Linux Audio

Check our new training course

Loading...
v5.14.15
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * lib/parser.c - simple parser for mount, etc. options.
  4 */
  5
  6#include <linux/ctype.h>
  7#include <linux/types.h>
  8#include <linux/export.h>
  9#include <linux/kstrtox.h>
 10#include <linux/parser.h>
 11#include <linux/slab.h>
 12#include <linux/string.h>
 13
 
 
 
 
 
 
 
 
 
 14/**
 15 * match_one - Determines if a string matches a simple pattern
 16 * @s: the string to examine for presence of the pattern
 17 * @p: the string containing the pattern
 18 * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
 19 * locations.
 20 *
 21 * Description: Determines if the pattern @p is present in string @s. Can only
 22 * match extremely simple token=arg style patterns. If the pattern is found,
 23 * the location(s) of the arguments will be returned in the @args array.
 24 */
 25static int match_one(char *s, const char *p, substring_t args[])
 26{
 27	char *meta;
 28	int argc = 0;
 29
 30	if (!p)
 31		return 1;
 32
 33	while(1) {
 34		int len = -1;
 35		meta = strchr(p, '%');
 36		if (!meta)
 37			return strcmp(p, s) == 0;
 38
 39		if (strncmp(p, s, meta-p))
 40			return 0;
 41
 42		s += meta - p;
 43		p = meta + 1;
 44
 45		if (isdigit(*p))
 46			len = simple_strtoul(p, (char **) &p, 10);
 47		else if (*p == '%') {
 48			if (*s++ != '%')
 49				return 0;
 50			p++;
 51			continue;
 52		}
 53
 54		if (argc >= MAX_OPT_ARGS)
 55			return 0;
 56
 57		args[argc].from = s;
 58		switch (*p++) {
 59		case 's': {
 60			size_t str_len = strlen(s);
 61
 62			if (str_len == 0)
 63				return 0;
 64			if (len == -1 || len > str_len)
 65				len = str_len;
 66			args[argc].to = s + len;
 67			break;
 68		}
 69		case 'd':
 70			simple_strtol(s, &args[argc].to, 0);
 71			goto num;
 72		case 'u':
 73			simple_strtoul(s, &args[argc].to, 0);
 74			goto num;
 75		case 'o':
 76			simple_strtoul(s, &args[argc].to, 8);
 77			goto num;
 78		case 'x':
 79			simple_strtoul(s, &args[argc].to, 16);
 80		num:
 81			if (args[argc].to == args[argc].from)
 82				return 0;
 83			break;
 84		default:
 85			return 0;
 86		}
 87		s = args[argc].to;
 88		argc++;
 89	}
 90}
 91
 92/**
 93 * match_token - Find a token (and optional args) in a string
 94 * @s: the string to examine for token/argument pairs
 95 * @table: match_table_t describing the set of allowed option tokens and the
 96 * arguments that may be associated with them. Must be terminated with a
 97 * &struct match_token whose pattern is set to the NULL pointer.
 98 * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
 99 * locations.
100 *
101 * Description: Detects which if any of a set of token strings has been passed
102 * to it. Tokens can include up to %MAX_OPT_ARGS instances of basic c-style
103 * format identifiers which will be taken into account when matching the
104 * tokens, and whose locations will be returned in the @args array.
105 */
106int match_token(char *s, const match_table_t table, substring_t args[])
107{
108	const struct match_token *p;
109
110	for (p = table; !match_one(s, p->pattern, args) ; p++)
111		;
112
113	return p->token;
114}
115EXPORT_SYMBOL(match_token);
116
117/**
118 * match_number - scan a number in the given base from a substring_t
119 * @s: substring to be scanned
120 * @result: resulting integer on success
121 * @base: base to use when converting string
122 *
123 * Description: Given a &substring_t and a base, attempts to parse the substring
124 * as a number in that base.
125 *
126 * Return: On success, sets @result to the integer represented by the
127 * string and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
128 */
129static int match_number(substring_t *s, int *result, int base)
130{
131	char *endp;
132	char *buf;
133	int ret;
134	long val;
135
136	buf = match_strdup(s);
137	if (!buf)
138		return -ENOMEM;
139
140	ret = 0;
141	val = simple_strtol(buf, &endp, base);
142	if (endp == buf)
143		ret = -EINVAL;
144	else if (val < (long)INT_MIN || val > (long)INT_MAX)
145		ret = -ERANGE;
146	else
147		*result = (int) val;
148	kfree(buf);
149	return ret;
150}
151
152/**
153 * match_u64int - scan a number in the given base from a substring_t
154 * @s: substring to be scanned
155 * @result: resulting u64 on success
156 * @base: base to use when converting string
157 *
158 * Description: Given a &substring_t and a base, attempts to parse the substring
159 * as a number in that base.
160 *
161 * Return: On success, sets @result to the integer represented by the
162 * string and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
163 */
164static int match_u64int(substring_t *s, u64 *result, int base)
165{
166	char *buf;
167	int ret;
168	u64 val;
169
170	buf = match_strdup(s);
171	if (!buf)
172		return -ENOMEM;
173
174	ret = kstrtoull(buf, base, &val);
175	if (!ret)
176		*result = val;
177	kfree(buf);
178	return ret;
179}
180
181/**
182 * match_int - scan a decimal representation of an integer from a substring_t
183 * @s: substring_t to be scanned
184 * @result: resulting integer on success
185 *
186 * Description: Attempts to parse the &substring_t @s as a decimal integer.
187 *
188 * Return: On success, sets @result to the integer represented by the string
189 * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
190 */
191int match_int(substring_t *s, int *result)
192{
193	return match_number(s, result, 0);
194}
195EXPORT_SYMBOL(match_int);
196
197/**
198 * match_uint - scan a decimal representation of an integer from a substring_t
199 * @s: substring_t to be scanned
200 * @result: resulting integer on success
201 *
202 * Description: Attempts to parse the &substring_t @s as a decimal integer.
203 *
204 * Return: On success, sets @result to the integer represented by the string
205 * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
206 */
207int match_uint(substring_t *s, unsigned int *result)
208{
209	int err = -ENOMEM;
210	char *buf = match_strdup(s);
211
212	if (buf) {
213		err = kstrtouint(buf, 10, result);
214		kfree(buf);
215	}
216	return err;
217}
218EXPORT_SYMBOL(match_uint);
219
220/**
221 * match_u64 - scan a decimal representation of a u64 from
222 *                  a substring_t
223 * @s: substring_t to be scanned
224 * @result: resulting unsigned long long on success
225 *
226 * Description: Attempts to parse the &substring_t @s as a long decimal
227 * integer.
228 *
229 * Return: On success, sets @result to the integer represented by the string
230 * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
231 */
232int match_u64(substring_t *s, u64 *result)
233{
234	return match_u64int(s, result, 0);
235}
236EXPORT_SYMBOL(match_u64);
237
238/**
239 * match_octal - scan an octal representation of an integer from a substring_t
240 * @s: substring_t to be scanned
241 * @result: resulting integer on success
242 *
243 * Description: Attempts to parse the &substring_t @s as an octal integer.
244 *
245 * Return: On success, sets @result to the integer represented by the string
246 * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
247 */
248int match_octal(substring_t *s, int *result)
249{
250	return match_number(s, result, 8);
251}
252EXPORT_SYMBOL(match_octal);
253
254/**
255 * match_hex - scan a hex representation of an integer from a substring_t
256 * @s: substring_t to be scanned
257 * @result: resulting integer on success
258 *
259 * Description: Attempts to parse the &substring_t @s as a hexadecimal integer.
260 *
261 * Return: On success, sets @result to the integer represented by the string
262 * and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
263 */
264int match_hex(substring_t *s, int *result)
265{
266	return match_number(s, result, 16);
267}
268EXPORT_SYMBOL(match_hex);
269
270/**
271 * match_wildcard - parse if a string matches given wildcard pattern
272 * @pattern: wildcard pattern
273 * @str: the string to be parsed
274 *
275 * Description: Parse the string @str to check if matches wildcard
276 * pattern @pattern. The pattern may contain two types of wildcards:
277 *   '*' - matches zero or more characters
278 *   '?' - matches one character
279 *
280 * Return: If the @str matches the @pattern, return true, else return false.
281 */
282bool match_wildcard(const char *pattern, const char *str)
283{
284	const char *s = str;
285	const char *p = pattern;
286	bool star = false;
287
288	while (*s) {
289		switch (*p) {
290		case '?':
291			s++;
292			p++;
293			break;
294		case '*':
295			star = true;
296			str = s;
297			if (!*++p)
298				return true;
299			pattern = p;
300			break;
301		default:
302			if (*s == *p) {
303				s++;
304				p++;
305			} else {
306				if (!star)
307					return false;
308				str++;
309				s = str;
310				p = pattern;
311			}
312			break;
313		}
314	}
315
316	if (*p == '*')
317		++p;
318	return !*p;
319}
320EXPORT_SYMBOL(match_wildcard);
321
322/**
323 * match_strlcpy - Copy the characters from a substring_t to a sized buffer
324 * @dest: where to copy to
325 * @src: &substring_t to copy
326 * @size: size of destination buffer
327 *
328 * Description: Copy the characters in &substring_t @src to the
329 * c-style string @dest.  Copy no more than @size - 1 characters, plus
330 * the terminating NUL.
331 *
332 * Return: length of @src.
333 */
334size_t match_strlcpy(char *dest, const substring_t *src, size_t size)
335{
336	size_t ret = src->to - src->from;
337
338	if (size) {
339		size_t len = ret >= size ? size - 1 : ret;
340		memcpy(dest, src->from, len);
341		dest[len] = '\0';
342	}
343	return ret;
344}
345EXPORT_SYMBOL(match_strlcpy);
346
347/**
348 * match_strdup - allocate a new string with the contents of a substring_t
349 * @s: &substring_t to copy
350 *
351 * Description: Allocates and returns a string filled with the contents of
352 * the &substring_t @s. The caller is responsible for freeing the returned
353 * string with kfree().
354 *
355 * Return: the address of the newly allocated NUL-terminated string or
356 * %NULL on error.
357 */
358char *match_strdup(const substring_t *s)
359{
360	return kmemdup_nul(s->from, s->to - s->from, GFP_KERNEL);
361}
362EXPORT_SYMBOL(match_strdup);
v6.13.7
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * lib/parser.c - simple parser for mount, etc. options.
  4 */
  5
  6#include <linux/ctype.h>
  7#include <linux/types.h>
  8#include <linux/export.h>
  9#include <linux/kstrtox.h>
 10#include <linux/parser.h>
 11#include <linux/slab.h>
 12#include <linux/string.h>
 13
 14/*
 15 * max size needed by different bases to express U64
 16 * HEX: "0xFFFFFFFFFFFFFFFF" --> 18
 17 * DEC: "18446744073709551615" --> 20
 18 * OCT: "01777777777777777777777" --> 23
 19 * pick the max one to define NUMBER_BUF_LEN
 20 */
 21#define NUMBER_BUF_LEN 24
 22
 23/**
 24 * match_one - Determines if a string matches a simple pattern
 25 * @s: the string to examine for presence of the pattern
 26 * @p: the string containing the pattern
 27 * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
 28 * locations.
 29 *
 30 * Description: Determines if the pattern @p is present in string @s. Can only
 31 * match extremely simple token=arg style patterns. If the pattern is found,
 32 * the location(s) of the arguments will be returned in the @args array.
 33 */
 34static int match_one(char *s, const char *p, substring_t args[])
 35{
 36	char *meta;
 37	int argc = 0;
 38
 39	if (!p)
 40		return 1;
 41
 42	while(1) {
 43		int len = -1;
 44		meta = strchr(p, '%');
 45		if (!meta)
 46			return strcmp(p, s) == 0;
 47
 48		if (strncmp(p, s, meta-p))
 49			return 0;
 50
 51		s += meta - p;
 52		p = meta + 1;
 53
 54		if (isdigit(*p))
 55			len = simple_strtoul(p, (char **) &p, 10);
 56		else if (*p == '%') {
 57			if (*s++ != '%')
 58				return 0;
 59			p++;
 60			continue;
 61		}
 62
 63		if (argc >= MAX_OPT_ARGS)
 64			return 0;
 65
 66		args[argc].from = s;
 67		switch (*p++) {
 68		case 's': {
 69			size_t str_len = strlen(s);
 70
 71			if (str_len == 0)
 72				return 0;
 73			if (len == -1 || len > str_len)
 74				len = str_len;
 75			args[argc].to = s + len;
 76			break;
 77		}
 78		case 'd':
 79			simple_strtol(s, &args[argc].to, 0);
 80			goto num;
 81		case 'u':
 82			simple_strtoul(s, &args[argc].to, 0);
 83			goto num;
 84		case 'o':
 85			simple_strtoul(s, &args[argc].to, 8);
 86			goto num;
 87		case 'x':
 88			simple_strtoul(s, &args[argc].to, 16);
 89		num:
 90			if (args[argc].to == args[argc].from)
 91				return 0;
 92			break;
 93		default:
 94			return 0;
 95		}
 96		s = args[argc].to;
 97		argc++;
 98	}
 99}
100
101/**
102 * match_token - Find a token (and optional args) in a string
103 * @s: the string to examine for token/argument pairs
104 * @table: match_table_t describing the set of allowed option tokens and the
105 * arguments that may be associated with them. Must be terminated with a
106 * &struct match_token whose pattern is set to the NULL pointer.
107 * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
108 * locations.
109 *
110 * Description: Detects which if any of a set of token strings has been passed
111 * to it. Tokens can include up to %MAX_OPT_ARGS instances of basic c-style
112 * format identifiers which will be taken into account when matching the
113 * tokens, and whose locations will be returned in the @args array.
114 */
115int match_token(char *s, const match_table_t table, substring_t args[])
116{
117	const struct match_token *p;
118
119	for (p = table; !match_one(s, p->pattern, args) ; p++)
120		;
121
122	return p->token;
123}
124EXPORT_SYMBOL(match_token);
125
126/**
127 * match_number - scan a number in the given base from a substring_t
128 * @s: substring to be scanned
129 * @result: resulting integer on success
130 * @base: base to use when converting string
131 *
132 * Description: Given a &substring_t and a base, attempts to parse the substring
133 * as a number in that base.
134 *
135 * Return: On success, sets @result to the integer represented by the
136 * string and returns 0. Returns -EINVAL or -ERANGE on failure.
137 */
138static int match_number(substring_t *s, int *result, int base)
139{
140	char *endp;
141	char buf[NUMBER_BUF_LEN];
142	int ret;
143	long val;
144
145	if (match_strlcpy(buf, s, NUMBER_BUF_LEN) >= NUMBER_BUF_LEN)
146		return -ERANGE;
 
 
147	ret = 0;
148	val = simple_strtol(buf, &endp, base);
149	if (endp == buf)
150		ret = -EINVAL;
151	else if (val < (long)INT_MIN || val > (long)INT_MAX)
152		ret = -ERANGE;
153	else
154		*result = (int) val;
 
155	return ret;
156}
157
158/**
159 * match_u64int - scan a number in the given base from a substring_t
160 * @s: substring to be scanned
161 * @result: resulting u64 on success
162 * @base: base to use when converting string
163 *
164 * Description: Given a &substring_t and a base, attempts to parse the substring
165 * as a number in that base.
166 *
167 * Return: On success, sets @result to the integer represented by the
168 * string and returns 0. Returns -EINVAL or -ERANGE on failure.
169 */
170static int match_u64int(substring_t *s, u64 *result, int base)
171{
172	char buf[NUMBER_BUF_LEN];
173	int ret;
174	u64 val;
175
176	if (match_strlcpy(buf, s, NUMBER_BUF_LEN) >= NUMBER_BUF_LEN)
177		return -ERANGE;
 
 
178	ret = kstrtoull(buf, base, &val);
179	if (!ret)
180		*result = val;
 
181	return ret;
182}
183
184/**
185 * match_int - scan a decimal representation of an integer from a substring_t
186 * @s: substring_t to be scanned
187 * @result: resulting integer on success
188 *
189 * Description: Attempts to parse the &substring_t @s as a decimal integer.
190 *
191 * Return: On success, sets @result to the integer represented by the string
192 * and returns 0. Returns -EINVAL or -ERANGE on failure.
193 */
194int match_int(substring_t *s, int *result)
195{
196	return match_number(s, result, 0);
197}
198EXPORT_SYMBOL(match_int);
199
200/**
201 * match_uint - scan a decimal representation of an integer from a substring_t
202 * @s: substring_t to be scanned
203 * @result: resulting integer on success
204 *
205 * Description: Attempts to parse the &substring_t @s as a decimal integer.
206 *
207 * Return: On success, sets @result to the integer represented by the string
208 * and returns 0. Returns -EINVAL or -ERANGE on failure.
209 */
210int match_uint(substring_t *s, unsigned int *result)
211{
212	char buf[NUMBER_BUF_LEN];
 
213
214	if (match_strlcpy(buf, s, NUMBER_BUF_LEN) >= NUMBER_BUF_LEN)
215		return -ERANGE;
216
217	return kstrtouint(buf, 10, result);
 
218}
219EXPORT_SYMBOL(match_uint);
220
221/**
222 * match_u64 - scan a decimal representation of a u64 from
223 *                  a substring_t
224 * @s: substring_t to be scanned
225 * @result: resulting unsigned long long on success
226 *
227 * Description: Attempts to parse the &substring_t @s as a long decimal
228 * integer.
229 *
230 * Return: On success, sets @result to the integer represented by the string
231 * and returns 0. Returns -EINVAL or -ERANGE on failure.
232 */
233int match_u64(substring_t *s, u64 *result)
234{
235	return match_u64int(s, result, 0);
236}
237EXPORT_SYMBOL(match_u64);
238
239/**
240 * match_octal - scan an octal representation of an integer from a substring_t
241 * @s: substring_t to be scanned
242 * @result: resulting integer on success
243 *
244 * Description: Attempts to parse the &substring_t @s as an octal integer.
245 *
246 * Return: On success, sets @result to the integer represented by the string
247 * and returns 0. Returns -EINVAL or -ERANGE on failure.
248 */
249int match_octal(substring_t *s, int *result)
250{
251	return match_number(s, result, 8);
252}
253EXPORT_SYMBOL(match_octal);
254
255/**
256 * match_hex - scan a hex representation of an integer from a substring_t
257 * @s: substring_t to be scanned
258 * @result: resulting integer on success
259 *
260 * Description: Attempts to parse the &substring_t @s as a hexadecimal integer.
261 *
262 * Return: On success, sets @result to the integer represented by the string
263 * and returns 0. Returns -EINVAL or -ERANGE on failure.
264 */
265int match_hex(substring_t *s, int *result)
266{
267	return match_number(s, result, 16);
268}
269EXPORT_SYMBOL(match_hex);
270
271/**
272 * match_wildcard - parse if a string matches given wildcard pattern
273 * @pattern: wildcard pattern
274 * @str: the string to be parsed
275 *
276 * Description: Parse the string @str to check if matches wildcard
277 * pattern @pattern. The pattern may contain two types of wildcards:
278 *   '*' - matches zero or more characters
279 *   '?' - matches one character
280 *
281 * Return: If the @str matches the @pattern, return true, else return false.
282 */
283bool match_wildcard(const char *pattern, const char *str)
284{
285	const char *s = str;
286	const char *p = pattern;
287	bool star = false;
288
289	while (*s) {
290		switch (*p) {
291		case '?':
292			s++;
293			p++;
294			break;
295		case '*':
296			star = true;
297			str = s;
298			if (!*++p)
299				return true;
300			pattern = p;
301			break;
302		default:
303			if (*s == *p) {
304				s++;
305				p++;
306			} else {
307				if (!star)
308					return false;
309				str++;
310				s = str;
311				p = pattern;
312			}
313			break;
314		}
315	}
316
317	if (*p == '*')
318		++p;
319	return !*p;
320}
321EXPORT_SYMBOL(match_wildcard);
322
323/**
324 * match_strlcpy - Copy the characters from a substring_t to a sized buffer
325 * @dest: where to copy to
326 * @src: &substring_t to copy
327 * @size: size of destination buffer
328 *
329 * Description: Copy the characters in &substring_t @src to the
330 * c-style string @dest.  Copy no more than @size - 1 characters, plus
331 * the terminating NUL.
332 *
333 * Return: length of @src.
334 */
335size_t match_strlcpy(char *dest, const substring_t *src, size_t size)
336{
337	size_t ret = src->to - src->from;
338
339	if (size) {
340		size_t len = ret >= size ? size - 1 : ret;
341		memcpy(dest, src->from, len);
342		dest[len] = '\0';
343	}
344	return ret;
345}
346EXPORT_SYMBOL(match_strlcpy);
347
348/**
349 * match_strdup - allocate a new string with the contents of a substring_t
350 * @s: &substring_t to copy
351 *
352 * Description: Allocates and returns a string filled with the contents of
353 * the &substring_t @s. The caller is responsible for freeing the returned
354 * string with kfree().
355 *
356 * Return: the address of the newly allocated NUL-terminated string or
357 * %NULL on error.
358 */
359char *match_strdup(const substring_t *s)
360{
361	return kmemdup_nul(s->from, s->to - s->from, GFP_KERNEL);
362}
363EXPORT_SYMBOL(match_strdup);