2 * lib/parser.c - simple parser for mount, etc. options.
4 * This source code is licensed under the GNU General Public License,
5 * Version 2. See the file COPYING for more details.
8 #include <linux/ctype.h>
9 #include <linux/types.h>
10 #include <linux/export.h>
11 #include <linux/parser.h>
12 #include <linux/slab.h>
13 #include <linux/string.h>
16 * match_one: - Determines if a string matches a simple pattern
17 * @s: the string to examine for presence of the pattern
18 * @p: the string containing the pattern
19 * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
22 * Description: Determines if the pattern @p is present in string @s. Can only
23 * match extremely simple token=arg style patterns. If the pattern is found,
24 * the location(s) of the arguments will be returned in the @args array.
26 static int match_one(char *s, const char *p, substring_t args[])
36 meta = strchr(p, '%');
38 return strcmp(p, s) == 0;
40 if (strncmp(p, s, meta-p))
47 len = simple_strtoul(p, (char **) &p, 10);
55 if (argc >= MAX_OPT_ARGS)
61 size_t str_len = strlen(s);
65 if (len == -1 || len > str_len)
67 args[argc].to = s + len;
71 simple_strtol(s, &args[argc].to, 0);
74 simple_strtoul(s, &args[argc].to, 0);
77 simple_strtoul(s, &args[argc].to, 8);
80 simple_strtoul(s, &args[argc].to, 16);
82 if (args[argc].to == args[argc].from)
94 * match_token: - Find a token (and optional args) in a string
95 * @s: the string to examine for token/argument pairs
96 * @table: match_table_t describing the set of allowed option tokens and the
97 * arguments that may be associated with them. Must be terminated with a
98 * &struct match_token whose pattern is set to the NULL pointer.
99 * @args: array of %MAX_OPT_ARGS &substring_t elements. Used to return match
102 * Description: Detects which if any of a set of token strings has been passed
103 * to it. Tokens can include up to MAX_OPT_ARGS instances of basic c-style
104 * format identifiers which will be taken into account when matching the
105 * tokens, and whose locations will be returned in the @args array.
107 int match_token(char *s, const match_table_t table, substring_t args[])
109 const struct match_token *p;
111 for (p = table; !match_one(s, p->pattern, args) ; p++)
116 EXPORT_SYMBOL(match_token);
119 * match_number: scan a number in the given base from a substring_t
120 * @s: substring to be scanned
121 * @result: resulting integer on success
122 * @base: base to use when converting string
124 * Description: Given a &substring_t and a base, attempts to parse the substring
125 * as a number in that base. On success, sets @result to the integer represented
126 * by the string and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
128 static int match_number(substring_t *s, int *result, int base)
135 buf = match_strdup(s);
140 val = simple_strtol(buf, &endp, base);
143 else if (val < (long)INT_MIN || val > (long)INT_MAX)
152 * match_u64int: scan a number in the given base from a substring_t
153 * @s: substring to be scanned
154 * @result: resulting u64 on success
155 * @base: base to use when converting string
157 * Description: Given a &substring_t and a base, attempts to parse the substring
158 * as a number in that base. On success, sets @result to the integer represented
159 * by the string and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
161 static int match_u64int(substring_t *s, u64 *result, int base)
167 buf = match_strdup(s);
171 ret = kstrtoull(buf, base, &val);
179 * match_int: - scan a decimal representation of an integer from a substring_t
180 * @s: substring_t to be scanned
181 * @result: resulting integer on success
183 * Description: Attempts to parse the &substring_t @s as a decimal integer. On
184 * success, sets @result to the integer represented by the string and returns 0.
185 * Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
187 int match_int(substring_t *s, int *result)
189 return match_number(s, result, 0);
191 EXPORT_SYMBOL(match_int);
194 * match_u64: - scan a decimal representation of a u64 from
196 * @s: substring_t to be scanned
197 * @result: resulting unsigned long long on success
199 * Description: Attempts to parse the &substring_t @s as a long decimal
200 * integer. On success, sets @result to the integer represented by the
201 * string and returns 0.
202 * Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
204 int match_u64(substring_t *s, u64 *result)
206 return match_u64int(s, result, 0);
208 EXPORT_SYMBOL(match_u64);
211 * match_octal: - scan an octal representation of an integer from a substring_t
212 * @s: substring_t to be scanned
213 * @result: resulting integer on success
215 * Description: Attempts to parse the &substring_t @s as an octal integer. On
216 * success, sets @result to the integer represented by the string and returns
217 * 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
219 int match_octal(substring_t *s, int *result)
221 return match_number(s, result, 8);
223 EXPORT_SYMBOL(match_octal);
226 * match_hex: - scan a hex representation of an integer from a substring_t
227 * @s: substring_t to be scanned
228 * @result: resulting integer on success
230 * Description: Attempts to parse the &substring_t @s as a hexadecimal integer.
231 * On success, sets @result to the integer represented by the string and
232 * returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
234 int match_hex(substring_t *s, int *result)
236 return match_number(s, result, 16);
238 EXPORT_SYMBOL(match_hex);
241 * match_wildcard: - parse if a string matches given wildcard pattern
242 * @pattern: wildcard pattern
243 * @str: the string to be parsed
245 * Description: Parse the string @str to check if matches wildcard
246 * pattern @pattern. The pattern may contain two type wildcardes:
247 * '*' - matches zero or more characters
248 * '?' - matches one character
249 * If it's matched, return true, else return false.
251 bool match_wildcard(const char *pattern, const char *str)
254 const char *p = pattern;
289 EXPORT_SYMBOL(match_wildcard);
292 * match_strlcpy: - Copy the characters from a substring_t to a sized buffer
293 * @dest: where to copy to
294 * @src: &substring_t to copy
295 * @size: size of destination buffer
297 * Description: Copy the characters in &substring_t @src to the
298 * c-style string @dest. Copy no more than @size - 1 characters, plus
299 * the terminating NUL. Return length of @src.
301 size_t match_strlcpy(char *dest, const substring_t *src, size_t size)
303 size_t ret = src->to - src->from;
306 size_t len = ret >= size ? size - 1 : ret;
307 memcpy(dest, src->from, len);
312 EXPORT_SYMBOL(match_strlcpy);
315 * match_strdup: - allocate a new string with the contents of a substring_t
316 * @s: &substring_t to copy
318 * Description: Allocates and returns a string filled with the contents of
319 * the &substring_t @s. The caller is responsible for freeing the returned
320 * string with kfree().
322 char *match_strdup(const substring_t *s)
324 return kmemdup_nul(s->from, s->to - s->from, GFP_KERNEL);
326 EXPORT_SYMBOL(match_strdup);