Line data Source code
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 6 : const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
27 : {
28 6 : if (*base == 0) {
29 5 : if (s[0] == '0') {
30 0 : if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
31 0 : *base = 16;
32 : else
33 0 : *base = 8;
34 : } else
35 5 : *base = 10;
36 : }
37 6 : if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
38 0 : s += 2;
39 6 : 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 6 : 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 6 : res = 0;
59 6 : rv = 0;
60 17 : while (max_chars--) {
61 11 : unsigned int c = *s;
62 11 : unsigned int lc = c | 0x20; /* don't tolower() this line */
63 : unsigned int val;
64 :
65 11 : if ('0' <= c && c <= '9')
66 : val = c - '0';
67 6 : else if ('a' <= lc && lc <= 'f')
68 0 : val = lc - 'a' + 10;
69 : else
70 : break;
71 :
72 5 : 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 5 : if (unlikely(res & (~0ull << 60))) {
79 0 : if (res > div_u64(ULLONG_MAX - val, base))
80 0 : rv |= KSTRTOX_OVERFLOW;
81 : }
82 5 : res = res * base + val;
83 5 : rv++;
84 5 : s++;
85 : }
86 6 : *p = res;
87 6 : return rv;
88 : }
89 :
90 : noinline
91 0 : unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
92 : {
93 0 : return _parse_integer_limit(s, base, p, INT_MAX);
94 : }
95 :
96 0 : 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 0 : s = _parse_integer_fixup_radix(s, &base);
102 0 : rv = _parse_integer(s, base, &_res);
103 0 : if (rv & KSTRTOX_OVERFLOW)
104 : return -ERANGE;
105 0 : if (rv == 0)
106 : return -EINVAL;
107 0 : s += rv;
108 0 : if (*s == '\n')
109 0 : s++;
110 0 : if (*s)
111 : return -EINVAL;
112 0 : *res = _res;
113 0 : 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 0 : int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
133 : {
134 0 : if (s[0] == '+')
135 0 : s++;
136 0 : 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 0 : int kstrtoll(const char *s, unsigned int base, long long *res)
157 : {
158 : unsigned long long tmp;
159 : int rv;
160 :
161 0 : if (s[0] == '-') {
162 0 : rv = _kstrtoull(s + 1, base, &tmp);
163 0 : if (rv < 0)
164 : return rv;
165 0 : if ((long long)-tmp > 0)
166 : return -ERANGE;
167 0 : *res = -tmp;
168 : } else {
169 0 : rv = kstrtoull(s, base, &tmp);
170 0 : if (rv < 0)
171 : return rv;
172 0 : if ((long long)tmp < 0)
173 : return -ERANGE;
174 0 : *res = tmp;
175 : }
176 : return 0;
177 : }
178 : EXPORT_SYMBOL(kstrtoll);
179 :
180 : /* Internal, do not use. */
181 0 : int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
182 : {
183 : unsigned long long tmp;
184 : int rv;
185 :
186 0 : rv = kstrtoull(s, base, &tmp);
187 0 : if (rv < 0)
188 : return rv;
189 : if (tmp != (unsigned long)tmp)
190 : return -ERANGE;
191 0 : *res = tmp;
192 0 : return 0;
193 : }
194 : EXPORT_SYMBOL(_kstrtoul);
195 :
196 : /* Internal, do not use. */
197 0 : int _kstrtol(const char *s, unsigned int base, long *res)
198 : {
199 : long long tmp;
200 : int rv;
201 :
202 0 : rv = kstrtoll(s, base, &tmp);
203 0 : if (rv < 0)
204 : return rv;
205 : if (tmp != (long)tmp)
206 : return -ERANGE;
207 0 : *res = tmp;
208 0 : 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 0 : int kstrtouint(const char *s, unsigned int base, unsigned int *res)
229 : {
230 : unsigned long long tmp;
231 : int rv;
232 :
233 0 : rv = kstrtoull(s, base, &tmp);
234 0 : if (rv < 0)
235 : return rv;
236 0 : if (tmp != (unsigned int)tmp)
237 : return -ERANGE;
238 0 : *res = tmp;
239 0 : 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 0 : int kstrtoint(const char *s, unsigned int base, int *res)
260 : {
261 : long long tmp;
262 : int rv;
263 :
264 0 : rv = kstrtoll(s, base, &tmp);
265 0 : if (rv < 0)
266 : return rv;
267 0 : if (tmp != (int)tmp)
268 : return -ERANGE;
269 0 : *res = tmp;
270 0 : return 0;
271 : }
272 : EXPORT_SYMBOL(kstrtoint);
273 :
274 : noinline
275 0 : int kstrtou16(const char *s, unsigned int base, u16 *res)
276 : {
277 : unsigned long long tmp;
278 : int rv;
279 :
280 0 : rv = kstrtoull(s, base, &tmp);
281 0 : if (rv < 0)
282 : return rv;
283 0 : if (tmp != (u16)tmp)
284 : return -ERANGE;
285 0 : *res = tmp;
286 0 : return 0;
287 : }
288 : EXPORT_SYMBOL(kstrtou16);
289 :
290 : noinline
291 0 : int kstrtos16(const char *s, unsigned int base, s16 *res)
292 : {
293 : long long tmp;
294 : int rv;
295 :
296 0 : rv = kstrtoll(s, base, &tmp);
297 0 : if (rv < 0)
298 : return rv;
299 0 : if (tmp != (s16)tmp)
300 : return -ERANGE;
301 0 : *res = tmp;
302 0 : return 0;
303 : }
304 : EXPORT_SYMBOL(kstrtos16);
305 :
306 : noinline
307 0 : int kstrtou8(const char *s, unsigned int base, u8 *res)
308 : {
309 : unsigned long long tmp;
310 : int rv;
311 :
312 0 : rv = kstrtoull(s, base, &tmp);
313 0 : if (rv < 0)
314 : return rv;
315 0 : if (tmp != (u8)tmp)
316 : return -ERANGE;
317 0 : *res = tmp;
318 0 : return 0;
319 : }
320 : EXPORT_SYMBOL(kstrtou8);
321 :
322 : noinline
323 0 : int kstrtos8(const char *s, unsigned int base, s8 *res)
324 : {
325 : long long tmp;
326 : int rv;
327 :
328 0 : rv = kstrtoll(s, base, &tmp);
329 0 : if (rv < 0)
330 : return rv;
331 0 : if (tmp != (s8)tmp)
332 : return -ERANGE;
333 0 : *res = tmp;
334 0 : 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 1 : int kstrtobool(const char *s, bool *res)
349 : {
350 1 : if (!s)
351 : return -EINVAL;
352 :
353 1 : switch (s[0]) {
354 : case 'y':
355 : case 'Y':
356 : case 't':
357 : case 'T':
358 : case '1':
359 1 : *res = true;
360 1 : return 0;
361 : case 'n':
362 : case 'N':
363 : case 'f':
364 : case 'F':
365 : case '0':
366 0 : *res = false;
367 0 : return 0;
368 : case 'o':
369 : case 'O':
370 0 : switch (s[1]) {
371 : case 'n':
372 : case 'N':
373 0 : *res = true;
374 0 : return 0;
375 : case 'f':
376 : case 'F':
377 0 : *res = false;
378 0 : 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 0 : 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 0 : count = min(count, sizeof(buf) - 1);
401 0 : if (copy_from_user(buf, s, count))
402 : return -EFAULT;
403 0 : buf[count] = '\0';
404 0 : 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 0 : kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long);
423 0 : kstrto_from_user(kstrtoll_from_user, kstrtoll, long long);
424 0 : kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long);
425 0 : kstrto_from_user(kstrtol_from_user, kstrtol, long);
426 0 : kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int);
427 0 : kstrto_from_user(kstrtoint_from_user, kstrtoint, int);
428 0 : kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
429 0 : kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
430 0 : kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
431 0 : kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);
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