xref: /openbmc/linux/net/tipc/group.c (revision 2127c01b)
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 
51 enum 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 
62 struct 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 
79 struct 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 
101 static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
102 				  int mtyp, struct sk_buff_head *xmitq);
103 
104 static 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 
114 static 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 
122 static 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 
140 u16 tipc_group_bc_snd_nxt(struct tipc_group *grp)
141 {
142 	return grp->bc_snd_nxt;
143 }
144 
145 static bool tipc_group_is_receiver(struct tipc_member *m)
146 {
147 	return m && m->state != MBR_JOINING && m->state != MBR_LEAVING;
148 }
149 
150 static bool tipc_group_is_sender(struct tipc_member *m)
151 {
152 	return m && m->state != MBR_JOINING && m->state != MBR_PUBLISHED;
153 }
154 
155 u32 tipc_group_exclude(struct tipc_group *grp)
156 {
157 	if (!grp->loopback)
158 		return grp->portid;
159 	return 0;
160 }
161 
162 struct 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 
196 void 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 
211 void 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 
231 static 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 
251 static 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 
262 static 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 
276 static void 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;
295 	}
296 	rb_link_node(&m->tree_node, parent, n);
297 	rb_insert_color(&m->tree_node, &grp->members);
298 }
299 
300 static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
301 						    u32 node, u32 port,
302 						    u32 instance, int state)
303 {
304 	struct tipc_member *m;
305 
306 	m = kzalloc(sizeof(*m), GFP_ATOMIC);
307 	if (!m)
308 		return NULL;
309 	INIT_LIST_HEAD(&m->list);
310 	INIT_LIST_HEAD(&m->small_win);
311 	__skb_queue_head_init(&m->deferredq);
312 	m->group = grp;
313 	m->node = node;
314 	m->port = port;
315 	m->instance = instance;
316 	m->bc_acked = grp->bc_snd_nxt - 1;
317 	grp->member_cnt++;
318 	tipc_group_add_to_tree(grp, m);
319 	tipc_nlist_add(&grp->dests, m->node);
320 	m->state = state;
321 	return m;
322 }
323 
324 void tipc_group_add_member(struct tipc_group *grp, u32 node,
325 			   u32 port, u32 instance)
326 {
327 	tipc_group_create_member(grp, node, port, instance, MBR_PUBLISHED);
328 }
329 
330 static void tipc_group_delete_member(struct tipc_group *grp,
331 				     struct tipc_member *m)
332 {
333 	rb_erase(&m->tree_node, &grp->members);
334 	grp->member_cnt--;
335 
336 	/* Check if we were waiting for replicast ack from this member */
337 	if (grp->bc_ackers && less(m->bc_acked, grp->bc_snd_nxt - 1))
338 		grp->bc_ackers--;
339 
340 	list_del_init(&m->list);
341 	list_del_init(&m->small_win);
342 	tipc_group_decr_active(grp, m);
343 
344 	/* If last member on a node, remove node from dest list */
345 	if (!tipc_group_find_node(grp, m->node))
346 		tipc_nlist_del(&grp->dests, m->node);
347 
348 	kfree(m);
349 }
350 
351 struct tipc_nlist *tipc_group_dests(struct tipc_group *grp)
352 {
353 	return &grp->dests;
354 }
355 
356 void tipc_group_self(struct tipc_group *grp, struct tipc_name_seq *seq,
357 		     int *scope)
358 {
359 	seq->type = grp->type;
360 	seq->lower = grp->instance;
361 	seq->upper = grp->instance;
362 	*scope = grp->scope;
363 }
364 
365 void tipc_group_update_member(struct tipc_member *m, int len)
366 {
367 	struct tipc_group *grp = m->group;
368 	struct tipc_member *_m, *tmp;
369 
370 	if (!tipc_group_is_receiver(m))
371 		return;
372 
373 	m->window -= len;
374 
375 	if (m->window >= ADV_IDLE)
376 		return;
377 
378 	list_del_init(&m->small_win);
379 
380 	/* Sort member into small_window members' list */
381 	list_for_each_entry_safe(_m, tmp, &grp->small_win, small_win) {
382 		if (_m->window > m->window)
383 			break;
384 	}
385 	list_add_tail(&m->small_win, &_m->small_win);
386 }
387 
388 void tipc_group_update_bc_members(struct tipc_group *grp, int len, bool ack)
389 {
390 	u16 prev = grp->bc_snd_nxt - 1;
391 	struct tipc_member *m;
392 	struct rb_node *n;
393 	u16 ackers = 0;
394 
395 	for (n = rb_first(&grp->members); n; n = rb_next(n)) {
396 		m = container_of(n, struct tipc_member, tree_node);
397 		if (tipc_group_is_receiver(m)) {
398 			tipc_group_update_member(m, len);
399 			m->bc_acked = prev;
400 			ackers++;
401 		}
402 	}
403 
404 	/* Mark number of acknowledges to expect, if any */
405 	if (ack)
406 		grp->bc_ackers = ackers;
407 	grp->bc_snd_nxt++;
408 }
409 
410 bool tipc_group_cong(struct tipc_group *grp, u32 dnode, u32 dport,
411 		     int len, struct tipc_member **mbr)
412 {
413 	struct sk_buff_head xmitq;
414 	struct tipc_member *m;
415 	int adv, state;
416 
417 	m = tipc_group_find_dest(grp, dnode, dport);
418 	if (!tipc_group_is_receiver(m)) {
419 		*mbr = NULL;
420 		return false;
421 	}
422 	*mbr = m;
423 
424 	if (m->window >= len)
425 		return false;
426 
427 	*grp->open = false;
428 
429 	/* If not fully advertised, do it now to prevent mutual blocking */
430 	adv = m->advertised;
431 	state = m->state;
432 	if (state == MBR_JOINED && adv == ADV_IDLE)
433 		return true;
434 	if (state == MBR_ACTIVE && adv == ADV_ACTIVE)
435 		return true;
436 	if (state == MBR_PENDING && adv == ADV_IDLE)
437 		return true;
438 	skb_queue_head_init(&xmitq);
439 	tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, &xmitq);
440 	tipc_node_distr_xmit(grp->net, &xmitq);
441 	return true;
442 }
443 
444 bool tipc_group_bc_cong(struct tipc_group *grp, int len)
445 {
446 	struct tipc_member *m = NULL;
447 
448 	/* If prev bcast was replicast, reject until all receivers have acked */
449 	if (grp->bc_ackers) {
450 		*grp->open = false;
451 		return true;
452 	}
453 	if (list_empty(&grp->small_win))
454 		return false;
455 
456 	m = list_first_entry(&grp->small_win, struct tipc_member, small_win);
457 	if (m->window >= len)
458 		return false;
459 
460 	return tipc_group_cong(grp, m->node, m->port, len, &m);
461 }
462 
463 /* tipc_group_sort_msg() - sort msg into queue by bcast sequence number
464  */
465 static void tipc_group_sort_msg(struct sk_buff *skb, struct sk_buff_head *defq)
466 {
467 	struct tipc_msg *_hdr, *hdr = buf_msg(skb);
468 	u16 bc_seqno = msg_grp_bc_seqno(hdr);
469 	struct sk_buff *_skb, *tmp;
470 	int mtyp = msg_type(hdr);
471 
472 	/* Bcast/mcast may be bypassed by ucast or other bcast, - sort it in */
473 	if (mtyp == TIPC_GRP_BCAST_MSG || mtyp == TIPC_GRP_MCAST_MSG) {
474 		skb_queue_walk_safe(defq, _skb, tmp) {
475 			_hdr = buf_msg(_skb);
476 			if (!less(bc_seqno, msg_grp_bc_seqno(_hdr)))
477 				continue;
478 			__skb_queue_before(defq, _skb, skb);
479 			return;
480 		}
481 		/* Bcast was not bypassed, - add to tail */
482 	}
483 	/* Unicasts are never bypassed, - always add to tail */
484 	__skb_queue_tail(defq, skb);
485 }
486 
487 /* tipc_group_filter_msg() - determine if we should accept arriving message
488  */
489 void tipc_group_filter_msg(struct tipc_group *grp, struct sk_buff_head *inputq,
490 			   struct sk_buff_head *xmitq)
491 {
492 	struct sk_buff *skb = __skb_dequeue(inputq);
493 	bool ack, deliver, update, leave = false;
494 	struct sk_buff_head *defq;
495 	struct tipc_member *m;
496 	struct tipc_msg *hdr;
497 	u32 node, port;
498 	int mtyp, blks;
499 
500 	if (!skb)
501 		return;
502 
503 	hdr = buf_msg(skb);
504 	node =  msg_orignode(hdr);
505 	port = msg_origport(hdr);
506 
507 	if (!msg_in_group(hdr))
508 		goto drop;
509 
510 	m = tipc_group_find_member(grp, node, port);
511 	if (!tipc_group_is_sender(m))
512 		goto drop;
513 
514 	if (less(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
515 		goto drop;
516 
517 	TIPC_SKB_CB(skb)->orig_member = m->instance;
518 	defq = &m->deferredq;
519 	tipc_group_sort_msg(skb, defq);
520 
521 	while ((skb = skb_peek(defq))) {
522 		hdr = buf_msg(skb);
523 		mtyp = msg_type(hdr);
524 		blks = msg_blocks(hdr);
525 		deliver = true;
526 		ack = false;
527 		update = false;
528 
529 		if (more(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
530 			break;
531 
532 		/* Decide what to do with message */
533 		switch (mtyp) {
534 		case TIPC_GRP_MCAST_MSG:
535 			if (msg_nameinst(hdr) != grp->instance) {
536 				update = true;
537 				deliver = false;
538 			}
539 			/* Fall thru */
540 		case TIPC_GRP_BCAST_MSG:
541 			m->bc_rcv_nxt++;
542 			ack = msg_grp_bc_ack_req(hdr);
543 			break;
544 		case TIPC_GRP_UCAST_MSG:
545 			break;
546 		case TIPC_GRP_MEMBER_EVT:
547 			if (m->state == MBR_LEAVING)
548 				leave = true;
549 			if (!grp->events)
550 				deliver = false;
551 			break;
552 		default:
553 			break;
554 		}
555 
556 		/* Execute decisions */
557 		__skb_dequeue(defq);
558 		if (deliver)
559 			__skb_queue_tail(inputq, skb);
560 		else
561 			kfree_skb(skb);
562 
563 		if (ack)
564 			tipc_group_proto_xmit(grp, m, GRP_ACK_MSG, xmitq);
565 
566 		if (leave) {
567 			__skb_queue_purge(defq);
568 			tipc_group_delete_member(grp, m);
569 			break;
570 		}
571 		if (!update)
572 			continue;
573 
574 		tipc_group_update_rcv_win(grp, blks, node, port, xmitq);
575 	}
576 	return;
577 drop:
578 	kfree_skb(skb);
579 }
580 
581 void tipc_group_update_rcv_win(struct tipc_group *grp, int blks, u32 node,
582 			       u32 port, struct sk_buff_head *xmitq)
583 {
584 	struct list_head *active = &grp->active;
585 	int max_active = grp->max_active;
586 	int reclaim_limit = max_active * 3 / 4;
587 	int active_cnt = grp->active_cnt;
588 	struct tipc_member *m, *rm, *pm;
589 
590 	m = tipc_group_find_member(grp, node, port);
591 	if (!m)
592 		return;
593 
594 	m->advertised -= blks;
595 
596 	switch (m->state) {
597 	case MBR_JOINED:
598 		/* First, decide if member can go active */
599 		if (active_cnt <= max_active) {
600 			m->state = MBR_ACTIVE;
601 			list_add_tail(&m->list, active);
602 			grp->active_cnt++;
603 			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
604 		} else {
605 			m->state = MBR_PENDING;
606 			list_add_tail(&m->list, &grp->pending);
607 		}
608 
609 		if (active_cnt < reclaim_limit)
610 			break;
611 
612 		/* Reclaim from oldest active member, if possible */
613 		if (!list_empty(active)) {
614 			rm = list_first_entry(active, struct tipc_member, list);
615 			rm->state = MBR_RECLAIMING;
616 			list_del_init(&rm->list);
617 			tipc_group_proto_xmit(grp, rm, GRP_RECLAIM_MSG, xmitq);
618 			break;
619 		}
620 		/* Nobody to reclaim from; - revert oldest pending to JOINED */
621 		pm = list_first_entry(&grp->pending, struct tipc_member, list);
622 		list_del_init(&pm->list);
623 		pm->state = MBR_JOINED;
624 		tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
625 		break;
626 	case MBR_ACTIVE:
627 		if (!list_is_last(&m->list, &grp->active))
628 			list_move_tail(&m->list, &grp->active);
629 		if (m->advertised > (ADV_ACTIVE * 3 / 4))
630 			break;
631 		tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
632 		break;
633 	case MBR_REMITTED:
634 		if (m->advertised > ADV_IDLE)
635 			break;
636 		m->state = MBR_JOINED;
637 		grp->active_cnt--;
638 		if (m->advertised < ADV_IDLE) {
639 			pr_warn_ratelimited("Rcv unexpected msg after REMIT\n");
640 			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
641 		}
642 
643 		if (list_empty(&grp->pending))
644 			return;
645 
646 		/* Set oldest pending member to active and advertise */
647 		pm = list_first_entry(&grp->pending, struct tipc_member, list);
648 		pm->state = MBR_ACTIVE;
649 		list_move_tail(&pm->list, &grp->active);
650 		grp->active_cnt++;
651 		tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
652 		break;
653 	case MBR_RECLAIMING:
654 	case MBR_JOINING:
655 	case MBR_LEAVING:
656 	default:
657 		break;
658 	}
659 }
660 
661 static void tipc_group_create_event(struct tipc_group *grp,
662 				    struct tipc_member *m,
663 				    u32 event, u16 seqno,
664 				    struct sk_buff_head *inputq)
665 {	u32 dnode = tipc_own_addr(grp->net);
666 	struct tipc_event evt;
667 	struct sk_buff *skb;
668 	struct tipc_msg *hdr;
669 
670 	memset(&evt, 0, sizeof(evt));
671 	evt.event = event;
672 	evt.found_lower = m->instance;
673 	evt.found_upper = m->instance;
674 	evt.port.ref = m->port;
675 	evt.port.node = m->node;
676 	evt.s.seq.type = grp->type;
677 	evt.s.seq.lower = m->instance;
678 	evt.s.seq.upper = m->instance;
679 
680 	skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_GRP_MEMBER_EVT,
681 			      GROUP_H_SIZE, sizeof(evt), dnode, m->node,
682 			      grp->portid, m->port, 0);
683 	if (!skb)
684 		return;
685 
686 	hdr = buf_msg(skb);
687 	msg_set_nametype(hdr, grp->type);
688 	msg_set_grp_evt(hdr, event);
689 	msg_set_dest_droppable(hdr, true);
690 	msg_set_grp_bc_seqno(hdr, seqno);
691 	memcpy(msg_data(hdr), &evt, sizeof(evt));
692 	TIPC_SKB_CB(skb)->orig_member = m->instance;
693 	__skb_queue_tail(inputq, skb);
694 }
695 
696 static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
697 				  int mtyp, struct sk_buff_head *xmitq)
698 {
699 	struct tipc_msg *hdr;
700 	struct sk_buff *skb;
701 	int adv = 0;
702 
703 	skb = tipc_msg_create(GROUP_PROTOCOL, mtyp, INT_H_SIZE, 0,
704 			      m->node, tipc_own_addr(grp->net),
705 			      m->port, grp->portid, 0);
706 	if (!skb)
707 		return;
708 
709 	if (m->state == MBR_ACTIVE)
710 		adv = ADV_ACTIVE - m->advertised;
711 	else if (m->state == MBR_JOINED || m->state == MBR_PENDING)
712 		adv = ADV_IDLE - m->advertised;
713 
714 	hdr = buf_msg(skb);
715 
716 	if (mtyp == GRP_JOIN_MSG) {
717 		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
718 		msg_set_adv_win(hdr, adv);
719 		m->advertised += adv;
720 	} else if (mtyp == GRP_LEAVE_MSG) {
721 		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
722 	} else if (mtyp == GRP_ADV_MSG) {
723 		msg_set_adv_win(hdr, adv);
724 		m->advertised += adv;
725 	} else if (mtyp == GRP_ACK_MSG) {
726 		msg_set_grp_bc_acked(hdr, m->bc_rcv_nxt);
727 	} else if (mtyp == GRP_REMIT_MSG) {
728 		msg_set_grp_remitted(hdr, m->window);
729 	}
730 	msg_set_dest_droppable(hdr, true);
731 	__skb_queue_tail(xmitq, skb);
732 }
733 
734 void tipc_group_proto_rcv(struct tipc_group *grp, bool *usr_wakeup,
735 			  struct tipc_msg *hdr, struct sk_buff_head *inputq,
736 			  struct sk_buff_head *xmitq)
737 {
738 	u32 node = msg_orignode(hdr);
739 	u32 port = msg_origport(hdr);
740 	struct tipc_member *m, *pm;
741 	u16 remitted, in_flight;
742 
743 	if (!grp)
744 		return;
745 
746 	if (grp->scope == TIPC_NODE_SCOPE && node != tipc_own_addr(grp->net))
747 		return;
748 
749 	m = tipc_group_find_member(grp, node, port);
750 
751 	switch (msg_type(hdr)) {
752 	case GRP_JOIN_MSG:
753 		if (!m)
754 			m = tipc_group_create_member(grp, node, port,
755 						     0, MBR_JOINING);
756 		if (!m)
757 			return;
758 		m->bc_syncpt = msg_grp_bc_syncpt(hdr);
759 		m->bc_rcv_nxt = m->bc_syncpt;
760 		m->window += msg_adv_win(hdr);
761 
762 		/* Wait until PUBLISH event is received if necessary */
763 		if (m->state != MBR_PUBLISHED)
764 			return;
765 
766 		/* Member can be taken into service */
767 		m->state = MBR_JOINED;
768 		tipc_group_open(m, usr_wakeup);
769 		tipc_group_update_member(m, 0);
770 		tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
771 		tipc_group_create_event(grp, m, TIPC_PUBLISHED,
772 					m->bc_syncpt, inputq);
773 		return;
774 	case GRP_LEAVE_MSG:
775 		if (!m)
776 			return;
777 		m->bc_syncpt = msg_grp_bc_syncpt(hdr);
778 		list_del_init(&m->list);
779 		tipc_group_open(m, usr_wakeup);
780 		tipc_group_decr_active(grp, m);
781 		m->state = MBR_LEAVING;
782 		tipc_group_create_event(grp, m, TIPC_WITHDRAWN,
783 					m->bc_syncpt, inputq);
784 		return;
785 	case GRP_ADV_MSG:
786 		if (!m)
787 			return;
788 		m->window += msg_adv_win(hdr);
789 		tipc_group_open(m, usr_wakeup);
790 		return;
791 	case GRP_ACK_MSG:
792 		if (!m)
793 			return;
794 		m->bc_acked = msg_grp_bc_acked(hdr);
795 		if (--grp->bc_ackers)
796 			return;
797 		list_del_init(&m->small_win);
798 		*m->group->open = true;
799 		*usr_wakeup = true;
800 		tipc_group_update_member(m, 0);
801 		return;
802 	case GRP_RECLAIM_MSG:
803 		if (!m)
804 			return;
805 		tipc_group_proto_xmit(grp, m, GRP_REMIT_MSG, xmitq);
806 		m->window = ADV_IDLE;
807 		tipc_group_open(m, usr_wakeup);
808 		return;
809 	case GRP_REMIT_MSG:
810 		if (!m || m->state != MBR_RECLAIMING)
811 			return;
812 
813 		remitted = msg_grp_remitted(hdr);
814 
815 		/* Messages preceding the REMIT still in receive queue */
816 		if (m->advertised > remitted) {
817 			m->state = MBR_REMITTED;
818 			in_flight = m->advertised - remitted;
819 			m->advertised = ADV_IDLE + in_flight;
820 			return;
821 		}
822 		/* This should never happen */
823 		if (m->advertised < remitted)
824 			pr_warn_ratelimited("Unexpected REMIT msg\n");
825 
826 		/* All messages preceding the REMIT have been read */
827 		m->state = MBR_JOINED;
828 		grp->active_cnt--;
829 		m->advertised = ADV_IDLE;
830 
831 		/* Set oldest pending member to active and advertise */
832 		if (list_empty(&grp->pending))
833 			return;
834 		pm = list_first_entry(&grp->pending, struct tipc_member, list);
835 		pm->state = MBR_ACTIVE;
836 		list_move_tail(&pm->list, &grp->active);
837 		grp->active_cnt++;
838 		if (pm->advertised <= (ADV_ACTIVE * 3 / 4))
839 			tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
840 		return;
841 	default:
842 		pr_warn("Received unknown GROUP_PROTO message\n");
843 	}
844 }
845 
846 /* tipc_group_member_evt() - receive and handle a member up/down event
847  */
848 void tipc_group_member_evt(struct tipc_group *grp,
849 			   bool *usr_wakeup,
850 			   int *sk_rcvbuf,
851 			   struct tipc_msg *hdr,
852 			   struct sk_buff_head *inputq,
853 			   struct sk_buff_head *xmitq)
854 {
855 	struct tipc_event *evt = (void *)msg_data(hdr);
856 	u32 instance = evt->found_lower;
857 	u32 node = evt->port.node;
858 	u32 port = evt->port.ref;
859 	int event = evt->event;
860 	struct tipc_member *m;
861 	struct net *net;
862 	u32 self;
863 
864 	if (!grp)
865 		return;
866 
867 	net = grp->net;
868 	self = tipc_own_addr(net);
869 	if (!grp->loopback && node == self && port == grp->portid)
870 		return;
871 
872 	m = tipc_group_find_member(grp, node, port);
873 
874 	switch (event) {
875 	case TIPC_PUBLISHED:
876 		/* Send and wait for arrival of JOIN message if necessary */
877 		if (!m) {
878 			m = tipc_group_create_member(grp, node, port, instance,
879 						     MBR_PUBLISHED);
880 			if (!m)
881 				break;
882 			tipc_group_update_member(m, 0);
883 			tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, xmitq);
884 			break;
885 		}
886 
887 		if (m->state != MBR_JOINING)
888 			break;
889 
890 		/* Member can be taken into service */
891 		m->instance = instance;
892 		m->state = MBR_JOINED;
893 		tipc_group_open(m, usr_wakeup);
894 		tipc_group_update_member(m, 0);
895 		tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, xmitq);
896 		tipc_group_create_event(grp, m, TIPC_PUBLISHED,
897 					m->bc_syncpt, inputq);
898 		break;
899 	case TIPC_WITHDRAWN:
900 		if (!m)
901 			break;
902 
903 		tipc_group_decr_active(grp, m);
904 		m->state = MBR_LEAVING;
905 		list_del_init(&m->list);
906 		tipc_group_open(m, usr_wakeup);
907 
908 		/* Only send event if no LEAVE message can be expected */
909 		if (!tipc_node_is_up(net, node))
910 			tipc_group_create_event(grp, m, TIPC_WITHDRAWN,
911 						m->bc_rcv_nxt, inputq);
912 		break;
913 	default:
914 		break;
915 	}
916 	*sk_rcvbuf = tipc_group_rcvbuf_limit(grp);
917 }
918 
919 int tipc_group_fill_sock_diag(struct tipc_group *grp, struct sk_buff *skb)
920 {
921 	struct nlattr *group = nla_nest_start_noflag(skb, TIPC_NLA_SOCK_GROUP);
922 
923 	if (!group)
924 		return -EMSGSIZE;
925 
926 	if (nla_put_u32(skb, TIPC_NLA_SOCK_GROUP_ID,
927 			grp->type) ||
928 	    nla_put_u32(skb, TIPC_NLA_SOCK_GROUP_INSTANCE,
929 			grp->instance) ||
930 	    nla_put_u32(skb, TIPC_NLA_SOCK_GROUP_BC_SEND_NEXT,
931 			grp->bc_snd_nxt))
932 		goto group_msg_cancel;
933 
934 	if (grp->scope == TIPC_NODE_SCOPE)
935 		if (nla_put_flag(skb, TIPC_NLA_SOCK_GROUP_NODE_SCOPE))
936 			goto group_msg_cancel;
937 
938 	if (grp->scope == TIPC_CLUSTER_SCOPE)
939 		if (nla_put_flag(skb, TIPC_NLA_SOCK_GROUP_CLUSTER_SCOPE))
940 			goto group_msg_cancel;
941 
942 	if (*grp->open)
943 		if (nla_put_flag(skb, TIPC_NLA_SOCK_GROUP_OPEN))
944 			goto group_msg_cancel;
945 
946 	nla_nest_end(skb, group);
947 	return 0;
948 
949 group_msg_cancel:
950 	nla_nest_cancel(skb, group);
951 	return -1;
952 }
953