aboutsummaryrefslogtreecommitdiffstats
path: root/net/tipc/config.c
blob: 2ee5a9a3cebf635cad2fbc688cc1f68c84654e44 (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
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
/*
 * net/tipc/config.c: TIPC configuration management code
 *
 * Copyright (c) 2002-2006, Ericsson AB
 * Copyright (c) 2004-2007, 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 "core.h"
#include "port.h"
#include "link.h"
#include "name_table.h"
#include "user_reg.h"
#include "config.h"

struct manager {
	u32 user_ref;
	u32 port_ref;
};

static struct manager mng = { 0};

static DEFINE_SPINLOCK(config_lock);

static const void *req_tlv_area;	/* request message TLV area */
static int req_tlv_space;		/* request message TLV area size */
static int rep_headroom;		/* reply message headroom to use */


struct sk_buff *tipc_cfg_reply_alloc(int payload_size)
{
	struct sk_buff *buf;

	buf = alloc_skb(rep_headroom + payload_size, GFP_ATOMIC);
	if (buf)
		skb_reserve(buf, rep_headroom);
	return buf;
}

int tipc_cfg_append_tlv(struct sk_buff *buf, int tlv_type,
			void *tlv_data, int tlv_data_size)
{
	struct tlv_desc *tlv = (struct tlv_desc *)skb_tail_pointer(buf);
	int new_tlv_space = TLV_SPACE(tlv_data_size);

	if (skb_tailroom(buf) < new_tlv_space) {
		dbg("tipc_cfg_append_tlv unable to append TLV\n");
		return 0;
	}
	skb_put(buf, new_tlv_space);
	tlv->tlv_type = htons(tlv_type);
	tlv->tlv_len  = htons(TLV_LENGTH(tlv_data_size));
	if (tlv_data_size && tlv_data)
		memcpy(TLV_DATA(tlv), tlv_data, tlv_data_size);
	return 1;
}

static struct sk_buff *tipc_cfg_reply_unsigned_type(u16 tlv_type, u32 value)
{
	struct sk_buff *buf;
	__be32 value_net;

	buf = tipc_cfg_reply_alloc(TLV_SPACE(sizeof(value)));
	if (buf) {
		value_net = htonl(value);
		tipc_cfg_append_tlv(buf, tlv_type, &value_net,
				    sizeof(value_net));
	}
	return buf;
}

static struct sk_buff *tipc_cfg_reply_unsigned(u32 value)
{
	return tipc_cfg_reply_unsigned_type(TIPC_TLV_UNSIGNED, value);
}

struct sk_buff *tipc_cfg_reply_string_type(u16 tlv_type, char *string)
{
	struct sk_buff *buf;
	int string_len = strlen(string) + 1;

	buf = tipc_cfg_reply_alloc(TLV_SPACE(string_len));
	if (buf)
		tipc_cfg_append_tlv(buf, tlv_type, string, string_len);
	return buf;
}

#define MAX_STATS_INFO 2000

static struct sk_buff *tipc_show_stats(void)
{
	struct sk_buff *buf;
	struct tlv_desc *rep_tlv;
	struct print_buf pb;
	int str_len;
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	value = ntohl(*(u32 *)TLV_DATA(req_tlv_area));
	if (value != 0)
		return tipc_cfg_reply_error_string("unsupported argument");

	buf = tipc_cfg_reply_alloc(TLV_SPACE(MAX_STATS_INFO));
	if (buf == NULL)
		return NULL;

	rep_tlv = (struct tlv_desc *)buf->data;
	tipc_printbuf_init(&pb, (char *)TLV_DATA(rep_tlv), MAX_STATS_INFO);

	tipc_printf(&pb, "TIPC version " TIPC_MOD_VER "\n");

	/* Use additional tipc_printf()'s to return more info ... */

	str_len = tipc_printbuf_validate(&pb);
	skb_put(buf, TLV_SPACE(str_len));
	TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);

	return buf;
}

static struct sk_buff *cfg_enable_bearer(void)
{
	struct tipc_bearer_config *args;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_BEARER_CONFIG))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	args = (struct tipc_bearer_config *)TLV_DATA(req_tlv_area);
	if (tipc_enable_bearer(args->name,
			       ntohl(args->detect_scope),
			       ntohl(args->priority)))
		return tipc_cfg_reply_error_string("unable to enable bearer");

	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_disable_bearer(void)
{
	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_BEARER_NAME))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	if (tipc_disable_bearer((char *)TLV_DATA(req_tlv_area)))
		return tipc_cfg_reply_error_string("unable to disable bearer");

	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_own_addr(void)
{
	u32 addr;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_NET_ADDR))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	addr = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (addr == tipc_own_addr)
		return tipc_cfg_reply_none();
	if (!tipc_addr_node_valid(addr))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (node address)");
	if (tipc_mode == TIPC_NET_MODE)
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
						   " (cannot change node address once assigned)");

	/*
	 * Must release all spinlocks before calling start_net() because
	 * Linux version of TIPC calls eth_media_start() which calls
	 * register_netdevice_notifier() which may block!
	 *
	 * Temporarily releasing the lock should be harmless for non-Linux TIPC,
	 * but Linux version of eth_media_start() should really be reworked
	 * so that it can be called with spinlocks held.
	 */

	spin_unlock_bh(&config_lock);
	tipc_core_start_net(addr);
	spin_lock_bh(&config_lock);
	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_remote_mng(void)
{
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	tipc_remote_management = (value != 0);
	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_max_publications(void)
{
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (value != delimit(value, 1, 65535))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (max publications must be 1-65535)");
	tipc_max_publications = value;
	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_max_subscriptions(void)
{
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);

	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (value != delimit(value, 1, 65535))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (max subscriptions must be 1-65535");
	tipc_max_subscriptions = value;
	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_max_ports(void)
{
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (value == tipc_max_ports)
		return tipc_cfg_reply_none();
	if (value != delimit(value, 127, 65535))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (max ports must be 127-65535)");
	if (tipc_mode != TIPC_NOT_RUNNING)
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
			" (cannot change max ports while TIPC is active)");
	tipc_max_ports = value;
	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_max_zones(void)
{
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (value == tipc_max_zones)
		return tipc_cfg_reply_none();
	if (value != delimit(value, 1, 255))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (max zones must be 1-255)");
	if (tipc_mode == TIPC_NET_MODE)
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
			" (cannot change max zones once TIPC has joined a network)");
	tipc_max_zones = value;
	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_max_clusters(void)
{
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (value != delimit(value, 1, 1))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (max clusters fixed at 1)");
	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_max_nodes(void)
{
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (value == tipc_max_nodes)
		return tipc_cfg_reply_none();
	if (value != delimit(value, 8, 2047))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (max nodes must be 8-2047)");
	if (tipc_mode == TIPC_NET_MODE)
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
			" (cannot change max nodes once TIPC has joined a network)");
	tipc_max_nodes = value;
	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_max_slaves(void)
{
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (value != 0)
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
						   " (max secondary nodes fixed at 0)");
	return tipc_cfg_reply_none();
}

static struct sk_buff *cfg_set_netid(void)
{
	u32 value;

	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
		return tipc_cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
	value = ntohl(*(__be32 *)TLV_DATA(req_tlv_area));
	if (value == tipc_net_id)
		return tipc_cfg_reply_none();
	if (value != delimit(value, 1, 9999))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (network id must be 1-9999)");
	if (tipc_mode == TIPC_NET_MODE)
		return tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
			" (cannot change network id once TIPC has joined a network)");
	tipc_net_id = value;
	return tipc_cfg_reply_none();
}

struct sk_buff *tipc_cfg_do_cmd(u32 orig_node, u16 cmd, const void *request_area,
				int request_space, int reply_headroom)
{
	struct sk_buff *rep_tlv_buf;

	spin_lock_bh(&config_lock);

	/* Save request and reply details in a well-known location */

	req_tlv_area = request_area;
	req_tlv_space = request_space;
	rep_headroom = reply_headroom;

	/* Check command authorization */

	if (likely(orig_node == tipc_own_addr)) {
		/* command is permitted */
	} else if (cmd >= 0x8000) {
		rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
							  " (cannot be done remotely)");
		goto exit;
	} else if (!tipc_remote_management) {
		rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NO_REMOTE);
		goto exit;
	}
	else if (cmd >= 0x4000) {
		u32 domain = 0;

		if ((tipc_nametbl_translate(TIPC_ZM_SRV, 0, &domain) == 0) ||
		    (domain != orig_node)) {
			rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_ZONE_MSTR);
			goto exit;
		}
	}

	/* Call appropriate processing routine */

	switch (cmd) {
	case TIPC_CMD_NOOP:
		rep_tlv_buf = tipc_cfg_reply_none();
		break;
	case TIPC_CMD_GET_NODES:
		rep_tlv_buf = tipc_node_get_nodes(req_tlv_area, req_tlv_space);
		break;
	case TIPC_CMD_GET_LINKS:
		rep_tlv_buf = tipc_node_get_links(req_tlv_area, req_tlv_space);
		break;
	case TIPC_CMD_SHOW_LINK_STATS:
		rep_tlv_buf = tipc_link_cmd_show_stats(req_tlv_area, req_tlv_space);
		break;
	case TIPC_CMD_RESET_LINK_STATS:
		rep_tlv_buf = tipc_link_cmd_reset_stats(req_tlv_area, req_tlv_space);
		break;
	case TIPC_CMD_SHOW_NAME_TABLE:
		rep_tlv_buf = tipc_nametbl_get(req_tlv_area, req_tlv_space);
		break;
	case TIPC_CMD_GET_BEARER_NAMES:
		rep_tlv_buf = tipc_bearer_get_names();
		break;
	case TIPC_CMD_GET_MEDIA_NAMES:
		rep_tlv_buf = tipc_media_get_names();
		break;
	case TIPC_CMD_SHOW_PORTS:
		rep_tlv_buf = tipc_port_get_ports();
		break;
	case TIPC_CMD_SET_LOG_SIZE:
		rep_tlv_buf = tipc_log_resize_cmd(req_tlv_area, req_tlv_space);
		break;
	case TIPC_CMD_DUMP_LOG:
		rep_tlv_buf = tipc_log_dump();
		break;
	case TIPC_CMD_SHOW_STATS:
		rep_tlv_buf = tipc_show_stats();
		break;
	case TIPC_CMD_SET_LINK_TOL:
	case TIPC_CMD_SET_LINK_PRI:
	case TIPC_CMD_SET_LINK_WINDOW:
		rep_tlv_buf = tipc_link_cmd_config(req_tlv_area, req_tlv_space, cmd);
		break;
	case TIPC_CMD_ENABLE_BEARER:
		rep_tlv_buf = cfg_enable_bearer();
		break;
	case TIPC_CMD_DISABLE_BEARER:
		rep_tlv_buf = cfg_disable_bearer();
		break;
	case TIPC_CMD_SET_NODE_ADDR:
		rep_tlv_buf = cfg_set_own_addr();
		break;
	case TIPC_CMD_SET_REMOTE_MNG:
		rep_tlv_buf = cfg_set_remote_mng();
		break;
	case TIPC_CMD_SET_MAX_PORTS:
		rep_tlv_buf = cfg_set_max_ports();
		break;
	case TIPC_CMD_SET_MAX_PUBL:
		rep_tlv_buf = cfg_set_max_publications();
		break;
	case TIPC_CMD_SET_MAX_SUBSCR:
		rep_tlv_buf = cfg_set_max_subscriptions();
		break;
	case TIPC_CMD_SET_MAX_ZONES:
		rep_tlv_buf = cfg_set_max_zones();
		break;
	case TIPC_CMD_SET_MAX_CLUSTERS:
		rep_tlv_buf = cfg_set_max_clusters();
		break;
	case TIPC_CMD_SET_MAX_NODES:
		rep_tlv_buf = cfg_set_max_nodes();
		break;
	case TIPC_CMD_SET_MAX_SLAVES:
		rep_tlv_buf = cfg_set_max_slaves();
		break;
	case TIPC_CMD_SET_NETID:
		rep_tlv_buf = cfg_set_netid();
		break;
	case TIPC_CMD_GET_REMOTE_MNG:
		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_remote_management);
		break;
	case TIPC_CMD_GET_MAX_PORTS:
		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_max_ports);
		break;
	case TIPC_CMD_GET_MAX_PUBL:
		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_max_publications);
		break;
	case TIPC_CMD_GET_MAX_SUBSCR:
		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_max_subscriptions);
		break;
	case TIPC_CMD_GET_MAX_ZONES:
		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_max_zones);
		break;
	case TIPC_CMD_GET_MAX_CLUSTERS:
		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_max_clusters);
		break;
	case TIPC_CMD_GET_MAX_NODES:
		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_max_nodes);
		break;
	case TIPC_CMD_GET_MAX_SLAVES:
		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_max_slaves);
		break;
	case TIPC_CMD_GET_NETID:
		rep_tlv_buf = tipc_cfg_reply_unsigned(tipc_net_id);
		break;
	case TIPC_CMD_NOT_NET_ADMIN:
		rep_tlv_buf =
			tipc_cfg_reply_error_string(TIPC_CFG_NOT_NET_ADMIN);
		break;
	default:
		rep_tlv_buf = tipc_cfg_reply_error_string(TIPC_CFG_NOT_SUPPORTED
							  " (unknown command)");
		break;
	}

	/* Return reply buffer */
exit:
	spin_unlock_bh(&config_lock);
	return rep_tlv_buf;
}

static void cfg_named_msg_event(void *userdata,
				u32 port_ref,
				struct sk_buff **buf,
				const unchar *msg,
				u32 size,
				u32 importance,
				struct tipc_portid const *orig,
				struct tipc_name_seq const *dest)
{
	struct tipc_cfg_msg_hdr *req_hdr;
	struct tipc_cfg_msg_hdr *rep_hdr;
	struct sk_buff *rep_buf;

	/* Validate configuration message header (ignore invalid message) */

	req_hdr = (struct tipc_cfg_msg_hdr *)msg;
	if ((size < sizeof(*req_hdr)) ||
	    (size != TCM_ALIGN(ntohl(req_hdr->tcm_len))) ||
	    (ntohs(req_hdr->tcm_flags) != TCM_F_REQUEST)) {
		warn("Invalid configuration message discarded\n");
		return;
	}

	/* Generate reply for request (if can't, return request) */

	rep_buf = tipc_cfg_do_cmd(orig->node,
				  ntohs(req_hdr->tcm_type),
				  msg + sizeof(*req_hdr),
				  size - sizeof(*req_hdr),
				  BUF_HEADROOM + MAX_H_SIZE + sizeof(*rep_hdr));
	if (rep_buf) {
		skb_push(rep_buf, sizeof(*rep_hdr));
		rep_hdr = (struct tipc_cfg_msg_hdr *)rep_buf->data;
		memcpy(rep_hdr, req_hdr, sizeof(*rep_hdr));
		rep_hdr->tcm_len = htonl(rep_buf->len);
		rep_hdr->tcm_flags &= htons(~TCM_F_REQUEST);
	} else {
		rep_buf = *buf;
		*buf = NULL;
	}

	/* NEED TO ADD CODE TO HANDLE FAILED SEND (SUCH AS CONGESTION) */
	tipc_send_buf2port(port_ref, orig, rep_buf, rep_buf->len);
}

int tipc_cfg_init(void)
{
	struct tipc_name_seq seq;
	int res;

	res = tipc_attach(&mng.user_ref, NULL, NULL);
	if (res)
		goto failed;

	res = tipc_createport(mng.user_ref, NULL, TIPC_CRITICAL_IMPORTANCE,
			      NULL, NULL, NULL,
			      NULL, cfg_named_msg_event, NULL,
			      NULL, &mng.port_ref);
	if (res)
		goto failed;

	seq.type = TIPC_CFG_SRV;
	seq.lower = seq.upper = tipc_own_addr;
	res = tipc_nametbl_publish_rsv(mng.port_ref, TIPC_ZONE_SCOPE, &seq);
	if (res)
		goto failed;

	return 0;

failed:
	err("Unable to create configuration service\n");
	tipc_detach(mng.user_ref);
	mng.user_ref = 0;
	return res;
}

void tipc_cfg_stop(void)
{
	if (mng.user_ref) {
		tipc_detach(mng.user_ref);
		mng.user_ref = 0;
	}
}