unlock(node);
505                         buf_discard(buf);
506                 }
507                 buf = NULL;
508                 tipc_node_lock(node);
509                 deferred = node->bclink.deferred_head;
510                 if (deferred && (buf_seqno(deferred) == mod(next_in + 1))) {
511                         buf = deferred;
512                         msg = buf_msg(buf);
513                         node->bclink.deferred_head = deferred->next;
514                         goto receive;
515                 }
516         } else if (less(next_in, seqno)) {
517                 u32 gap_after = node->bclink.gap_after;
518                 u32 gap_to = node->bclink.gap_to;
519
520                 if (tipc_link_defer_pkt(&node->bclink.deferred_head,
521                                         &node->bclink.deferred_tail,
522                                         buf)) {
523                         node->bclink.nack_sync++;
524                         bcl->stats.deferred_recv++;
525                         if (seqno == mod(gap_after + 1))
526                                 node->bclink.gap_after = seqno;
527                         else if (less(gap_after, seqno) && less(seqno, gap_to))
528                                 node->bclink.gap_to = seqno;
529                 }
530                 buf = NULL;
531                 if (bclink_ack_allowed(node->bclink.nack_sync)) {
532                         if (gap_to != gap_after)
533                                 bclink_send_nack(node);
534                         bclink_set_gap(node);
535                 }
536         } else {
537                 bcl->stats.duplicates++;
538         }
539 unlock:
540         tipc_node_unlock(node);
541 exit:
542         buf_discard(buf);
543 }
544
545 u32 tipc_bclink_acks_missing(struct tipc_node *n_ptr)
546 {
547         return (n_ptr->bclink.supported &&
548                 (tipc_bclink_get_last_sent() != n_ptr->bclink.acked));
549 }
550
551
552 /**
553  * tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer
554  *
555  * Send packet over as many bearers as necessary to reach all nodes
556  * that have joined the broadcast link.
557  *
558  * Returns 0 (packet sent successfully) under all circumstances,
559  * since the broadcast link's pseudo-bearer never blocks
560  */
561
562 static int tipc_bcbearer_send(struct sk_buff *buf,
563                               struct tipc_bearer *unused1,
564                               struct tipc_media_addr *unused2)
565 {
566         int bp_index;
567
568         /*
569          * Prepare broadcast link message for reliable transmission,
570          * if first time trying to send it;
571          * preparation is skipped for broadcast link protocol messages
572          * since they are sent in an unreliable manner and don't need it
573          */
574
575         if (likely(!msg_non_seq(buf_msg(buf)))) {
576                 struct tipc_msg *msg;
577
578                 bcbuf_set_acks(buf, tipc_bcast_nmap.count);
579                 msg = buf_msg(buf);
580                 msg_set_non_seq(msg, 1);
581                 msg_set_mc_netid(msg, tipc_net_id);
582                 bcl->stats.sent_info++;
583
584                 if (WARN_ON(!tipc_bcast_nmap.count)) {
585                         dump_stack();
586                         return 0;
587                 }
588         }
589
590         /* Send buffer over bearers until all targets reached */
591
592         bcbearer->remains = tipc_bcast_nmap;
593
594         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
595                 struct tipc_bearer *p = bcbearer->bpairs[bp_index].primary;
596                 struct tipc_bearer *s = bcbearer->bpairs[bp_index].secondary;
597
598                 if (!p)
599                         break;  /* no more bearers to try */
600
601                 tipc_nmap_diff(&bcbearer->remains, &p->nodes, &bcbearer->remains_new);
602                 if (bcbearer->remains_new.count == bcbearer->remains.count)
603                         continue;       /* bearer pair doesn't add anything */
604
605                 if (p->blocked ||
606                     p->media->send_msg(buf, p, &p->media->bcast_addr)) {
607                         /* unable to send on primary bearer */
608                         if (!s || s->blocked ||
609                             s->media->send_msg(buf, s,
610                                                &s->media->bcast_addr)) {
611                                 /* unable to send on either bearer */
612                                 continue;
613                         }
614                 }
615
616                 if (s) {
617                         bcbearer->bpairs[bp_index].primary = s;
618                         bcbearer->bpairs[bp_index].secondary = p;
619                 }
620
621                 if (bcbearer->remains_new.count == 0)
622                         break;  /* all targets reached */
623
624                 bcbearer->remains = bcbearer->remains_new;
625         }
626
627         return 0;
628 }
629
630 /**
631  * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer
632  */
633
634 void tipc_bcbearer_sort(void)
635 {
636         struct bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
637         struct bcbearer_pair *bp_curr;
638         int b_index;
639         int pri;
640
641         spin_lock_bh(&bc_lock);
642
643         /* Group bearers by priority (can assume max of two per priority) */
644
645         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
646
647         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
648                 struct tipc_bearer *b = &tipc_bearers[b_index];
649
650                 if (!b->active || !b->nodes.count)
651                         continue;
652
653                 if (!bp_temp[b->priority].primary)
654                         bp_temp[b->priority].primary = b;
655                 else
656                         bp_temp[b->priority].secondary = b;
657         }
658
659         /* Create array of bearer pairs for broadcasting */
660
661         bp_curr = bcbearer->bpairs;
662         memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
663
664         for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) {
665
666                 if (!bp_temp[pri].primary)
667                         continue;
668
669                 bp_curr->primary = bp_temp[pri].primary;
670
671                 if (bp_temp[pri].secondary) {
672                         if (tipc_nmap_equal(&bp_temp[pri].primary->nodes,
673                                             &bp_temp[pri].secondary->nodes)) {
674                                 bp_curr->secondary = bp_temp[pri].secondary;
675                         } else {
676                                 bp_curr++;
677                                 bp_curr->primary = bp_temp[pri].secondary;
678                         }
679                 }
680
681                 bp_curr++;
682         }
683
684         spin_unlock_bh(&bc_lock);
685 }
686
687
688 int tipc_bclink_stats(char *buf, const u32 buf_size)
689 {
690         struct print_buf pb;
691
692         if (!bcl)
693                 return 0;
694
695         tipc_printbuf_init(&pb, buf, buf_size);
696
697         spin_lock_bh(&bc_lock);
698
699         tipc_printf(&pb, "Link <%s>\n"
700                          "  Window:%u packets\n",
701                     bcl->name, bcl->queue_limit[0]);
702         tipc_printf(&pb, "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
703                     bcl->stats.recv_info,
704                     bcl->stats.recv_fragments,
705                     bcl->stats.recv_fragmented,
706                     bcl->stats.recv_bundles,
707                     bcl->stats.recv_bundled);
708         tipc_printf(&pb, "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
709                     bcl->stats.sent_info,
710                     bcl->stats.sent_fragments,
711                     bcl->stats.sent_fragmented,
712                     bcl->stats.sent_bundles,
713                     bcl->stats.sent_bundled);
714         tipc_printf(&pb, "  RX naks:%u defs:%u dups:%u\n",
715                     bcl->stats.recv_nacks,
716                     bcl->stats.deferred_recv,
717                     bcl->stats.duplicates);
718         tipc_printf(&pb, "  TX naks:%u acks:%u dups:%u\n",
719                     bcl->stats.sent_nacks,
720                     bcl->stats.sent_acks,
721                     bcl->stats.retransmitted);
722         tipc_printf(&pb, "  Congestion bearer:%u link:%u  Send queue max:%u avg:%u\n",
723                     bcl->stats.bearer_congs,
724                     bcl->stats.link_congs,
725                     bcl->stats.max_queue_sz,
726                     bcl->stats.queue_sz_counts
727                     ? (bcl->stats.accu_queue_sz / bcl->stats.queue_sz_counts)
728                     : 0);
729
730         spin_unlock_bh(&bc_lock);
731         return tipc_printbuf_validate(&pb);
732 }
733
734 int tipc_bclink_reset_stats(void)
735 {
736         if (!bcl)
737                 return -ENOPROTOOPT;
738
739         spin_lock_bh(&bc_lock);
740         memset(&bcl->stats, 0, sizeof(bcl->stats));
741         spin_unlock_bh(&bc_lock);
742         return 0;
743 }
744
745 int tipc_bclink_set_queue_limits(u32 limit)
746 {
747         if (!bcl)
748                 return -ENOPROTOOPT;
749         if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
750                 return -EINVAL;
751
752         spin_lock_bh(&bc_lock);
753         tipc_link_set_queue_limits(bcl, limit);
754         spin_unlock_bh(&bc_lock);
755         return 0;
756 }
757
758 void tipc_bclink_init(void)
759 {
760         INIT_LIST_HEAD(&bcbearer->bearer.cong_links);
761         bcbearer->bearer.media = &bcbearer->media;
762         bcbearer->media.send_msg = tipc_bcbearer_send;
763         sprintf(bcbearer->media.name, "tipc-broadcast");
764
765         INIT_LIST_HEAD(&bcl->waiting_ports);
766         bcl->next_out_no = 1;
767         spin_lock_init(&bclink->node.lock);
768         bcl->owner = &bclink->node;
769         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
770         tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
771         bcl->b_ptr = &bcbearer->bearer;
772         bcl->state = WORKING_WORKING;
773         strlcpy(bcl->name, tipc_bclink_name, TIPC_MAX_LINK_NAME);
774 }
775
776 void tipc_bclink_stop(void)
777 {
778         spin_lock_bh(&bc_lock);
779         tipc_link_stop(bcl);
780         spin_unlock_bh(&bc_lock);
781
782         memset(bclink, 0, sizeof(*bclink));
783         memset(bcbearer, 0, sizeof(*bcbearer));
784 }
785
786
787 /**
788  * tipc_nmap_add - add a node to a node map
789  */
790
791 void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node)
792 {
793         int n = tipc_node(node);
794         int w = n / WSIZE;
795         u32 mask = (1 << (n % WSIZE));
796
797         if ((nm_ptr->map[w] & mask) == 0) {
798                 nm_ptr->count++;
799                 nm_ptr->map[w] |= mask;
800         }
801 }
802
803 /**
804  * tipc_nmap_remove - remove a node from a node map
805  */
806
807 void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node)
808 {
809         int n = tipc_node(node);
810         int w = n / WSIZE;
811         u32 mask = (1 << (n % WSIZE));
812
813         if ((nm_ptr->map[w] & mask) != 0) {
814                 nm_ptr->map[w] &= ~mask;
815                 nm_ptr->count--;
816         }
817 }
818
819 /**
820  * tipc_nmap_diff - find differences between node maps
821  * @nm_a: input node map A
822  * @nm_b: input node map B
823  * @nm_diff: output node map A-B (i.e. nodes of A that are not in B)
824  */
825
826 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
827                            struct tipc_node_map *nm_b,
828                            struct tipc_node_map *nm_diff)
829 {
830         int stop = ARRAY_SIZE(nm_a->map);
831         int w;
832         int b;
833         u32 map;
834
835         memset(nm_diff, 0, sizeof(*nm_diff));
836         for (w = 0; w < stop; w++) {
837                 map = nm_a->map[w] ^ (nm_a->map[w] & nm_b->map[w]);
838                 nm_diff->map[w] = map;
839                 if (map != 0) {
840                         for (b = 0 ; b < WSIZE; b++) {
841                                 if (map & (1 << b))
842                                         nm_diff->count++;
843                         }
844                 }
845         }
846 }
847
848 /**
849  * tipc_port_list_add - add a port to a port list, ensuring no duplicates
850  */
851
852 void tipc_port_list_add(struct port_list *pl_ptr, u32 port)
853 {
854         struct port_list *item = pl_ptr;
855         int i;
856         int item_sz = PLSIZE;
857         int cnt = pl_ptr->count;
858
859         for (; ; cnt -= item_sz, item = item->next) {
860                 if (cnt < PLSIZE)
861                         item_sz = cnt;
862                 for (i = 0; i < item_sz; i++)
863                         if (item->ports[i] == port)
864                                 return;
865                 if (i < PLSIZE) {
866                         item->ports[i] = port;
867                         pl_ptr->count++;
868                         return;
869                 }
870                 if (!item->next) {
871                         item->next = kmalloc(sizeof(*item), GFP_ATOMIC);
872                         if (!item->next) {
873                                 warn("Incomplete multicast delivery, no memory\n");
874                                 return;
875                         }
876                         item->next->next = NULL;
877                 }
878         }
879 }
880
881 /**
882  * tipc_port_list_free - free dynamically created entries in port_list chain
883  *
884  */
885
886 void tipc_port_list_free(struct port_list *pl_ptr)
887 {
888         struct port_list *item;
889         struct port_list *next;
890
891         for (item = pl_ptr->next; item; item = next) {
892                 next = item->next;
893                 kfree(item);
894         }
895 }
896