1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Convert integer string representation to an integer. |
4 | * If an integer doesn't fit into specified type, -E is returned. |
5 | * |
6 | * Integer starts with optional sign. |
7 | * kstrtou*() functions do not accept sign "-". |
8 | * |
9 | * Radix 0 means autodetection: leading "0x" implies radix 16, |
10 | * leading "0" implies radix 8, otherwise radix is 10. |
11 | * Autodetection hints work after optional sign, but not before. |
12 | * |
13 | * If -E is returned, result is not touched. |
14 | */ |
15 | #include <linux/ctype.h> |
16 | #include <linux/errno.h> |
17 | #include <linux/export.h> |
18 | #include <linux/kstrtox.h> |
19 | #include <linux/math64.h> |
20 | #include <linux/types.h> |
21 | #include <linux/uaccess.h> |
22 | |
23 | #include "kstrtox.h" |
24 | |
25 | noinline |
26 | const char *_parse_integer_fixup_radix(const char *s, unsigned int *base) |
27 | { |
28 | if (*base == 0) { |
29 | if (s[0] == '0') { |
30 | if (_tolower(c: s[1]) == 'x' && isxdigit(s[2])) |
31 | *base = 16; |
32 | else |
33 | *base = 8; |
34 | } else |
35 | *base = 10; |
36 | } |
37 | if (*base == 16 && s[0] == '0' && _tolower(c: s[1]) == 'x') |
38 | s += 2; |
39 | return s; |
40 | } |
41 | |
42 | /* |
43 | * Convert non-negative integer string representation in explicitly given radix |
44 | * to an integer. A maximum of max_chars characters will be converted. |
45 | * |
46 | * Return number of characters consumed maybe or-ed with overflow bit. |
47 | * If overflow occurs, result integer (incorrect) is still returned. |
48 | * |
49 | * Don't you dare use this function. |
50 | */ |
51 | noinline |
52 | unsigned int _parse_integer_limit(const char *s, unsigned int base, unsigned long long *p, |
53 | size_t max_chars) |
54 | { |
55 | unsigned long long res; |
56 | unsigned int rv; |
57 | |
58 | res = 0; |
59 | rv = 0; |
60 | while (max_chars--) { |
61 | unsigned int c = *s; |
62 | unsigned int lc = _tolower(c); |
63 | unsigned int val; |
64 | |
65 | if ('0' <= c && c <= '9') |
66 | val = c - '0'; |
67 | else if ('a' <= lc && lc <= 'f') |
68 | val = lc - 'a' + 10; |
69 | else |
70 | break; |
71 | |
72 | if (val >= base) |
73 | break; |
74 | /* |
75 | * Check for overflow only if we are within range of |
76 | * it in the max base we support (16) |
77 | */ |
78 | if (unlikely(res & (~0ull << 60))) { |
79 | if (res > div_u64(ULLONG_MAX - val, divisor: base)) |
80 | rv |= KSTRTOX_OVERFLOW; |
81 | } |
82 | res = res * base + val; |
83 | rv++; |
84 | s++; |
85 | } |
86 | *p = res; |
87 | return rv; |
88 | } |
89 | |
90 | noinline |
91 | unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p) |
92 | { |
93 | return _parse_integer_limit(s, base, p, INT_MAX); |
94 | } |
95 | |
96 | static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) |
97 | { |
98 | unsigned long long _res; |
99 | unsigned int rv; |
100 | |
101 | s = _parse_integer_fixup_radix(s, base: &base); |
102 | rv = _parse_integer(s, base, p: &_res); |
103 | if (rv & KSTRTOX_OVERFLOW) |
104 | return -ERANGE; |
105 | if (rv == 0) |
106 | return -EINVAL; |
107 | s += rv; |
108 | if (*s == '\n') |
109 | s++; |
110 | if (*s) |
111 | return -EINVAL; |
112 | *res = _res; |
113 | return 0; |
114 | } |
115 | |
116 | /** |
117 | * kstrtoull - convert a string to an unsigned long long |
118 | * @s: The start of the string. The string must be null-terminated, and may also |
119 | * include a single newline before its terminating null. The first character |
120 | * may also be a plus sign, but not a minus sign. |
121 | * @base: The number base to use. The maximum supported base is 16. If base is |
122 | * given as 0, then the base of the string is automatically detected with the |
123 | * conventional semantics - If it begins with 0x the number will be parsed as a |
124 | * hexadecimal (case insensitive), if it otherwise begins with 0, it will be |
125 | * parsed as an octal number. Otherwise it will be parsed as a decimal. |
126 | * @res: Where to write the result of the conversion on success. |
127 | * |
128 | * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. |
129 | * Preferred over simple_strtoull(). Return code must be checked. |
130 | */ |
131 | noinline |
132 | int kstrtoull(const char *s, unsigned int base, unsigned long long *res) |
133 | { |
134 | if (s[0] == '+') |
135 | s++; |
136 | return _kstrtoull(s, base, res); |
137 | } |
138 | EXPORT_SYMBOL(kstrtoull); |
139 | |
140 | /** |
141 | * kstrtoll - convert a string to a long long |
142 | * @s: The start of the string. The string must be null-terminated, and may also |
143 | * include a single newline before its terminating null. The first character |
144 | * may also be a plus sign or a minus sign. |
145 | * @base: The number base to use. The maximum supported base is 16. If base is |
146 | * given as 0, then the base of the string is automatically detected with the |
147 | * conventional semantics - If it begins with 0x the number will be parsed as a |
148 | * hexadecimal (case insensitive), if it otherwise begins with 0, it will be |
149 | * parsed as an octal number. Otherwise it will be parsed as a decimal. |
150 | * @res: Where to write the result of the conversion on success. |
151 | * |
152 | * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. |
153 | * Preferred over simple_strtoll(). Return code must be checked. |
154 | */ |
155 | noinline |
156 | int kstrtoll(const char *s, unsigned int base, long long *res) |
157 | { |
158 | unsigned long long tmp; |
159 | int rv; |
160 | |
161 | if (s[0] == '-') { |
162 | rv = _kstrtoull(s: s + 1, base, res: &tmp); |
163 | if (rv < 0) |
164 | return rv; |
165 | if ((long long)-tmp > 0) |
166 | return -ERANGE; |
167 | *res = -tmp; |
168 | } else { |
169 | rv = kstrtoull(s, base, &tmp); |
170 | if (rv < 0) |
171 | return rv; |
172 | if ((long long)tmp < 0) |
173 | return -ERANGE; |
174 | *res = tmp; |
175 | } |
176 | return 0; |
177 | } |
178 | EXPORT_SYMBOL(kstrtoll); |
179 | |
180 | /* Internal, do not use. */ |
181 | int _kstrtoul(const char *s, unsigned int base, unsigned long *res) |
182 | { |
183 | unsigned long long tmp; |
184 | int rv; |
185 | |
186 | rv = kstrtoull(s, base, &tmp); |
187 | if (rv < 0) |
188 | return rv; |
189 | if (tmp != (unsigned long)tmp) |
190 | return -ERANGE; |
191 | *res = tmp; |
192 | return 0; |
193 | } |
194 | EXPORT_SYMBOL(_kstrtoul); |
195 | |
196 | /* Internal, do not use. */ |
197 | int _kstrtol(const char *s, unsigned int base, long *res) |
198 | { |
199 | long long tmp; |
200 | int rv; |
201 | |
202 | rv = kstrtoll(s, base, &tmp); |
203 | if (rv < 0) |
204 | return rv; |
205 | if (tmp != (long)tmp) |
206 | return -ERANGE; |
207 | *res = tmp; |
208 | return 0; |
209 | } |
210 | EXPORT_SYMBOL(_kstrtol); |
211 | |
212 | /** |
213 | * kstrtouint - convert a string to an unsigned int |
214 | * @s: The start of the string. The string must be null-terminated, and may also |
215 | * include a single newline before its terminating null. The first character |
216 | * may also be a plus sign, but not a minus sign. |
217 | * @base: The number base to use. The maximum supported base is 16. If base is |
218 | * given as 0, then the base of the string is automatically detected with the |
219 | * conventional semantics - If it begins with 0x the number will be parsed as a |
220 | * hexadecimal (case insensitive), if it otherwise begins with 0, it will be |
221 | * parsed as an octal number. Otherwise it will be parsed as a decimal. |
222 | * @res: Where to write the result of the conversion on success. |
223 | * |
224 | * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. |
225 | * Preferred over simple_strtoul(). Return code must be checked. |
226 | */ |
227 | noinline |
228 | int kstrtouint(const char *s, unsigned int base, unsigned int *res) |
229 | { |
230 | unsigned long long tmp; |
231 | int rv; |
232 | |
233 | rv = kstrtoull(s, base, &tmp); |
234 | if (rv < 0) |
235 | return rv; |
236 | if (tmp != (unsigned int)tmp) |
237 | return -ERANGE; |
238 | *res = tmp; |
239 | return 0; |
240 | } |
241 | EXPORT_SYMBOL(kstrtouint); |
242 | |
243 | /** |
244 | * kstrtoint - convert a string to an int |
245 | * @s: The start of the string. The string must be null-terminated, and may also |
246 | * include a single newline before its terminating null. The first character |
247 | * may also be a plus sign or a minus sign. |
248 | * @base: The number base to use. The maximum supported base is 16. If base is |
249 | * given as 0, then the base of the string is automatically detected with the |
250 | * conventional semantics - If it begins with 0x the number will be parsed as a |
251 | * hexadecimal (case insensitive), if it otherwise begins with 0, it will be |
252 | * parsed as an octal number. Otherwise it will be parsed as a decimal. |
253 | * @res: Where to write the result of the conversion on success. |
254 | * |
255 | * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. |
256 | * Preferred over simple_strtol(). Return code must be checked. |
257 | */ |
258 | noinline |
259 | int kstrtoint(const char *s, unsigned int base, int *res) |
260 | { |
261 | long long tmp; |
262 | int rv; |
263 | |
264 | rv = kstrtoll(s, base, &tmp); |
265 | if (rv < 0) |
266 | return rv; |
267 | if (tmp != (int)tmp) |
268 | return -ERANGE; |
269 | *res = tmp; |
270 | return 0; |
271 | } |
272 | EXPORT_SYMBOL(kstrtoint); |
273 | |
274 | noinline |
275 | int kstrtou16(const char *s, unsigned int base, u16 *res) |
276 | { |
277 | unsigned long long tmp; |
278 | int rv; |
279 | |
280 | rv = kstrtoull(s, base, &tmp); |
281 | if (rv < 0) |
282 | return rv; |
283 | if (tmp != (u16)tmp) |
284 | return -ERANGE; |
285 | *res = tmp; |
286 | return 0; |
287 | } |
288 | EXPORT_SYMBOL(kstrtou16); |
289 | |
290 | noinline |
291 | int kstrtos16(const char *s, unsigned int base, s16 *res) |
292 | { |
293 | long long tmp; |
294 | int rv; |
295 | |
296 | rv = kstrtoll(s, base, &tmp); |
297 | if (rv < 0) |
298 | return rv; |
299 | if (tmp != (s16)tmp) |
300 | return -ERANGE; |
301 | *res = tmp; |
302 | return 0; |
303 | } |
304 | EXPORT_SYMBOL(kstrtos16); |
305 | |
306 | noinline |
307 | int kstrtou8(const char *s, unsigned int base, u8 *res) |
308 | { |
309 | unsigned long long tmp; |
310 | int rv; |
311 | |
312 | rv = kstrtoull(s, base, &tmp); |
313 | if (rv < 0) |
314 | return rv; |
315 | if (tmp != (u8)tmp) |
316 | return -ERANGE; |
317 | *res = tmp; |
318 | return 0; |
319 | } |
320 | EXPORT_SYMBOL(kstrtou8); |
321 | |
322 | noinline |
323 | int kstrtos8(const char *s, unsigned int base, s8 *res) |
324 | { |
325 | long long tmp; |
326 | int rv; |
327 | |
328 | rv = kstrtoll(s, base, &tmp); |
329 | if (rv < 0) |
330 | return rv; |
331 | if (tmp != (s8)tmp) |
332 | return -ERANGE; |
333 | *res = tmp; |
334 | return 0; |
335 | } |
336 | EXPORT_SYMBOL(kstrtos8); |
337 | |
338 | /** |
339 | * kstrtobool - convert common user inputs into boolean values |
340 | * @s: input string |
341 | * @res: result |
342 | * |
343 | * This routine returns 0 iff the first character is one of 'YyTt1NnFf0', or |
344 | * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value |
345 | * pointed to by res is updated upon finding a match. |
346 | */ |
347 | noinline |
348 | int kstrtobool(const char *s, bool *res) |
349 | { |
350 | if (!s) |
351 | return -EINVAL; |
352 | |
353 | switch (s[0]) { |
354 | case 'y': |
355 | case 'Y': |
356 | case 't': |
357 | case 'T': |
358 | case '1': |
359 | *res = true; |
360 | return 0; |
361 | case 'n': |
362 | case 'N': |
363 | case 'f': |
364 | case 'F': |
365 | case '0': |
366 | *res = false; |
367 | return 0; |
368 | case 'o': |
369 | case 'O': |
370 | switch (s[1]) { |
371 | case 'n': |
372 | case 'N': |
373 | *res = true; |
374 | return 0; |
375 | case 'f': |
376 | case 'F': |
377 | *res = false; |
378 | return 0; |
379 | default: |
380 | break; |
381 | } |
382 | break; |
383 | default: |
384 | break; |
385 | } |
386 | |
387 | return -EINVAL; |
388 | } |
389 | EXPORT_SYMBOL(kstrtobool); |
390 | |
391 | /* |
392 | * Since "base" would be a nonsense argument, this open-codes the |
393 | * _from_user helper instead of using the helper macro below. |
394 | */ |
395 | int kstrtobool_from_user(const char __user *s, size_t count, bool *res) |
396 | { |
397 | /* Longest string needed to differentiate, newline, terminator */ |
398 | char buf[4]; |
399 | |
400 | count = min(count, sizeof(buf) - 1); |
401 | if (copy_from_user(to: buf, from: s, n: count)) |
402 | return -EFAULT; |
403 | buf[count] = '\0'; |
404 | return kstrtobool(buf, res); |
405 | } |
406 | EXPORT_SYMBOL(kstrtobool_from_user); |
407 | |
408 | #define kstrto_from_user(f, g, type) \ |
409 | int f(const char __user *s, size_t count, unsigned int base, type *res) \ |
410 | { \ |
411 | /* sign, base 2 representation, newline, terminator */ \ |
412 | char buf[1 + sizeof(type) * 8 + 1 + 1]; \ |
413 | \ |
414 | count = min(count, sizeof(buf) - 1); \ |
415 | if (copy_from_user(buf, s, count)) \ |
416 | return -EFAULT; \ |
417 | buf[count] = '\0'; \ |
418 | return g(buf, base, res); \ |
419 | } \ |
420 | EXPORT_SYMBOL(f) |
421 | |
422 | kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long); |
423 | kstrto_from_user(kstrtoll_from_user, kstrtoll, long long); |
424 | kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long); |
425 | kstrto_from_user(kstrtol_from_user, kstrtol, long); |
426 | kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int); |
427 | kstrto_from_user(kstrtoint_from_user, kstrtoint, int); |
428 | kstrto_from_user(kstrtou16_from_user, kstrtou16, u16); |
429 | kstrto_from_user(kstrtos16_from_user, kstrtos16, s16); |
430 | kstrto_from_user(kstrtou8_from_user, kstrtou8, u8); |
431 | kstrto_from_user(kstrtos8_from_user, kstrtos8, s8); |
432 | |