[fio.git] / lib / pattern.c

#include "fio.h"
#include "strntol.h"
#include "pattern.h"
#include "../oslib/strcasestr.h"

/**
 * parse_string() - parses string in double quotes, like "abc"
 * @beg - string input
 * @out - output buffer where parsed number should be put
 * @out_len - length of the output buffer
 * @filled - pointer where number of bytes successfully
 *           parsed will be put
 *
 * Returns the end pointer where parsing has been stopped.
 * In case of parsing error or lack of bytes in output buffer
 * NULL will be returned.
 */
static const char *parse_string(const char *beg, char *out,
				unsigned int out_len,
				unsigned int *filled)
{
	const char *end;

	if (!out_len)
		return NULL;

	assert(*beg == '"');
	beg++;
	end = strchr(beg, '"');
	if (!end)
		return NULL;
	if (end - beg > out_len)
		return NULL;

	memcpy(out, beg, end - beg);
	*filled = end - beg;

	/* Catch up quote */
	return end + 1;
}

/**
 * parse_number() - parses numbers
 * @beg - string input
 * @out - output buffer where parsed number should be put
 * @out_len - length of the output buffer
 * @filled - pointer where number of bytes successfully
 *           parsed will be put
 *
 * Supports decimals in the range [INT_MIN, INT_MAX] and
 * hexidecimals of any size, which should be started with
 * prefix 0x or 0X.
 *
 * Returns the end pointer where parsing has been stopped.
 * In case of parsing error or lack of bytes in output buffer
 * NULL will be returned.
 */
static const char *parse_number(const char *beg, char *out,
				unsigned int out_len,
				unsigned int *filled)
{
	const char *end;
	unsigned int val;
	long lval;
	int num, i;

	if (!out_len)
		return NULL;

	num = 0;
	sscanf(beg, "0%*[xX]%*[0-9a-fA-F]%n", &num);
	if (num == 0) {
		/* Here we are trying to parse decimal */

		char *_end;

		/* Looking ahead */
		_end = strcasestr(beg, "0x");
		if (_end)
			num = _end - beg;
		if (num)
			lval = strntol(beg, num, &_end, 10);
		else
			lval = strtol(beg, &_end, 10);
		if (beg == _end || lval > INT_MAX || lval < INT_MIN)
			return NULL;
		end = _end;
		i = 0;
		if (!lval) {
			num    = 0;
			out[i] = 0x00;
			i      = 1;
		} else {
			val = (unsigned int)lval;
			for (; val && out_len; out_len--, i++, val >>= 8)
				out[i] = val & 0xff;
			if (val)
				return NULL;
		}
	} else {
		assert(num > 2);

		/* Catch up 0x prefix */
		num -= 2;
		beg += 2;

		/* Look back, handle this combined string: 0xff0x14 */
		if (beg[num] && !strncasecmp(&beg[num - 1], "0x", 2))
			num--;

		end  = beg + num;

		for (i = 0; num && out_len;
		     out_len--, i++, num -= 2, beg += 2) {
			const char *fmt;

			fmt = (num & 1 ? "%1hhx" : "%2hhx");
			sscanf(beg, fmt, &out[i]);
			if (num & 1) {
				num++;
				beg--;
			}
		}
		if (num)
			return NULL;
	}

	*filled = i;
	return end;

}

/**
 * parse_format() - parses formats, like %o, etc
 * @in - string input
 * @out - output buffer where space for format should be reserved
 * @parsed - number of bytes which were already parsed so far
 * @out_len - length of the output buffer
 * @fmt_desc - format descritor array, what we expect to find
 * @fmt_desc_sz - size of the format descritor array
 * @fmt - format array, the output
 * @fmt_sz - size of format array
 *
 * This function tries to find formats, e.g.:
 *   %o - offset of the block
 *
 * In case of successfull parsing it fills the format param
 * with proper offset and the size of the expected value, which
 * should be pasted into buffer using the format 'func' callback.
 *
 * Returns the end pointer where parsing has been stopped.
 * In case of parsing error or lack of bytes in output buffer
 * NULL will be returned.
 */
static const char *parse_format(const char *in, char *out, unsigned int parsed,
				unsigned int out_len, unsigned int *filled,
				const struct pattern_fmt_desc *fmt_desc,
				unsigned int fmt_desc_sz,
				struct pattern_fmt *fmt, unsigned int fmt_sz)
{
	int i;
	struct pattern_fmt *f = NULL;
	unsigned int len = 0;

	if (!out_len || !fmt_desc || !fmt_desc_sz || !fmt || !fmt_sz)
		return NULL;

	assert(*in == '%');

	for (i = 0; i < fmt_desc_sz; i++) {
		const struct pattern_fmt_desc *desc;

		desc = &fmt_desc[i];
		len  = strlen(desc->fmt);
		if (0 == strncmp(in, desc->fmt, len)) {
			fmt->desc = desc;
			fmt->off  = parsed;
			f = fmt;
			break;
		}
	}

	if (!f)
		return NULL;
	if (f->desc->len > out_len)
		return NULL;

	memset(out, '\0', f->desc->len);
	*filled = f->desc->len;

	return in + len;
}

/**
 * parse_and_fill_pattern() - Parses combined input, which consists of strings,
 *                            numbers and pattern formats.
 * @in - string input
 * @in_len - size of the input string
 * @out - output buffer where parsed result will be put
 * @out_len - lengths of the output buffer
 * @fmt_desc - array of pattern format descriptors [input]
 * @fmt_desc_sz - size of the format descriptor array
 * @fmt - array of pattern formats [output]
 * @fmt_sz - pointer where the size of pattern formats array stored [input],
 *           after successfull parsing this pointer will contain the number
 *           of parsed formats if any [output].
 *
 * strings:
 *   bytes sequence in double quotes, e.g. "123".
 *   NOTE: there is no way to escape quote, so "123\"abc" does not work.
 *
 * numbers:
 *   hexidecimal - sequence of hex bytes starting from 0x or 0X prefix,
 *                 e.g. 0xff12ceff1100ff
 *   decimal     - decimal number in range [INT_MIN, INT_MAX]
 *
 * formats:
 *   %o - offset of block, reserved 8 bytes.
 *
 * Explicit examples of combined string:
 * #1                  #2                 #3        #4
 *    in="abcd"          in=-1024           in=66     in=0xFF0X1
 *   out=61 62 63 64    out=00 fc ff ff    out=42    out=ff 01
 *
 * #5                                #6
 *    in=%o                            in="123"0xFFeeCC
 *   out=00 00 00 00 00 00 00 00      out=31 32 33 ff ec cc
 *
 * #7
 *   in=-100xab"1"%o"2"
 *  out=f6 ff ff ff ab 31 00 00 00 00 00 00 00 00 32
 *
 * #9
 *    in=%o0xdeadbeef%o
 *   out=00 00 00 00 00 00 00 00 de ad be ef 00 00 00 00 00 00 00 00
 *
 * #10
 *    in=0xfefefefefefefefefefefefefefefefefefefefefe
 *   out=fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
 *
 * Returns number of bytes filled or err < 0 in case of failure.
 */
int parse_and_fill_pattern(const char *in, unsigned int in_len,
			   char *out, unsigned int out_len,
			   const struct pattern_fmt_desc *fmt_desc,
			   unsigned int fmt_desc_sz,
			   struct pattern_fmt *fmt,
			   unsigned int *fmt_sz_out)
{
	const char *beg, *end, *out_beg = out;
	unsigned int total = 0, fmt_rem = 0;

	if (!in || !in_len || !out || !out_len)
		return -EINVAL;
	if (fmt_sz_out)
		fmt_rem = *fmt_sz_out;

	beg = in;
	do {
		unsigned int filled;
		int parsed_fmt;

		filled     = 0;
		parsed_fmt = 0;

		switch (*beg) {
		case '"':
			end = parse_string(beg, out, out_len, &filled);
			break;
		case '%':
			end = parse_format(beg, out, out - out_beg, out_len,
					   &filled, fmt_desc, fmt_desc_sz,
					   fmt, fmt_rem);
			parsed_fmt = 1;
			break;
		default:
			end = parse_number(beg, out, out_len, &filled);
			break;
		}

		if (!end)
			return -EINVAL;

		if (parsed_fmt) {
			assert(fmt_rem);
			fmt_rem--;
			fmt++;
		}

		assert(end - beg <= in_len);
		in_len -= end - beg;
		beg     = end;

		assert(filled);
		assert(filled <= out_len);
		out_len -= filled;
		out     += filled;
		total   += filled;

	} while (in_len);

	if (fmt_sz_out)
		*fmt_sz_out -= fmt_rem;
	return total;
}

/**
 * dup_pattern() - Duplicates part of the pattern all over the buffer.
 *
 * Returns 0 in case of success or errno < 0 in case of failure.
 */
static int dup_pattern(char *out, unsigned int out_len, unsigned int pattern_len)
{
	unsigned int left, len, off;

	if (out_len <= pattern_len)
		/* Normal case */
		return 0;

	off  = pattern_len;
	left = (out_len - off);
	len  = min(left, off);

	/* Duplicate leftover */
	while (left) {
		memcpy(out + off, out, len);
		left -= len;
		off <<= 1;
		len   = min(left, off);
	}

	return 0;
}

/**
 * cpy_pattern() - Copies pattern to the buffer.
 *
 * Function copies pattern along the whole buffer.
 *
 * Returns 0 in case of success or errno < 0 in case of failure.
 */
int cpy_pattern(const char *pattern, unsigned int pattern_len,
		char *out, unsigned int out_len)
{
	unsigned int len;

	if (!pattern || !pattern_len || !out || !out_len)
		return -EINVAL;

	/* Copy pattern */
	len = min(pattern_len, out_len);
	memcpy(out, pattern, len);

	/* Spread filled chunk all over the buffer */
	return dup_pattern(out, out_len, pattern_len);
}

/**
 * cmp_pattern() - Compares pattern and buffer.
 *
 * For the sake of performance this function avoids any loops.
 * Firstly it tries to compare the buffer itself, checking that
 * buffer consists of repeating patterns along the buffer size.
 *
 * If the difference is not found then the function tries to compare
 * buffer and pattern.
 *
 * Returns 0 in case of success or errno < 0 in case of failure.
 */
int cmp_pattern(const char *pattern, unsigned int pattern_size,
		unsigned int off, const char *buf, unsigned int len)
{
	int rc;
	unsigned int size;

	/* Find the difference in buffer */
	if (len > pattern_size) {
		rc = memcmp(buf, buf + pattern_size, len - pattern_size);
		if (rc)
			return -EILSEQ;
	}
	/* Compare second part of the pattern with buffer */
	if (off) {
		size = min(len, pattern_size - off);
		rc = memcmp(buf, pattern + off, size);
		if (rc)
			return -EILSEQ;
		buf += size;
		len -= size;
	}
	/* Compare first part of the pattern or the whole pattern
	 * with buffer */
	if (len) {
		size = min(len, (off ? off : pattern_size));
		rc = memcmp(buf, pattern, size);
		if (rc)
			return -EILSEQ;
	}

	return 0;
}

/**
 * paste_format_inplace() - Pastes parsed formats to the pattern.
 *
 * This function pastes formats to the pattern. If @fmt_sz is 0
 * function does nothing and pattern buffer is left untouched.
 *
 * Returns 0 in case of success or errno < 0 in case of failure.
 */
int paste_format_inplace(char *pattern, unsigned int pattern_len,
			 struct pattern_fmt *fmt, unsigned int fmt_sz,
			 void *priv)
{
	int i, rc;
	unsigned int len;

	if (!pattern || !pattern_len || !fmt)
		return -EINVAL;

	/* Paste formats for first pattern chunk */
	for (i = 0; i < fmt_sz; i++) {
		struct pattern_fmt *f;

		f = &fmt[i];
		if (pattern_len <= f->off)
			break;
		len = min(pattern_len - f->off, f->desc->len);
		rc  = f->desc->paste(pattern + f->off, len, priv);
		if (rc)
			return rc;
	}

	return 0;
}

/**
 * paste_format() - Pastes parsed formats to the buffer.
 *
 * This function copies pattern to the buffer, pastes format
 * into it and then duplicates pattern all over the buffer size.
 *
 * Returns 0 in case of success or errno < 0 in case of failure.
 */
int paste_format(const char *pattern, unsigned int pattern_len,
		 struct pattern_fmt *fmt, unsigned int fmt_sz,
		 char *out, unsigned int out_len, void *priv)
{
	int rc;
	unsigned int len;

	if (!pattern || !pattern_len || !out || !out_len)
		return -EINVAL;

	/* Copy pattern */
	len = min(pattern_len, out_len);
	memcpy(out, pattern, len);

	rc = paste_format_inplace(out, len, fmt, fmt_sz, priv);
	if (rc)
		return rc;

	/* Spread filled chunk all over the buffer */
	return dup_pattern(out, out_len, pattern_len);
}
Commit	Line	Data
634bd210 RP	1	#include "fio.h"
	2	#include "strntol.h"
	3	#include "pattern.h"
a328eb9a	4	#include "../oslib/strcasestr.h"
634bd210 RP	5
	6	/**
	7	* parse_string() - parses string in double quotes, like "abc"
	8	* @beg - string input
	9	* @out - output buffer where parsed number should be put
	10	* @out_len - length of the output buffer
	11	* @filled - pointer where number of bytes successfully
	12	* parsed will be put
	13	*
	14	* Returns the end pointer where parsing has been stopped.
	15	* In case of parsing error or lack of bytes in output buffer
	16	* NULL will be returned.
	17	*/
	18	static const char parse_string(const char beg, char *out,
	19	unsigned int out_len,
	20	unsigned int *filled)
	21	{
	22	const char *end;
	23
	24	if (!out_len)
	25	return NULL;
	26
	27	assert(*beg == '"');
	28	beg++;
	29	end = strchr(beg, '"');
	30	if (!end)
	31	return NULL;
	32	if (end - beg > out_len)
	33	return NULL;
	34
	35	memcpy(out, beg, end - beg);
	36	*filled = end - beg;
	37
	38	/* Catch up quote */
	39	return end + 1;
	40	}
	41
	42	/**
	43	* parse_number() - parses numbers
	44	* @beg - string input
	45	* @out - output buffer where parsed number should be put
	46	* @out_len - length of the output buffer
	47	* @filled - pointer where number of bytes successfully
	48	* parsed will be put
	49	*
	50	* Supports decimals in the range [INT_MIN, INT_MAX] and
	51	* hexidecimals of any size, which should be started with
	52	* prefix 0x or 0X.
	53	*
	54	* Returns the end pointer where parsing has been stopped.
	55	* In case of parsing error or lack of bytes in output buffer
	56	* NULL will be returned.
	57	*/
	58	static const char parse_number(const char beg, char *out,
	59	unsigned int out_len,
	60	unsigned int *filled)
	61	{
	62	const char *end;
	63	unsigned int val;
	64	long lval;
	65	int num, i;
	66
	67	if (!out_len)
	68	return NULL;
69
70	num = 0;
71	sscanf(beg, "0%[xX]%[0-9a-fA-F]%n", &num);
72	if (num == 0) {
73	/* Here we are trying to parse decimal */
74
75	char *_end;
76
77	/* Looking ahead */
78	_end = strcasestr(beg, "0x");
79	if (_end)
80	num = _end - beg;
81	if (num)
82	lval = strntol(beg, num, &_end, 10);
83	else
84	lval = strtol(beg, &_end, 10);
85	if (beg == _end \|\| lval > INT_MAX \|\| lval < INT_MIN)
86	return NULL;
87	end = _end;
88	i = 0;
89	if (!lval) {
90	num = 0;
91	out[i] = 0x00;
92	i = 1;
93	} else {
94	val = (unsigned int)lval;
95	for (; val && out_len; out_len--, i++, val >>= 8)
96	out[i] = val & 0xff;
97	if (val)
98	return NULL;
99	}
100	} else {
101	assert(num > 2);
102
103	/* Catch up 0x prefix */
104	num -= 2;
105	beg += 2;
106
107	/* Look back, handle this combined string: 0xff0x14 */
108	if (beg[num] && !strncasecmp(&beg[num - 1], "0x", 2))
109	num--;
110
111	end = beg + num;
112
113	for (i = 0; num && out_len;
114	out_len--, i++, num -= 2, beg += 2) {
115	const char *fmt;
116
117	fmt = (num & 1 ? "%1hhx" : "%2hhx");
118	sscanf(beg, fmt, &out[i]);
119	if (num & 1) {
120	num++;
121	beg--;
122	}
123	}
124	if (num)
125	return NULL;
126	}
127
128	*filled = i;
129	return end;
130
131	}
132
133	/**
134	* parse_format() - parses formats, like %o, etc
135	* @in - string input
136	* @out - output buffer where space for format should be reserved
137	* @parsed - number of bytes which were already parsed so far
138	* @out_len - length of the output buffer
139	* @fmt_desc - format descritor array, what we expect to find
140	* @fmt_desc_sz - size of the format descritor array
141	* @fmt - format array, the output
142	* @fmt_sz - size of format array
143	*
144	* This function tries to find formats, e.g.:
145	* %o - offset of the block
146	*
147	* In case of successfull parsing it fills the format param
148	* with proper offset and the size of the expected value, which
149	* should be pasted into buffer using the format 'func' callback.
150	*
151	* Returns the end pointer where parsing has been stopped.
152	* In case of parsing error or lack of bytes in output buffer
153	* NULL will be returned.
154	*/
155	static const char parse_format(const char in, char *out, unsigned int parsed,
156	unsigned int out_len, unsigned int *filled,
157	const struct pattern_fmt_desc *fmt_desc,
158	unsigned int fmt_desc_sz,
159	struct pattern_fmt *fmt, unsigned int fmt_sz)
160	{
161	int i;
162	struct pattern_fmt *f = NULL;
163	unsigned int len = 0;
164
165	if (!out_len \|\| !fmt_desc \|\| !fmt_desc_sz \|\| !fmt \|\| !fmt_sz)
166	return NULL;
167
168	assert(*in == '%');
169
170	for (i = 0; i < fmt_desc_sz; i++) {
171	const struct pattern_fmt_desc *desc;
172
173	desc = &fmt_desc[i];
174	len = strlen(desc->fmt);
175	if (0 == strncmp(in, desc->fmt, len)) {
176	fmt->desc = desc;
177	fmt->off = parsed;
178	f = fmt;
179	break;
180	}
181	}
182
183	if (!f)
184	return NULL;
185	if (f->desc->len > out_len)
186	return NULL;
187
188	memset(out, '\0', f->desc->len);
189	*filled = f->desc->len;
190
191	return in + len;
192	}
193
194	/**
195	* parse_and_fill_pattern() - Parses combined input, which consists of strings,
196	* numbers and pattern formats.
197	* @in - string input
198	* @in_len - size of the input string
199	* @out - output buffer where parsed result will be put
200	* @out_len - lengths of the output buffer
201	* @fmt_desc - array of pattern format descriptors [input]
202	* @fmt_desc_sz - size of the format descriptor array
203	* @fmt - array of pattern formats [output]
204	* @fmt_sz - pointer where the size of pattern formats array stored [input],
205	* after successfull parsing this pointer will contain the number
206	* of parsed formats if any [output].
207	*
208	* strings:
209	* bytes sequence in double quotes, e.g. "123".
210	* NOTE: there is no way to escape quote, so "123\"abc" does not work.
211	*
212	* numbers:
213	* hexidecimal - sequence of hex bytes starting from 0x or 0X prefix,
214	* e.g. 0xff12ceff1100ff
215	* decimal - decimal number in range [INT_MIN, INT_MAX]
216	*
217	* formats:
218	* %o - offset of block, reserved 8 bytes.
219	*
220	* Explicit examples of combined string:
221	* #1 #2 #3 #4
222	* in="abcd" in=-1024 in=66 in=0xFF0X1
223	* out=61 62 63 64 out=00 fc ff ff out=42 out=ff 01
224	*
225	* #5 #6
226	* in=%o in="123"0xFFeeCC
227	* out=00 00 00 00 00 00 00 00 out=31 32 33 ff ec cc
228	*
229	* #7
230	* in=-100xab"1"%o"2"
231	* out=f6 ff ff ff ab 31 00 00 00 00 00 00 00 00 32
232	*
233	* #9
234	* in=%o0xdeadbeef%o
235	* out=00 00 00 00 00 00 00 00 de ad be ef 00 00 00 00 00 00 00 00
236	*
237	* #10
238	* in=0xfefefefefefefefefefefefefefefefefefefefefe
239	* out=fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe fe
240	*
241	* Returns number of bytes filled or err < 0 in case of failure.
242	*/
243	int parse_and_fill_pattern(const char *in, unsigned int in_len,
244	char *out, unsigned int out_len,
245	const struct pattern_fmt_desc *fmt_desc,
246	unsigned int fmt_desc_sz,
247	struct pattern_fmt *fmt,
248	unsigned int *fmt_sz_out)
249	{
250	const char beg, end, *out_beg = out;
251	unsigned int total = 0, fmt_rem = 0;
252
253	if (!in \|\| !in_len \|\| !out \|\| !out_len)
254	return -EINVAL;
255	if (fmt_sz_out)
256	fmt_rem = *fmt_sz_out;
257
258	beg = in;
259	do {
260	unsigned int filled;
261	int parsed_fmt;
262
263	filled = 0;
264	parsed_fmt = 0;
265
266	switch (*beg) {
267	case '"':
268	end = parse_string(beg, out, out_len, &filled);
269	break;
270	case '%':
271	end = parse_format(beg, out, out - out_beg, out_len,
272	&filled, fmt_desc, fmt_desc_sz,
273	fmt, fmt_rem);
274	parsed_fmt = 1;
275	break;
276	default:
277	end = parse_number(beg, out, out_len, &filled);
278	break;
279	}
280
281	if (!end)
282	return -EINVAL;
283
284	if (parsed_fmt) {
285	assert(fmt_rem);
286	fmt_rem--;
287	fmt++;
288	}
289
290	assert(end - beg <= in_len);
291	in_len -= end - beg;
292	beg = end;
293
294	assert(filled);
295	assert(filled <= out_len);
296	out_len -= filled;
297	out += filled;
298	total += filled;
299
300	} while (in_len);
301
302	if (fmt_sz_out)
303	*fmt_sz_out -= fmt_rem;
304	return total;
305	}
306
307	/**
308	* dup_pattern() - Duplicates part of the pattern all over the buffer.
309	*
310	* Returns 0 in case of success or errno < 0 in case of failure.
311	*/
312	static int dup_pattern(char *out, unsigned int out_len, unsigned int pattern_len)
313	{
314	unsigned int left, len, off;
315
316	if (out_len <= pattern_len)
317	/* Normal case */
318	return 0;
319
320	off = pattern_len;
321	left = (out_len - off);
322	len = min(left, off);
323
324	/* Duplicate leftover */
325	while (left) {
326	memcpy(out + off, out, len);
327	left -= len;
328	off <<= 1;
329	len = min(left, off);
330	}
331
332	return 0;
333	}
334
335	/**
336	* cpy_pattern() - Copies pattern to the buffer.
337	*
338	* Function copies pattern along the whole buffer.
339	*
340	* Returns 0 in case of success or errno < 0 in case of failure.
341	*/
342	int cpy_pattern(const char *pattern, unsigned int pattern_len,
343	char *out, unsigned int out_len)
344	{
345	unsigned int len;
346
347	if (!pattern \|\| !pattern_len \|\| !out \|\| !out_len)
348	return -EINVAL;
349
350	/* Copy pattern */
351	len = min(pattern_len, out_len);
352	memcpy(out, pattern, len);
353
354	/* Spread filled chunk all over the buffer */
355	return dup_pattern(out, out_len, pattern_len);
356	}
357
358	/**
359	* cmp_pattern() - Compares pattern and buffer.
360	*
361	* For the sake of performance this function avoids any loops.
362	* Firstly it tries to compare the buffer itself, checking that
363	* buffer consists of repeating patterns along the buffer size.
364	*
365	* If the difference is not found then the function tries to compare
366	* buffer and pattern.
367	*
368	* Returns 0 in case of success or errno < 0 in case of failure.
369	*/
370	int cmp_pattern(const char *pattern, unsigned int pattern_size,
371	unsigned int off, const char *buf, unsigned int len)
372	{
373	int rc;
374	unsigned int size;
375
376	/* Find the difference in buffer */
377	if (len > pattern_size) {
378	rc = memcmp(buf, buf + pattern_size, len - pattern_size);
379	if (rc)
380	return -EILSEQ;
381	}
382	/* Compare second part of the pattern with buffer */
383	if (off) {
384	size = min(len, pattern_size - off);
385	rc = memcmp(buf, pattern + off, size);
386	if (rc)
387	return -EILSEQ;
388	buf += size;
389	len -= size;
390	}
391	/* Compare first part of the pattern or the whole pattern
392	* with buffer */
393	if (len) {
394	size = min(len, (off ? off : pattern_size));
395	rc = memcmp(buf, pattern, size);
396	if (rc)
397	return -EILSEQ;
398	}
399
400	return 0;
401	}
402
403	/**
404	* paste_format_inplace() - Pastes parsed formats to the pattern.
405	*
406	* This function pastes formats to the pattern. If @fmt_sz is 0
407	* function does nothing and pattern buffer is left untouched.
408	*
409	* Returns 0 in case of success or errno < 0 in case of failure.
410	*/
411	int paste_format_inplace(char *pattern, unsigned int pattern_len,
412	struct pattern_fmt *fmt, unsigned int fmt_sz,
413	void *priv)
414	{
415	int i, rc;
416	unsigned int len;
417
418	if (!pattern \|\| !pattern_len \|\| !fmt)
419	return -EINVAL;
420
421	/* Paste formats for first pattern chunk */
422	for (i = 0; i < fmt_sz; i++) {
423	struct pattern_fmt *f;
424
425	f = &fmt[i];
426	if (pattern_len <= f->off)
427	break;
428	len = min(pattern_len - f->off, f->desc->len);
429	rc = f->desc->paste(pattern + f->off, len, priv);
430	if (rc)
431	return rc;
432	}
433
434	return 0;
435	}
436
437	/**
438	* paste_format() - Pastes parsed formats to the buffer.
439	*
440	* This function copies pattern to the buffer, pastes format
441	* into it and then duplicates pattern all over the buffer size.
442	*
443	* Returns 0 in case of success or errno < 0 in case of failure.
444	*/
445	int paste_format(const char *pattern, unsigned int pattern_len,
446	struct pattern_fmt *fmt, unsigned int fmt_sz,
447	char out, unsigned int out_len, void priv)
448	{
449	int rc;
450	unsigned int len;
451
452	if (!pattern \|\| !pattern_len \|\| !out \|\| !out_len)
453	return -EINVAL;
454
455	/* Copy pattern */
456	len = min(pattern_len, out_len);
457	memcpy(out, pattern, len);
458
459	rc = paste_format_inplace(out, len, fmt, fmt_sz, priv);
460	if (rc)
461	return rc;
462
463	/* Spread filled chunk all over the buffer */
464	return dup_pattern(out, out_len, pattern_len);
465	}