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  1/*
  2 * net/tipc/group.c: TIPC group messaging code
  3 *
  4 * Copyright (c) 2017, Ericsson AB
  5 * All rights reserved.
  6 *
  7 * Redistribution and use in source and binary forms, with or without
  8 * modification, are permitted provided that the following conditions are met:
  9 *
 10 * 1. Redistributions of source code must retain the above copyright
 11 *    notice, this list of conditions and the following disclaimer.
 12 * 2. Redistributions in binary form must reproduce the above copyright
 13 *    notice, this list of conditions and the following disclaimer in the
 14 *    documentation and/or other materials provided with the distribution.
 15 * 3. Neither the names of the copyright holders nor the names of its
 16 *    contributors may be used to endorse or promote products derived from
 17 *    this software without specific prior written permission.
 18 *
 19 * Alternatively, this software may be distributed under the terms of the
 20 * GNU General Public License ("GPL") version 2 as published by the Free
 21 * Software Foundation.
 22 *
 23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 24 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 27 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 33 * POSSIBILITY OF SUCH DAMAGE.
 34 */
 35
 36#include "core.h"
 37#include "addr.h"
 38#include "group.h"
 39#include "bcast.h"
 40#include "topsrv.h"
 41#include "msg.h"
 42#include "socket.h"
 43#include "node.h"
 44#include "name_table.h"
 45#include "subscr.h"
 46
 47#define ADV_UNIT (((MAX_MSG_SIZE + MAX_H_SIZE) / FLOWCTL_BLK_SZ) + 1)
 48#define ADV_IDLE ADV_UNIT
 49#define ADV_ACTIVE (ADV_UNIT * 12)
 50
 51enum mbr_state {
 52	MBR_JOINING,
 53	MBR_PUBLISHED,
 54	MBR_JOINED,
 55	MBR_PENDING,
 56	MBR_ACTIVE,
 57	MBR_RECLAIMING,
 58	MBR_REMITTED,
 59	MBR_LEAVING
 60};
 61
 62struct tipc_member {
 63	struct rb_node tree_node;
 64	struct list_head list;
 65	struct list_head small_win;
 66	struct sk_buff_head deferredq;
 67	struct tipc_group *group;
 68	u32 node;
 69	u32 port;
 70	u32 instance;
 71	enum mbr_state state;
 72	u16 advertised;
 73	u16 window;
 74	u16 bc_rcv_nxt;
 75	u16 bc_syncpt;
 76	u16 bc_acked;
 77};
 78
 79struct tipc_group {
 80	struct rb_root members;
 81	struct list_head small_win;
 82	struct list_head pending;
 83	struct list_head active;
 84	struct tipc_nlist dests;
 85	struct net *net;
 86	int subid;
 87	u32 type;
 88	u32 instance;
 89	u32 scope;
 90	u32 portid;
 91	u16 member_cnt;
 92	u16 active_cnt;
 93	u16 max_active;
 94	u16 bc_snd_nxt;
 95	u16 bc_ackers;
 96	bool *open;
 97	bool loopback;
 98	bool events;
 99};
100
101static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
102				  int mtyp, struct sk_buff_head *xmitq);
103
104static void tipc_group_open(struct tipc_member *m, bool *wakeup)
105{
106	*wakeup = false;
107	if (list_empty(&m->small_win))
108		return;
109	list_del_init(&m->small_win);
110	*m->group->open = true;
111	*wakeup = true;
112}
113
114static void tipc_group_decr_active(struct tipc_group *grp,
115				   struct tipc_member *m)
116{
117	if (m->state == MBR_ACTIVE || m->state == MBR_RECLAIMING ||
118	    m->state == MBR_REMITTED)
119		grp->active_cnt--;
120}
121
122static int tipc_group_rcvbuf_limit(struct tipc_group *grp)
123{
124	int max_active, active_pool, idle_pool;
125	int mcnt = grp->member_cnt + 1;
126
127	/* Limit simultaneous reception from other members */
128	max_active = min(mcnt / 8, 64);
129	max_active = max(max_active, 16);
130	grp->max_active = max_active;
131
132	/* Reserve blocks for active and idle members */
133	active_pool = max_active * ADV_ACTIVE;
134	idle_pool = (mcnt - max_active) * ADV_IDLE;
135
136	/* Scale to bytes, considering worst-case truesize/msgsize ratio */
137	return (active_pool + idle_pool) * FLOWCTL_BLK_SZ * 4;
138}
139
140u16 tipc_group_bc_snd_nxt(struct tipc_group *grp)
141{
142	return grp->bc_snd_nxt;
143}
144
145static bool tipc_group_is_receiver(struct tipc_member *m)
146{
147	return m && m->state != MBR_JOINING && m->state != MBR_LEAVING;
148}
149
150static bool tipc_group_is_sender(struct tipc_member *m)
151{
152	return m && m->state != MBR_JOINING && m->state != MBR_PUBLISHED;
153}
154
155u32 tipc_group_exclude(struct tipc_group *grp)
156{
157	if (!grp->loopback)
158		return grp->portid;
159	return 0;
160}
161
162struct tipc_group *tipc_group_create(struct net *net, u32 portid,
163				     struct tipc_group_req *mreq,
164				     bool *group_is_open)
165{
166	u32 filter = TIPC_SUB_PORTS | TIPC_SUB_NO_STATUS;
167	bool global = mreq->scope != TIPC_NODE_SCOPE;
168	struct tipc_group *grp;
169	u32 type = mreq->type;
170
171	grp = kzalloc(sizeof(*grp), GFP_ATOMIC);
172	if (!grp)
173		return NULL;
174	tipc_nlist_init(&grp->dests, tipc_own_addr(net));
175	INIT_LIST_HEAD(&grp->small_win);
176	INIT_LIST_HEAD(&grp->active);
177	INIT_LIST_HEAD(&grp->pending);
178	grp->members = RB_ROOT;
179	grp->net = net;
180	grp->portid = portid;
181	grp->type = type;
182	grp->instance = mreq->instance;
183	grp->scope = mreq->scope;
184	grp->loopback = mreq->flags & TIPC_GROUP_LOOPBACK;
185	grp->events = mreq->flags & TIPC_GROUP_MEMBER_EVTS;
186	grp->open = group_is_open;
187	*grp->open = false;
188	filter |= global ? TIPC_SUB_CLUSTER_SCOPE : TIPC_SUB_NODE_SCOPE;
189	if (tipc_topsrv_kern_subscr(net, portid, type, 0, ~0,
190				    filter, &grp->subid))
191		return grp;
192	kfree(grp);
193	return NULL;
194}
195
196void tipc_group_join(struct net *net, struct tipc_group *grp, int *sk_rcvbuf)
197{
198	struct rb_root *tree = &grp->members;
199	struct tipc_member *m, *tmp;
200	struct sk_buff_head xmitq;
201
202	__skb_queue_head_init(&xmitq);
203	rbtree_postorder_for_each_entry_safe(m, tmp, tree, tree_node) {
204		tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, &xmitq);
205		tipc_group_update_member(m, 0);
206	}
207	tipc_node_distr_xmit(net, &xmitq);
208	*sk_rcvbuf = tipc_group_rcvbuf_limit(grp);
209}
210
211void tipc_group_delete(struct net *net, struct tipc_group *grp)
212{
213	struct rb_root *tree = &grp->members;
214	struct tipc_member *m, *tmp;
215	struct sk_buff_head xmitq;
216
217	__skb_queue_head_init(&xmitq);
218
219	rbtree_postorder_for_each_entry_safe(m, tmp, tree, tree_node) {
220		tipc_group_proto_xmit(grp, m, GRP_LEAVE_MSG, &xmitq);
221		__skb_queue_purge(&m->deferredq);
222		list_del(&m->list);
223		kfree(m);
224	}
225	tipc_node_distr_xmit(net, &xmitq);
226	tipc_nlist_purge(&grp->dests);
227	tipc_topsrv_kern_unsubscr(net, grp->subid);
228	kfree(grp);
229}
230
231static struct tipc_member *tipc_group_find_member(struct tipc_group *grp,
232						  u32 node, u32 port)
233{
234	struct rb_node *n = grp->members.rb_node;
235	u64 nkey, key = (u64)node << 32 | port;
236	struct tipc_member *m;
237
238	while (n) {
239		m = container_of(n, struct tipc_member, tree_node);
240		nkey = (u64)m->node << 32 | m->port;
241		if (key < nkey)
242			n = n->rb_left;
243		else if (key > nkey)
244			n = n->rb_right;
245		else
246			return m;
247	}
248	return NULL;
249}
250
251static struct tipc_member *tipc_group_find_dest(struct tipc_group *grp,
252						u32 node, u32 port)
253{
254	struct tipc_member *m;
255
256	m = tipc_group_find_member(grp, node, port);
257	if (m && tipc_group_is_receiver(m))
258		return m;
259	return NULL;
260}
261
262static struct tipc_member *tipc_group_find_node(struct tipc_group *grp,
263						u32 node)
264{
265	struct tipc_member *m;
266	struct rb_node *n;
267
268	for (n = rb_first(&grp->members); n; n = rb_next(n)) {
269		m = container_of(n, struct tipc_member, tree_node);
270		if (m->node == node)
271			return m;
272	}
273	return NULL;
274}
275
276static int tipc_group_add_to_tree(struct tipc_group *grp,
277				  struct tipc_member *m)
278{
279	u64 nkey, key = (u64)m->node << 32 | m->port;
280	struct rb_node **n, *parent = NULL;
281	struct tipc_member *tmp;
282
283	n = &grp->members.rb_node;
284	while (*n) {
285		tmp = container_of(*n, struct tipc_member, tree_node);
286		parent = *n;
287		tmp = container_of(parent, struct tipc_member, tree_node);
288		nkey = (u64)tmp->node << 32 | tmp->port;
289		if (key < nkey)
290			n = &(*n)->rb_left;
291		else if (key > nkey)
292			n = &(*n)->rb_right;
293		else
294			return -EEXIST;
295	}
296	rb_link_node(&m->tree_node, parent, n);
297	rb_insert_color(&m->tree_node, &grp->members);
298	return 0;
299}
300
301static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
302						    u32 node, u32 port,
303						    u32 instance, int state)
304{
305	struct tipc_member *m;
306	int ret;
307
308	m = kzalloc(sizeof(*m), GFP_ATOMIC);
309	if (!m)
310		return NULL;
311	INIT_LIST_HEAD(&m->list);
312	INIT_LIST_HEAD(&m->small_win);
313	__skb_queue_head_init(&m->deferredq);
314	m->group = grp;
315	m->node = node;
316	m->port = port;
317	m->instance = instance;
318	m->bc_acked = grp->bc_snd_nxt - 1;
319	ret = tipc_group_add_to_tree(grp, m);
320	if (ret < 0) {
321		kfree(m);
322		return NULL;
323	}
324	grp->member_cnt++;
325	tipc_nlist_add(&grp->dests, m->node);
326	m->state = state;
327	return m;
328}
329
330void tipc_group_add_member(struct tipc_group *grp, u32 node,
331			   u32 port, u32 instance)
332{
333	tipc_group_create_member(grp, node, port, instance, MBR_PUBLISHED);
334}
335
336static void tipc_group_delete_member(struct tipc_group *grp,
337				     struct tipc_member *m)
338{
339	rb_erase(&m->tree_node, &grp->members);
340	grp->member_cnt--;
341
342	/* Check if we were waiting for replicast ack from this member */
343	if (grp->bc_ackers && less(m->bc_acked, grp->bc_snd_nxt - 1))
344		grp->bc_ackers--;
345
346	list_del_init(&m->list);
347	list_del_init(&m->small_win);
348	tipc_group_decr_active(grp, m);
349
350	/* If last member on a node, remove node from dest list */
351	if (!tipc_group_find_node(grp, m->node))
352		tipc_nlist_del(&grp->dests, m->node);
353
354	kfree(m);
355}
356
357struct tipc_nlist *tipc_group_dests(struct tipc_group *grp)
358{
359	return &grp->dests;
360}
361
362void tipc_group_self(struct tipc_group *grp, struct tipc_name_seq *seq,
363		     int *scope)
364{
365	seq->type = grp->type;
366	seq->lower = grp->instance;
367	seq->upper = grp->instance;
368	*scope = grp->scope;
369}
370
371void tipc_group_update_member(struct tipc_member *m, int len)
372{
373	struct tipc_group *grp = m->group;
374	struct tipc_member *_m, *tmp;
375
376	if (!tipc_group_is_receiver(m))
377		return;
378
379	m->window -= len;
380
381	if (m->window >= ADV_IDLE)
382		return;
383
384	list_del_init(&m->small_win);
385
386	/* Sort member into small_window members' list */
387	list_for_each_entry_safe(_m, tmp, &grp->small_win, small_win) {
388		if (_m->window > m->window)
389			break;
390	}
391	list_add_tail(&m->small_win, &_m->small_win);
392}
393
394void tipc_group_update_bc_members(struct tipc_group *grp, int len, bool ack)
395{
396	u16 prev = grp->bc_snd_nxt - 1;
397	struct tipc_member *m;
398	struct rb_node *n;
399	u16 ackers = 0;
400
401	for (n = rb_first(&grp->members); n; n = rb_next(n)) {
402		m = container_of(n, struct tipc_member, tree_node);
403		if (tipc_group_is_receiver(m)) {
404			tipc_group_update_member(m, len);
405			m->bc_acked = prev;
406			ackers++;
407		}
408	}
409
410	/* Mark number of acknowledges to expect, if any */
411	if (ack)
412		grp->bc_ackers = ackers;
413	grp->bc_snd_nxt++;
414}
415
416bool tipc_group_cong(struct tipc_group *grp, u32 dnode, u32 dport,
417		     int len, struct tipc_member **mbr)
418{
419	struct sk_buff_head xmitq;
420	struct tipc_member *m;
421	int adv, state;
422
423	m = tipc_group_find_dest(grp, dnode, dport);
424	if (!tipc_group_is_receiver(m)) {
425		*mbr = NULL;
426		return false;
427	}
428	*mbr = m;
429
430	if (m->window >= len)
431		return false;
432
433	*grp->open = false;
434
435	/* If not fully advertised, do it now to prevent mutual blocking */
436	adv = m->advertised;
437	state = m->state;
438	if (state == MBR_JOINED && adv == ADV_IDLE)
439		return true;
440	if (state == MBR_ACTIVE && adv == ADV_ACTIVE)
441		return true;
442	if (state == MBR_PENDING && adv == ADV_IDLE)
443		return true;
444	__skb_queue_head_init(&xmitq);
445	tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, &xmitq);
446	tipc_node_distr_xmit(grp->net, &xmitq);
447	return true;
448}
449
450bool tipc_group_bc_cong(struct tipc_group *grp, int len)
451{
452	struct tipc_member *m = NULL;
453
454	/* If prev bcast was replicast, reject until all receivers have acked */
455	if (grp->bc_ackers) {
456		*grp->open = false;
457		return true;
458	}
459	if (list_empty(&grp->small_win))
460		return false;
461
462	m = list_first_entry(&grp->small_win, struct tipc_member, small_win);
463	if (m->window >= len)
464		return false;
465
466	return tipc_group_cong(grp, m->node, m->port, len, &m);
467}
468
469/* tipc_group_sort_msg() - sort msg into queue by bcast sequence number
470 */
471static void tipc_group_sort_msg(struct sk_buff *skb, struct sk_buff_head *defq)
472{
473	struct tipc_msg *_hdr, *hdr = buf_msg(skb);
474	u16 bc_seqno = msg_grp_bc_seqno(hdr);
475	struct sk_buff *_skb, *tmp;
476	int mtyp = msg_type(hdr);
477
478	/* Bcast/mcast may be bypassed by ucast or other bcast, - sort it in */
479	if (mtyp == TIPC_GRP_BCAST_MSG || mtyp == TIPC_GRP_MCAST_MSG) {
480		skb_queue_walk_safe(defq, _skb, tmp) {
481			_hdr = buf_msg(_skb);
482			if (!less(bc_seqno, msg_grp_bc_seqno(_hdr)))
483				continue;
484			__skb_queue_before(defq, _skb, skb);
485			return;
486		}
487		/* Bcast was not bypassed, - add to tail */
488	}
489	/* Unicasts are never bypassed, - always add to tail */
490	__skb_queue_tail(defq, skb);
491}
492
493/* tipc_group_filter_msg() - determine if we should accept arriving message
494 */
495void tipc_group_filter_msg(struct tipc_group *grp, struct sk_buff_head *inputq,
496			   struct sk_buff_head *xmitq)
497{
498	struct sk_buff *skb = __skb_dequeue(inputq);
499	bool ack, deliver, update, leave = false;
500	struct sk_buff_head *defq;
501	struct tipc_member *m;
502	struct tipc_msg *hdr;
503	u32 node, port;
504	int mtyp, blks;
505
506	if (!skb)
507		return;
508
509	hdr = buf_msg(skb);
510	node =  msg_orignode(hdr);
511	port = msg_origport(hdr);
512
513	if (!msg_in_group(hdr))
514		goto drop;
515
516	m = tipc_group_find_member(grp, node, port);
517	if (!tipc_group_is_sender(m))
518		goto drop;
519
520	if (less(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
521		goto drop;
522
523	TIPC_SKB_CB(skb)->orig_member = m->instance;
524	defq = &m->deferredq;
525	tipc_group_sort_msg(skb, defq);
526
527	while ((skb = skb_peek(defq))) {
528		hdr = buf_msg(skb);
529		mtyp = msg_type(hdr);
530		blks = msg_blocks(hdr);
531		deliver = true;
532		ack = false;
533		update = false;
534
535		if (more(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
536			break;
537
538		/* Decide what to do with message */
539		switch (mtyp) {
540		case TIPC_GRP_MCAST_MSG:
541			if (msg_nameinst(hdr) != grp->instance) {
542				update = true;
543				deliver = false;
544			}
545			fallthrough;
546		case TIPC_GRP_BCAST_MSG:
547			m->bc_rcv_nxt++;
548			ack = msg_grp_bc_ack_req(hdr);
549			break;
550		case TIPC_GRP_UCAST_MSG:
551			break;
552		case TIPC_GRP_MEMBER_EVT:
553			if (m->state == MBR_LEAVING)
554				leave = true;
555			if (!grp->events)
556				deliver = false;
557			break;
558		default:
559			break;
560		}
561
562		/* Execute decisions */
563		__skb_dequeue(defq);
564		if (deliver)
565			__skb_queue_tail(inputq, skb);
566		else
567			kfree_skb(skb);
568
569		if (ack)
570			tipc_group_proto_xmit(grp, m, GRP_ACK_MSG, xmitq);
571
572		if (leave) {
573			__skb_queue_purge(defq);
574			tipc_group_delete_member(grp, m);
575			break;
576		}
577		if (!update)
578			continue;
579
580		tipc_group_update_rcv_win(grp, blks, node, port, xmitq);
581	}
582	return;
583drop:
584	kfree_skb(skb);
585}
586
587void tipc_group_update_rcv_win(struct tipc_group *grp, int blks, u32 node,
588			       u32 port, struct sk_buff_head *xmitq)
589{
590	struct list_head *active = &grp->active;
591	int max_active = grp->max_active;
592	int reclaim_limit = max_active * 3 / 4;
593	int active_cnt = grp->active_cnt;
594	struct tipc_member *m, *rm, *pm;
595
596	m = tipc_group_find_member(grp, node, port);
597	if (!m)
598		return;
599
600	m->advertised -= blks;
601
602	switch (m->state) {
603	case MBR_JOINED:
604		/* First, decide if member can go active */
605		if (active_cnt <= max_active) {
606			m->state = MBR_ACTIVE;
607			list_add_tail(&m->list, active);
608			grp->active_cnt++;
609			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
610		} else {
611			m->state = MBR_PENDING;
612			list_add_tail(&m->list, &grp->pending);
613		}
614
615		if (active_cnt < reclaim_limit)
616			break;
617
618		/* Reclaim from oldest active member, if possible */
619		if (!list_empty(active)) {
620			rm = list_first_entry(active, struct tipc_member, list);
621			rm->state = MBR_RECLAIMING;
622			list_del_init(&rm->list);
623			tipc_group_proto_xmit(grp, rm, GRP_RECLAIM_MSG, xmitq);
624			break;
625		}
626		/* Nobody to reclaim from; - revert oldest pending to JOINED */
627		pm = list_first_entry(&grp->pending, struct tipc_member, list);
628		list_del_init(&pm->list);
629		pm->state = MBR_JOINED;
630		tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
631		break;
632	case MBR_ACTIVE:
633		if (!list_is_last(&m->list, &grp->active))
634			list_move_tail(&m->list, &grp->active);
635		if (m->advertised > (ADV_ACTIVE * 3 / 4))
636			break;
637		tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
638		break;
639	case MBR_REMITTED:
640		if (m->advertised > ADV_IDLE)
641			break;
642		m->state = MBR_JOINED;
643		grp->active_cnt--;
644		if (m->advertised < ADV_IDLE) {
645			pr_warn_ratelimited("Rcv unexpected msg after REMIT\n");
646			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
647		}
648
649		if (list_empty(&grp->pending))
650			return;
651
652		/* Set oldest pending member to active and advertise */
653		pm = list_first_entry(&grp->pending, struct tipc_member, list);
654		pm->state = MBR_ACTIVE;
655		list_move_tail(&pm->list, &grp->active);
656		grp->active_cnt++;
657		tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
658		break;
659	case MBR_RECLAIMING:
660	case MBR_JOINING:
661	case MBR_LEAVING:
662	default:
663		break;
664	}
665}
666
667static void tipc_group_create_event(struct tipc_group *grp,
668				    struct tipc_member *m,
669				    u32 event, u16 seqno,
670				    struct sk_buff_head *inputq)
671{	u32 dnode = tipc_own_addr(grp->net);
672	struct tipc_event evt;
673	struct sk_buff *skb;
674	struct tipc_msg *hdr;
675
676	memset(&evt, 0, sizeof(evt));
677	evt.event = event;
678	evt.found_lower = m->instance;
679	evt.found_upper = m->instance;
680	evt.port.ref = m->port;
681	evt.port.node = m->node;
682	evt.s.seq.type = grp->type;
683	evt.s.seq.lower = m->instance;
684	evt.s.seq.upper = m->instance;
685
686	skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_GRP_MEMBER_EVT,
687			      GROUP_H_SIZE, sizeof(evt), dnode, m->node,
688			      grp->portid, m->port, 0);
689	if (!skb)
690		return;
691
692	hdr = buf_msg(skb);
693	msg_set_nametype(hdr, grp->type);
694	msg_set_grp_evt(hdr, event);
695	msg_set_dest_droppable(hdr, true);
696	msg_set_grp_bc_seqno(hdr, seqno);
697	memcpy(msg_data(hdr), &evt, sizeof(evt));
698	TIPC_SKB_CB(skb)->orig_member = m->instance;
699	__skb_queue_tail(inputq, skb);
700}
701
702static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
703				  int mtyp, struct sk_buff_head *xmitq)
704{
705	struct tipc_msg *hdr;
706	struct sk_buff *skb;
707	int adv = 0;
708
709	skb = tipc_msg_create(GROUP_PROTOCOL, mtyp, INT_H_SIZE, 0,
710			      m->node, tipc_own_addr(grp->net),
711			      m->port, grp->portid, 0);
712	if (!skb)
713		return;
714
715	if (m->state == MBR_ACTIVE)
716		adv = ADV_ACTIVE - m->advertised;
717	else if (m->state == MBR_JOINED || m->state == MBR_PENDING)
718		adv = ADV_IDLE - m->advertised;
719
720	hdr = buf_msg(skb);
721
722	if (mtyp == GRP_JOIN_MSG) {
723		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
724		msg_set_adv_win(hdr, adv);
725		m->advertised += adv;
726	} else if (mtyp == GRP_LEAVE_MSG) {
727		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
728	} else if (mtyp == GRP_ADV_MSG) {
729		msg_set_adv_win(hdr, adv);
730		m->advertised += adv;
731	} else if (mtyp == GRP_ACK_MSG) {
732		msg_set_grp_bc_acked(hdr, m->bc_rcv_nxt);
733	} else if (mtyp == GRP_REMIT_MSG) {
734		msg_set_grp_remitted(hdr, m->window);
735	}
736	msg_set_dest_droppable(hdr, true);
737	__skb_queue_tail(xmitq, skb);
738}
739
740void tipc_group_proto_rcv(struct tipc_group *grp, bool *usr_wakeup,
741			  struct tipc_msg *hdr, struct sk_buff_head *inputq,
742			  struct sk_buff_head *xmitq)
743{
744	u32 node = msg_orignode(hdr);
745	u32 port = msg_origport(hdr);
746	struct tipc_member *m, *pm;
747	u16 remitted, in_flight;
748
749	if (!grp)
750		return;
751
752	if (grp->scope == TIPC_NODE_SCOPE && node != tipc_own_addr(grp->net))
753		return;
754
755	m = tipc_group_find_member(grp, node, port);
756
757	switch (msg_type(hdr)) {
758	case GRP_JOIN_MSG:
759		if (!m)
760			m = tipc_group_create_member(grp, node, port,
761						     0, MBR_JOINING);
762		if (!m)
763			return;
764		m->bc_syncpt = msg_grp_bc_syncpt(hdr);
765		m->bc_rcv_nxt = m->bc_syncpt;
766		m->window += msg_adv_win(hdr);
767
768		/* Wait until PUBLISH event is received if necessary */
769		if (m->state != MBR_PUBLISHED)
770			return;
771
772		/* Member can be taken into service */
773		m->state = MBR_JOINED;
774		tipc_group_open(m, usr_wakeup);
775		tipc_group_update_member(m, 0);
776		tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
777		tipc_group_create_event(grp, m, TIPC_PUBLISHED,
778					m->bc_syncpt, inputq);
779		return;
780	case GRP_LEAVE_MSG:
781		if (!m)
782			return;
783		m->bc_syncpt = msg_grp_bc_syncpt(hdr);
784		list_del_init(&m->list);
785		tipc_group_open(m, usr_wakeup);
786		tipc_group_decr_active(grp, m);
787		m->state = MBR_LEAVING;
788		tipc_group_create_event(grp, m, TIPC_WITHDRAWN,
789					m->bc_syncpt, inputq);
790		return;
791	case GRP_ADV_MSG:
792		if (!m)
793			return;
794		m->window += msg_adv_win(hdr);
795		tipc_group_open(m, usr_wakeup);
796		return;
797	case GRP_ACK_MSG:
798		if (!m)
799			return;
800		m->bc_acked = msg_grp_bc_acked(hdr);
801		if (--grp->bc_ackers)
802			return;
803		list_del_init(&m->small_win);
804		*m->group->open = true;
805		*usr_wakeup = true;
806		tipc_group_update_member(m, 0);
807		return;
808	case GRP_RECLAIM_MSG:
809		if (!m)
810			return;
811		tipc_group_proto_xmit(grp, m, GRP_REMIT_MSG, xmitq);
812		m->window = ADV_IDLE;
813		tipc_group_open(m, usr_wakeup);
814		return;
815	case GRP_REMIT_MSG:
816		if (!m || m->state != MBR_RECLAIMING)
817			return;
818
819		remitted = msg_grp_remitted(hdr);
820
821		/* Messages preceding the REMIT still in receive queue */
822		if (m->advertised > remitted) {
823			m->state = MBR_REMITTED;
824			in_flight = m->advertised - remitted;
825			m->advertised = ADV_IDLE + in_flight;
826			return;
827		}
828		/* This should never happen */
829		if (m->advertised < remitted)
830			pr_warn_ratelimited("Unexpected REMIT msg\n");
831
832		/* All messages preceding the REMIT have been read */
833		m->state = MBR_JOINED;
834		grp->active_cnt--;
835		m->advertised = ADV_IDLE;
836
837		/* Set oldest pending member to active and advertise */
838		if (list_empty(&grp->pending))
839			return;
840		pm = list_first_entry(&grp->pending, struct tipc_member, list);
841		pm->state = MBR_ACTIVE;
842		list_move_tail(&pm->list, &grp->active);
843		grp->active_cnt++;
844		if (pm->advertised <= (ADV_ACTIVE * 3 / 4))
845			tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
846		return;
847	default:
848		pr_warn("Received unknown GROUP_PROTO message\n");
849	}
850}
851
852/* tipc_group_member_evt() - receive and handle a member up/down event
853 */
854void tipc_group_member_evt(struct tipc_group *grp,
855			   bool *usr_wakeup,
856			   int *sk_rcvbuf,
857			   struct tipc_msg *hdr,
858			   struct sk_buff_head *inputq,
859			   struct sk_buff_head *xmitq)
860{
861	struct tipc_event *evt = (void *)msg_data(hdr);
862	u32 instance = evt->found_lower;
863	u32 node = evt->port.node;
864	u32 port = evt->port.ref;
865	int event = evt->event;
866	struct tipc_member *m;
867	struct net *net;
868	u32 self;
869
870	if (!grp)
871		return;
872
873	net = grp->net;
874	self = tipc_own_addr(net);
875	if (!grp->loopback && node == self && port == grp->portid)
876		return;
877
878	m = tipc_group_find_member(grp, node, port);
879
880	switch (event) {
881	case TIPC_PUBLISHED:
882		/* Send and wait for arrival of JOIN message if necessary */
883		if (!m) {
884			m = tipc_group_create_member(grp, node, port, instance,
885						     MBR_PUBLISHED);
886			if (!m)
887				break;
888			tipc_group_update_member(m, 0);
889			tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, xmitq);
890			break;
891		}
892
893		if (m->state != MBR_JOINING)
894			break;
895
896		/* Member can be taken into service */
897		m->instance = instance;
898		m->state = MBR_JOINED;
899		tipc_group_open(m, usr_wakeup);
900		tipc_group_update_member(m, 0);
901		tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, xmitq);
902		tipc_group_create_event(grp, m, TIPC_PUBLISHED,
903					m->bc_syncpt, inputq);
904		break;
905	case TIPC_WITHDRAWN:
906		if (!m)
907			break;
908
909		tipc_group_decr_active(grp, m);
910		m->state = MBR_LEAVING;
911		list_del_init(&m->list);
912		tipc_group_open(m, usr_wakeup);
913
914		/* Only send event if no LEAVE message can be expected */
915		if (!tipc_node_is_up(net, node))
916			tipc_group_create_event(grp, m, TIPC_WITHDRAWN,
917						m->bc_rcv_nxt, inputq);
918		break;
919	default:
920		break;
921	}
922	*sk_rcvbuf = tipc_group_rcvbuf_limit(grp);
923}
924
925int tipc_group_fill_sock_diag(struct tipc_group *grp, struct sk_buff *skb)
926{
927	struct nlattr *group = nla_nest_start_noflag(skb, TIPC_NLA_SOCK_GROUP);
928
929	if (!group)
930		return -EMSGSIZE;
931
932	if (nla_put_u32(skb, TIPC_NLA_SOCK_GROUP_ID,
933			grp->type) ||
934	    nla_put_u32(skb, TIPC_NLA_SOCK_GROUP_INSTANCE,
935			grp->instance) ||
936	    nla_put_u32(skb, TIPC_NLA_SOCK_GROUP_BC_SEND_NEXT,
937			grp->bc_snd_nxt))
938		goto group_msg_cancel;
939
940	if (grp->scope == TIPC_NODE_SCOPE)
941		if (nla_put_flag(skb, TIPC_NLA_SOCK_GROUP_NODE_SCOPE))
942			goto group_msg_cancel;
943
944	if (grp->scope == TIPC_CLUSTER_SCOPE)
945		if (nla_put_flag(skb, TIPC_NLA_SOCK_GROUP_CLUSTER_SCOPE))
946			goto group_msg_cancel;
947
948	if (*grp->open)
949		if (nla_put_flag(skb, TIPC_NLA_SOCK_GROUP_OPEN))
950			goto group_msg_cancel;
951
952	nla_nest_end(skb, group);
953	return 0;
954
955group_msg_cancel:
956	nla_nest_cancel(skb, group);
957	return -1;
958}