aboutsummaryrefslogtreecommitdiff
path: root/net/tipc/dbg.c
blob: d8af4c28695d21202aeeb4a3ce155c1b46a780c1 (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
/*
 * net/tipc/dbg.c: TIPC print buffer routines for debugging
 * 
 * Copyright (c) 1996-2006, Ericsson AB
 * Copyright (c) 2005-2006, 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 "config.h"
#include "dbg.h"

static char print_string[TIPC_PB_MAX_STR];
static DEFINE_SPINLOCK(print_lock);

static struct print_buf null_buf = { NULL, 0, NULL, NULL };
struct print_buf *TIPC_NULL = &null_buf;

static struct print_buf cons_buf = { NULL, 0, NULL, NULL };
struct print_buf *TIPC_CONS = &cons_buf;

static struct print_buf log_buf = { NULL, 0, NULL, NULL };
struct print_buf *TIPC_LOG = &log_buf;


#define FORMAT(PTR,LEN,FMT) \
{\
       va_list args;\
       va_start(args, FMT);\
       LEN = vsprintf(PTR, FMT, args);\
       va_end(args);\
       *(PTR + LEN) = '\0';\
}

/*
 * Locking policy when using print buffers.
 *
 * The following routines use 'print_lock' for protection:
 * 1) tipc_printf()  - to protect its print buffer(s) and 'print_string'
 * 2) TIPC_TEE()     - to protect its print buffer(s)
 * 3) tipc_dump()    - to protect its print buffer(s) and 'print_string'
 * 4) tipc_log_XXX() - to protect TIPC_LOG
 *
 * All routines of the form tipc_printbuf_XXX() rely on the caller to prevent
 * simultaneous use of the print buffer(s) being manipulated.
 */

/**
 * tipc_printbuf_init - initialize print buffer to empty
 * @pb: pointer to print buffer structure
 * @raw: pointer to character array used by print buffer
 * @size: size of character array
 *
 * Makes the print buffer a null device that discards anything written to it
 * if the character array is too small (or absent).
 */

void tipc_printbuf_init(struct print_buf *pb, char *raw, u32 size)
{
	pb->buf = raw;
	pb->crs = raw;
	pb->size = size;
	pb->next = NULL;

	if (size < TIPC_PB_MIN_SIZE) {
		pb->buf = NULL;
	} else if (raw) {
		pb->buf[0] = 0;
		pb->buf[size-1] = ~0;
	}
}

/**
 * tipc_printbuf_reset - reinitialize print buffer to empty state
 * @pb: pointer to print buffer structure
 */

void tipc_printbuf_reset(struct print_buf *pb)
{
	tipc_printbuf_init(pb, pb->buf, pb->size);
}

/**
 * tipc_printbuf_empty - test if print buffer is in empty state
 * @pb: pointer to print buffer structure
 *
 * Returns non-zero if print buffer is empty.
 */

int tipc_printbuf_empty(struct print_buf *pb)
{
	return (!pb->buf || (pb->crs == pb->buf));
}

/**
 * tipc_printbuf_validate - check for print buffer overflow
 * @pb: pointer to print buffer structure
 * 
 * Verifies that a print buffer has captured all data written to it. 
 * If data has been lost, linearize buffer and prepend an error message
 * 
 * Returns length of print buffer data string (including trailing NUL)
 */

int tipc_printbuf_validate(struct print_buf *pb)
{
        char *err = "\n\n*** PRINT BUFFER OVERFLOW ***\n\n";
        char *cp_buf;
        struct print_buf cb;

	if (!pb->buf)
		return 0;

	if (pb->buf[pb->size - 1] == 0) {
                cp_buf = kmalloc(pb->size, GFP_ATOMIC);
                if (cp_buf != NULL){
                        tipc_printbuf_init(&cb, cp_buf, pb->size);
                        tipc_printbuf_move(&cb, pb);
                        tipc_printbuf_move(pb, &cb);
                        kfree(cp_buf);
                        memcpy(pb->buf, err, strlen(err));
                } else {
                        tipc_printbuf_reset(pb);
                        tipc_printf(pb, err);
                }
	}
	return (pb->crs - pb->buf + 1);
}

/**
 * tipc_printbuf_move - move print buffer contents to another print buffer
 * @pb_to: pointer to destination print buffer structure
 * @pb_from: pointer to source print buffer structure
 * 
 * Current contents of destination print buffer (if any) are discarded.
 * Source print buffer becomes empty if a successful move occurs.
 */

void tipc_printbuf_move(struct print_buf *pb_to, struct print_buf *pb_from)
{
	int len;

	/* Handle the cases where contents can't be moved */

	if (!pb_to->buf)
		return;

	if (!pb_from->buf) {
		tipc_printbuf_reset(pb_to);
		return;
	}

	if (pb_to->size < pb_from->size) {
		tipc_printbuf_reset(pb_to);
		tipc_printf(pb_to, "*** PRINT BUFFER MOVE ERROR ***");
		return;
	}

	/* Copy data from char after cursor to end (if used) */

	len = pb_from->buf + pb_from->size - pb_from->crs - 2;
	if ((pb_from->buf[pb_from->size-1] == 0) && (len > 0)) {
		strcpy(pb_to->buf, pb_from->crs + 1);
		pb_to->crs = pb_to->buf + len;
	} else
		pb_to->crs = pb_to->buf;

	/* Copy data from start to cursor (always) */

	len = pb_from->crs - pb_from->buf;
	strcpy(pb_to->crs, pb_from->buf);
	pb_to->crs += len;

	tipc_printbuf_reset(pb_from);
}

/**
 * tipc_printf - append formatted output to print buffer chain
 * @pb: pointer to chain of print buffers (may be NULL)
 * @fmt: formatted info to be printed
 */

void tipc_printf(struct print_buf *pb, const char *fmt, ...)
{
	int chars_to_add;
	int chars_left;
	char save_char;
	struct print_buf *pb_next;

	spin_lock_bh(&print_lock);
	FORMAT(print_string, chars_to_add, fmt);
	if (chars_to_add >= TIPC_PB_MAX_STR)
		strcpy(print_string, "*** PRINT BUFFER STRING TOO LONG ***");

	while (pb) {
		if (pb == TIPC_CONS)
			printk(print_string);
		else if (pb->buf) {
			chars_left = pb->buf + pb->size - pb->crs - 1;
			if (chars_to_add <= chars_left) {
				strcpy(pb->crs, print_string);
				pb->crs += chars_to_add;
			} else if (chars_to_add >= (pb->size - 1)) {
				strcpy(pb->buf, print_string + chars_to_add + 1
				       - pb->size);
				pb->crs = pb->buf + pb->size - 1;
			} else {
				strcpy(pb->buf, print_string + chars_left);
                                save_char = print_string[chars_left];
                                print_string[chars_left] = 0;
                                strcpy(pb->crs, print_string);
                                print_string[chars_left] = save_char;
                                pb->crs = pb->buf + chars_to_add - chars_left;
                        }
                }
		pb_next = pb->next;
		pb->next = NULL;
		pb = pb_next;
	}
	spin_unlock_bh(&print_lock);
}

/**
 * TIPC_TEE - perform next output operation on both print buffers  
 * @b0: pointer to chain of print buffers (may be NULL)
 * @b1: pointer to print buffer to add to chain
 *
 * Returns pointer to print buffer chain.
 */

struct print_buf *TIPC_TEE(struct print_buf *b0, struct print_buf *b1)
{
	struct print_buf *pb = b0;

	if (!b0 || (b0 == b1))
		return b1;

	spin_lock_bh(&print_lock);
	while (pb->next) {
		if ((pb->next == b1) || (pb->next == b0))
			pb->next = pb->next->next;
		else
			pb = pb->next;
	}
	pb->next = b1;
	spin_unlock_bh(&print_lock);
	return b0;
}

/**
 * print_to_console - write string of bytes to console in multiple chunks
 */

static void print_to_console(char *crs, int len)
{
	int rest = len;

	while (rest > 0) {
		int sz = rest < TIPC_PB_MAX_STR ? rest : TIPC_PB_MAX_STR;
		char c = crs[sz];

		crs[sz] = 0;
		printk((const char *)crs);
		crs[sz] = c;
		rest -= sz;
		crs += sz;
	}
}

/**
 * printbuf_dump - write print buffer contents to console
 */

static void printbuf_dump(struct print_buf *pb)
{
	int len;

	if (!pb->buf) {
		printk("*** PRINT BUFFER NOT ALLOCATED ***");
		return;
	}

	/* Dump print buffer from char after cursor to end (if used) */

	len = pb->buf + pb->size - pb->crs - 2;
	if ((pb->buf[pb->size - 1] == 0) && (len > 0))
		print_to_console(pb->crs + 1, len);

	/* Dump print buffer from start to cursor (always) */

	len = pb->crs - pb->buf;
	print_to_console(pb->buf, len);
}

/**
 * tipc_dump - dump non-console print buffer(s) to console
 * @pb: pointer to chain of print buffers
 */

void tipc_dump(struct print_buf *pb, const char *fmt, ...)
{
	struct print_buf *pb_next;
	int len;

	spin_lock_bh(&print_lock);
	FORMAT(print_string, len, fmt);
	printk(print_string);

	for (; pb; pb = pb->next) {
		if (pb != TIPC_CONS) {
			printk("\n---- Start of %s log dump ----\n\n",
			       (pb == TIPC_LOG) ? "global" : "local");
			printbuf_dump(pb);
			tipc_printbuf_reset(pb);
			printk("\n---- End of dump ----\n");
		}
		pb_next = pb->next;
		pb->next = NULL;
		pb = pb_next;
	}
	spin_unlock_bh(&print_lock);
}

/**
 * tipc_log_stop - free up TIPC log print buffer 
 */

void tipc_log_stop(void)
{
	spin_lock_bh(&print_lock);
	if (TIPC_LOG->buf) {
		kfree(TIPC_LOG->buf);
		TIPC_LOG->buf = NULL;
	}
	spin_unlock_bh(&print_lock);
}

/**
 * tipc_log_reinit - (re)initialize TIPC log print buffer
 * @log_size: print buffer size to use
 */

void tipc_log_reinit(int log_size)
{
	tipc_log_stop();

	if (log_size) {
		if (log_size < TIPC_PB_MIN_SIZE)
			log_size = TIPC_PB_MIN_SIZE;
		spin_lock_bh(&print_lock);
		tipc_printbuf_init(TIPC_LOG, kmalloc(log_size, GFP_ATOMIC),
				   log_size);
		spin_unlock_bh(&print_lock);
	}
}

/**
 * tipc_log_resize - reconfigure size of TIPC log buffer
 */

struct sk_buff *tipc_log_resize(const void *req_tlv_area, int req_tlv_space)
{
	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 = *(u32 *)TLV_DATA(req_tlv_area);
	value = ntohl(value);
	if (value != delimit(value, 0, 32768))
		return tipc_cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
						   " (log size must be 0-32768)");
	tipc_log_reinit(value);
	return tipc_cfg_reply_none();
}

/**
 * tipc_log_dump - capture TIPC log buffer contents in configuration message
 */

struct sk_buff *tipc_log_dump(void)
{
	struct sk_buff *reply;

	spin_lock_bh(&print_lock);
	if (!TIPC_LOG->buf)
		reply = tipc_cfg_reply_ultra_string("log not activated\n");
	else if (tipc_printbuf_empty(TIPC_LOG))
		reply = tipc_cfg_reply_ultra_string("log is empty\n");
	else {
		struct tlv_desc *rep_tlv;
		struct print_buf pb;
		int str_len;

		str_len = min(TIPC_LOG->size, 32768u);
		reply = tipc_cfg_reply_alloc(TLV_SPACE(str_len));
		if (reply) {
			rep_tlv = (struct tlv_desc *)reply->data;
			tipc_printbuf_init(&pb, TLV_DATA(rep_tlv), str_len);
			tipc_printbuf_move(&pb, TIPC_LOG);
			str_len = strlen(TLV_DATA(rep_tlv)) + 1;
			skb_put(reply, TLV_SPACE(str_len));
			TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
		}
	}
	spin_unlock_bh(&print_lock);
	return reply;
}