summaryrefslogtreecommitdiff
path: root/net/tipc/bcast.c
blob: ae469b37d85262e89e99f22784c7fa10b3d4bcb7 (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
/*
 * net/tipc/bcast.c: TIPC broadcast code
 *
 * Copyright (c) 2004-2006, 2014-2015, 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 "name_distr.h"
#include "link.h"
#include "node.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
 */
struct tipc_bc_base {
	struct tipc_link *link;
	struct sk_buff_head inputq;
	int dests[MAX_BEARERS];
	int primary_bearer;
};

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

int tipc_bcast_get_mtu(struct net *net)
{
	return tipc_link_mtu(tipc_bc_sndlink(net));
}

/* 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;

	bb->primary_bearer = INVALID_BEARER_ID;

	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);

		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;
	}
}

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);
}

/* tipc_bcast_xmit - deliver buffer chain to all nodes in cluster
 *                    and to identified node local sockets
 * @net: the applicable net namespace
 * @list: chain of buffers containing message
 * Consumes the buffer chain, except when returning -ELINKCONG
 * Returns 0 if success, otherwise errno: -ELINKCONG,-EHOSTUNREACH,-EMSGSIZE
 */
int tipc_bcast_xmit(struct net *net, struct sk_buff_head *list)
{
	struct tipc_link *l = tipc_bc_sndlink(net);
	struct sk_buff_head xmitq, inputq, rcvq;
	int rc = 0;

	__skb_queue_head_init(&rcvq);
	__skb_queue_head_init(&xmitq);
	skb_queue_head_init(&inputq);

	/* Prepare message clone for local node */
	if (unlikely(!tipc_msg_reassemble(list, &rcvq)))
		return -EHOSTUNREACH;

	tipc_bcast_lock(net);
	if (tipc_link_bc_peers(l))
		rc = tipc_link_xmit(l, list, &xmitq);
	tipc_bcast_unlock(net);

	/* Don't send to local node if adding to link failed */
	if (unlikely(rc)) {
		__skb_queue_purge(&rcvq);
		return rc;
	}

	/* Broadcast to all nodes, inluding local node */
	tipc_bcbase_xmit(net, &xmitq);
	tipc_sk_mcast_rcv(net, &rcvq, &inputq);
	__skb_queue_purge(list);
	return 0;
}

/* 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, u32 acked)
{
	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_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
 */
void 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;

	__skb_queue_head_init(&xmitq);

	tipc_bcast_lock(net);
	if (msg_type(hdr) == STATE_MSG) {
		tipc_link_bc_ack_rcv(l, msg_bcast_ack(hdr), &xmitq);
		tipc_link_bc_sync_rcv(l, hdr, &xmitq);
	} else {
		tipc_link_bc_init_rcv(l, hdr);
	}
	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_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_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_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,
				 U16_MAX,
				 BCLINK_WIN_DEFAULT,
				 0,
				 &bb->inputq,
				 NULL,
				 NULL,
				 &l))
		goto enomem;
	bb->link = l;
	tn->bcl = l;
	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);
}