xref: /linux/net/tipc/group.c (revision f79e4d5f92a129a1159c973735007d4ddc8541f3)
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 int tipc_group_size(struct tipc_group *grp)
163 {
164 	return grp->member_cnt;
165 }
166 
167 struct tipc_group *tipc_group_create(struct net *net, u32 portid,
168 				     struct tipc_group_req *mreq,
169 				     bool *group_is_open)
170 {
171 	u32 filter = TIPC_SUB_PORTS | TIPC_SUB_NO_STATUS;
172 	bool global = mreq->scope != TIPC_NODE_SCOPE;
173 	struct tipc_group *grp;
174 	u32 type = mreq->type;
175 
176 	grp = kzalloc(sizeof(*grp), GFP_ATOMIC);
177 	if (!grp)
178 		return NULL;
179 	tipc_nlist_init(&grp->dests, tipc_own_addr(net));
180 	INIT_LIST_HEAD(&grp->small_win);
181 	INIT_LIST_HEAD(&grp->active);
182 	INIT_LIST_HEAD(&grp->pending);
183 	grp->members = RB_ROOT;
184 	grp->net = net;
185 	grp->portid = portid;
186 	grp->type = type;
187 	grp->instance = mreq->instance;
188 	grp->scope = mreq->scope;
189 	grp->loopback = mreq->flags & TIPC_GROUP_LOOPBACK;
190 	grp->events = mreq->flags & TIPC_GROUP_MEMBER_EVTS;
191 	grp->open = group_is_open;
192 	*grp->open = false;
193 	filter |= global ? TIPC_SUB_CLUSTER_SCOPE : TIPC_SUB_NODE_SCOPE;
194 	if (tipc_topsrv_kern_subscr(net, portid, type, 0, ~0,
195 				    filter, &grp->subid))
196 		return grp;
197 	kfree(grp);
198 	return NULL;
199 }
200 
201 void tipc_group_join(struct net *net, struct tipc_group *grp, int *sk_rcvbuf)
202 {
203 	struct rb_root *tree = &grp->members;
204 	struct tipc_member *m, *tmp;
205 	struct sk_buff_head xmitq;
206 
207 	skb_queue_head_init(&xmitq);
208 	rbtree_postorder_for_each_entry_safe(m, tmp, tree, tree_node) {
209 		tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, &xmitq);
210 		tipc_group_update_member(m, 0);
211 	}
212 	tipc_node_distr_xmit(net, &xmitq);
213 	*sk_rcvbuf = tipc_group_rcvbuf_limit(grp);
214 }
215 
216 void tipc_group_delete(struct net *net, struct tipc_group *grp)
217 {
218 	struct rb_root *tree = &grp->members;
219 	struct tipc_member *m, *tmp;
220 	struct sk_buff_head xmitq;
221 
222 	__skb_queue_head_init(&xmitq);
223 
224 	rbtree_postorder_for_each_entry_safe(m, tmp, tree, tree_node) {
225 		tipc_group_proto_xmit(grp, m, GRP_LEAVE_MSG, &xmitq);
226 		list_del(&m->list);
227 		kfree(m);
228 	}
229 	tipc_node_distr_xmit(net, &xmitq);
230 	tipc_nlist_purge(&grp->dests);
231 	tipc_topsrv_kern_unsubscr(net, grp->subid);
232 	kfree(grp);
233 }
234 
235 struct tipc_member *tipc_group_find_member(struct tipc_group *grp,
236 					   u32 node, u32 port)
237 {
238 	struct rb_node *n = grp->members.rb_node;
239 	u64 nkey, key = (u64)node << 32 | port;
240 	struct tipc_member *m;
241 
242 	while (n) {
243 		m = container_of(n, struct tipc_member, tree_node);
244 		nkey = (u64)m->node << 32 | m->port;
245 		if (key < nkey)
246 			n = n->rb_left;
247 		else if (key > nkey)
248 			n = n->rb_right;
249 		else
250 			return m;
251 	}
252 	return NULL;
253 }
254 
255 static struct tipc_member *tipc_group_find_dest(struct tipc_group *grp,
256 						u32 node, u32 port)
257 {
258 	struct tipc_member *m;
259 
260 	m = tipc_group_find_member(grp, node, port);
261 	if (m && tipc_group_is_receiver(m))
262 		return m;
263 	return NULL;
264 }
265 
266 static struct tipc_member *tipc_group_find_node(struct tipc_group *grp,
267 						u32 node)
268 {
269 	struct tipc_member *m;
270 	struct rb_node *n;
271 
272 	for (n = rb_first(&grp->members); n; n = rb_next(n)) {
273 		m = container_of(n, struct tipc_member, tree_node);
274 		if (m->node == node)
275 			return m;
276 	}
277 	return NULL;
278 }
279 
280 static void tipc_group_add_to_tree(struct tipc_group *grp,
281 				   struct tipc_member *m)
282 {
283 	u64 nkey, key = (u64)m->node << 32 | m->port;
284 	struct rb_node **n, *parent = NULL;
285 	struct tipc_member *tmp;
286 
287 	n = &grp->members.rb_node;
288 	while (*n) {
289 		tmp = container_of(*n, struct tipc_member, tree_node);
290 		parent = *n;
291 		tmp = container_of(parent, struct tipc_member, tree_node);
292 		nkey = (u64)tmp->node << 32 | tmp->port;
293 		if (key < nkey)
294 			n = &(*n)->rb_left;
295 		else if (key > nkey)
296 			n = &(*n)->rb_right;
297 		else
298 			return;
299 	}
300 	rb_link_node(&m->tree_node, parent, n);
301 	rb_insert_color(&m->tree_node, &grp->members);
302 }
303 
304 static struct tipc_member *tipc_group_create_member(struct tipc_group *grp,
305 						    u32 node, u32 port,
306 						    u32 instance, int state)
307 {
308 	struct tipc_member *m;
309 
310 	m = kzalloc(sizeof(*m), GFP_ATOMIC);
311 	if (!m)
312 		return NULL;
313 	INIT_LIST_HEAD(&m->list);
314 	INIT_LIST_HEAD(&m->small_win);
315 	__skb_queue_head_init(&m->deferredq);
316 	m->group = grp;
317 	m->node = node;
318 	m->port = port;
319 	m->instance = instance;
320 	m->bc_acked = grp->bc_snd_nxt - 1;
321 	grp->member_cnt++;
322 	tipc_group_add_to_tree(grp, m);
323 	tipc_nlist_add(&grp->dests, m->node);
324 	m->state = state;
325 	return m;
326 }
327 
328 void tipc_group_add_member(struct tipc_group *grp, u32 node,
329 			   u32 port, u32 instance)
330 {
331 	tipc_group_create_member(grp, node, port, instance, MBR_PUBLISHED);
332 }
333 
334 static void tipc_group_delete_member(struct tipc_group *grp,
335 				     struct tipc_member *m)
336 {
337 	rb_erase(&m->tree_node, &grp->members);
338 	grp->member_cnt--;
339 
340 	/* Check if we were waiting for replicast ack from this member */
341 	if (grp->bc_ackers && less(m->bc_acked, grp->bc_snd_nxt - 1))
342 		grp->bc_ackers--;
343 
344 	list_del_init(&m->list);
345 	list_del_init(&m->small_win);
346 	tipc_group_decr_active(grp, m);
347 
348 	/* If last member on a node, remove node from dest list */
349 	if (!tipc_group_find_node(grp, m->node))
350 		tipc_nlist_del(&grp->dests, m->node);
351 
352 	kfree(m);
353 }
354 
355 struct tipc_nlist *tipc_group_dests(struct tipc_group *grp)
356 {
357 	return &grp->dests;
358 }
359 
360 void tipc_group_self(struct tipc_group *grp, struct tipc_name_seq *seq,
361 		     int *scope)
362 {
363 	seq->type = grp->type;
364 	seq->lower = grp->instance;
365 	seq->upper = grp->instance;
366 	*scope = grp->scope;
367 }
368 
369 void tipc_group_update_member(struct tipc_member *m, int len)
370 {
371 	struct tipc_group *grp = m->group;
372 	struct tipc_member *_m, *tmp;
373 
374 	if (!tipc_group_is_receiver(m))
375 		return;
376 
377 	m->window -= len;
378 
379 	if (m->window >= ADV_IDLE)
380 		return;
381 
382 	list_del_init(&m->small_win);
383 
384 	/* Sort member into small_window members' list */
385 	list_for_each_entry_safe(_m, tmp, &grp->small_win, small_win) {
386 		if (_m->window > m->window)
387 			break;
388 	}
389 	list_add_tail(&m->small_win, &_m->small_win);
390 }
391 
392 void tipc_group_update_bc_members(struct tipc_group *grp, int len, bool ack)
393 {
394 	u16 prev = grp->bc_snd_nxt - 1;
395 	struct tipc_member *m;
396 	struct rb_node *n;
397 	u16 ackers = 0;
398 
399 	for (n = rb_first(&grp->members); n; n = rb_next(n)) {
400 		m = container_of(n, struct tipc_member, tree_node);
401 		if (tipc_group_is_receiver(m)) {
402 			tipc_group_update_member(m, len);
403 			m->bc_acked = prev;
404 			ackers++;
405 		}
406 	}
407 
408 	/* Mark number of acknowledges to expect, if any */
409 	if (ack)
410 		grp->bc_ackers = ackers;
411 	grp->bc_snd_nxt++;
412 }
413 
414 bool tipc_group_cong(struct tipc_group *grp, u32 dnode, u32 dport,
415 		     int len, struct tipc_member **mbr)
416 {
417 	struct sk_buff_head xmitq;
418 	struct tipc_member *m;
419 	int adv, state;
420 
421 	m = tipc_group_find_dest(grp, dnode, dport);
422 	if (!tipc_group_is_receiver(m)) {
423 		*mbr = NULL;
424 		return false;
425 	}
426 	*mbr = m;
427 
428 	if (m->window >= len)
429 		return false;
430 
431 	*grp->open = false;
432 
433 	/* If not fully advertised, do it now to prevent mutual blocking */
434 	adv = m->advertised;
435 	state = m->state;
436 	if (state == MBR_JOINED && adv == ADV_IDLE)
437 		return true;
438 	if (state == MBR_ACTIVE && adv == ADV_ACTIVE)
439 		return true;
440 	if (state == MBR_PENDING && adv == ADV_IDLE)
441 		return true;
442 	skb_queue_head_init(&xmitq);
443 	tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, &xmitq);
444 	tipc_node_distr_xmit(grp->net, &xmitq);
445 	return true;
446 }
447 
448 bool tipc_group_bc_cong(struct tipc_group *grp, int len)
449 {
450 	struct tipc_member *m = NULL;
451 
452 	/* If prev bcast was replicast, reject until all receivers have acked */
453 	if (grp->bc_ackers) {
454 		*grp->open = false;
455 		return true;
456 	}
457 	if (list_empty(&grp->small_win))
458 		return false;
459 
460 	m = list_first_entry(&grp->small_win, struct tipc_member, small_win);
461 	if (m->window >= len)
462 		return false;
463 
464 	return tipc_group_cong(grp, m->node, m->port, len, &m);
465 }
466 
467 /* tipc_group_sort_msg() - sort msg into queue by bcast sequence number
468  */
469 static void tipc_group_sort_msg(struct sk_buff *skb, struct sk_buff_head *defq)
470 {
471 	struct tipc_msg *_hdr, *hdr = buf_msg(skb);
472 	u16 bc_seqno = msg_grp_bc_seqno(hdr);
473 	struct sk_buff *_skb, *tmp;
474 	int mtyp = msg_type(hdr);
475 
476 	/* Bcast/mcast may be bypassed by ucast or other bcast, - sort it in */
477 	if (mtyp == TIPC_GRP_BCAST_MSG || mtyp == TIPC_GRP_MCAST_MSG) {
478 		skb_queue_walk_safe(defq, _skb, tmp) {
479 			_hdr = buf_msg(_skb);
480 			if (!less(bc_seqno, msg_grp_bc_seqno(_hdr)))
481 				continue;
482 			__skb_queue_before(defq, _skb, skb);
483 			return;
484 		}
485 		/* Bcast was not bypassed, - add to tail */
486 	}
487 	/* Unicasts are never bypassed, - always add to tail */
488 	__skb_queue_tail(defq, skb);
489 }
490 
491 /* tipc_group_filter_msg() - determine if we should accept arriving message
492  */
493 void tipc_group_filter_msg(struct tipc_group *grp, struct sk_buff_head *inputq,
494 			   struct sk_buff_head *xmitq)
495 {
496 	struct sk_buff *skb = __skb_dequeue(inputq);
497 	bool ack, deliver, update, leave = false;
498 	struct sk_buff_head *defq;
499 	struct tipc_member *m;
500 	struct tipc_msg *hdr;
501 	u32 node, port;
502 	int mtyp, blks;
503 
504 	if (!skb)
505 		return;
506 
507 	hdr = buf_msg(skb);
508 	node =  msg_orignode(hdr);
509 	port = msg_origport(hdr);
510 
511 	if (!msg_in_group(hdr))
512 		goto drop;
513 
514 	m = tipc_group_find_member(grp, node, port);
515 	if (!tipc_group_is_sender(m))
516 		goto drop;
517 
518 	if (less(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
519 		goto drop;
520 
521 	TIPC_SKB_CB(skb)->orig_member = m->instance;
522 	defq = &m->deferredq;
523 	tipc_group_sort_msg(skb, defq);
524 
525 	while ((skb = skb_peek(defq))) {
526 		hdr = buf_msg(skb);
527 		mtyp = msg_type(hdr);
528 		blks = msg_blocks(hdr);
529 		deliver = true;
530 		ack = false;
531 		update = false;
532 
533 		if (more(msg_grp_bc_seqno(hdr), m->bc_rcv_nxt))
534 			break;
535 
536 		/* Decide what to do with message */
537 		switch (mtyp) {
538 		case TIPC_GRP_MCAST_MSG:
539 			if (msg_nameinst(hdr) != grp->instance) {
540 				update = true;
541 				deliver = false;
542 			}
543 			/* Fall thru */
544 		case TIPC_GRP_BCAST_MSG:
545 			m->bc_rcv_nxt++;
546 			ack = msg_grp_bc_ack_req(hdr);
547 			break;
548 		case TIPC_GRP_UCAST_MSG:
549 			break;
550 		case TIPC_GRP_MEMBER_EVT:
551 			if (m->state == MBR_LEAVING)
552 				leave = true;
553 			if (!grp->events)
554 				deliver = false;
555 			break;
556 		default:
557 			break;
558 		}
559 
560 		/* Execute decisions */
561 		__skb_dequeue(defq);
562 		if (deliver)
563 			__skb_queue_tail(inputq, skb);
564 		else
565 			kfree_skb(skb);
566 
567 		if (ack)
568 			tipc_group_proto_xmit(grp, m, GRP_ACK_MSG, xmitq);
569 
570 		if (leave) {
571 			__skb_queue_purge(defq);
572 			tipc_group_delete_member(grp, m);
573 			break;
574 		}
575 		if (!update)
576 			continue;
577 
578 		tipc_group_update_rcv_win(grp, blks, node, port, xmitq);
579 	}
580 	return;
581 drop:
582 	kfree_skb(skb);
583 }
584 
585 void tipc_group_update_rcv_win(struct tipc_group *grp, int blks, u32 node,
586 			       u32 port, struct sk_buff_head *xmitq)
587 {
588 	struct list_head *active = &grp->active;
589 	int max_active = grp->max_active;
590 	int reclaim_limit = max_active * 3 / 4;
591 	int active_cnt = grp->active_cnt;
592 	struct tipc_member *m, *rm, *pm;
593 
594 	m = tipc_group_find_member(grp, node, port);
595 	if (!m)
596 		return;
597 
598 	m->advertised -= blks;
599 
600 	switch (m->state) {
601 	case MBR_JOINED:
602 		/* First, decide if member can go active */
603 		if (active_cnt <= max_active) {
604 			m->state = MBR_ACTIVE;
605 			list_add_tail(&m->list, active);
606 			grp->active_cnt++;
607 			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
608 		} else {
609 			m->state = MBR_PENDING;
610 			list_add_tail(&m->list, &grp->pending);
611 		}
612 
613 		if (active_cnt < reclaim_limit)
614 			break;
615 
616 		/* Reclaim from oldest active member, if possible */
617 		if (!list_empty(active)) {
618 			rm = list_first_entry(active, struct tipc_member, list);
619 			rm->state = MBR_RECLAIMING;
620 			list_del_init(&rm->list);
621 			tipc_group_proto_xmit(grp, rm, GRP_RECLAIM_MSG, xmitq);
622 			break;
623 		}
624 		/* Nobody to reclaim from; - revert oldest pending to JOINED */
625 		pm = list_first_entry(&grp->pending, struct tipc_member, list);
626 		list_del_init(&pm->list);
627 		pm->state = MBR_JOINED;
628 		tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
629 		break;
630 	case MBR_ACTIVE:
631 		if (!list_is_last(&m->list, &grp->active))
632 			list_move_tail(&m->list, &grp->active);
633 		if (m->advertised > (ADV_ACTIVE * 3 / 4))
634 			break;
635 		tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
636 		break;
637 	case MBR_REMITTED:
638 		if (m->advertised > ADV_IDLE)
639 			break;
640 		m->state = MBR_JOINED;
641 		grp->active_cnt--;
642 		if (m->advertised < ADV_IDLE) {
643 			pr_warn_ratelimited("Rcv unexpected msg after REMIT\n");
644 			tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
645 		}
646 
647 		if (list_empty(&grp->pending))
648 			return;
649 
650 		/* Set oldest pending member to active and advertise */
651 		pm = list_first_entry(&grp->pending, struct tipc_member, list);
652 		pm->state = MBR_ACTIVE;
653 		list_move_tail(&pm->list, &grp->active);
654 		grp->active_cnt++;
655 		tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
656 		break;
657 	case MBR_RECLAIMING:
658 	case MBR_JOINING:
659 	case MBR_LEAVING:
660 	default:
661 		break;
662 	}
663 }
664 
665 static void tipc_group_create_event(struct tipc_group *grp,
666 				    struct tipc_member *m,
667 				    u32 event, u16 seqno,
668 				    struct sk_buff_head *inputq)
669 {	u32 dnode = tipc_own_addr(grp->net);
670 	struct tipc_event evt;
671 	struct sk_buff *skb;
672 	struct tipc_msg *hdr;
673 
674 	evt.event = event;
675 	evt.found_lower = m->instance;
676 	evt.found_upper = m->instance;
677 	evt.port.ref = m->port;
678 	evt.port.node = m->node;
679 	evt.s.seq.type = grp->type;
680 	evt.s.seq.lower = m->instance;
681 	evt.s.seq.upper = m->instance;
682 
683 	skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_GRP_MEMBER_EVT,
684 			      GROUP_H_SIZE, sizeof(evt), dnode, m->node,
685 			      grp->portid, m->port, 0);
686 	if (!skb)
687 		return;
688 
689 	hdr = buf_msg(skb);
690 	msg_set_nametype(hdr, grp->type);
691 	msg_set_grp_evt(hdr, event);
692 	msg_set_dest_droppable(hdr, true);
693 	msg_set_grp_bc_seqno(hdr, seqno);
694 	memcpy(msg_data(hdr), &evt, sizeof(evt));
695 	TIPC_SKB_CB(skb)->orig_member = m->instance;
696 	__skb_queue_tail(inputq, skb);
697 }
698 
699 static void tipc_group_proto_xmit(struct tipc_group *grp, struct tipc_member *m,
700 				  int mtyp, struct sk_buff_head *xmitq)
701 {
702 	struct tipc_msg *hdr;
703 	struct sk_buff *skb;
704 	int adv = 0;
705 
706 	skb = tipc_msg_create(GROUP_PROTOCOL, mtyp, INT_H_SIZE, 0,
707 			      m->node, tipc_own_addr(grp->net),
708 			      m->port, grp->portid, 0);
709 	if (!skb)
710 		return;
711 
712 	if (m->state == MBR_ACTIVE)
713 		adv = ADV_ACTIVE - m->advertised;
714 	else if (m->state == MBR_JOINED || m->state == MBR_PENDING)
715 		adv = ADV_IDLE - m->advertised;
716 
717 	hdr = buf_msg(skb);
718 
719 	if (mtyp == GRP_JOIN_MSG) {
720 		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
721 		msg_set_adv_win(hdr, adv);
722 		m->advertised += adv;
723 	} else if (mtyp == GRP_LEAVE_MSG) {
724 		msg_set_grp_bc_syncpt(hdr, grp->bc_snd_nxt);
725 	} else if (mtyp == GRP_ADV_MSG) {
726 		msg_set_adv_win(hdr, adv);
727 		m->advertised += adv;
728 	} else if (mtyp == GRP_ACK_MSG) {
729 		msg_set_grp_bc_acked(hdr, m->bc_rcv_nxt);
730 	} else if (mtyp == GRP_REMIT_MSG) {
731 		msg_set_grp_remitted(hdr, m->window);
732 	}
733 	msg_set_dest_droppable(hdr, true);
734 	__skb_queue_tail(xmitq, skb);
735 }
736 
737 void tipc_group_proto_rcv(struct tipc_group *grp, bool *usr_wakeup,
738 			  struct tipc_msg *hdr, struct sk_buff_head *inputq,
739 			  struct sk_buff_head *xmitq)
740 {
741 	u32 node = msg_orignode(hdr);
742 	u32 port = msg_origport(hdr);
743 	struct tipc_member *m, *pm;
744 	u16 remitted, in_flight;
745 
746 	if (!grp)
747 		return;
748 
749 	if (grp->scope == TIPC_NODE_SCOPE && node != tipc_own_addr(grp->net))
750 		return;
751 
752 	m = tipc_group_find_member(grp, node, port);
753 
754 	switch (msg_type(hdr)) {
755 	case GRP_JOIN_MSG:
756 		if (!m)
757 			m = tipc_group_create_member(grp, node, port,
758 						     0, MBR_JOINING);
759 		if (!m)
760 			return;
761 		m->bc_syncpt = msg_grp_bc_syncpt(hdr);
762 		m->bc_rcv_nxt = m->bc_syncpt;
763 		m->window += msg_adv_win(hdr);
764 
765 		/* Wait until PUBLISH event is received if necessary */
766 		if (m->state != MBR_PUBLISHED)
767 			return;
768 
769 		/* Member can be taken into service */
770 		m->state = MBR_JOINED;
771 		tipc_group_open(m, usr_wakeup);
772 		tipc_group_update_member(m, 0);
773 		tipc_group_proto_xmit(grp, m, GRP_ADV_MSG, xmitq);
774 		tipc_group_create_event(grp, m, TIPC_PUBLISHED,
775 					m->bc_syncpt, inputq);
776 		return;
777 	case GRP_LEAVE_MSG:
778 		if (!m)
779 			return;
780 		m->bc_syncpt = msg_grp_bc_syncpt(hdr);
781 		list_del_init(&m->list);
782 		tipc_group_open(m, usr_wakeup);
783 		tipc_group_decr_active(grp, m);
784 		m->state = MBR_LEAVING;
785 		tipc_group_create_event(grp, m, TIPC_WITHDRAWN,
786 					m->bc_syncpt, inputq);
787 		return;
788 	case GRP_ADV_MSG:
789 		if (!m)
790 			return;
791 		m->window += msg_adv_win(hdr);
792 		tipc_group_open(m, usr_wakeup);
793 		return;
794 	case GRP_ACK_MSG:
795 		if (!m)
796 			return;
797 		m->bc_acked = msg_grp_bc_acked(hdr);
798 		if (--grp->bc_ackers)
799 			return;
800 		list_del_init(&m->small_win);
801 		*m->group->open = true;
802 		*usr_wakeup = true;
803 		tipc_group_update_member(m, 0);
804 		return;
805 	case GRP_RECLAIM_MSG:
806 		if (!m)
807 			return;
808 		tipc_group_proto_xmit(grp, m, GRP_REMIT_MSG, xmitq);
809 		m->window = ADV_IDLE;
810 		tipc_group_open(m, usr_wakeup);
811 		return;
812 	case GRP_REMIT_MSG:
813 		if (!m || m->state != MBR_RECLAIMING)
814 			return;
815 
816 		remitted = msg_grp_remitted(hdr);
817 
818 		/* Messages preceding the REMIT still in receive queue */
819 		if (m->advertised > remitted) {
820 			m->state = MBR_REMITTED;
821 			in_flight = m->advertised - remitted;
822 			m->advertised = ADV_IDLE + in_flight;
823 			return;
824 		}
825 		/* This should never happen */
826 		if (m->advertised < remitted)
827 			pr_warn_ratelimited("Unexpected REMIT msg\n");
828 
829 		/* All messages preceding the REMIT have been read */
830 		m->state = MBR_JOINED;
831 		grp->active_cnt--;
832 		m->advertised = ADV_IDLE;
833 
834 		/* Set oldest pending member to active and advertise */
835 		if (list_empty(&grp->pending))
836 			return;
837 		pm = list_first_entry(&grp->pending, struct tipc_member, list);
838 		pm->state = MBR_ACTIVE;
839 		list_move_tail(&pm->list, &grp->active);
840 		grp->active_cnt++;
841 		if (pm->advertised <= (ADV_ACTIVE * 3 / 4))
842 			tipc_group_proto_xmit(grp, pm, GRP_ADV_MSG, xmitq);
843 		return;
844 	default:
845 		pr_warn("Received unknown GROUP_PROTO message\n");
846 	}
847 }
848 
849 /* tipc_group_member_evt() - receive and handle a member up/down event
850  */
851 void tipc_group_member_evt(struct tipc_group *grp,
852 			   bool *usr_wakeup,
853 			   int *sk_rcvbuf,
854 			   struct tipc_msg *hdr,
855 			   struct sk_buff_head *inputq,
856 			   struct sk_buff_head *xmitq)
857 {
858 	struct tipc_event *evt = (void *)msg_data(hdr);
859 	u32 instance = evt->found_lower;
860 	u32 node = evt->port.node;
861 	u32 port = evt->port.ref;
862 	int event = evt->event;
863 	struct tipc_member *m;
864 	struct net *net;
865 	u32 self;
866 
867 	if (!grp)
868 		return;
869 
870 	net = grp->net;
871 	self = tipc_own_addr(net);
872 	if (!grp->loopback && node == self && port == grp->portid)
873 		return;
874 
875 	m = tipc_group_find_member(grp, node, port);
876 
877 	switch (event) {
878 	case TIPC_PUBLISHED:
879 		/* Send and wait for arrival of JOIN message if necessary */
880 		if (!m) {
881 			m = tipc_group_create_member(grp, node, port, instance,
882 						     MBR_PUBLISHED);
883 			if (!m)
884 				break;
885 			tipc_group_update_member(m, 0);
886 			tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, xmitq);
887 			break;
888 		}
889 
890 		if (m->state != MBR_JOINING)
891 			break;
892 
893 		/* Member can be taken into service */
894 		m->instance = instance;
895 		m->state = MBR_JOINED;
896 		tipc_group_open(m, usr_wakeup);
897 		tipc_group_update_member(m, 0);
898 		tipc_group_proto_xmit(grp, m, GRP_JOIN_MSG, xmitq);
899 		tipc_group_create_event(grp, m, TIPC_PUBLISHED,
900 					m->bc_syncpt, inputq);
901 		break;
902 	case TIPC_WITHDRAWN:
903 		if (!m)
904 			break;
905 
906 		tipc_group_decr_active(grp, m);
907 		m->state = MBR_LEAVING;
908 		list_del_init(&m->list);
909 		tipc_group_open(m, usr_wakeup);
910 
911 		/* Only send event if no LEAVE message can be expected */
912 		if (!tipc_node_is_up(net, node))
913 			tipc_group_create_event(grp, m, TIPC_WITHDRAWN,
914 						m->bc_rcv_nxt, inputq);
915 		break;
916 	default:
917 		break;
918 	}
919 	*sk_rcvbuf = tipc_group_rcvbuf_limit(grp);
920 }
921