1 // SPDX-License-Identifier: GPL-2.0-only
3 * lib/parser.c - simple parser for mount, etc. options.
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>
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
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.
25 static int match_one(char *s, const char *p, substring_t args[])
35 meta = strchr(p, '%');
37 return strcmp(p, s) == 0;
39 if (strncmp(p, s, meta-p))
46 len = simple_strtoul(p, (char **) &p, 10);
54 if (argc >= MAX_OPT_ARGS)
60 size_t str_len = strlen(s);
64 if (len == -1 || len > str_len)
66 args[argc].to = s + len;
70 simple_strtol(s, &args[argc].to, 0);
73 simple_strtoul(s, &args[argc].to, 0);
76 simple_strtoul(s, &args[argc].to, 8);
79 simple_strtoul(s, &args[argc].to, 16);
81 if (args[argc].to == args[argc].from)
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
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.
106 int match_token(char *s, const match_table_t table, substring_t args[])
108 const struct match_token *p;
110 for (p = table; !match_one(s, p->pattern, args) ; p++)
115 EXPORT_SYMBOL(match_token);
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
123 * Description: Given a &substring_t and a base, attempts to parse the substring
124 * as a number in that base. On success, sets @result to the integer represented
125 * by the string and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
127 static int match_number(substring_t *s, int *result, int base)
134 buf = match_strdup(s);
139 val = simple_strtol(buf, &endp, base);
142 else if (val < (long)INT_MIN || val > (long)INT_MAX)
151 * match_u64int: scan a number in the given base from a substring_t
152 * @s: substring to be scanned
153 * @result: resulting u64 on success
154 * @base: base to use when converting string
156 * Description: Given a &substring_t and a base, attempts to parse the substring
157 * as a number in that base. On success, sets @result to the integer represented
158 * by the string and returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
160 static int match_u64int(substring_t *s, u64 *result, int base)
166 buf = match_strdup(s);
170 ret = kstrtoull(buf, base, &val);
178 * match_int: - scan a decimal representation of an integer from a substring_t
179 * @s: substring_t to be scanned
180 * @result: resulting integer on success
182 * Description: Attempts to parse the &substring_t @s as a decimal integer. On
183 * success, sets @result to the integer represented by the string and returns 0.
184 * Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
186 int match_int(substring_t *s, int *result)
188 return match_number(s, result, 0);
190 EXPORT_SYMBOL(match_int);
193 * match_u64: - scan a decimal representation of a u64 from
195 * @s: substring_t to be scanned
196 * @result: resulting unsigned long long on success
198 * Description: Attempts to parse the &substring_t @s as a long decimal
199 * integer. On success, sets @result to the integer represented by the
200 * string and returns 0.
201 * Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
203 int match_u64(substring_t *s, u64 *result)
205 return match_u64int(s, result, 0);
207 EXPORT_SYMBOL(match_u64);
210 * match_octal: - scan an octal representation of an integer from a substring_t
211 * @s: substring_t to be scanned
212 * @result: resulting integer on success
214 * Description: Attempts to parse the &substring_t @s as an octal integer. On
215 * success, sets @result to the integer represented by the string and returns
216 * 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
218 int match_octal(substring_t *s, int *result)
220 return match_number(s, result, 8);
222 EXPORT_SYMBOL(match_octal);
225 * match_hex: - scan a hex representation of an integer from a substring_t
226 * @s: substring_t to be scanned
227 * @result: resulting integer on success
229 * Description: Attempts to parse the &substring_t @s as a hexadecimal integer.
230 * On success, sets @result to the integer represented by the string and
231 * returns 0. Returns -ENOMEM, -EINVAL, or -ERANGE on failure.
233 int match_hex(substring_t *s, int *result)
235 return match_number(s, result, 16);
237 EXPORT_SYMBOL(match_hex);
240 * match_wildcard: - parse if a string matches given wildcard pattern
241 * @pattern: wildcard pattern
242 * @str: the string to be parsed
244 * Description: Parse the string @str to check if matches wildcard
245 * pattern @pattern. The pattern may contain two type wildcardes:
246 * '*' - matches zero or more characters
247 * '?' - matches one character
248 * If it's matched, return true, else return false.
250 bool match_wildcard(const char *pattern, const char *str)
253 const char *p = pattern;
288 EXPORT_SYMBOL(match_wildcard);
291 * match_strlcpy: - Copy the characters from a substring_t to a sized buffer
292 * @dest: where to copy to
293 * @src: &substring_t to copy
294 * @size: size of destination buffer
296 * Description: Copy the characters in &substring_t @src to the
297 * c-style string @dest. Copy no more than @size - 1 characters, plus
298 * the terminating NUL. Return length of @src.
300 size_t match_strlcpy(char *dest, const substring_t *src, size_t size)
302 size_t ret = src->to - src->from;
305 size_t len = ret >= size ? size - 1 : ret;
306 memcpy(dest, src->from, len);
311 EXPORT_SYMBOL(match_strlcpy);
314 * match_strdup: - allocate a new string with the contents of a substring_t
315 * @s: &substring_t to copy
317 * Description: Allocates and returns a string filled with the contents of
318 * the &substring_t @s. The caller is responsible for freeing the returned
319 * string with kfree().
321 char *match_strdup(const substring_t *s)
323 return kmemdup_nul(s->from, s->to - s->from, GFP_KERNEL);
325 EXPORT_SYMBOL(match_strdup);