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)
134 size_t len = s->to - s->from;
136 buf = kmalloc(len + 1, GFP_KERNEL);
139 memcpy(buf, s->from, len);
143 val = simple_strtol(buf, &endp, base);
146 else if (val < (long)INT_MIN || val > (long)INT_MAX)
155 * match_int: - scan a decimal representation of an integer from a substring_t
156 * @s: substring_t to be scanned
157 * @result: resulting integer on success
159 * Description: Attempts to parse the &substring_t @s as a decimal integer. On
160 * success, sets @result to the integer represented by the string and returns 0.
161 * Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
163 int match_int(substring_t *s, int *result)
165 return match_number(s, result, 0);
167 EXPORT_SYMBOL(match_int);
170 * match_octal: - scan an octal representation of an integer from a substring_t
171 * @s: substring_t to be scanned
172 * @result: resulting integer on success
174 * Description: Attempts to parse the &substring_t @s as an octal integer. On
175 * success, sets @result to the integer represented by the string and returns
176 * 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
178 int match_octal(substring_t *s, int *result)
180 return match_number(s, result, 8);
182 EXPORT_SYMBOL(match_octal);
185 * match_hex: - scan a hex representation of an integer from a substring_t
186 * @s: substring_t to be scanned
187 * @result: resulting integer on success
189 * Description: Attempts to parse the &substring_t @s as a hexadecimal integer.
190 * On success, sets @result to the integer represented by the string and
191 * returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
193 int match_hex(substring_t *s, int *result)
195 return match_number(s, result, 16);
197 EXPORT_SYMBOL(match_hex);
200 * match_wildcard: - parse if a string matches given wildcard pattern
201 * @pattern: wildcard pattern
202 * @str: the string to be parsed
204 * Description: Parse the string @str to check if matches wildcard
205 * pattern @pattern. The pattern may contain two type wildcardes:
206 * '*' - matches zero or more characters
207 * '?' - matches one character
208 * If it's matched, return true, else return false.
210 bool match_wildcard(const char *pattern, const char *str)
213 const char *p = pattern;
248 EXPORT_SYMBOL(match_wildcard);
251 * match_strlcpy: - Copy the characters from a substring_t to a sized buffer
252 * @dest: where to copy to
253 * @src: &substring_t to copy
254 * @size: size of destination buffer
256 * Description: Copy the characters in &substring_t @src to the
257 * c-style string @dest. Copy no more than @size - 1 characters, plus
258 * the terminating NUL. Return length of @src.
260 size_t match_strlcpy(char *dest, const substring_t *src, size_t size)
262 size_t ret = src->to - src->from;
265 size_t len = ret >= size ? size - 1 : ret;
266 memcpy(dest, src->from, len);
271 EXPORT_SYMBOL(match_strlcpy);
274 * match_strdup: - allocate a new string with the contents of a substring_t
275 * @s: &substring_t to copy
277 * Description: Allocates and returns a string filled with the contents of
278 * the &substring_t @s. The caller is responsible for freeing the returned
279 * string with kfree().
281 char *match_strdup(const substring_t *s)
283 size_t sz = s->to - s->from + 1;
284 char *p = kmalloc(sz, GFP_KERNEL);
286 match_strlcpy(p, s, sz);
289 EXPORT_SYMBOL(match_strdup);