summaryrefslogtreecommitdiff
path: root/net/tipc/group.c
blob: efb5714e7a85c601a9a5440496e6b9413454a681 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
/*
 * net/tipc/group.c: TIPC group messaging code
 *
 * Copyright (c) 2017, Ericsson AB
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include "core.h"
#include "addr.h"
#include "group.h"
#include "bcast.h"
#include "server.h"
#include "msg.h"
#include "socket.h"
#include "node.h"
#include "name_table.h"
#include "subscr.h"

#define ADV_UNIT (((MAX_MSG_SIZE + MAX_H_SIZE) / FLOWCTL_BLK_SZ) + 1)
#define ADV_IDLE ADV_UNIT
#define ADV_ACTIVE (ADV_UNIT * 12)

enum mbr_state {
	MBR_QUARANTINED,
	MBR_DISCOVERED,
	MBR_JOINING,
	MBR_PUBLISHED,
	MBR_JOINED,
	MBR_PENDING,
	MBR_ACTIVE,
	MBR_RECLAIMING,
	MBR_REMITTED,
	MBR_LEAVING
};

struct tipc_member {
	struct rb_node tree_node;
	struct list_head list;
	struct list_head congested;
	struct sk_buff *event_msg;
	struct sk_buff_head deferredq;
	struct tipc_group *group;
	u32 node;
	u32 port;
	u32 instance;
	enum mbr_state state;
	u16 advertised;
	u16 window;
	u16 bc_rcv_nxt;
	u16 bc_syncpt;
	u16 bc_acked;
	bool usr_pending;
};

struct tipc_group {
	struct rb_root members;
	struct list_head congested;
	struct list_head pending;
	struct list_head active;
	struct list_head reclaiming;
	struct tipc_nlist dests;
	struct net *net;
	int subid;
	u32 type;
	u32 instance;
	u32 domain;
	u32 scope;
	u32 portid;
	u16 member_cnt;
	u16 active_cnt;
	u16 max_active;
	u16 bc_snd_nxt;
	u16 bc_ackers;
	bool loopback;
	bool events;
};

static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
				  int mtyp, struct sk_buff_head *xmitq);

static void tipc_group_decr_active(struct tipc_group *grp,
				   struct tipc_member *m)
{
	if (m->state == MBR_ACTIVE || m->state == MBR_RECLAIMING)
		grp->active_cnt--;
}

static int tipc_group_rcvbuf_limit(struct tipc_group *grp)
{
	int max_active, active_pool, idle_pool;
	int mcnt = grp->member_cnt + 1;

	/* Limit simultaneous reception from other members */
	max_active = min(mcnt / 8, 64);
	max_active = max(max_active, 16);
	grp->max_active = max_active;

	/* Reserve blocks for active and idle members */
	active_pool = max_active * ADV_ACTIVE;
	idle_pool = (mcnt - max_active) * ADV_IDLE;

	/* Scale to bytes, considering worst-case truesize/msgsize ratio */
	return (active_pool + idle_pool) * FLOWCTL_BLK_SZ * 4;
}

u16 tipc_group_bc_snd_nxt(struct tipc_group *grp)
{
	return grp->bc_snd_nxt;
}

static bool tipc_group_is_enabled(struct tipc_member *m)
{
	return m->state != MBR_QUARANTINED && m->state != MBR_LEAVING;
}

static bool tipc_group_is_receiver(struct tipc_member *m)
{
	return m && m->state >= MBR_JOINED;
}

u32 tipc_group_exclude(struct tipc_group *grp)
{
	if (!grp->loopback)
		return grp->portid;
	return 0;
}

int tipc_group_size(struct tipc_group *grp)
{
	return grp->member_cnt;
}

struct tipc_group *tipc_group_create(struct net *net, u32 portid,
				     struct tipc_group_req *mreq)
{
	struct tipc_group *grp;
	u32 type = mreq->type;

	grp = kzalloc(sizeof(*grp), GFP_ATOMIC);
	if (!grp)
		return NULL;
	tipc_nlist_init(&grp->dests, tipc_own_addr(net));
	INIT_LIST_HEAD(&grp->congested);
	INIT_LIST_HEAD(&grp->active);
	INIT_LIST_HEAD(&grp->pending);
	INIT_LIST_HEAD(&grp->reclaiming);
	grp->members = RB_ROOT;
	grp->net = net;
	grp->portid = portid;
	grp->domain = addr_domain(net, mreq->scope);
	grp->type = type;
	grp->instance = mreq->instance;
	grp->scope = mreq->scope;
	grp->loopback = mreq->flags & TIPC_GROUP_LOOPBACK;
	grp->events = mreq->flags & TIPC_GROUP_MEMBER_EVTS;
	if (tipc_topsrv_kern_subscr(net, portid, type, 0, ~0, &grp->subid))
		return grp;
	kfree(grp);
	return NULL;
}

void tipc_group_delete(struct net *net, struct tipc_group *grp)
{
	struct rb_root *tree = &grp->members;
	struct tipc_member *m, *tmp;
	struct sk_buff_head xmitq;

	__skb_queue_head_init(&xmitq);

	rbtree_postorder_for_each_entry_safe(m, tmp, tree, tree_node) {
		tipc_group_proto_xmit(grp, m, GRP_LEAVE_MSG, &xmitq);
		list_del(&m->list);
		kfree(m);
	}
	tipc_node_distr_xmit(net, &xmitq);
	tipc_nlist_purge(&grp->dests);
	tipc_topsrv_kern_unsubscr(net, grp->subid);
	kfree(grp);
}

struct tipc_member *tipc_group_find_member(struct tipc_group *grp,
					   u32 node, u32 port)
{
	struct rb_node *n = grp->members.rb_node;
	u64 nkey, key = (u64)node << 32 | port;
	struct tipc_member *m;

	while (n) {
		m = container_of(n, struct tipc_member, tree_node);
		nkey = (u64)m->node << 32 | m->port;
		if (key < nkey)
			n = n->rb_left;
		else if (key > nkey)
			n = n->rb_right;
		else
			return m;
	}
	return NULL;
}

static struct tipc_member *tipc_group_find_dest(struct tipc_group *grp,
						u32 node, u32 port)
{
	struct tipc_member *m;

	m = tipc_group_find_member(grp, node, port);
	if (m && tipc_group_is_enabled(m))
		return m;
	return NULL;
}

static struct tipc_member *tipc_group_find_node(struct tipc_group *grp,
						u32 node)
{
	struct tipc_member *m;
	struct rb_node *n;

	for (n = rb_first(&grp->members); n; n = rb_next(n)) {
		m = container_of(n, struct tipc_member, tree_node);
		if (m->node == node)
			return m;
	}
	return NULL;
}

static void tipc_group_add_to_tree(struct tipc_group *grp,
				   struct tipc_member *m)
{
	u64 nkey, key = (u64)m->node << 32 | m->port;
	struct rb_node **n, *parent = NULL;
	struct tipc_member *tmp;

	n = &grp->members.rb_node;
	while (*n) {
		tmp = container_of(*n, struct tipc_member, tree_node);
		parent = *n;
		tmp = container_of(parent, struct tipc_member, tree_node);
		nkey = (u64)tmp->node << 32 | tmp->port;
		if (key < nkey)
			n = &(*n)->rb_left;
		else if (key > nkey)
			n = &(*n)->rb_right;
		else
			return;
	}
	rb_link_node(&m->tree_node, parent, n);
	rb_insert_color(&m->tree_node, &grp->members);
}

static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
						    u32 node, u32 port,
						    int state)
{
	struct tipc_member *m;

	m = kzalloc(sizeof(*m), GFP_ATOMIC);
	if (!m)
		return NULL;
	INIT_LIST_HEAD(&m->list);
	INIT_LIST_HEAD(&m->congested);
	__skb_queue_head_init(&m->deferredq);
	m->group = grp;
	m->node = node;
	m->port = port;
	m->bc_acked = grp->bc_snd_nxt - 1;
	grp->member_cnt++;
	tipc_group_add_to_tree(grp, m);
	tipc_nlist_add(&grp->dests, m->node);
	m->state = state;
	return m;
}

void tipc_group_add_member(struct tipc_group *grp, u32 node, u32 port)
{
	tipc_group_create_member(grp, node, port, MBR_DISCOVERED);
}

static void tipc_group_delete_member(struct tipc_group *grp,
				     struct tipc_member *m)
{
	rb_erase(&m->tree_node, &grp->members);
	grp->member_cnt--;

	/* Check if we were waiting for replicast ack from this member */
	if (grp->bc_ackers && less(m->bc_acked, grp->bc_snd_nxt - 1))
		grp->bc_ackers--;

	list_del_init(&m->list);
	list_del_init(&m->congested);
	tipc_group_decr_active(grp, m);

	/* If last member on a node, remove node from dest list */
	if (!tipc_group_find_node(grp, m->node))
		tipc_nlist_del(&grp->dests, m->node);

	kfree(m);
}

struct tipc_nlist *tipc_group_dests(struct tipc_group *grp)
{
	return &grp->dests;
}

void tipc_group_self(struct tipc_group *grp, struct tipc_name_seq *seq,
		     int *scope)
{
	seq->type = grp->type;
	seq->lower = grp->instance;
	seq->upper = grp->instance;
	*scope = grp->scope;
}

void tipc_group_update_member(struct tipc_member *m, int len)
{
	struct tipc_group *grp = m->group;
	struct tipc_member *_m, *tmp;

	if (!tipc_group_is_enabled(m))
		return;

	m->window -= len;

	if (m->window >= ADV_IDLE)
		return;

	if (!list_empty(&m->congested))
		return;

	/* Sort member into congested members' list */
	list_for_each_entry_safe(_m, tmp, &grp->congested, congested) {
		if (m->window > _m->window)
			continue;
		list_add_tail(&m->congested, &_m->congested);
		return;
	}
	list_add_tail(&m->congested, &grp->congested);
}

void tipc_group_update_bc_members(struct tipc_group *grp, int len, bool ack)
{
	u16 prev = grp->bc_snd_nxt - 1;
	struct tipc_member *m;
	struct rb_node *n;

	for (n = rb_first(&grp->members); n; n = rb_next(n)) {
		m = container_of(n, struct tipc_member, tree_node);
		if (tipc_group_is_enabled(m)) {
			tipc_group_update_member(m, len);
			m->bc_acked = prev;
		}
	}

	/* Mark number of acknowledges to expect, if any */
	if (ack)
		grp->bc_ackers = grp->member_cnt;
	grp->bc_snd_nxt++;
}

bool tipc_group_cong(struct tipc_group *grp, u32 dnode, u32 dport,
		     int len, struct tipc_member **mbr)
{
	struct sk_buff_head xmitq;
	struct tipc_member *m;
	int adv, state;

	m = tipc_group_find_dest(grp, dnode, dport);
	*mbr = m;
	if (!m)
		return false;
	if (m->usr_pending)
		return true;
	if (m->window >= len)
		return false;
	m->usr_pending = true;

	/* If not fully advertised, do it now to prevent mutual blocking */
	adv = m->advertised;
	state = m->state;
	if (state < MBR_JOINED)
		return true;
	if (state == MBR_JOINED && adv == ADV_IDLE)
		return true;
	if (state == MBR_ACTIVE && adv == ADV_ACTIVE)
		return true;
	if (state == MBR_PENDING && adv == ADV_IDLE)
		return true;
	skb_queue_head_init(&xmitq);
	tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, &xmitq);
	tipc_node_distr_xmit(grp->net, &xmitq);
	return true;
}

bool tipc_group_bc_cong(struct tipc_group *grp, int len)
{
	struct tipc_member *m = NULL;

	/* If prev bcast was replicast, reject until all receivers have acked */
	if (grp->bc_ackers)
		return true;

	if (list_empty(&grp->congested))
		return false;

	m = list_first_entry(&grp->congested, struct tipc_member, congested);
	if (m->window >= len)
		return false;

	return tipc_group_cong(grp, m->node, m->port, len, &m);
}

/* tipc_group_sort_msg() - sort msg into queue by bcast sequence number
 */
static void tipc_group_sort_msg(struct sk_buff *skb, struct sk_buff_head *defq)
{
	struct tipc_msg *_hdr, *hdr = buf_msg(skb);
	u16 bc_seqno = msg_grp_bc_seqno(hdr);
	struct sk_buff *_skb, *tmp;
	int mtyp = msg_type(hdr);

	/* Bcast/mcast may be bypassed by ucast or other bcast, - sort it in */
	if (mtyp == TIPC_GRP_BCAST_MSG || mtyp == TIPC_GRP_MCAST_MSG) {
		skb_queue_walk_safe(defq, _skb, tmp) {
			_hdr = buf_msg(_skb);
			if (!less(bc_seqno, msg_grp_bc_seqno(_hdr)))
				continue;
			__skb_queue_before(defq, _skb, skb);
			return;
		}
		/* Bcast was not bypassed, - add to tail */
	}
	/* Unicasts are never bypassed, - always add to tail */
	__skb_queue_tail(defq, skb);
}

/* tipc_group_filter_msg() - determine if we should accept arriving message
 */
void tipc_group_filter_msg(struct tipc_group *grp, struct sk_buff_head *inputq,
			   struct sk_buff_head *xmitq)
{
	struct sk_buff *skb = __skb_dequeue(inputq);
	bool ack, deliver, update, leave = false;
	struct sk_buff_head *defq;
	struct tipc_member *m;
	struct tipc_msg *hdr;
	u32 node, port;
	int mtyp, blks;

	if (!skb)
		return;

	hdr = buf_msg(skb);
	node =  msg_orignode(hdr);
	port = msg_origport(hdr);

	if (!msg_in_group(hdr))
		goto drop;

	m = tipc_group_find_member(grp, node, port);
	if (!tipc_group_is_receiver(m))
		goto drop;

	if (less(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
		goto drop;

	TIPC_SKB_CB(skb)->orig_member = m->instance;
	defq = &m->deferredq;
	tipc_group_sort_msg(skb, defq);

	while ((skb = skb_peek(defq))) {
		hdr = buf_msg(skb);
		mtyp = msg_type(hdr);
		blks = msg_blocks(hdr);
		deliver = true;
		ack = false;
		update = false;

		if (more(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
			break;

		/* Decide what to do with message */
		switch (mtyp) {
		case TIPC_GRP_MCAST_MSG:
			if (msg_nameinst(hdr) != grp->instance) {
				update = true;
				deliver = false;
			}
			/* Fall thru */
		case TIPC_GRP_BCAST_MSG:
			m->bc_rcv_nxt++;
			ack = msg_grp_bc_ack_req(hdr);
			break;
		case TIPC_GRP_UCAST_MSG:
			break;
		case TIPC_GRP_MEMBER_EVT:
			if (m->state == MBR_LEAVING)
				leave = true;
			if (!grp->events)
				deliver = false;
			break;
		default:
			break;
		}

		/* Execute decisions */
		__skb_dequeue(defq);
		if (deliver)
			__skb_queue_tail(inputq, skb);
		else
			kfree_skb(skb);

		if (ack)
			tipc_group_proto_xmit(grp, m, GRP_ACK_MSG, xmitq);

		if (leave) {
			__skb_queue_purge(defq);
			tipc_group_delete_member(grp, m);
			break;
		}
		if (!update)
			continue;

		tipc_group_update_rcv_win(grp, blks, node, port, xmitq);
	}
	return;
drop:
	kfree_skb(skb);
}

void tipc_group_update_rcv_win(struct tipc_group *grp, int blks, u32 node,
			       u32 port, struct sk_buff_head *xmitq)
{
	struct list_head *active = &grp->active;
	int max_active = grp->max_active;
	int reclaim_limit = max_active * 3 / 4;
	int active_cnt = grp->active_cnt;
	struct tipc_member *m, *rm;

	m = tipc_group_find_member(grp, node, port);
	if (!m)
		return;

	m->advertised -= blks;

	switch (m->state) {
	case MBR_JOINED:
		/* Reclaim advertised space from least active member */
		if (!list_empty(active) && active_cnt >= reclaim_limit) {
			rm = list_first_entry(active, struct tipc_member, list);
			rm->state = MBR_RECLAIMING;
			list_move_tail(&rm->list, &grp->reclaiming);
			tipc_group_proto_xmit(grp, rm, GRP_RECLAIM_MSG, xmitq);
		}
		/* If max active, become pending and wait for reclaimed space */
		if (active_cnt >= max_active) {
			m->state = MBR_PENDING;
			list_add_tail(&m->list, &grp->pending);
			break;
		}
		/* Otherwise become active */
		m->state = MBR_ACTIVE;
		list_add_tail(&m->list, &grp->active);
		grp->active_cnt++;
		/* Fall through */
	case MBR_ACTIVE:
		if (!list_is_last(&m->list, &grp->active))
			list_move_tail(&m->list, &grp->active);
		if (m->advertised > (ADV_ACTIVE * 3 / 4))
			break;
		tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
		break;
	case MBR_REMITTED:
		if (m->advertised > ADV_IDLE)
			break;
		m->state = MBR_JOINED;
		if (m->advertised < ADV_IDLE) {
			pr_warn_ratelimited("Rcv unexpected msg after REMIT\n");
			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
		}
		break;
	case MBR_RECLAIMING:
	case MBR_DISCOVERED:
	case MBR_JOINING:
	case MBR_LEAVING:
	default:
		break;
	}
}

static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
				  int mtyp, struct sk_buff_head *xmitq)
{
	struct tipc_msg *hdr;
	struct sk_buff *skb;
	int adv = 0;

	skb = tipc_msg_create(GROUP_PROTOCOL, mtyp, INT_H_SIZE, 0,
			      m->node, tipc_own_addr(grp->net),
			      m->port, grp->portid, 0);
	if (!skb)
		return;

	if (m->state == MBR_ACTIVE)
		adv = ADV_ACTIVE - m->advertised;
	else if (m->state == MBR_JOINED || m->state == MBR_PENDING)
		adv = ADV_IDLE - m->advertised;

	hdr = buf_msg(skb);

	if (mtyp == GRP_JOIN_MSG) {
		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
		msg_set_adv_win(hdr, adv);
		m->advertised += adv;
	} else if (mtyp == GRP_LEAVE_MSG) {
		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
	} else if (mtyp == GRP_ADV_MSG) {
		msg_set_adv_win(hdr, adv);
		m->advertised += adv;
	} else if (mtyp == GRP_ACK_MSG) {
		msg_set_grp_bc_acked(hdr, m->bc_rcv_nxt);
	} else if (mtyp == GRP_REMIT_MSG) {
		msg_set_grp_remitted(hdr, m->window);
	}
	msg_set_dest_droppable(hdr, true);
	__skb_queue_tail(xmitq, skb);
}

void tipc_group_proto_rcv(struct tipc_group *grp, bool *usr_wakeup,
			  struct tipc_msg *hdr, struct sk_buff_head *inputq,
			  struct sk_buff_head *xmitq)
{
	u32 node = msg_orignode(hdr);
	u32 port = msg_origport(hdr);
	struct tipc_member *m, *pm;
	struct tipc_msg *ehdr;
	u16 remitted, in_flight;

	if (!grp)
		return;

	m = tipc_group_find_member(grp, node, port);

	switch (msg_type(hdr)) {
	case GRP_JOIN_MSG:
		if (!m)
			m = tipc_group_create_member(grp, node, port,
						     MBR_QUARANTINED);
		if (!m)
			return;
		m->bc_syncpt = msg_grp_bc_syncpt(hdr);
		m->bc_rcv_nxt = m->bc_syncpt;
		m->window += msg_adv_win(hdr);

		/* Wait until PUBLISH event is received */
		if (m->state == MBR_DISCOVERED) {
			m->state = MBR_JOINING;
		} else if (m->state == MBR_PUBLISHED) {
			m->state = MBR_JOINED;
			*usr_wakeup = true;
			m->usr_pending = false;
			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
			ehdr = buf_msg(m->event_msg);
			msg_set_grp_bc_seqno(ehdr, m->bc_syncpt);
			__skb_queue_tail(inputq, m->event_msg);
		}
		if (m->window < ADV_IDLE)
			tipc_group_update_member(m, 0);
		else
			list_del_init(&m->congested);
		return;
	case GRP_LEAVE_MSG:
		if (!m)
			return;
		m->bc_syncpt = msg_grp_bc_syncpt(hdr);

		/* Wait until WITHDRAW event is received */
		if (m->state != MBR_LEAVING) {
			tipc_group_decr_active(grp, m);
			m->state = MBR_LEAVING;
			return;
		}
		/* Otherwise deliver already received WITHDRAW event */
		ehdr = buf_msg(m->event_msg);
		msg_set_grp_bc_seqno(ehdr, m->bc_syncpt);
		__skb_queue_tail(inputq, m->event_msg);
		*usr_wakeup = true;
		list_del_init(&m->congested);
		return;
	case GRP_ADV_MSG:
		if (!m)
			return;
		m->window += msg_adv_win(hdr);
		*usr_wakeup = m->usr_pending;
		m->usr_pending = false;
		list_del_init(&m->congested);
		return;
	case GRP_ACK_MSG:
		if (!m)
			return;
		m->bc_acked = msg_grp_bc_acked(hdr);
		if (--grp->bc_ackers)
			break;
		*usr_wakeup = true;
		m->usr_pending = false;
		return;
	case GRP_RECLAIM_MSG:
		if (!m)
			return;
		*usr_wakeup = m->usr_pending;
		m->usr_pending = false;
		tipc_group_proto_xmit(grp, m, GRP_REMIT_MSG, xmitq);
		m->window = ADV_IDLE;
		return;
	case GRP_REMIT_MSG:
		if (!m || m->state != MBR_RECLAIMING)
			return;

		list_del_init(&m->list);
		grp->active_cnt--;
		remitted = msg_grp_remitted(hdr);

		/* Messages preceding the REMIT still in receive queue */
		if (m->advertised > remitted) {
			m->state = MBR_REMITTED;
			in_flight = m->advertised - remitted;
		}
		/* All messages preceding the REMIT have been read */
		if (m->advertised <= remitted) {
			m->state = MBR_JOINED;
			in_flight = 0;
		}
		/* ..and the REMIT overtaken by more messages => re-advertise */
		if (m->advertised < remitted)
			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);

		m->advertised = ADV_IDLE + in_flight;

		/* Set oldest pending member to active and advertise */
		if (list_empty(&grp->pending))
			return;
		pm = list_first_entry(&grp->pending, struct tipc_member, list);
		pm->state = MBR_ACTIVE;
		list_move_tail(&pm->list, &grp->active);
		grp->active_cnt++;
		if (pm->advertised <= (ADV_ACTIVE * 3 / 4))
			tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
		return;
	default:
		pr_warn("Received unknown GROUP_PROTO message\n");
	}
}

/* tipc_group_member_evt() - receive and handle a member up/down event
 */
void tipc_group_member_evt(struct tipc_group *grp,
			   bool *usr_wakeup,
			   int *sk_rcvbuf,
			   struct sk_buff *skb,
			   struct sk_buff_head *inputq,
			   struct sk_buff_head *xmitq)
{
	struct tipc_msg *hdr = buf_msg(skb);
	struct tipc_event *evt = (void *)msg_data(hdr);
	u32 instance = evt->found_lower;
	u32 node = evt->port.node;
	u32 port = evt->port.ref;
	int event = evt->event;
	struct tipc_member *m;
	struct net *net;
	bool node_up;
	u32 self;

	if (!grp)
		goto drop;

	net = grp->net;
	self = tipc_own_addr(net);
	if (!grp->loopback && node == self && port == grp->portid)
		goto drop;

	/* Convert message before delivery to user */
	msg_set_hdr_sz(hdr, GROUP_H_SIZE);
	msg_set_user(hdr, TIPC_CRITICAL_IMPORTANCE);
	msg_set_type(hdr, TIPC_GRP_MEMBER_EVT);
	msg_set_origport(hdr, port);
	msg_set_orignode(hdr, node);
	msg_set_nametype(hdr, grp->type);
	msg_set_grp_evt(hdr, event);

	m = tipc_group_find_member(grp, node, port);

	if (event == TIPC_PUBLISHED) {
		if (!m)
			m = tipc_group_create_member(grp, node, port,
						     MBR_DISCOVERED);
		if (!m)
			goto drop;

		/* Hold back event if JOIN message not yet received */
		if (m->state == MBR_DISCOVERED) {
			m->event_msg = skb;
			m->state = MBR_PUBLISHED;
		} else {
			msg_set_grp_bc_seqno(hdr, m->bc_syncpt);
			__skb_queue_tail(inputq, skb);
			m->state = MBR_JOINED;
			*usr_wakeup = true;
			m->usr_pending = false;
		}
		m->instance = instance;
		TIPC_SKB_CB(skb)->orig_member = m->instance;
		tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, xmitq);
		if (m->window < ADV_IDLE)
			tipc_group_update_member(m, 0);
		else
			list_del_init(&m->congested);
	} else if (event == TIPC_WITHDRAWN) {
		if (!m)
			goto drop;

		TIPC_SKB_CB(skb)->orig_member = m->instance;

		*usr_wakeup = true;
		m->usr_pending = false;
		node_up = tipc_node_is_up(net, node);

		/* Hold back event if more messages might be expected */
		if (m->state != MBR_LEAVING && node_up) {
			m->event_msg = skb;
			tipc_group_decr_active(grp, m);
			m->state = MBR_LEAVING;
		} else {
			if (node_up)
				msg_set_grp_bc_seqno(hdr, m->bc_syncpt);
			else
				msg_set_grp_bc_seqno(hdr, m->bc_rcv_nxt);
			__skb_queue_tail(inputq, skb);
		}
		list_del_init(&m->congested);
	}
	*sk_rcvbuf = tipc_group_rcvbuf_limit(grp);
	return;
drop:
	kfree_skb(skb);
}