summaryrefslogtreecommitdiff
path: root/net/tipc/bcast.c
blob: 37892b3909afc110990c11f5a12197ad506b3a02 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
/*
 * net/tipc/bcast.c: TIPC broadcast code
 *
 * Copyright (c) 2004-2006, 2014-2017, Ericsson AB
 * Copyright (c) 2004, Intel Corporation.
 * Copyright (c) 2005, 2010-2011, Wind River Systems
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the names of the copyright holders nor the names of its
 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
 *
 * Alternatively, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") version 2 as published by the Free
 * Software Foundation.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/tipc_config.h>
#include "socket.h"
#include "msg.h"
#include "bcast.h"
#include "link.h"
#include "name_table.h"

#define BCLINK_WIN_DEFAULT  50	/* bcast link window size (default) */
#define BCLINK_WIN_MIN      32	/* bcast minimum link window size */

const char tipc_bclink_name[] = "broadcast-link";

/**
 * struct tipc_bc_base - base structure for keeping broadcast send state
 * @link: broadcast send link structure
 * @inputq: data input queue; will only carry SOCK_WAKEUP messages
 * @dest: array keeping number of reachable destinations per bearer
 * @primary_bearer: a bearer having links to all broadcast destinations, if any
 * @bcast_support: indicates if primary bearer, if any, supports broadcast
 * @rcast_support: indicates if all peer nodes support replicast
 * @rc_ratio: dest count as percentage of cluster size where send method changes
 * @bc_threshold: calculated drom rc_ratio; if dests > threshold use broadcast
 */
struct tipc_bc_base {
	struct tipc_link *link;
	struct sk_buff_head inputq;
	int dests[MAX_BEARERS];
	int primary_bearer;
	bool bcast_support;
	bool rcast_support;
	int rc_ratio;
	int bc_threshold;
};

static struct tipc_bc_base *tipc_bc_base(struct net *net)
{
	return tipc_net(net)->bcbase;
}

/* tipc_bcast_get_mtu(): -get the MTU currently used by broadcast link
 * Note: the MTU is decremented to give room for a tunnel header, in
 * case the message needs to be sent as replicast
 */
int tipc_bcast_get_mtu(struct net *net)
{
	return tipc_link_mtu(tipc_bc_sndlink(net)) - INT_H_SIZE;
}

void tipc_bcast_disable_rcast(struct net *net)
{
	tipc_bc_base(net)->rcast_support = false;
}

static void tipc_bcbase_calc_bc_threshold(struct net *net)
{
	struct tipc_bc_base *bb = tipc_bc_base(net);
	int cluster_size = tipc_link_bc_peers(tipc_bc_sndlink(net));

	bb->bc_threshold = 1 + (cluster_size * bb->rc_ratio / 100);
}

/* tipc_bcbase_select_primary(): find a bearer with links to all destinations,
 *                               if any, and make it primary bearer
 */
static void tipc_bcbase_select_primary(struct net *net)
{
	struct tipc_bc_base *bb = tipc_bc_base(net);
	int all_dests =  tipc_link_bc_peers(bb->link);
	int i, mtu, prim;

	bb->primary_bearer = INVALID_BEARER_ID;
	bb->bcast_support = true;

	if (!all_dests)
		return;

	for (i = 0; i < MAX_BEARERS; i++) {
		if (!bb->dests[i])
			continue;

		mtu = tipc_bearer_mtu(net, i);
		if (mtu < tipc_link_mtu(bb->link))
			tipc_link_set_mtu(bb->link, mtu);
		bb->bcast_support &= tipc_bearer_bcast_support(net, i);
		if (bb->dests[i] < all_dests)
			continue;

		bb->primary_bearer = i;

		/* Reduce risk that all nodes select same primary */
		if ((i ^ tipc_own_addr(net)) & 1)
			break;
	}
	prim = bb->primary_bearer;
	if (prim != INVALID_BEARER_ID)
		bb->bcast_support = tipc_bearer_bcast_support(net, prim);
}

void tipc_bcast_inc_bearer_dst_cnt(struct net *net, int bearer_id)
{
	struct tipc_bc_base *bb = tipc_bc_base(net);

	tipc_bcast_lock(net);
	bb->dests[bearer_id]++;
	tipc_bcbase_select_primary(net);
	tipc_bcast_unlock(net);
}

void tipc_bcast_dec_bearer_dst_cnt(struct net *net, int bearer_id)
{
	struct tipc_bc_base *bb = tipc_bc_base(net);

	tipc_bcast_lock(net);
	bb->dests[bearer_id]--;
	tipc_bcbase_select_primary(net);
	tipc_bcast_unlock(net);
}

/* tipc_bcbase_xmit - broadcast a packet queue across one or more bearers
 *
 * Note that number of reachable destinations, as indicated in the dests[]
 * array, may transitionally differ from the number of destinations indicated
 * in each sent buffer. We can sustain this. Excess destination nodes will
 * drop and never acknowledge the unexpected packets, and missing destinations
 * will either require retransmission (if they are just about to be added to
 * the bearer), or be removed from the buffer's 'ackers' counter (if they
 * just went down)
 */
static void tipc_bcbase_xmit(struct net *net, struct sk_buff_head *xmitq)
{
	int bearer_id;
	struct tipc_bc_base *bb = tipc_bc_base(net);
	struct sk_buff *skb, *_skb;
	struct sk_buff_head _xmitq;

	if (skb_queue_empty(xmitq))
		return;

	/* The typical case: at least one bearer has links to all nodes */
	bearer_id = bb->primary_bearer;
	if (bearer_id >= 0) {
		tipc_bearer_bc_xmit(net, bearer_id, xmitq);
		return;
	}

	/* We have to transmit across all bearers */
	skb_queue_head_init(&_xmitq);
	for (bearer_id = 0; bearer_id < MAX_BEARERS; bearer_id++) {
		if (!bb->dests[bearer_id])
			continue;

		skb_queue_walk(xmitq, skb) {
			_skb = pskb_copy_for_clone(skb, GFP_ATOMIC);
			if (!_skb)
				break;
			__skb_queue_tail(&_xmitq, _skb);
		}
		tipc_bearer_bc_xmit(net, bearer_id, &_xmitq);
	}
	__skb_queue_purge(xmitq);
	__skb_queue_purge(&_xmitq);
}

static void tipc_bcast_select_xmit_method(struct net *net, int dests,
					  struct tipc_mc_method *method)
{
	struct tipc_bc_base *bb = tipc_bc_base(net);
	unsigned long exp = method->expires;

	/* Broadcast supported by used bearer/bearers? */
	if (!bb->bcast_support) {
		method->rcast = true;
		return;
	}
	/* Any destinations which don't support replicast ? */
	if (!bb->rcast_support) {
		method->rcast = false;
		return;
	}
	/* Can current method be changed ? */
	method->expires = jiffies + TIPC_METHOD_EXPIRE;
	if (method->mandatory || time_before(jiffies, exp))
		return;

	/* Determine method to use now */
	method->rcast = dests <= bb->bc_threshold;
}

/* tipc_bcast_xmit - broadcast the buffer chain to all external nodes
 * @net: the applicable net namespace
 * @pkts: chain of buffers containing message
 * @cong_link_cnt: set to 1 if broadcast link is congested, otherwise 0
 * Consumes the buffer chain.
 * Returns 0 if success, otherwise errno: -EHOSTUNREACH,-EMSGSIZE
 */
static int tipc_bcast_xmit(struct net *net, struct sk_buff_head *pkts,
			   u16 *cong_link_cnt)
{
	struct tipc_link *l = tipc_bc_sndlink(net);
	struct sk_buff_head xmitq;
	int rc = 0;

	skb_queue_head_init(&xmitq);
	tipc_bcast_lock(net);
	if (tipc_link_bc_peers(l))
		rc = tipc_link_xmit(l, pkts, &xmitq);
	tipc_bcast_unlock(net);
	tipc_bcbase_xmit(net, &xmitq);
	__skb_queue_purge(pkts);
	if (rc == -ELINKCONG) {
		*cong_link_cnt = 1;
		rc = 0;
	}
	return rc;
}

/* tipc_rcast_xmit - replicate and send a message to given destination nodes
 * @net: the applicable net namespace
 * @pkts: chain of buffers containing message
 * @dests: list of destination nodes
 * @cong_link_cnt: returns number of congested links
 * @cong_links: returns identities of congested links
 * Returns 0 if success, otherwise errno
 */
static int tipc_rcast_xmit(struct net *net, struct sk_buff_head *pkts,
			   struct tipc_nlist *dests, u16 *cong_link_cnt)
{
	struct tipc_dest *dst, *tmp;
	struct sk_buff_head _pkts;
	u32 dnode, selector;

	selector = msg_link_selector(buf_msg(skb_peek(pkts)));
	skb_queue_head_init(&_pkts);

	list_for_each_entry_safe(dst, tmp, &dests->list, list) {
		dnode = dst->node;
		if (!tipc_msg_pskb_copy(dnode, pkts, &_pkts))
			return -ENOMEM;

		/* Any other return value than -ELINKCONG is ignored */
		if (tipc_node_xmit(net, &_pkts, dnode, selector) == -ELINKCONG)
			(*cong_link_cnt)++;
	}
	return 0;
}

/* tipc_mcast_xmit - deliver message to indicated destination nodes
 *                   and to identified node local sockets
 * @net: the applicable net namespace
 * @pkts: chain of buffers containing message
 * @method: send method to be used
 * @dests: destination nodes for message.
 * @cong_link_cnt: returns number of encountered congested destination links
 * Consumes buffer chain.
 * Returns 0 if success, otherwise errno
 */
int tipc_mcast_xmit(struct net *net, struct sk_buff_head *pkts,
		    struct tipc_mc_method *method, struct tipc_nlist *dests,
		    u16 *cong_link_cnt)
{
	struct sk_buff_head inputq, localq;
	int rc = 0;

	skb_queue_head_init(&inputq);
	skb_queue_head_init(&localq);

	/* Clone packets before they are consumed by next call */
	if (dests->local && !tipc_msg_reassemble(pkts, &localq)) {
		rc = -ENOMEM;
		goto exit;
	}
	/* Send according to determined transmit method */
	if (dests->remote) {
		tipc_bcast_select_xmit_method(net, dests->remote, method);
		if (method->rcast)
			rc = tipc_rcast_xmit(net, pkts, dests, cong_link_cnt);
		else
			rc = tipc_bcast_xmit(net, pkts, cong_link_cnt);
	}

	if (dests->local)
		tipc_sk_mcast_rcv(net, &localq, &inputq);
exit:
	/* This queue should normally be empty by now */
	__skb_queue_purge(pkts);
	return rc;
}

/* tipc_bcast_rcv - receive a broadcast packet, and deliver to rcv link
 *
 * RCU is locked, no other locks set
 */
int tipc_bcast_rcv(struct net *net, struct tipc_link *l, struct sk_buff *skb)
{
	struct tipc_msg *hdr = buf_msg(skb);
	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
	struct sk_buff_head xmitq;
	int rc;

	__skb_queue_head_init(&xmitq);

	if (msg_mc_netid(hdr) != tipc_netid(net) || !tipc_link_is_up(l)) {
		kfree_skb(skb);
		return 0;
	}

	tipc_bcast_lock(net);
	if (msg_user(hdr) == BCAST_PROTOCOL)
		rc = tipc_link_bc_nack_rcv(l, skb, &xmitq);
	else
		rc = tipc_link_rcv(l, skb, NULL);
	tipc_bcast_unlock(net);

	tipc_bcbase_xmit(net, &xmitq);

	/* Any socket wakeup messages ? */
	if (!skb_queue_empty(inputq))
		tipc_sk_rcv(net, inputq);

	return rc;
}

/* tipc_bcast_ack_rcv - receive and handle a broadcast acknowledge
 *
 * RCU is locked, no other locks set
 */
void tipc_bcast_ack_rcv(struct net *net, struct tipc_link *l,
			struct tipc_msg *hdr)
{
	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
	u16 acked = msg_bcast_ack(hdr);
	struct sk_buff_head xmitq;

	/* Ignore bc acks sent by peer before bcast synch point was received */
	if (msg_bc_ack_invalid(hdr))
		return;

	__skb_queue_head_init(&xmitq);

	tipc_bcast_lock(net);
	tipc_link_bc_ack_rcv(l, acked, &xmitq);
	tipc_bcast_unlock(net);

	tipc_bcbase_xmit(net, &xmitq);

	/* Any socket wakeup messages ? */
	if (!skb_queue_empty(inputq))
		tipc_sk_rcv(net, inputq);
}

/* tipc_bcast_synch_rcv -  check and update rcv link with peer's send state
 *
 * RCU is locked, no other locks set
 */
int tipc_bcast_sync_rcv(struct net *net, struct tipc_link *l,
			struct tipc_msg *hdr)
{
	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
	struct sk_buff_head xmitq;
	int rc = 0;

	__skb_queue_head_init(&xmitq);

	tipc_bcast_lock(net);
	if (msg_type(hdr) != STATE_MSG) {
		tipc_link_bc_init_rcv(l, hdr);
	} else if (!msg_bc_ack_invalid(hdr)) {
		tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq);
		rc = tipc_link_bc_sync_rcv(l, hdr, &xmitq);
	}
	tipc_bcast_unlock(net);

	tipc_bcbase_xmit(net, &xmitq);

	/* Any socket wakeup messages ? */
	if (!skb_queue_empty(inputq))
		tipc_sk_rcv(net, inputq);
	return rc;
}

/* tipc_bcast_add_peer - add a peer node to broadcast link and bearer
 *
 * RCU is locked, node lock is set
 */
void tipc_bcast_add_peer(struct net *net, struct tipc_link *uc_l,
			 struct sk_buff_head *xmitq)
{
	struct tipc_link *snd_l = tipc_bc_sndlink(net);

	tipc_bcast_lock(net);
	tipc_link_add_bc_peer(snd_l, uc_l, xmitq);
	tipc_bcbase_select_primary(net);
	tipc_bcbase_calc_bc_threshold(net);
	tipc_bcast_unlock(net);
}

/* tipc_bcast_remove_peer - remove a peer node from broadcast link and bearer
 *
 * RCU is locked, node lock is set
 */
void tipc_bcast_remove_peer(struct net *net, struct tipc_link *rcv_l)
{
	struct tipc_link *snd_l = tipc_bc_sndlink(net);
	struct sk_buff_head *inputq = &tipc_bc_base(net)->inputq;
	struct sk_buff_head xmitq;

	__skb_queue_head_init(&xmitq);

	tipc_bcast_lock(net);
	tipc_link_remove_bc_peer(snd_l, rcv_l, &xmitq);
	tipc_bcbase_select_primary(net);
	tipc_bcbase_calc_bc_threshold(net);
	tipc_bcast_unlock(net);

	tipc_bcbase_xmit(net, &xmitq);

	/* Any socket wakeup messages ? */
	if (!skb_queue_empty(inputq))
		tipc_sk_rcv(net, inputq);
}

int tipc_bclink_reset_stats(struct net *net)
{
	struct tipc_link *l = tipc_bc_sndlink(net);

	if (!l)
		return -ENOPROTOOPT;

	tipc_bcast_lock(net);
	tipc_link_reset_stats(l);
	tipc_bcast_unlock(net);
	return 0;
}

static int tipc_bc_link_set_queue_limits(struct net *net, u32 limit)
{
	struct tipc_link *l = tipc_bc_sndlink(net);

	if (!l)
		return -ENOPROTOOPT;
	if (limit < BCLINK_WIN_MIN)
		limit = BCLINK_WIN_MIN;
	if (limit > TIPC_MAX_LINK_WIN)
		return -EINVAL;
	tipc_bcast_lock(net);
	tipc_link_set_queue_limits(l, limit);
	tipc_bcast_unlock(net);
	return 0;
}

int tipc_nl_bc_link_set(struct net *net, struct nlattr *attrs[])
{
	int err;
	u32 win;
	struct nlattr *props[TIPC_NLA_PROP_MAX + 1];

	if (!attrs[TIPC_NLA_LINK_PROP])
		return -EINVAL;

	err = tipc_nl_parse_link_prop(attrs[TIPC_NLA_LINK_PROP], props);
	if (err)
		return err;

	if (!props[TIPC_NLA_PROP_WIN])
		return -EOPNOTSUPP;

	win = nla_get_u32(props[TIPC_NLA_PROP_WIN]);

	return tipc_bc_link_set_queue_limits(net, win);
}

int tipc_bcast_init(struct net *net)
{
	struct tipc_net *tn = tipc_net(net);
	struct tipc_bc_base *bb = NULL;
	struct tipc_link *l = NULL;

	bb = kzalloc(sizeof(*bb), GFP_ATOMIC);
	if (!bb)
		goto enomem;
	tn->bcbase = bb;
	spin_lock_init(&tipc_net(net)->bclock);

	if (!tipc_link_bc_create(net, 0, 0,
				 FB_MTU,
				 BCLINK_WIN_DEFAULT,
				 0,
				 &bb->inputq,
				 NULL,
				 NULL,
				 &l))
		goto enomem;
	bb->link = l;
	tn->bcl = l;
	bb->rc_ratio = 25;
	bb->rcast_support = true;
	return 0;
enomem:
	kfree(bb);
	kfree(l);
	return -ENOMEM;
}

void tipc_bcast_stop(struct net *net)
{
	struct tipc_net *tn = net_generic(net, tipc_net_id);

	synchronize_net();
	kfree(tn->bcbase);
	kfree(tn->bcl);
}

void tipc_nlist_init(struct tipc_nlist *nl, u32 self)
{
	memset(nl, 0, sizeof(*nl));
	INIT_LIST_HEAD(&nl->list);
	nl->self = self;
}

void tipc_nlist_add(struct tipc_nlist *nl, u32 node)
{
	if (node == nl->self)
		nl->local = true;
	else if (tipc_dest_push(&nl->list, node, 0))
		nl->remote++;
}

void tipc_nlist_del(struct tipc_nlist *nl, u32 node)
{
	if (node == nl->self)
		nl->local = false;
	else if (tipc_dest_del(&nl->list, node, 0))
		nl->remote--;
}

void tipc_nlist_purge(struct tipc_nlist *nl)
{
	tipc_dest_list_purge(&nl->list);
	nl->remote = 0;
	nl->local = 0;
}