xref: /kernel/linux/linux-5.10/net/tipc/monitor.c (revision 8c2ecf20)
1/*
2 * net/tipc/monitor.c
3 *
4 * Copyright (c) 2016, 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 <net/genetlink.h>
37#include "core.h"
38#include "addr.h"
39#include "monitor.h"
40#include "bearer.h"
41
42#define MAX_MON_DOMAIN       64
43#define MON_TIMEOUT          120000
44#define MAX_PEER_DOWN_EVENTS 4
45
46/* struct tipc_mon_domain: domain record to be transferred between peers
47 * @len: actual size of domain record
48 * @gen: current generation of sender's domain
49 * @ack_gen: most recent generation of self's domain acked by peer
50 * @member_cnt: number of domain member nodes described in this record
51 * @up_map: bit map indicating which of the members the sender considers up
52 * @members: identity of the domain members
53 */
54struct tipc_mon_domain {
55	u16 len;
56	u16 gen;
57	u16 ack_gen;
58	u16 member_cnt;
59	u64 up_map;
60	u32 members[MAX_MON_DOMAIN];
61};
62
63/* struct tipc_peer: state of a peer node and its domain
64 * @addr: tipc node identity of peer
65 * @head_map: shows which other nodes currently consider peer 'up'
66 * @domain: most recent domain record from peer
67 * @hash: position in hashed lookup list
68 * @list: position in linked list, in circular ascending order by 'addr'
69 * @applied: number of reported domain members applied on this monitor list
70 * @is_up: peer is up as seen from this node
71 * @is_head: peer is assigned domain head as seen from this node
72 * @is_local: peer is in local domain and should be continuously monitored
73 * @down_cnt: - numbers of other peers which have reported this on lost
74 */
75struct tipc_peer {
76	u32 addr;
77	struct tipc_mon_domain *domain;
78	struct hlist_node hash;
79	struct list_head list;
80	u8 applied;
81	u8 down_cnt;
82	bool is_up;
83	bool is_head;
84	bool is_local;
85};
86
87struct tipc_monitor {
88	struct hlist_head peers[NODE_HTABLE_SIZE];
89	int peer_cnt;
90	struct tipc_peer *self;
91	rwlock_t lock;
92	struct tipc_mon_domain cache;
93	u16 list_gen;
94	u16 dom_gen;
95	struct net *net;
96	struct timer_list timer;
97	unsigned long timer_intv;
98};
99
100static struct tipc_monitor *tipc_monitor(struct net *net, int bearer_id)
101{
102	return tipc_net(net)->monitors[bearer_id];
103}
104
105const int tipc_max_domain_size = sizeof(struct tipc_mon_domain);
106
107/* dom_rec_len(): actual length of domain record for transport
108 */
109static int dom_rec_len(struct tipc_mon_domain *dom, u16 mcnt)
110{
111	return ((void *)&dom->members - (void *)dom) + (mcnt * sizeof(u32));
112}
113
114/* dom_size() : calculate size of own domain based on number of peers
115 */
116static int dom_size(int peers)
117{
118	int i = 0;
119
120	while ((i * i) < peers)
121		i++;
122	return i < MAX_MON_DOMAIN ? i : MAX_MON_DOMAIN;
123}
124
125static void map_set(u64 *up_map, int i, unsigned int v)
126{
127	*up_map &= ~(1ULL << i);
128	*up_map |= ((u64)v << i);
129}
130
131static int map_get(u64 up_map, int i)
132{
133	return (up_map & (1ULL << i)) >> i;
134}
135
136static struct tipc_peer *peer_prev(struct tipc_peer *peer)
137{
138	return list_last_entry(&peer->list, struct tipc_peer, list);
139}
140
141static struct tipc_peer *peer_nxt(struct tipc_peer *peer)
142{
143	return list_first_entry(&peer->list, struct tipc_peer, list);
144}
145
146static struct tipc_peer *peer_head(struct tipc_peer *peer)
147{
148	while (!peer->is_head)
149		peer = peer_prev(peer);
150	return peer;
151}
152
153static struct tipc_peer *get_peer(struct tipc_monitor *mon, u32 addr)
154{
155	struct tipc_peer *peer;
156	unsigned int thash = tipc_hashfn(addr);
157
158	hlist_for_each_entry(peer, &mon->peers[thash], hash) {
159		if (peer->addr == addr)
160			return peer;
161	}
162	return NULL;
163}
164
165static struct tipc_peer *get_self(struct net *net, int bearer_id)
166{
167	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
168
169	return mon->self;
170}
171
172static inline bool tipc_mon_is_active(struct net *net, struct tipc_monitor *mon)
173{
174	struct tipc_net *tn = tipc_net(net);
175
176	return mon->peer_cnt > tn->mon_threshold;
177}
178
179/* mon_identify_lost_members() : - identify amd mark potentially lost members
180 */
181static void mon_identify_lost_members(struct tipc_peer *peer,
182				      struct tipc_mon_domain *dom_bef,
183				      int applied_bef)
184{
185	struct tipc_peer *member = peer;
186	struct tipc_mon_domain *dom_aft = peer->domain;
187	int applied_aft = peer->applied;
188	int i;
189
190	for (i = 0; i < applied_bef; i++) {
191		member = peer_nxt(member);
192
193		/* Do nothing if self or peer already see member as down */
194		if (!member->is_up || !map_get(dom_bef->up_map, i))
195			continue;
196
197		/* Loss of local node must be detected by active probing */
198		if (member->is_local)
199			continue;
200
201		/* Start probing if member was removed from applied domain */
202		if (!applied_aft || (applied_aft < i)) {
203			member->down_cnt = 1;
204			continue;
205		}
206
207		/* Member loss is confirmed if it is still in applied domain */
208		if (!map_get(dom_aft->up_map, i))
209			member->down_cnt++;
210	}
211}
212
213/* mon_apply_domain() : match a peer's domain record against monitor list
214 */
215static void mon_apply_domain(struct tipc_monitor *mon,
216			     struct tipc_peer *peer)
217{
218	struct tipc_mon_domain *dom = peer->domain;
219	struct tipc_peer *member;
220	u32 addr;
221	int i;
222
223	if (!dom || !peer->is_up)
224		return;
225
226	/* Scan across domain members and match against monitor list */
227	peer->applied = 0;
228	member = peer_nxt(peer);
229	for (i = 0; i < dom->member_cnt; i++) {
230		addr = dom->members[i];
231		if (addr != member->addr)
232			return;
233		peer->applied++;
234		member = peer_nxt(member);
235	}
236}
237
238/* mon_update_local_domain() : update after peer addition/removal/up/down
239 */
240static void mon_update_local_domain(struct tipc_monitor *mon)
241{
242	struct tipc_peer *self = mon->self;
243	struct tipc_mon_domain *cache = &mon->cache;
244	struct tipc_mon_domain *dom = self->domain;
245	struct tipc_peer *peer = self;
246	u64 prev_up_map = dom->up_map;
247	u16 member_cnt, i;
248	bool diff;
249
250	/* Update local domain size based on current size of cluster */
251	member_cnt = dom_size(mon->peer_cnt) - 1;
252	self->applied = member_cnt;
253
254	/* Update native and cached outgoing local domain records */
255	dom->len = dom_rec_len(dom, member_cnt);
256	diff = dom->member_cnt != member_cnt;
257	dom->member_cnt = member_cnt;
258	for (i = 0; i < member_cnt; i++) {
259		peer = peer_nxt(peer);
260		diff |= dom->members[i] != peer->addr;
261		dom->members[i] = peer->addr;
262		map_set(&dom->up_map, i, peer->is_up);
263		cache->members[i] = htonl(peer->addr);
264	}
265	diff |= dom->up_map != prev_up_map;
266	if (!diff)
267		return;
268	dom->gen = ++mon->dom_gen;
269	cache->len = htons(dom->len);
270	cache->gen = htons(dom->gen);
271	cache->member_cnt = htons(member_cnt);
272	cache->up_map = cpu_to_be64(dom->up_map);
273	mon_apply_domain(mon, self);
274}
275
276/* mon_update_neighbors() : update preceding neighbors of added/removed peer
277 */
278static void mon_update_neighbors(struct tipc_monitor *mon,
279				 struct tipc_peer *peer)
280{
281	int dz, i;
282
283	dz = dom_size(mon->peer_cnt);
284	for (i = 0; i < dz; i++) {
285		mon_apply_domain(mon, peer);
286		peer = peer_prev(peer);
287	}
288}
289
290/* mon_assign_roles() : reassign peer roles after a network change
291 * The monitor list is consistent at this stage; i.e., each peer is monitoring
292 * a set of domain members as matched between domain record and the monitor list
293 */
294static void mon_assign_roles(struct tipc_monitor *mon, struct tipc_peer *head)
295{
296	struct tipc_peer *peer = peer_nxt(head);
297	struct tipc_peer *self = mon->self;
298	int i = 0;
299
300	for (; peer != self; peer = peer_nxt(peer)) {
301		peer->is_local = false;
302
303		/* Update domain member */
304		if (i++ < head->applied) {
305			peer->is_head = false;
306			if (head == self)
307				peer->is_local = true;
308			continue;
309		}
310		/* Assign next domain head */
311		if (!peer->is_up)
312			continue;
313		if (peer->is_head)
314			break;
315		head = peer;
316		head->is_head = true;
317		i = 0;
318	}
319	mon->list_gen++;
320}
321
322void tipc_mon_remove_peer(struct net *net, u32 addr, int bearer_id)
323{
324	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
325	struct tipc_peer *self;
326	struct tipc_peer *peer, *prev, *head;
327
328	if (!mon)
329		return;
330
331	self = get_self(net, bearer_id);
332	write_lock_bh(&mon->lock);
333	peer = get_peer(mon, addr);
334	if (!peer)
335		goto exit;
336	prev = peer_prev(peer);
337	list_del(&peer->list);
338	hlist_del(&peer->hash);
339	kfree(peer->domain);
340	kfree(peer);
341	mon->peer_cnt--;
342	head = peer_head(prev);
343	if (head == self)
344		mon_update_local_domain(mon);
345	mon_update_neighbors(mon, prev);
346
347	/* Revert to full-mesh monitoring if we reach threshold */
348	if (!tipc_mon_is_active(net, mon)) {
349		list_for_each_entry(peer, &self->list, list) {
350			kfree(peer->domain);
351			peer->domain = NULL;
352			peer->applied = 0;
353		}
354	}
355	mon_assign_roles(mon, head);
356exit:
357	write_unlock_bh(&mon->lock);
358}
359
360static bool tipc_mon_add_peer(struct tipc_monitor *mon, u32 addr,
361			      struct tipc_peer **peer)
362{
363	struct tipc_peer *self = mon->self;
364	struct tipc_peer *cur, *prev, *p;
365
366	p = kzalloc(sizeof(*p), GFP_ATOMIC);
367	*peer = p;
368	if (!p)
369		return false;
370	p->addr = addr;
371
372	/* Add new peer to lookup list */
373	INIT_LIST_HEAD(&p->list);
374	hlist_add_head(&p->hash, &mon->peers[tipc_hashfn(addr)]);
375
376	/* Sort new peer into iterator list, in ascending circular order */
377	prev = self;
378	list_for_each_entry(cur, &self->list, list) {
379		if ((addr > prev->addr) && (addr < cur->addr))
380			break;
381		if (((addr < cur->addr) || (addr > prev->addr)) &&
382		    (prev->addr > cur->addr))
383			break;
384		prev = cur;
385	}
386	list_add_tail(&p->list, &cur->list);
387	mon->peer_cnt++;
388	mon_update_neighbors(mon, p);
389	return true;
390}
391
392void tipc_mon_peer_up(struct net *net, u32 addr, int bearer_id)
393{
394	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
395	struct tipc_peer *self = get_self(net, bearer_id);
396	struct tipc_peer *peer, *head;
397
398	write_lock_bh(&mon->lock);
399	peer = get_peer(mon, addr);
400	if (!peer && !tipc_mon_add_peer(mon, addr, &peer))
401		goto exit;
402	peer->is_up = true;
403	head = peer_head(peer);
404	if (head == self)
405		mon_update_local_domain(mon);
406	mon_assign_roles(mon, head);
407exit:
408	write_unlock_bh(&mon->lock);
409}
410
411void tipc_mon_peer_down(struct net *net, u32 addr, int bearer_id)
412{
413	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
414	struct tipc_peer *self;
415	struct tipc_peer *peer, *head;
416	struct tipc_mon_domain *dom;
417	int applied;
418
419	if (!mon)
420		return;
421
422	self = get_self(net, bearer_id);
423	write_lock_bh(&mon->lock);
424	peer = get_peer(mon, addr);
425	if (!peer) {
426		pr_warn("Mon: unknown link %x/%u DOWN\n", addr, bearer_id);
427		goto exit;
428	}
429	applied = peer->applied;
430	peer->applied = 0;
431	dom = peer->domain;
432	peer->domain = NULL;
433	if (peer->is_head)
434		mon_identify_lost_members(peer, dom, applied);
435	kfree(dom);
436	peer->is_up = false;
437	peer->is_head = false;
438	peer->is_local = false;
439	peer->down_cnt = 0;
440	head = peer_head(peer);
441	if (head == self)
442		mon_update_local_domain(mon);
443	mon_assign_roles(mon, head);
444exit:
445	write_unlock_bh(&mon->lock);
446}
447
448/* tipc_mon_rcv - process monitor domain event message
449 */
450void tipc_mon_rcv(struct net *net, void *data, u16 dlen, u32 addr,
451		  struct tipc_mon_state *state, int bearer_id)
452{
453	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
454	struct tipc_mon_domain *arrv_dom = data;
455	struct tipc_mon_domain dom_bef;
456	struct tipc_mon_domain *dom;
457	struct tipc_peer *peer;
458	u16 new_member_cnt = ntohs(arrv_dom->member_cnt);
459	int new_dlen = dom_rec_len(arrv_dom, new_member_cnt);
460	u16 new_gen = ntohs(arrv_dom->gen);
461	u16 acked_gen = ntohs(arrv_dom->ack_gen);
462	bool probing = state->probing;
463	int i, applied_bef;
464
465	state->probing = false;
466
467	/* Sanity check received domain record */
468	if (new_member_cnt > MAX_MON_DOMAIN)
469		return;
470	if (dlen < dom_rec_len(arrv_dom, 0))
471		return;
472	if (dlen != dom_rec_len(arrv_dom, new_member_cnt))
473		return;
474	if ((dlen < new_dlen) || ntohs(arrv_dom->len) != new_dlen)
475		return;
476
477	/* Synch generation numbers with peer if link just came up */
478	if (!state->synched) {
479		state->peer_gen = new_gen - 1;
480		state->acked_gen = acked_gen;
481		state->synched = true;
482	}
483
484	if (more(acked_gen, state->acked_gen))
485		state->acked_gen = acked_gen;
486
487	/* Drop duplicate unless we are waiting for a probe response */
488	if (!more(new_gen, state->peer_gen) && !probing)
489		return;
490
491	write_lock_bh(&mon->lock);
492	peer = get_peer(mon, addr);
493	if (!peer || !peer->is_up)
494		goto exit;
495
496	/* Peer is confirmed, stop any ongoing probing */
497	peer->down_cnt = 0;
498
499	/* Task is done for duplicate record */
500	if (!more(new_gen, state->peer_gen))
501		goto exit;
502
503	state->peer_gen = new_gen;
504
505	/* Cache current domain record for later use */
506	dom_bef.member_cnt = 0;
507	dom = peer->domain;
508	if (dom)
509		memcpy(&dom_bef, dom, dom->len);
510
511	/* Transform and store received domain record */
512	if (!dom || (dom->len < new_dlen)) {
513		kfree(dom);
514		dom = kmalloc(new_dlen, GFP_ATOMIC);
515		peer->domain = dom;
516		if (!dom)
517			goto exit;
518	}
519	dom->len = new_dlen;
520	dom->gen = new_gen;
521	dom->member_cnt = new_member_cnt;
522	dom->up_map = be64_to_cpu(arrv_dom->up_map);
523	for (i = 0; i < new_member_cnt; i++)
524		dom->members[i] = ntohl(arrv_dom->members[i]);
525
526	/* Update peers affected by this domain record */
527	applied_bef = peer->applied;
528	mon_apply_domain(mon, peer);
529	mon_identify_lost_members(peer, &dom_bef, applied_bef);
530	mon_assign_roles(mon, peer_head(peer));
531exit:
532	write_unlock_bh(&mon->lock);
533}
534
535void tipc_mon_prep(struct net *net, void *data, int *dlen,
536		   struct tipc_mon_state *state, int bearer_id)
537{
538	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
539	struct tipc_mon_domain *dom = data;
540	u16 gen = mon->dom_gen;
541	u16 len;
542
543	/* Send invalid record if not active */
544	if (!tipc_mon_is_active(net, mon)) {
545		dom->len = 0;
546		return;
547	}
548
549	/* Send only a dummy record with ack if peer has acked our last sent */
550	if (likely(state->acked_gen == gen)) {
551		len = dom_rec_len(dom, 0);
552		*dlen = len;
553		dom->len = htons(len);
554		dom->gen = htons(gen);
555		dom->ack_gen = htons(state->peer_gen);
556		dom->member_cnt = 0;
557		return;
558	}
559	/* Send the full record */
560	read_lock_bh(&mon->lock);
561	len = ntohs(mon->cache.len);
562	*dlen = len;
563	memcpy(data, &mon->cache, len);
564	read_unlock_bh(&mon->lock);
565	dom->ack_gen = htons(state->peer_gen);
566}
567
568void tipc_mon_get_state(struct net *net, u32 addr,
569			struct tipc_mon_state *state,
570			int bearer_id)
571{
572	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
573	struct tipc_peer *peer;
574
575	if (!tipc_mon_is_active(net, mon)) {
576		state->probing = false;
577		state->monitoring = true;
578		return;
579	}
580
581	/* Used cached state if table has not changed */
582	if (!state->probing &&
583	    (state->list_gen == mon->list_gen) &&
584	    (state->acked_gen == mon->dom_gen))
585		return;
586
587	read_lock_bh(&mon->lock);
588	peer = get_peer(mon, addr);
589	if (peer) {
590		state->probing = state->acked_gen != mon->dom_gen;
591		state->probing |= peer->down_cnt;
592		state->reset |= peer->down_cnt >= MAX_PEER_DOWN_EVENTS;
593		state->monitoring = peer->is_local;
594		state->monitoring |= peer->is_head;
595		state->list_gen = mon->list_gen;
596	}
597	read_unlock_bh(&mon->lock);
598}
599
600static void mon_timeout(struct timer_list *t)
601{
602	struct tipc_monitor *mon = from_timer(mon, t, timer);
603	struct tipc_peer *self;
604	int best_member_cnt = dom_size(mon->peer_cnt) - 1;
605
606	write_lock_bh(&mon->lock);
607	self = mon->self;
608	if (self && (best_member_cnt != self->applied)) {
609		mon_update_local_domain(mon);
610		mon_assign_roles(mon, self);
611	}
612	write_unlock_bh(&mon->lock);
613	mod_timer(&mon->timer, jiffies + mon->timer_intv);
614}
615
616int tipc_mon_create(struct net *net, int bearer_id)
617{
618	struct tipc_net *tn = tipc_net(net);
619	struct tipc_monitor *mon;
620	struct tipc_peer *self;
621	struct tipc_mon_domain *dom;
622
623	if (tn->monitors[bearer_id])
624		return 0;
625
626	mon = kzalloc(sizeof(*mon), GFP_ATOMIC);
627	self = kzalloc(sizeof(*self), GFP_ATOMIC);
628	dom = kzalloc(sizeof(*dom), GFP_ATOMIC);
629	if (!mon || !self || !dom) {
630		kfree(mon);
631		kfree(self);
632		kfree(dom);
633		return -ENOMEM;
634	}
635	tn->monitors[bearer_id] = mon;
636	rwlock_init(&mon->lock);
637	mon->net = net;
638	mon->peer_cnt = 1;
639	mon->self = self;
640	self->domain = dom;
641	self->addr = tipc_own_addr(net);
642	self->is_up = true;
643	self->is_head = true;
644	INIT_LIST_HEAD(&self->list);
645	timer_setup(&mon->timer, mon_timeout, 0);
646	mon->timer_intv = msecs_to_jiffies(MON_TIMEOUT + (tn->random & 0xffff));
647	mod_timer(&mon->timer, jiffies + mon->timer_intv);
648	return 0;
649}
650
651void tipc_mon_delete(struct net *net, int bearer_id)
652{
653	struct tipc_net *tn = tipc_net(net);
654	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
655	struct tipc_peer *self;
656	struct tipc_peer *peer, *tmp;
657
658	if (!mon)
659		return;
660
661	self = get_self(net, bearer_id);
662	write_lock_bh(&mon->lock);
663	tn->monitors[bearer_id] = NULL;
664	list_for_each_entry_safe(peer, tmp, &self->list, list) {
665		list_del(&peer->list);
666		hlist_del(&peer->hash);
667		kfree(peer->domain);
668		kfree(peer);
669	}
670	mon->self = NULL;
671	write_unlock_bh(&mon->lock);
672	del_timer_sync(&mon->timer);
673	kfree(self->domain);
674	kfree(self);
675	kfree(mon);
676}
677
678void tipc_mon_reinit_self(struct net *net)
679{
680	struct tipc_monitor *mon;
681	int bearer_id;
682
683	for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
684		mon = tipc_monitor(net, bearer_id);
685		if (!mon)
686			continue;
687		write_lock_bh(&mon->lock);
688		mon->self->addr = tipc_own_addr(net);
689		write_unlock_bh(&mon->lock);
690	}
691}
692
693int tipc_nl_monitor_set_threshold(struct net *net, u32 cluster_size)
694{
695	struct tipc_net *tn = tipc_net(net);
696
697	if (cluster_size > TIPC_CLUSTER_SIZE)
698		return -EINVAL;
699
700	tn->mon_threshold = cluster_size;
701
702	return 0;
703}
704
705int tipc_nl_monitor_get_threshold(struct net *net)
706{
707	struct tipc_net *tn = tipc_net(net);
708
709	return tn->mon_threshold;
710}
711
712static int __tipc_nl_add_monitor_peer(struct tipc_peer *peer,
713				      struct tipc_nl_msg *msg)
714{
715	struct tipc_mon_domain *dom = peer->domain;
716	struct nlattr *attrs;
717	void *hdr;
718
719	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
720			  NLM_F_MULTI, TIPC_NL_MON_PEER_GET);
721	if (!hdr)
722		return -EMSGSIZE;
723
724	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MON_PEER);
725	if (!attrs)
726		goto msg_full;
727
728	if (nla_put_u32(msg->skb, TIPC_NLA_MON_PEER_ADDR, peer->addr))
729		goto attr_msg_full;
730	if (nla_put_u32(msg->skb, TIPC_NLA_MON_PEER_APPLIED, peer->applied))
731		goto attr_msg_full;
732
733	if (peer->is_up)
734		if (nla_put_flag(msg->skb, TIPC_NLA_MON_PEER_UP))
735			goto attr_msg_full;
736	if (peer->is_local)
737		if (nla_put_flag(msg->skb, TIPC_NLA_MON_PEER_LOCAL))
738			goto attr_msg_full;
739	if (peer->is_head)
740		if (nla_put_flag(msg->skb, TIPC_NLA_MON_PEER_HEAD))
741			goto attr_msg_full;
742
743	if (dom) {
744		if (nla_put_u32(msg->skb, TIPC_NLA_MON_PEER_DOMGEN, dom->gen))
745			goto attr_msg_full;
746		if (nla_put_u64_64bit(msg->skb, TIPC_NLA_MON_PEER_UPMAP,
747				      dom->up_map, TIPC_NLA_MON_PEER_PAD))
748			goto attr_msg_full;
749		if (nla_put(msg->skb, TIPC_NLA_MON_PEER_MEMBERS,
750			    dom->member_cnt * sizeof(u32), &dom->members))
751			goto attr_msg_full;
752	}
753
754	nla_nest_end(msg->skb, attrs);
755	genlmsg_end(msg->skb, hdr);
756	return 0;
757
758attr_msg_full:
759	nla_nest_cancel(msg->skb, attrs);
760msg_full:
761	genlmsg_cancel(msg->skb, hdr);
762
763	return -EMSGSIZE;
764}
765
766int tipc_nl_add_monitor_peer(struct net *net, struct tipc_nl_msg *msg,
767			     u32 bearer_id, u32 *prev_node)
768{
769	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
770	struct tipc_peer *peer;
771
772	if (!mon)
773		return -EINVAL;
774
775	read_lock_bh(&mon->lock);
776	peer = mon->self;
777	do {
778		if (*prev_node) {
779			if (peer->addr == *prev_node)
780				*prev_node = 0;
781			else
782				continue;
783		}
784		if (__tipc_nl_add_monitor_peer(peer, msg)) {
785			*prev_node = peer->addr;
786			read_unlock_bh(&mon->lock);
787			return -EMSGSIZE;
788		}
789	} while ((peer = peer_nxt(peer)) != mon->self);
790	read_unlock_bh(&mon->lock);
791
792	return 0;
793}
794
795int __tipc_nl_add_monitor(struct net *net, struct tipc_nl_msg *msg,
796			  u32 bearer_id)
797{
798	struct tipc_monitor *mon = tipc_monitor(net, bearer_id);
799	char bearer_name[TIPC_MAX_BEARER_NAME];
800	struct nlattr *attrs;
801	void *hdr;
802	int ret;
803
804	ret = tipc_bearer_get_name(net, bearer_name, bearer_id);
805	if (ret || !mon)
806		return 0;
807
808	hdr = genlmsg_put(msg->skb, msg->portid, msg->seq, &tipc_genl_family,
809			  NLM_F_MULTI, TIPC_NL_MON_GET);
810	if (!hdr)
811		return -EMSGSIZE;
812
813	attrs = nla_nest_start_noflag(msg->skb, TIPC_NLA_MON);
814	if (!attrs)
815		goto msg_full;
816
817	read_lock_bh(&mon->lock);
818	if (nla_put_u32(msg->skb, TIPC_NLA_MON_REF, bearer_id))
819		goto attr_msg_full;
820	if (tipc_mon_is_active(net, mon))
821		if (nla_put_flag(msg->skb, TIPC_NLA_MON_ACTIVE))
822			goto attr_msg_full;
823	if (nla_put_string(msg->skb, TIPC_NLA_MON_BEARER_NAME, bearer_name))
824		goto attr_msg_full;
825	if (nla_put_u32(msg->skb, TIPC_NLA_MON_PEERCNT, mon->peer_cnt))
826		goto attr_msg_full;
827	if (nla_put_u32(msg->skb, TIPC_NLA_MON_LISTGEN, mon->list_gen))
828		goto attr_msg_full;
829
830	read_unlock_bh(&mon->lock);
831	nla_nest_end(msg->skb, attrs);
832	genlmsg_end(msg->skb, hdr);
833
834	return 0;
835
836attr_msg_full:
837	read_unlock_bh(&mon->lock);
838	nla_nest_cancel(msg->skb, attrs);
839msg_full:
840	genlmsg_cancel(msg->skb, hdr);
841
842	return -EMSGSIZE;
843}
844