Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck...
[cascardo/linux.git] / net / tipc / bcast.c
1 /*
2  * net/tipc/bcast.c: TIPC broadcast code
3  *
4  * Copyright (c) 2004-2006, 2014, 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 "socket.h"
42 #include "msg.h"
43 #include "bcast.h"
44 #include "name_distr.h"
45
46 #define MAX_PKT_DEFAULT_MCAST   1500    /* bcast link max packet size (fixed) */
47 #define BCLINK_WIN_DEFAULT      20      /* bcast link window size (default) */
48 #define BCBEARER                MAX_BEARERS
49
50 /**
51  * struct tipc_bcbearer_pair - a pair of bearers used by broadcast link
52  * @primary: pointer to primary bearer
53  * @secondary: pointer to secondary bearer
54  *
55  * Bearers must have same priority and same set of reachable destinations
56  * to be paired.
57  */
58
59 struct tipc_bcbearer_pair {
60         struct tipc_bearer *primary;
61         struct tipc_bearer *secondary;
62 };
63
64 /**
65  * struct tipc_bcbearer - bearer used by broadcast link
66  * @bearer: (non-standard) broadcast bearer structure
67  * @media: (non-standard) broadcast media structure
68  * @bpairs: array of bearer pairs
69  * @bpairs_temp: temporary array of bearer pairs used by tipc_bcbearer_sort()
70  * @remains: temporary node map used by tipc_bcbearer_send()
71  * @remains_new: temporary node map used tipc_bcbearer_send()
72  *
73  * Note: The fields labelled "temporary" are incorporated into the bearer
74  * to avoid consuming potentially limited stack space through the use of
75  * large local variables within multicast routines.  Concurrent access is
76  * prevented through use of the spinlock "bclink_lock".
77  */
78 struct tipc_bcbearer {
79         struct tipc_bearer bearer;
80         struct tipc_media media;
81         struct tipc_bcbearer_pair bpairs[MAX_BEARERS];
82         struct tipc_bcbearer_pair bpairs_temp[TIPC_MAX_LINK_PRI + 1];
83         struct tipc_node_map remains;
84         struct tipc_node_map remains_new;
85 };
86
87 /**
88  * struct tipc_bclink - link used for broadcast messages
89  * @lock: spinlock governing access to structure
90  * @link: (non-standard) broadcast link structure
91  * @node: (non-standard) node structure representing b'cast link's peer node
92  * @flags: represent bclink states
93  * @bcast_nodes: map of broadcast-capable nodes
94  * @retransmit_to: node that most recently requested a retransmit
95  *
96  * Handles sequence numbering, fragmentation, bundling, etc.
97  */
98 struct tipc_bclink {
99         spinlock_t lock;
100         struct tipc_link link;
101         struct tipc_node node;
102         unsigned int flags;
103         struct tipc_node_map bcast_nodes;
104         struct tipc_node *retransmit_to;
105 };
106
107 static struct tipc_bcbearer *bcbearer;
108 static struct tipc_bclink *bclink;
109 static struct tipc_link *bcl;
110
111 const char tipc_bclink_name[] = "broadcast-link";
112
113 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
114                            struct tipc_node_map *nm_b,
115                            struct tipc_node_map *nm_diff);
116 static void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node);
117 static void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node);
118
119 static void tipc_bclink_lock(void)
120 {
121         spin_lock_bh(&bclink->lock);
122 }
123
124 static void tipc_bclink_unlock(void)
125 {
126         struct tipc_node *node = NULL;
127
128         if (likely(!bclink->flags)) {
129                 spin_unlock_bh(&bclink->lock);
130                 return;
131         }
132
133         if (bclink->flags & TIPC_BCLINK_RESET) {
134                 bclink->flags &= ~TIPC_BCLINK_RESET;
135                 node = tipc_bclink_retransmit_to();
136         }
137         spin_unlock_bh(&bclink->lock);
138
139         if (node)
140                 tipc_link_reset_all(node);
141 }
142
143 uint  tipc_bclink_get_mtu(void)
144 {
145         return MAX_PKT_DEFAULT_MCAST;
146 }
147
148 void tipc_bclink_set_flags(unsigned int flags)
149 {
150         bclink->flags |= flags;
151 }
152
153 static u32 bcbuf_acks(struct sk_buff *buf)
154 {
155         return (u32)(unsigned long)TIPC_SKB_CB(buf)->handle;
156 }
157
158 static void bcbuf_set_acks(struct sk_buff *buf, u32 acks)
159 {
160         TIPC_SKB_CB(buf)->handle = (void *)(unsigned long)acks;
161 }
162
163 static void bcbuf_decr_acks(struct sk_buff *buf)
164 {
165         bcbuf_set_acks(buf, bcbuf_acks(buf) - 1);
166 }
167
168 void tipc_bclink_add_node(u32 addr)
169 {
170         tipc_bclink_lock();
171         tipc_nmap_add(&bclink->bcast_nodes, addr);
172         tipc_bclink_unlock();
173 }
174
175 void tipc_bclink_remove_node(u32 addr)
176 {
177         tipc_bclink_lock();
178         tipc_nmap_remove(&bclink->bcast_nodes, addr);
179         tipc_bclink_unlock();
180 }
181
182 static void bclink_set_last_sent(void)
183 {
184         if (bcl->next_out)
185                 bcl->fsm_msg_cnt = mod(buf_seqno(bcl->next_out) - 1);
186         else
187                 bcl->fsm_msg_cnt = mod(bcl->next_out_no - 1);
188 }
189
190 u32 tipc_bclink_get_last_sent(void)
191 {
192         return bcl->fsm_msg_cnt;
193 }
194
195 static void bclink_update_last_sent(struct tipc_node *node, u32 seqno)
196 {
197         node->bclink.last_sent = less_eq(node->bclink.last_sent, seqno) ?
198                                                 seqno : node->bclink.last_sent;
199 }
200
201
202 /**
203  * tipc_bclink_retransmit_to - get most recent node to request retransmission
204  *
205  * Called with bclink_lock locked
206  */
207 struct tipc_node *tipc_bclink_retransmit_to(void)
208 {
209         return bclink->retransmit_to;
210 }
211
212 /**
213  * bclink_retransmit_pkt - retransmit broadcast packets
214  * @after: sequence number of last packet to *not* retransmit
215  * @to: sequence number of last packet to retransmit
216  *
217  * Called with bclink_lock locked
218  */
219 static void bclink_retransmit_pkt(u32 after, u32 to)
220 {
221         struct sk_buff *buf;
222
223         buf = bcl->first_out;
224         while (buf && less_eq(buf_seqno(buf), after))
225                 buf = buf->next;
226         tipc_link_retransmit(bcl, buf, mod(to - after));
227 }
228
229 /**
230  * tipc_bclink_acknowledge - handle acknowledgement of broadcast packets
231  * @n_ptr: node that sent acknowledgement info
232  * @acked: broadcast sequence # that has been acknowledged
233  *
234  * Node is locked, bclink_lock unlocked.
235  */
236 void tipc_bclink_acknowledge(struct tipc_node *n_ptr, u32 acked)
237 {
238         struct sk_buff *crs;
239         struct sk_buff *next;
240         unsigned int released = 0;
241
242         tipc_bclink_lock();
243         /* Bail out if tx queue is empty (no clean up is required) */
244         crs = bcl->first_out;
245         if (!crs)
246                 goto exit;
247
248         /* Determine which messages need to be acknowledged */
249         if (acked == INVALID_LINK_SEQ) {
250                 /*
251                  * Contact with specified node has been lost, so need to
252                  * acknowledge sent messages only (if other nodes still exist)
253                  * or both sent and unsent messages (otherwise)
254                  */
255                 if (bclink->bcast_nodes.count)
256                         acked = bcl->fsm_msg_cnt;
257                 else
258                         acked = bcl->next_out_no;
259         } else {
260                 /*
261                  * Bail out if specified sequence number does not correspond
262                  * to a message that has been sent and not yet acknowledged
263                  */
264                 if (less(acked, buf_seqno(crs)) ||
265                     less(bcl->fsm_msg_cnt, acked) ||
266                     less_eq(acked, n_ptr->bclink.acked))
267                         goto exit;
268         }
269
270         /* Skip over packets that node has previously acknowledged */
271         while (crs && less_eq(buf_seqno(crs), n_ptr->bclink.acked))
272                 crs = crs->next;
273
274         /* Update packets that node is now acknowledging */
275
276         while (crs && less_eq(buf_seqno(crs), acked)) {
277                 next = crs->next;
278
279                 if (crs != bcl->next_out)
280                         bcbuf_decr_acks(crs);
281                 else {
282                         bcbuf_set_acks(crs, 0);
283                         bcl->next_out = next;
284                         bclink_set_last_sent();
285                 }
286
287                 if (bcbuf_acks(crs) == 0) {
288                         bcl->first_out = next;
289                         bcl->out_queue_size--;
290                         kfree_skb(crs);
291                         released = 1;
292                 }
293                 crs = next;
294         }
295         n_ptr->bclink.acked = acked;
296
297         /* Try resolving broadcast link congestion, if necessary */
298
299         if (unlikely(bcl->next_out)) {
300                 tipc_link_push_queue(bcl);
301                 bclink_set_last_sent();
302         }
303         if (unlikely(released && !list_empty(&bcl->waiting_ports)))
304                 tipc_link_wakeup_ports(bcl, 0);
305 exit:
306         tipc_bclink_unlock();
307 }
308
309 /**
310  * tipc_bclink_update_link_state - update broadcast link state
311  *
312  * RCU and node lock set
313  */
314 void tipc_bclink_update_link_state(struct tipc_node *n_ptr, u32 last_sent)
315 {
316         struct sk_buff *buf;
317
318         /* Ignore "stale" link state info */
319
320         if (less_eq(last_sent, n_ptr->bclink.last_in))
321                 return;
322
323         /* Update link synchronization state; quit if in sync */
324
325         bclink_update_last_sent(n_ptr, last_sent);
326
327         if (n_ptr->bclink.last_sent == n_ptr->bclink.last_in)
328                 return;
329
330         /* Update out-of-sync state; quit if loss is still unconfirmed */
331
332         if ((++n_ptr->bclink.oos_state) == 1) {
333                 if (n_ptr->bclink.deferred_size < (TIPC_MIN_LINK_WIN / 2))
334                         return;
335                 n_ptr->bclink.oos_state++;
336         }
337
338         /* Don't NACK if one has been recently sent (or seen) */
339
340         if (n_ptr->bclink.oos_state & 0x1)
341                 return;
342
343         /* Send NACK */
344
345         buf = tipc_buf_acquire(INT_H_SIZE);
346         if (buf) {
347                 struct tipc_msg *msg = buf_msg(buf);
348
349                 tipc_msg_init(msg, BCAST_PROTOCOL, STATE_MSG,
350                               INT_H_SIZE, n_ptr->addr);
351                 msg_set_non_seq(msg, 1);
352                 msg_set_mc_netid(msg, tipc_net_id);
353                 msg_set_bcast_ack(msg, n_ptr->bclink.last_in);
354                 msg_set_bcgap_after(msg, n_ptr->bclink.last_in);
355                 msg_set_bcgap_to(msg, n_ptr->bclink.deferred_head
356                                  ? buf_seqno(n_ptr->bclink.deferred_head) - 1
357                                  : n_ptr->bclink.last_sent);
358
359                 tipc_bclink_lock();
360                 tipc_bearer_send(MAX_BEARERS, buf, NULL);
361                 bcl->stats.sent_nacks++;
362                 tipc_bclink_unlock();
363                 kfree_skb(buf);
364
365                 n_ptr->bclink.oos_state++;
366         }
367 }
368
369 /**
370  * bclink_peek_nack - monitor retransmission requests sent by other nodes
371  *
372  * Delay any upcoming NACK by this node if another node has already
373  * requested the first message this node is going to ask for.
374  */
375 static void bclink_peek_nack(struct tipc_msg *msg)
376 {
377         struct tipc_node *n_ptr = tipc_node_find(msg_destnode(msg));
378
379         if (unlikely(!n_ptr))
380                 return;
381
382         tipc_node_lock(n_ptr);
383
384         if (n_ptr->bclink.recv_permitted &&
385             (n_ptr->bclink.last_in != n_ptr->bclink.last_sent) &&
386             (n_ptr->bclink.last_in == msg_bcgap_after(msg)))
387                 n_ptr->bclink.oos_state = 2;
388
389         tipc_node_unlock(n_ptr);
390 }
391
392 /* tipc_bclink_xmit - broadcast buffer chain to all nodes in cluster
393  *                    and to identified node local sockets
394  * @buf: chain of buffers containing message
395  * Consumes the buffer chain, except when returning -ELINKCONG
396  * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
397  */
398 int tipc_bclink_xmit(struct sk_buff *buf)
399 {
400         int rc = 0;
401         int bc = 0;
402         struct sk_buff *clbuf;
403
404         /* Prepare clone of message for local node */
405         clbuf = tipc_msg_reassemble(buf);
406         if (unlikely(!clbuf)) {
407                 kfree_skb_list(buf);
408                 return -EHOSTUNREACH;
409         }
410
411         /* Broadcast to all other nodes */
412         if (likely(bclink)) {
413                 tipc_bclink_lock();
414                 if (likely(bclink->bcast_nodes.count)) {
415                         rc = __tipc_link_xmit(bcl, buf);
416                         if (likely(!rc)) {
417                                 bclink_set_last_sent();
418                                 bcl->stats.queue_sz_counts++;
419                                 bcl->stats.accu_queue_sz += bcl->out_queue_size;
420                         }
421                         bc = 1;
422                 }
423                 tipc_bclink_unlock();
424         }
425
426         if (unlikely(!bc))
427                 kfree_skb_list(buf);
428
429         /* Deliver message clone */
430         if (likely(!rc))
431                 tipc_sk_mcast_rcv(clbuf);
432         else
433                 kfree_skb(clbuf);
434
435         return rc;
436 }
437
438 /**
439  * bclink_accept_pkt - accept an incoming, in-sequence broadcast packet
440  *
441  * Called with both sending node's lock and bclink_lock taken.
442  */
443 static void bclink_accept_pkt(struct tipc_node *node, u32 seqno)
444 {
445         bclink_update_last_sent(node, seqno);
446         node->bclink.last_in = seqno;
447         node->bclink.oos_state = 0;
448         bcl->stats.recv_info++;
449
450         /*
451          * Unicast an ACK periodically, ensuring that
452          * all nodes in the cluster don't ACK at the same time
453          */
454
455         if (((seqno - tipc_own_addr) % TIPC_MIN_LINK_WIN) == 0) {
456                 tipc_link_proto_xmit(node->active_links[node->addr & 1],
457                                      STATE_MSG, 0, 0, 0, 0, 0);
458                 bcl->stats.sent_acks++;
459         }
460 }
461
462 /**
463  * tipc_bclink_rcv - receive a broadcast packet, and deliver upwards
464  *
465  * RCU is locked, no other locks set
466  */
467 void tipc_bclink_rcv(struct sk_buff *buf)
468 {
469         struct tipc_msg *msg = buf_msg(buf);
470         struct tipc_node *node;
471         u32 next_in;
472         u32 seqno;
473         int deferred = 0;
474
475         /* Screen out unwanted broadcast messages */
476
477         if (msg_mc_netid(msg) != tipc_net_id)
478                 goto exit;
479
480         node = tipc_node_find(msg_prevnode(msg));
481         if (unlikely(!node))
482                 goto exit;
483
484         tipc_node_lock(node);
485         if (unlikely(!node->bclink.recv_permitted))
486                 goto unlock;
487
488         /* Handle broadcast protocol message */
489
490         if (unlikely(msg_user(msg) == BCAST_PROTOCOL)) {
491                 if (msg_type(msg) != STATE_MSG)
492                         goto unlock;
493                 if (msg_destnode(msg) == tipc_own_addr) {
494                         tipc_bclink_acknowledge(node, msg_bcast_ack(msg));
495                         tipc_node_unlock(node);
496                         tipc_bclink_lock();
497                         bcl->stats.recv_nacks++;
498                         bclink->retransmit_to = node;
499                         bclink_retransmit_pkt(msg_bcgap_after(msg),
500                                               msg_bcgap_to(msg));
501                         tipc_bclink_unlock();
502                 } else {
503                         tipc_node_unlock(node);
504                         bclink_peek_nack(msg);
505                 }
506                 goto exit;
507         }
508
509         /* Handle in-sequence broadcast message */
510
511         seqno = msg_seqno(msg);
512         next_in = mod(node->bclink.last_in + 1);
513
514         if (likely(seqno == next_in)) {
515 receive:
516                 /* Deliver message to destination */
517
518                 if (likely(msg_isdata(msg))) {
519                         tipc_bclink_lock();
520                         bclink_accept_pkt(node, seqno);
521                         tipc_bclink_unlock();
522                         tipc_node_unlock(node);
523                         if (likely(msg_mcast(msg)))
524                                 tipc_sk_mcast_rcv(buf);
525                         else
526                                 kfree_skb(buf);
527                 } else if (msg_user(msg) == MSG_BUNDLER) {
528                         tipc_bclink_lock();
529                         bclink_accept_pkt(node, seqno);
530                         bcl->stats.recv_bundles++;
531                         bcl->stats.recv_bundled += msg_msgcnt(msg);
532                         tipc_bclink_unlock();
533                         tipc_node_unlock(node);
534                         tipc_link_bundle_rcv(buf);
535                 } else if (msg_user(msg) == MSG_FRAGMENTER) {
536                         tipc_buf_append(&node->bclink.reasm_buf, &buf);
537                         if (unlikely(!buf && !node->bclink.reasm_buf))
538                                 goto unlock;
539                         tipc_bclink_lock();
540                         bclink_accept_pkt(node, seqno);
541                         bcl->stats.recv_fragments++;
542                         if (buf) {
543                                 bcl->stats.recv_fragmented++;
544                                 msg = buf_msg(buf);
545                                 tipc_bclink_unlock();
546                                 goto receive;
547                         }
548                         tipc_bclink_unlock();
549                         tipc_node_unlock(node);
550                 } else if (msg_user(msg) == NAME_DISTRIBUTOR) {
551                         tipc_bclink_lock();
552                         bclink_accept_pkt(node, seqno);
553                         tipc_bclink_unlock();
554                         tipc_node_unlock(node);
555                         tipc_named_rcv(buf);
556                 } else {
557                         tipc_bclink_lock();
558                         bclink_accept_pkt(node, seqno);
559                         tipc_bclink_unlock();
560                         tipc_node_unlock(node);
561                         kfree_skb(buf);
562                 }
563                 buf = NULL;
564
565                 /* Determine new synchronization state */
566
567                 tipc_node_lock(node);
568                 if (unlikely(!tipc_node_is_up(node)))
569                         goto unlock;
570
571                 if (node->bclink.last_in == node->bclink.last_sent)
572                         goto unlock;
573
574                 if (!node->bclink.deferred_head) {
575                         node->bclink.oos_state = 1;
576                         goto unlock;
577                 }
578
579                 msg = buf_msg(node->bclink.deferred_head);
580                 seqno = msg_seqno(msg);
581                 next_in = mod(next_in + 1);
582                 if (seqno != next_in)
583                         goto unlock;
584
585                 /* Take in-sequence message from deferred queue & deliver it */
586
587                 buf = node->bclink.deferred_head;
588                 node->bclink.deferred_head = buf->next;
589                 buf->next = NULL;
590                 node->bclink.deferred_size--;
591                 goto receive;
592         }
593
594         /* Handle out-of-sequence broadcast message */
595
596         if (less(next_in, seqno)) {
597                 deferred = tipc_link_defer_pkt(&node->bclink.deferred_head,
598                                                &node->bclink.deferred_tail,
599                                                buf);
600                 node->bclink.deferred_size += deferred;
601                 bclink_update_last_sent(node, seqno);
602                 buf = NULL;
603         }
604
605         tipc_bclink_lock();
606
607         if (deferred)
608                 bcl->stats.deferred_recv++;
609         else
610                 bcl->stats.duplicates++;
611
612         tipc_bclink_unlock();
613
614 unlock:
615         tipc_node_unlock(node);
616 exit:
617         kfree_skb(buf);
618 }
619
620 u32 tipc_bclink_acks_missing(struct tipc_node *n_ptr)
621 {
622         return (n_ptr->bclink.recv_permitted &&
623                 (tipc_bclink_get_last_sent() != n_ptr->bclink.acked));
624 }
625
626
627 /**
628  * tipc_bcbearer_send - send a packet through the broadcast pseudo-bearer
629  *
630  * Send packet over as many bearers as necessary to reach all nodes
631  * that have joined the broadcast link.
632  *
633  * Returns 0 (packet sent successfully) under all circumstances,
634  * since the broadcast link's pseudo-bearer never blocks
635  */
636 static int tipc_bcbearer_send(struct sk_buff *buf, struct tipc_bearer *unused1,
637                               struct tipc_media_addr *unused2)
638 {
639         int bp_index;
640         struct tipc_msg *msg = buf_msg(buf);
641
642         /* Prepare broadcast link message for reliable transmission,
643          * if first time trying to send it;
644          * preparation is skipped for broadcast link protocol messages
645          * since they are sent in an unreliable manner and don't need it
646          */
647         if (likely(!msg_non_seq(buf_msg(buf)))) {
648                 bcbuf_set_acks(buf, bclink->bcast_nodes.count);
649                 msg_set_non_seq(msg, 1);
650                 msg_set_mc_netid(msg, tipc_net_id);
651                 bcl->stats.sent_info++;
652
653                 if (WARN_ON(!bclink->bcast_nodes.count)) {
654                         dump_stack();
655                         return 0;
656                 }
657         }
658
659         /* Send buffer over bearers until all targets reached */
660         bcbearer->remains = bclink->bcast_nodes;
661
662         for (bp_index = 0; bp_index < MAX_BEARERS; bp_index++) {
663                 struct tipc_bearer *p = bcbearer->bpairs[bp_index].primary;
664                 struct tipc_bearer *s = bcbearer->bpairs[bp_index].secondary;
665                 struct tipc_bearer *bp[2] = {p, s};
666                 struct tipc_bearer *b = bp[msg_link_selector(msg)];
667                 struct sk_buff *tbuf;
668
669                 if (!p)
670                         break; /* No more bearers to try */
671                 if (!b)
672                         b = p;
673                 tipc_nmap_diff(&bcbearer->remains, &b->nodes,
674                                &bcbearer->remains_new);
675                 if (bcbearer->remains_new.count == bcbearer->remains.count)
676                         continue; /* Nothing added by bearer pair */
677
678                 if (bp_index == 0) {
679                         /* Use original buffer for first bearer */
680                         tipc_bearer_send(b->identity, buf, &b->bcast_addr);
681                 } else {
682                         /* Avoid concurrent buffer access */
683                         tbuf = pskb_copy_for_clone(buf, GFP_ATOMIC);
684                         if (!tbuf)
685                                 break;
686                         tipc_bearer_send(b->identity, tbuf, &b->bcast_addr);
687                         kfree_skb(tbuf); /* Bearer keeps a clone */
688                 }
689                 if (bcbearer->remains_new.count == 0)
690                         break; /* All targets reached */
691
692                 bcbearer->remains = bcbearer->remains_new;
693         }
694
695         return 0;
696 }
697
698 /**
699  * tipc_bcbearer_sort - create sets of bearer pairs used by broadcast bearer
700  */
701 void tipc_bcbearer_sort(struct tipc_node_map *nm_ptr, u32 node, bool action)
702 {
703         struct tipc_bcbearer_pair *bp_temp = bcbearer->bpairs_temp;
704         struct tipc_bcbearer_pair *bp_curr;
705         struct tipc_bearer *b;
706         int b_index;
707         int pri;
708
709         tipc_bclink_lock();
710
711         if (action)
712                 tipc_nmap_add(nm_ptr, node);
713         else
714                 tipc_nmap_remove(nm_ptr, node);
715
716         /* Group bearers by priority (can assume max of two per priority) */
717         memset(bp_temp, 0, sizeof(bcbearer->bpairs_temp));
718
719         rcu_read_lock();
720         for (b_index = 0; b_index < MAX_BEARERS; b_index++) {
721                 b = rcu_dereference_rtnl(bearer_list[b_index]);
722                 if (!b || !b->nodes.count)
723                         continue;
724
725                 if (!bp_temp[b->priority].primary)
726                         bp_temp[b->priority].primary = b;
727                 else
728                         bp_temp[b->priority].secondary = b;
729         }
730         rcu_read_unlock();
731
732         /* Create array of bearer pairs for broadcasting */
733         bp_curr = bcbearer->bpairs;
734         memset(bcbearer->bpairs, 0, sizeof(bcbearer->bpairs));
735
736         for (pri = TIPC_MAX_LINK_PRI; pri >= 0; pri--) {
737
738                 if (!bp_temp[pri].primary)
739                         continue;
740
741                 bp_curr->primary = bp_temp[pri].primary;
742
743                 if (bp_temp[pri].secondary) {
744                         if (tipc_nmap_equal(&bp_temp[pri].primary->nodes,
745                                             &bp_temp[pri].secondary->nodes)) {
746                                 bp_curr->secondary = bp_temp[pri].secondary;
747                         } else {
748                                 bp_curr++;
749                                 bp_curr->primary = bp_temp[pri].secondary;
750                         }
751                 }
752
753                 bp_curr++;
754         }
755
756         tipc_bclink_unlock();
757 }
758
759
760 int tipc_bclink_stats(char *buf, const u32 buf_size)
761 {
762         int ret;
763         struct tipc_stats *s;
764
765         if (!bcl)
766                 return 0;
767
768         tipc_bclink_lock();
769
770         s = &bcl->stats;
771
772         ret = tipc_snprintf(buf, buf_size, "Link <%s>\n"
773                             "  Window:%u packets\n",
774                             bcl->name, bcl->queue_limit[0]);
775         ret += tipc_snprintf(buf + ret, buf_size - ret,
776                              "  RX packets:%u fragments:%u/%u bundles:%u/%u\n",
777                              s->recv_info, s->recv_fragments,
778                              s->recv_fragmented, s->recv_bundles,
779                              s->recv_bundled);
780         ret += tipc_snprintf(buf + ret, buf_size - ret,
781                              "  TX packets:%u fragments:%u/%u bundles:%u/%u\n",
782                              s->sent_info, s->sent_fragments,
783                              s->sent_fragmented, s->sent_bundles,
784                              s->sent_bundled);
785         ret += tipc_snprintf(buf + ret, buf_size - ret,
786                              "  RX naks:%u defs:%u dups:%u\n",
787                              s->recv_nacks, s->deferred_recv, s->duplicates);
788         ret += tipc_snprintf(buf + ret, buf_size - ret,
789                              "  TX naks:%u acks:%u dups:%u\n",
790                              s->sent_nacks, s->sent_acks, s->retransmitted);
791         ret += tipc_snprintf(buf + ret, buf_size - ret,
792                              "  Congestion link:%u  Send queue max:%u avg:%u\n",
793                              s->link_congs, s->max_queue_sz,
794                              s->queue_sz_counts ?
795                              (s->accu_queue_sz / s->queue_sz_counts) : 0);
796
797         tipc_bclink_unlock();
798         return ret;
799 }
800
801 int tipc_bclink_reset_stats(void)
802 {
803         if (!bcl)
804                 return -ENOPROTOOPT;
805
806         tipc_bclink_lock();
807         memset(&bcl->stats, 0, sizeof(bcl->stats));
808         tipc_bclink_unlock();
809         return 0;
810 }
811
812 int tipc_bclink_set_queue_limits(u32 limit)
813 {
814         if (!bcl)
815                 return -ENOPROTOOPT;
816         if ((limit < TIPC_MIN_LINK_WIN) || (limit > TIPC_MAX_LINK_WIN))
817                 return -EINVAL;
818
819         tipc_bclink_lock();
820         tipc_link_set_queue_limits(bcl, limit);
821         tipc_bclink_unlock();
822         return 0;
823 }
824
825 int tipc_bclink_init(void)
826 {
827         bcbearer = kzalloc(sizeof(*bcbearer), GFP_ATOMIC);
828         if (!bcbearer)
829                 return -ENOMEM;
830
831         bclink = kzalloc(sizeof(*bclink), GFP_ATOMIC);
832         if (!bclink) {
833                 kfree(bcbearer);
834                 return -ENOMEM;
835         }
836
837         bcl = &bclink->link;
838         bcbearer->bearer.media = &bcbearer->media;
839         bcbearer->media.send_msg = tipc_bcbearer_send;
840         sprintf(bcbearer->media.name, "tipc-broadcast");
841
842         spin_lock_init(&bclink->lock);
843         INIT_LIST_HEAD(&bcl->waiting_ports);
844         bcl->next_out_no = 1;
845         spin_lock_init(&bclink->node.lock);
846         bcl->owner = &bclink->node;
847         bcl->max_pkt = MAX_PKT_DEFAULT_MCAST;
848         tipc_link_set_queue_limits(bcl, BCLINK_WIN_DEFAULT);
849         bcl->bearer_id = MAX_BEARERS;
850         rcu_assign_pointer(bearer_list[MAX_BEARERS], &bcbearer->bearer);
851         bcl->state = WORKING_WORKING;
852         strlcpy(bcl->name, tipc_bclink_name, TIPC_MAX_LINK_NAME);
853         return 0;
854 }
855
856 void tipc_bclink_stop(void)
857 {
858         tipc_bclink_lock();
859         tipc_link_purge_queues(bcl);
860         tipc_bclink_unlock();
861
862         RCU_INIT_POINTER(bearer_list[BCBEARER], NULL);
863         synchronize_net();
864         kfree(bcbearer);
865         kfree(bclink);
866 }
867
868 /**
869  * tipc_nmap_add - add a node to a node map
870  */
871 static void tipc_nmap_add(struct tipc_node_map *nm_ptr, u32 node)
872 {
873         int n = tipc_node(node);
874         int w = n / WSIZE;
875         u32 mask = (1 << (n % WSIZE));
876
877         if ((nm_ptr->map[w] & mask) == 0) {
878                 nm_ptr->count++;
879                 nm_ptr->map[w] |= mask;
880         }
881 }
882
883 /**
884  * tipc_nmap_remove - remove a node from a node map
885  */
886 static void tipc_nmap_remove(struct tipc_node_map *nm_ptr, u32 node)
887 {
888         int n = tipc_node(node);
889         int w = n / WSIZE;
890         u32 mask = (1 << (n % WSIZE));
891
892         if ((nm_ptr->map[w] & mask) != 0) {
893                 nm_ptr->map[w] &= ~mask;
894                 nm_ptr->count--;
895         }
896 }
897
898 /**
899  * tipc_nmap_diff - find differences between node maps
900  * @nm_a: input node map A
901  * @nm_b: input node map B
902  * @nm_diff: output node map A-B (i.e. nodes of A that are not in B)
903  */
904 static void tipc_nmap_diff(struct tipc_node_map *nm_a,
905                            struct tipc_node_map *nm_b,
906                            struct tipc_node_map *nm_diff)
907 {
908         int stop = ARRAY_SIZE(nm_a->map);
909         int w;
910         int b;
911         u32 map;
912
913         memset(nm_diff, 0, sizeof(*nm_diff));
914         for (w = 0; w < stop; w++) {
915                 map = nm_a->map[w] ^ (nm_a->map[w] & nm_b->map[w]);
916                 nm_diff->map[w] = map;
917                 if (map != 0) {
918                         for (b = 0 ; b < WSIZE; b++) {
919                                 if (map & (1 << b))
920                                         nm_diff->count++;
921                         }
922                 }
923         }
924 }
925
926 /**
927  * tipc_port_list_add - add a port to a port list, ensuring no duplicates
928  */
929 void tipc_port_list_add(struct tipc_port_list *pl_ptr, u32 port)
930 {
931         struct tipc_port_list *item = pl_ptr;
932         int i;
933         int item_sz = PLSIZE;
934         int cnt = pl_ptr->count;
935
936         for (; ; cnt -= item_sz, item = item->next) {
937                 if (cnt < PLSIZE)
938                         item_sz = cnt;
939                 for (i = 0; i < item_sz; i++)
940                         if (item->ports[i] == port)
941                                 return;
942                 if (i < PLSIZE) {
943                         item->ports[i] = port;
944                         pl_ptr->count++;
945                         return;
946                 }
947                 if (!item->next) {
948                         item->next = kmalloc(sizeof(*item), GFP_ATOMIC);
949                         if (!item->next) {
950                                 pr_warn("Incomplete multicast delivery, no memory\n");
951                                 return;
952                         }
953                         item->next->next = NULL;
954                 }
955         }
956 }
957
958 /**
959  * tipc_port_list_free - free dynamically created entries in port_list chain
960  *
961  */
962 void tipc_port_list_free(struct tipc_port_list *pl_ptr)
963 {
964         struct tipc_port_list *item;
965         struct tipc_port_list *next;
966
967         for (item = pl_ptr->next; item; item = next) {
968                 next = item->next;
969                 kfree(item);
970         }
971 }