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Thomas Gleixner40b0b3f2019-06-03 07:44:46 +02001// SPDX-License-Identifier: GPL-2.0-only
Linus Torvalds1da177e2005-04-16 15:20:36 -07002/*
3 * lib/parser.c - simple parser for mount, etc. options.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 */
5
6#include <linux/ctype.h>
Paul Gortmaker8bc3bcc2011-11-16 21:29:17 -05007#include <linux/types.h>
8#include <linux/export.h>
Andy Shevchenko4c527292021-06-30 18:56:10 -07009#include <linux/kstrtox.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/parser.h>
11#include <linux/slab.h>
12#include <linux/string.h>
13
Li Lingfeng67222c42023-01-20 11:23:52 +080014/*
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
Linus Torvalds1da177e2005-04-16 15:20:36 -070023/**
BingJing Changb9bffa12021-01-29 13:00:37 +080024 * match_one - Determines if a string matches a simple pattern
Lucas De Marchi25985ed2011-03-30 22:57:33 -030025 * @s: the string to examine for presence of the pattern
Linus Torvalds1da177e2005-04-16 15:20:36 -070026 * @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 */
David Howellsef4533f2007-05-03 03:10:39 -070034static int match_one(char *s, const char *p, substring_t args[])
Linus Torvalds1da177e2005-04-16 15:20:36 -070035{
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))
David Howellsef4533f2007-05-03 03:10:39 -070055 len = simple_strtoul(p, (char **) &p, 10);
Linus Torvalds1da177e2005-04-16 15:20:36 -070056 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++) {
André Goddard Rosab5f54b02009-12-14 18:01:08 -080068 case 's': {
69 size_t str_len = strlen(s);
70
71 if (str_len == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070072 return 0;
André Goddard Rosab5f54b02009-12-14 18:01:08 -080073 if (len == -1 || len > str_len)
74 len = str_len;
Linus Torvalds1da177e2005-04-16 15:20:36 -070075 args[argc].to = s + len;
76 break;
André Goddard Rosab5f54b02009-12-14 18:01:08 -080077 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 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/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800102 * match_token - Find a token (and optional args) in a string
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103 * @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
Randy Dunlapedd93342021-05-06 18:03:49 -0700111 * to it. Tokens can include up to %MAX_OPT_ARGS instances of basic c-style
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112 * format identifiers which will be taken into account when matching the
113 * tokens, and whose locations will be returned in the @args array.
114 */
Steven Whitehousea447c092008-10-13 10:46:57 +0100115int match_token(char *s, const match_table_t table, substring_t args[])
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116{
David Howellsef4533f2007-05-03 03:10:39 -0700117 const struct match_token *p;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118
119 for (p = table; !match_one(s, p->pattern, args) ; p++)
120 ;
121
122 return p->token;
123}
Andrew Mortona3d2cca2014-01-23 15:54:13 -0800124EXPORT_SYMBOL(match_token);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700125
126/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800127 * match_number - scan a number in the given base from a substring_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128 * @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
Randy Dunlapedd93342021-05-06 18:03:49 -0700133 * as a number in that base.
134 *
135 * Return: On success, sets @result to the integer represented by the
Eric Biggers359d6252023-02-23 20:26:18 -0800136 * string and returns 0. Returns -EINVAL or -ERANGE on failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700137 */
138static int match_number(substring_t *s, int *result, int base)
139{
140 char *endp;
Li Lingfeng67222c42023-01-20 11:23:52 +0800141 char buf[NUMBER_BUF_LEN];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142 int ret;
Alex Elder77dd3b02012-10-04 17:13:16 -0700143 long val;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Li Lingfeng67222c42023-01-20 11:23:52 +0800145 if (match_strlcpy(buf, s, NUMBER_BUF_LEN) >= NUMBER_BUF_LEN)
146 return -ERANGE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700147 ret = 0;
Alex Elder77dd3b02012-10-04 17:13:16 -0700148 val = simple_strtol(buf, &endp, base);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 if (endp == buf)
150 ret = -EINVAL;
Alex Elder77dd3b02012-10-04 17:13:16 -0700151 else if (val < (long)INT_MIN || val > (long)INT_MAX)
152 ret = -ERANGE;
153 else
154 *result = (int) val;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 return ret;
156}
157
158/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800159 * match_u64int - scan a number in the given base from a substring_t
James Smarta3171782016-10-21 23:51:54 +0300160 * @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
Randy Dunlapedd93342021-05-06 18:03:49 -0700165 * as a number in that base.
166 *
167 * Return: On success, sets @result to the integer represented by the
Eric Biggers359d6252023-02-23 20:26:18 -0800168 * string and returns 0. Returns -EINVAL or -ERANGE on failure.
James Smarta3171782016-10-21 23:51:54 +0300169 */
170static int match_u64int(substring_t *s, u64 *result, int base)
171{
Li Lingfeng67222c42023-01-20 11:23:52 +0800172 char buf[NUMBER_BUF_LEN];
James Smarta3171782016-10-21 23:51:54 +0300173 int ret;
174 u64 val;
James Smarta3171782016-10-21 23:51:54 +0300175
Li Lingfeng67222c42023-01-20 11:23:52 +0800176 if (match_strlcpy(buf, s, NUMBER_BUF_LEN) >= NUMBER_BUF_LEN)
177 return -ERANGE;
James Smarta3171782016-10-21 23:51:54 +0300178 ret = kstrtoull(buf, base, &val);
179 if (!ret)
180 *result = val;
James Smarta3171782016-10-21 23:51:54 +0300181 return ret;
182}
183
184/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800185 * match_int - scan a decimal representation of an integer from a substring_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 * @s: substring_t to be scanned
187 * @result: resulting integer on success
188 *
Randy Dunlapedd93342021-05-06 18:03:49 -0700189 * 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
Eric Biggers359d6252023-02-23 20:26:18 -0800192 * and returns 0. Returns -EINVAL or -ERANGE on failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 */
194int match_int(substring_t *s, int *result)
195{
196 return match_number(s, result, 0);
197}
Andrew Mortona3d2cca2014-01-23 15:54:13 -0800198EXPORT_SYMBOL(match_int);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
Randy Dunlapedd93342021-05-06 18:03:49 -0700200/**
BingJing Chang01531ac2021-01-29 12:52:42 +0800201 * 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 *
Randy Dunlapedd93342021-05-06 18:03:49 -0700205 * 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
Eric Biggers359d6252023-02-23 20:26:18 -0800208 * and returns 0. Returns -EINVAL or -ERANGE on failure.
BingJing Chang01531ac2021-01-29 12:52:42 +0800209 */
210int match_uint(substring_t *s, unsigned int *result)
211{
Li Lingfeng67222c42023-01-20 11:23:52 +0800212 char buf[NUMBER_BUF_LEN];
BingJing Chang01531ac2021-01-29 12:52:42 +0800213
Li Lingfeng67222c42023-01-20 11:23:52 +0800214 if (match_strlcpy(buf, s, NUMBER_BUF_LEN) >= NUMBER_BUF_LEN)
215 return -ERANGE;
216
217 return kstrtouint(buf, 10, result);
BingJing Chang01531ac2021-01-29 12:52:42 +0800218}
219EXPORT_SYMBOL(match_uint);
220
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800222 * match_u64 - scan a decimal representation of a u64 from
James Smarta3171782016-10-21 23:51:54 +0300223 * 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
Randy Dunlapedd93342021-05-06 18:03:49 -0700228 * integer.
229 *
230 * Return: On success, sets @result to the integer represented by the string
Eric Biggers359d6252023-02-23 20:26:18 -0800231 * and returns 0. Returns -EINVAL or -ERANGE on failure.
James Smarta3171782016-10-21 23:51:54 +0300232 */
233int match_u64(substring_t *s, u64 *result)
234{
235 return match_u64int(s, result, 0);
236}
237EXPORT_SYMBOL(match_u64);
238
239/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800240 * match_octal - scan an octal representation of an integer from a substring_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241 * @s: substring_t to be scanned
242 * @result: resulting integer on success
243 *
Randy Dunlapedd93342021-05-06 18:03:49 -0700244 * 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
Eric Biggers359d6252023-02-23 20:26:18 -0800247 * and returns 0. Returns -EINVAL or -ERANGE on failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 */
249int match_octal(substring_t *s, int *result)
250{
251 return match_number(s, result, 8);
252}
Andrew Mortona3d2cca2014-01-23 15:54:13 -0800253EXPORT_SYMBOL(match_octal);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254
255/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800256 * match_hex - scan a hex representation of an integer from a substring_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700257 * @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.
Randy Dunlapedd93342021-05-06 18:03:49 -0700261 *
262 * Return: On success, sets @result to the integer represented by the string
Eric Biggers359d6252023-02-23 20:26:18 -0800263 * and returns 0. Returns -EINVAL or -ERANGE on failure.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264 */
265int match_hex(substring_t *s, int *result)
266{
267 return match_number(s, result, 16);
268}
Andrew Mortona3d2cca2014-01-23 15:54:13 -0800269EXPORT_SYMBOL(match_hex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270
271/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800272 * match_wildcard - parse if a string matches given wildcard pattern
Du, Changbinaace0502014-01-23 15:54:12 -0800273 * @pattern: wildcard pattern
274 * @str: the string to be parsed
275 *
276 * Description: Parse the string @str to check if matches wildcard
Randy Dunlapedd93342021-05-06 18:03:49 -0700277 * pattern @pattern. The pattern may contain two types of wildcards:
Du, Changbinaace0502014-01-23 15:54:12 -0800278 * '*' - matches zero or more characters
279 * '?' - matches one character
Randy Dunlapedd93342021-05-06 18:03:49 -0700280 *
281 * Return: If the @str matches the @pattern, return true, else return false.
Du, Changbinaace0502014-01-23 15:54:12 -0800282 */
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}
Andrew Mortona3d2cca2014-01-23 15:54:13 -0800321EXPORT_SYMBOL(match_wildcard);
Du, Changbinaace0502014-01-23 15:54:12 -0800322
323/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800324 * match_strlcpy - Copy the characters from a substring_t to a sized buffer
Markus Armbrusterb32a09d2008-02-26 09:57:11 -0600325 * @dest: where to copy to
326 * @src: &substring_t to copy
327 * @size: size of destination buffer
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328 *
Markus Armbrusterb32a09d2008-02-26 09:57:11 -0600329 * Description: Copy the characters in &substring_t @src to the
330 * c-style string @dest. Copy no more than @size - 1 characters, plus
Randy Dunlapedd93342021-05-06 18:03:49 -0700331 * the terminating NUL.
332 *
333 * Return: length of @src.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 */
Markus Armbrusterb32a09d2008-02-26 09:57:11 -0600335size_t match_strlcpy(char *dest, const substring_t *src, size_t size)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336{
Markus Armbrusterb32a09d2008-02-26 09:57:11 -0600337 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345}
Andrew Mortona3d2cca2014-01-23 15:54:13 -0800346EXPORT_SYMBOL(match_strlcpy);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
348/**
BingJing Changb9bffa12021-01-29 13:00:37 +0800349 * match_strdup - allocate a new string with the contents of a substring_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 * @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().
Randy Dunlapedd93342021-05-06 18:03:49 -0700355 *
356 * Return: the address of the newly allocated NUL-terminated string or
357 * %NULL on error.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 */
David Howellsef4533f2007-05-03 03:10:39 -0700359char *match_strdup(const substring_t *s)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360{
Eric Biggers30f7bc92018-10-30 15:05:22 -0700361 return kmemdup_nul(s->from, s->to - s->from, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363EXPORT_SYMBOL(match_strdup);