[deliverable/linux.git] / net / tipc / dbg.c

/*
 * net/tipc/dbg.c: TIPC print buffer routines for debuggign
 * 
 * Copyright (c) 2003-2006, Ericsson AB
 * Copyright (c) 2005, 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"

#define MAX_STRING 512

static char print_string[MAX_STRING];
static spinlock_t print_lock = SPIN_LOCK_UNLOCKED;

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

static struct print_buf log_buf = { NULL, 0, NULL, NULL };
struct print_buf *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.
 *
 * 1) Routines of the form printbuf_XXX() rely on the caller to prevent
 *    simultaneous use of the print buffer(s) being manipulated.
 * 2) tipc_printf() uses 'print_lock' to prevent simultaneous use of
 *    'print_string' and to protect its print buffer(s).
 * 3) TEE() uses 'print_lock' to protect its print buffer(s).
 * 4) Routines of the form log_XXX() uses 'print_lock' to protect LOG.
 */

/**
 * printbuf_init - initialize print buffer to empty
 */

void printbuf_init(struct print_buf *pb, char *raw, u32 sz)
{
	if (!pb || !raw || (sz < (MAX_STRING + 1)))
		return;

	pb->crs = pb->buf = raw;
	pb->size = sz;
	pb->next = 0;
	pb->buf[0] = 0;
	pb->buf[sz-1] = ~0;
}

/**
 * printbuf_reset - reinitialize print buffer to empty state
 */

void printbuf_reset(struct print_buf *pb)
{
	if (pb && pb->buf)
		printbuf_init(pb, pb->buf, pb->size);
}

/**
 * printbuf_empty - test if print buffer is in empty state
 */

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

/**
 * printbuf_validate - check for print buffer overflow
 * 
 * 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 NULL)
 */

int printbuf_validate(struct print_buf *pb)
{
        char *err = "             *** PRINT BUFFER WRAPPED AROUND ***\n";
        char *cp_buf;
        struct print_buf cb;

	if (!pb || !pb->buf)
		return 0;

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

/**
 * printbuf_move - move print buffer contents to another print buffer
 * 
 * Current contents of destination print buffer (if any) are discarded.
 * Source print buffer becomes empty if a successful move occurs.
 */

void 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 || !pb_to->buf)
		return;

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

	if (pb_to->size < pb_from->size) {
		printbuf_reset(pb_to);
		tipc_printf(pb_to, "*** PRINT BUFFER OVERFLOW ***");
		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;

	printbuf_reset(pb_from);
}

/**
 * tipc_printf - append formatted output to print buffer chain
 */

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 >= MAX_STRING)
		strcpy(print_string, "*** STRING TOO LONG ***");

	while (pb) {
		if (pb == 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 {
				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 = 0;
		pb = pb_next;
	}
	spin_unlock_bh(&print_lock);
}

/**
 * TEE - perform next output operation on both print buffers  
 */

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

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

	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 < MAX_STRING ? rest : MAX_STRING;
		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;

	/* 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
 */

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

	spin_lock_bh(&print_lock);
	FORMAT(CONS->buf, len, fmt);
	printk(CONS->buf);

	for (; pb; pb = pb->next) {
		if (pb == CONS)
			continue;
		printk("\n---- Start of dump,%s log ----\n\n", 
		       (pb == LOG) ? "global" : "local");
		printbuf_dump(pb);
		printbuf_reset(pb);
		printk("\n-------- End of dump --------\n");
	}
	spin_unlock_bh(&print_lock);
}

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

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

/**
 * log_reinit - set TIPC log print buffer to specified size
 */

void log_reinit(int log_size)
{
	log_stop();

	if (log_size) {
		if (log_size <= MAX_STRING)
			log_size = MAX_STRING + 1;
		spin_lock_bh(&print_lock);
		printbuf_init(LOG, kmalloc(log_size, GFP_ATOMIC), log_size);
		spin_unlock_bh(&print_lock);
	}
}

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

struct sk_buff *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 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 cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
					      " (log size must be 0-32768)");
	log_reinit(value);
	return cfg_reply_none();
}

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

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

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

		str_len = min(LOG->size, 32768u);
		reply = cfg_reply_alloc(TLV_SPACE(str_len));
		if (reply) {
			rep_tlv = (struct tlv_desc *)reply->data;
			printbuf_init(&pb, TLV_DATA(rep_tlv), str_len);
			printbuf_move(&pb, 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;
}
Commit	Line	Data
b97bf3fd PL	1	/*
	2	* net/tipc/dbg.c: TIPC print buffer routines for debuggign
	3	*
9da1c8b6	4	* Copyright (c) 2003-2006, Ericsson AB
b97bf3fd	5	* Copyright (c) 2005, Wind River Systems
b97bf3fd PL	6	* All rights reserved.
b97bf3fd PL	7	*
9ea1fd3c	8	* Redistribution and use in source and binary forms, with or without
b97bf3fd PL	9	* modification, are permitted provided that the following conditions are met:
b97bf3fd PL	10	*
9ea1fd3c PL	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
	16	* 3. Neither the names of the copyright holders nor the names of its
	17	* contributors may be used to endorse or promote products derived from
	18	* this software without specific prior written permission.
b97bf3fd	19	*
9ea1fd3c PL	20	* Alternatively, this software may be distributed under the terms of the
	21	* GNU General Public License ("GPL") version 2 as published by the Free
	22	* Software Foundation.
	23	*
	24	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
	25	* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	26	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	27	* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
	28	* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	29	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	30	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
	31	* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
	32	* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
	33	* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
b97bf3fd PL	34	* POSSIBILITY OF SUCH DAMAGE.
	35	*/
	36
	37	#include "core.h"
	38	#include "config.h"
	39	#include "dbg.h"
	40
	41	#define MAX_STRING 512
	42
	43	static char print_string[MAX_STRING];
	44	static spinlock_t print_lock = SPIN_LOCK_UNLOCKED;
	45
	46	static struct print_buf cons_buf = { NULL, 0, NULL, NULL };
	47	struct print_buf *CONS = &cons_buf;
	48
	49	static struct print_buf log_buf = { NULL, 0, NULL, NULL };
	50	struct print_buf *LOG = &log_buf;
	51
	52
	53	#define FORMAT(PTR,LEN,FMT) \
	54	{\
	55	va_list args;\
	56	va_start(args, FMT);\
	57	LEN = vsprintf(PTR, FMT, args);\
	58	va_end(args);\
	59	*(PTR + LEN) = '\0';\
	60	}
	61
	62	/*
	63	* Locking policy when using print buffers.
	64	*
	65	* 1) Routines of the form printbuf_XXX() rely on the caller to prevent
	66	* simultaneous use of the print buffer(s) being manipulated.
	67	* 2) tipc_printf() uses 'print_lock' to prevent simultaneous use of
	68	* 'print_string' and to protect its print buffer(s).
	69	* 3) TEE() uses 'print_lock' to protect its print buffer(s).
	70	* 4) Routines of the form log_XXX() uses 'print_lock' to protect LOG.
	71	*/
	72
	73	/**
	74	* printbuf_init - initialize print buffer to empty
	75	*/
	76
	77	void printbuf_init(struct print_buf pb, char raw, u32 sz)
	78	{
	79	if (!pb \|\| !raw \|\| (sz < (MAX_STRING + 1)))
	80	return;
	81
	82	pb->crs = pb->buf = raw;
	83	pb->size = sz;
	84	pb->next = 0;
	85	pb->buf[0] = 0;
	86	pb->buf[sz-1] = ~0;
	87	}
	88
	89	/**
	90	* printbuf_reset - reinitialize print buffer to empty state
	91	*/
	92
	93	void printbuf_reset(struct print_buf *pb)
	94	{
	95	if (pb && pb->buf)
	96	printbuf_init(pb, pb->buf, pb->size);
	97	}
98
99	/**
100	* printbuf_empty - test if print buffer is in empty state
101	*/
102
103	int printbuf_empty(struct print_buf *pb)
104	{
105	return (!pb \|\| !pb->buf \|\| (pb->crs == pb->buf));
106	}
107
108	/**
109	* printbuf_validate - check for print buffer overflow
110	*
111	* Verifies that a print buffer has captured all data written to it.
112	* If data has been lost, linearize buffer and prepend an error message
113	*
114	* Returns length of print buffer data string (including trailing NULL)
115	*/
116
117	int printbuf_validate(struct print_buf *pb)
118	{
119	char err = " PRINT BUFFER WRAPPED AROUND *\n";
120	char *cp_buf;
121	struct print_buf cb;
122
123	if (!pb \|\| !pb->buf)
124	return 0;
125
126	if (pb->buf[pb->size - 1] == '\0') {
127	cp_buf = kmalloc(pb->size, GFP_ATOMIC);
128	if (cp_buf != NULL){
129	printbuf_init(&cb, cp_buf, pb->size);
130	printbuf_move(&cb, pb);
131	printbuf_move(pb, &cb);
132	kfree(cp_buf);
133	memcpy(pb->buf, err, strlen(err));
134	} else {
135	printbuf_reset(pb);
136	tipc_printf(pb, err);
137	}
138	}
139	return (pb->crs - pb->buf + 1);
140	}
141
142	/**
143	* printbuf_move - move print buffer contents to another print buffer
144	*
145	* Current contents of destination print buffer (if any) are discarded.
146	* Source print buffer becomes empty if a successful move occurs.
147	*/
148
149	void printbuf_move(struct print_buf pb_to, struct print_buf pb_from)
150	{
151	int len;
152
153	/* Handle the cases where contents can't be moved */
154
155	if (!pb_to \|\| !pb_to->buf)
156	return;
157
158	if (!pb_from \|\| !pb_from->buf) {
159	printbuf_reset(pb_to);
160	return;
161	}
162
163	if (pb_to->size < pb_from->size) {
164	printbuf_reset(pb_to);
165	tipc_printf(pb_to, "* PRINT BUFFER OVERFLOW *");
166	return;
167	}
168
169	/* Copy data from char after cursor to end (if used) */
170	len = pb_from->buf + pb_from->size - pb_from->crs - 2;
171	if ((pb_from->buf[pb_from->size-1] == 0) && (len > 0)) {
172	strcpy(pb_to->buf, pb_from->crs + 1);
173	pb_to->crs = pb_to->buf + len;
174	} else
175	pb_to->crs = pb_to->buf;
176
177	/* Copy data from start to cursor (always) */
178	len = pb_from->crs - pb_from->buf;
179	strcpy(pb_to->crs, pb_from->buf);
180	pb_to->crs += len;
181
182	printbuf_reset(pb_from);
183	}
184
185	/**
186	* tipc_printf - append formatted output to print buffer chain
187	*/
188
189	void tipc_printf(struct print_buf pb, const char fmt, ...)
190	{
191	int chars_to_add;
192	int chars_left;
193	char save_char;
194	struct print_buf *pb_next;
195
196	spin_lock_bh(&print_lock);
197	FORMAT(print_string, chars_to_add, fmt);
198	if (chars_to_add >= MAX_STRING)
199	strcpy(print_string, "* STRING TOO LONG *");
200
201	while (pb) {
202	if (pb == CONS)
203	printk(print_string);
204	else if (pb->buf) {
205	chars_left = pb->buf + pb->size - pb->crs - 1;
206	if (chars_to_add <= chars_left) {
207	strcpy(pb->crs, print_string);
208	pb->crs += chars_to_add;
209	} else {
210	strcpy(pb->buf, print_string + chars_left);
211	save_char = print_string[chars_left];
212	print_string[chars_left] = 0;
213	strcpy(pb->crs, print_string);
214	print_string[chars_left] = save_char;
215	pb->crs = pb->buf + chars_to_add - chars_left;
216	}
217	}
218	pb_next = pb->next;
219	pb->next = 0;
220	pb = pb_next;
221	}
222	spin_unlock_bh(&print_lock);
223	}
224
225	/**
226	* TEE - perform next output operation on both print buffers
227	*/
228
229	struct print_buf TEE(struct print_buf b0, struct print_buf *b1)
230	{
231	struct print_buf *pb = b0;
232
233	if (!b0 \|\| (b0 == b1))
234	return b1;
235	if (!b1)
236	return b0;
237
238	spin_lock_bh(&print_lock);
239	while (pb->next) {
240	if ((pb->next == b1) \|\| (pb->next == b0))
241	pb->next = pb->next->next;
242	else
243	pb = pb->next;
244	}
245	pb->next = b1;
246	spin_unlock_bh(&print_lock);
247	return b0;
248	}
249
250	/**
251	* print_to_console - write string of bytes to console in multiple chunks
252	*/
253
254	static void print_to_console(char *crs, int len)
255	{
256	int rest = len;
257
258	while (rest > 0) {
259	int sz = rest < MAX_STRING ? rest : MAX_STRING;
260	char c = crs[sz];
261
262	crs[sz] = 0;
263	printk((const char *)crs);
264	crs[sz] = c;
265	rest -= sz;
266	crs += sz;
267	}
268	}
269
270	/**
271	* printbuf_dump - write print buffer contents to console
272	*/
273
274	static void printbuf_dump(struct print_buf *pb)
275	{
276	int len;
277
278	/* Dump print buffer from char after cursor to end (if used) */
279	len = pb->buf + pb->size - pb->crs - 2;
280	if ((pb->buf[pb->size - 1] == 0) && (len > 0))
281	print_to_console(pb->crs + 1, len);
282
283	/* Dump print buffer from start to cursor (always) */
284	len = pb->crs - pb->buf;
285	print_to_console(pb->buf, len);
286	}
287
288	/**
289	* tipc_dump - dump non-console print buffer(s) to console
290	*/
291
292	void tipc_dump(struct print_buf pb, const char fmt, ...)
293	{
294	int len;
295
296	spin_lock_bh(&print_lock);
297	FORMAT(CONS->buf, len, fmt);
298	printk(CONS->buf);
299
300	for (; pb; pb = pb->next) {
301	if (pb == CONS)
302	continue;
303	printk("\n---- Start of dump,%s log ----\n\n",
304	(pb == LOG) ? "global" : "local");
305	printbuf_dump(pb);
306	printbuf_reset(pb);
307	printk("\n-------- End of dump --------\n");
308	}
309	spin_unlock_bh(&print_lock);
310	}
311
312	/**
313	* log_stop - free up TIPC log print buffer
314	*/
315
316	void log_stop(void)
317	{
318	spin_lock_bh(&print_lock);
319	if (LOG->buf) {
320	kfree(LOG->buf);
321	LOG->buf = NULL;
322	}
323	spin_unlock_bh(&print_lock);
324	}
325
326	/**
327	* log_reinit - set TIPC log print buffer to specified size
328	*/
329
330	void log_reinit(int log_size)
331	{
332	log_stop();
333
334	if (log_size) {
335	if (log_size <= MAX_STRING)
336	log_size = MAX_STRING + 1;
337	spin_lock_bh(&print_lock);
338	printbuf_init(LOG, kmalloc(log_size, GFP_ATOMIC), log_size);
339	spin_unlock_bh(&print_lock);
340	}
341	}
342
343	/**
344	* log_resize - reconfigure size of TIPC log buffer
345	*/
346
347	struct sk_buff log_resize(const void req_tlv_area, int req_tlv_space)
348	{
349	u32 value;
350
351	if (!TLV_CHECK(req_tlv_area, req_tlv_space, TIPC_TLV_UNSIGNED))
352	return cfg_reply_error_string(TIPC_CFG_TLV_ERROR);
353
354	value = (u32 )TLV_DATA(req_tlv_area);
355	value = ntohl(value);
356	if (value != delimit(value, 0, 32768))
357	return cfg_reply_error_string(TIPC_CFG_INVALID_VALUE
358	" (log size must be 0-32768)");
359	log_reinit(value);
360	return cfg_reply_none();
361	}
362
363	/**
364	* log_dump - capture TIPC log buffer contents in configuration message
365	*/
366
367	struct sk_buff *log_dump(void)
368	{
369	struct sk_buff *reply;
370
371	spin_lock_bh(&print_lock);
372	if (!LOG->buf)
373	reply = cfg_reply_ultra_string("log not activated\n");
374	else if (printbuf_empty(LOG))
375	reply = cfg_reply_ultra_string("log is empty\n");
376	else {
377	struct tlv_desc *rep_tlv;
378	struct print_buf pb;
379	int str_len;
380
381	str_len = min(LOG->size, 32768u);
382	reply = cfg_reply_alloc(TLV_SPACE(str_len));
383	if (reply) {
384	rep_tlv = (struct tlv_desc *)reply->data;
385	printbuf_init(&pb, TLV_DATA(rep_tlv), str_len);
386	printbuf_move(&pb, LOG);
387	str_len = strlen(TLV_DATA(rep_tlv)) + 1;
388	skb_put(reply, TLV_SPACE(str_len));
389	TLV_SET(rep_tlv, TIPC_TLV_ULTRA_STRING, NULL, str_len);
390	}
391	}
392	spin_unlock_bh(&print_lock);
393	return reply;
394	}
395