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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
25const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
26{
27 if (*base == 0) {
28 if (s[0] == '0') {
29 if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
30 *base = 16;
31 else
32 *base = 8;
33 } else
34 *base = 10;
35 }
36 if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
37 s += 2;
38 return s;
39}
40
41/*
42 * Convert non-negative integer string representation in explicitly given radix
43 * to an integer. A maximum of max_chars characters will be converted.
44 *
45 * Return number of characters consumed maybe or-ed with overflow bit.
46 * If overflow occurs, result integer (incorrect) is still returned.
47 *
48 * Don't you dare use this function.
49 */
50unsigned int _parse_integer_limit(const char *s, unsigned int base, unsigned long long *p,
51 size_t max_chars)
52{
53 unsigned long long res;
54 unsigned int rv;
55
56 res = 0;
57 rv = 0;
58 while (max_chars--) {
59 unsigned int c = *s;
60 unsigned int lc = c | 0x20; /* don't tolower() this line */
61 unsigned int val;
62
63 if ('0' <= c && c <= '9')
64 val = c - '0';
65 else if ('a' <= lc && lc <= 'f')
66 val = lc - 'a' + 10;
67 else
68 break;
69
70 if (val >= base)
71 break;
72 /*
73 * Check for overflow only if we are within range of
74 * it in the max base we support (16)
75 */
76 if (unlikely(res & (~0ull << 60))) {
77 if (res > div_u64(ULLONG_MAX - val, base))
78 rv |= KSTRTOX_OVERFLOW;
79 }
80 res = res * base + val;
81 rv++;
82 s++;
83 }
84 *p = res;
85 return rv;
86}
87
88unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
89{
90 return _parse_integer_limit(s, base, p, INT_MAX);
91}
92
93static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
94{
95 unsigned long long _res;
96 unsigned int rv;
97
98 s = _parse_integer_fixup_radix(s, &base);
99 rv = _parse_integer(s, base, &_res);
100 if (rv & KSTRTOX_OVERFLOW)
101 return -ERANGE;
102 if (rv == 0)
103 return -EINVAL;
104 s += rv;
105 if (*s == '\n')
106 s++;
107 if (*s)
108 return -EINVAL;
109 *res = _res;
110 return 0;
111}
112
113/**
114 * kstrtoull - convert a string to an unsigned long long
115 * @s: The start of the string. The string must be null-terminated, and may also
116 * include a single newline before its terminating null. The first character
117 * may also be a plus sign, but not a minus sign.
118 * @base: The number base to use. The maximum supported base is 16. If base is
119 * given as 0, then the base of the string is automatically detected with the
120 * conventional semantics - If it begins with 0x the number will be parsed as a
121 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
122 * parsed as an octal number. Otherwise it will be parsed as a decimal.
123 * @res: Where to write the result of the conversion on success.
124 *
125 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
126 * Preferred over simple_strtoull(). Return code must be checked.
127 */
128int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
129{
130 if (s[0] == '+')
131 s++;
132 return _kstrtoull(s, base, res);
133}
134EXPORT_SYMBOL(kstrtoull);
135
136/**
137 * kstrtoll - convert a string to a long long
138 * @s: The start of the string. The string must be null-terminated, and may also
139 * include a single newline before its terminating null. The first character
140 * may also be a plus sign or a minus sign.
141 * @base: The number base to use. The maximum supported base is 16. If base is
142 * given as 0, then the base of the string is automatically detected with the
143 * conventional semantics - If it begins with 0x the number will be parsed as a
144 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
145 * parsed as an octal number. Otherwise it will be parsed as a decimal.
146 * @res: Where to write the result of the conversion on success.
147 *
148 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
149 * Preferred over simple_strtoll(). Return code must be checked.
150 */
151int kstrtoll(const char *s, unsigned int base, long long *res)
152{
153 unsigned long long tmp;
154 int rv;
155
156 if (s[0] == '-') {
157 rv = _kstrtoull(s + 1, base, &tmp);
158 if (rv < 0)
159 return rv;
160 if ((long long)-tmp > 0)
161 return -ERANGE;
162 *res = -tmp;
163 } else {
164 rv = kstrtoull(s, base, &tmp);
165 if (rv < 0)
166 return rv;
167 if ((long long)tmp < 0)
168 return -ERANGE;
169 *res = tmp;
170 }
171 return 0;
172}
173EXPORT_SYMBOL(kstrtoll);
174
175/* Internal, do not use. */
176int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
177{
178 unsigned long long tmp;
179 int rv;
180
181 rv = kstrtoull(s, base, &tmp);
182 if (rv < 0)
183 return rv;
184 if (tmp != (unsigned long)tmp)
185 return -ERANGE;
186 *res = tmp;
187 return 0;
188}
189EXPORT_SYMBOL(_kstrtoul);
190
191/* Internal, do not use. */
192int _kstrtol(const char *s, unsigned int base, long *res)
193{
194 long long tmp;
195 int rv;
196
197 rv = kstrtoll(s, base, &tmp);
198 if (rv < 0)
199 return rv;
200 if (tmp != (long)tmp)
201 return -ERANGE;
202 *res = tmp;
203 return 0;
204}
205EXPORT_SYMBOL(_kstrtol);
206
207/**
208 * kstrtouint - convert a string to an unsigned int
209 * @s: The start of the string. The string must be null-terminated, and may also
210 * include a single newline before its terminating null. The first character
211 * may also be a plus sign, but not a minus sign.
212 * @base: The number base to use. The maximum supported base is 16. If base is
213 * given as 0, then the base of the string is automatically detected with the
214 * conventional semantics - If it begins with 0x the number will be parsed as a
215 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
216 * parsed as an octal number. Otherwise it will be parsed as a decimal.
217 * @res: Where to write the result of the conversion on success.
218 *
219 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
220 * Preferred over simple_strtoul(). Return code must be checked.
221 */
222int kstrtouint(const char *s, unsigned int base, unsigned int *res)
223{
224 unsigned long long tmp;
225 int rv;
226
227 rv = kstrtoull(s, base, &tmp);
228 if (rv < 0)
229 return rv;
230 if (tmp != (unsigned int)tmp)
231 return -ERANGE;
232 *res = tmp;
233 return 0;
234}
235EXPORT_SYMBOL(kstrtouint);
236
237/**
238 * kstrtoint - convert a string to an int
239 * @s: The start of the string. The string must be null-terminated, and may also
240 * include a single newline before its terminating null. The first character
241 * may also be a plus sign or a minus sign.
242 * @base: The number base to use. The maximum supported base is 16. If base is
243 * given as 0, then the base of the string is automatically detected with the
244 * conventional semantics - If it begins with 0x the number will be parsed as a
245 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be
246 * parsed as an octal number. Otherwise it will be parsed as a decimal.
247 * @res: Where to write the result of the conversion on success.
248 *
249 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error.
250 * Preferred over simple_strtol(). Return code must be checked.
251 */
252int kstrtoint(const char *s, unsigned int base, int *res)
253{
254 long long tmp;
255 int rv;
256
257 rv = kstrtoll(s, base, &tmp);
258 if (rv < 0)
259 return rv;
260 if (tmp != (int)tmp)
261 return -ERANGE;
262 *res = tmp;
263 return 0;
264}
265EXPORT_SYMBOL(kstrtoint);
266
267int kstrtou16(const char *s, unsigned int base, u16 *res)
268{
269 unsigned long long tmp;
270 int rv;
271
272 rv = kstrtoull(s, base, &tmp);
273 if (rv < 0)
274 return rv;
275 if (tmp != (u16)tmp)
276 return -ERANGE;
277 *res = tmp;
278 return 0;
279}
280EXPORT_SYMBOL(kstrtou16);
281
282int kstrtos16(const char *s, unsigned int base, s16 *res)
283{
284 long long tmp;
285 int rv;
286
287 rv = kstrtoll(s, base, &tmp);
288 if (rv < 0)
289 return rv;
290 if (tmp != (s16)tmp)
291 return -ERANGE;
292 *res = tmp;
293 return 0;
294}
295EXPORT_SYMBOL(kstrtos16);
296
297int kstrtou8(const char *s, unsigned int base, u8 *res)
298{
299 unsigned long long tmp;
300 int rv;
301
302 rv = kstrtoull(s, base, &tmp);
303 if (rv < 0)
304 return rv;
305 if (tmp != (u8)tmp)
306 return -ERANGE;
307 *res = tmp;
308 return 0;
309}
310EXPORT_SYMBOL(kstrtou8);
311
312int kstrtos8(const char *s, unsigned int base, s8 *res)
313{
314 long long tmp;
315 int rv;
316
317 rv = kstrtoll(s, base, &tmp);
318 if (rv < 0)
319 return rv;
320 if (tmp != (s8)tmp)
321 return -ERANGE;
322 *res = tmp;
323 return 0;
324}
325EXPORT_SYMBOL(kstrtos8);
326
327/**
328 * kstrtobool - convert common user inputs into boolean values
329 * @s: input string
330 * @res: result
331 *
332 * This routine returns 0 iff the first character is one of 'Yy1Nn0', or
333 * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value
334 * pointed to by res is updated upon finding a match.
335 */
336int kstrtobool(const char *s, bool *res)
337{
338 if (!s)
339 return -EINVAL;
340
341 switch (s[0]) {
342 case 'y':
343 case 'Y':
344 case '1':
345 *res = true;
346 return 0;
347 case 'n':
348 case 'N':
349 case '0':
350 *res = false;
351 return 0;
352 case 'o':
353 case 'O':
354 switch (s[1]) {
355 case 'n':
356 case 'N':
357 *res = true;
358 return 0;
359 case 'f':
360 case 'F':
361 *res = false;
362 return 0;
363 default:
364 break;
365 }
366 break;
367 default:
368 break;
369 }
370
371 return -EINVAL;
372}
373EXPORT_SYMBOL(kstrtobool);
374
375/*
376 * Since "base" would be a nonsense argument, this open-codes the
377 * _from_user helper instead of using the helper macro below.
378 */
379int kstrtobool_from_user(const char __user *s, size_t count, bool *res)
380{
381 /* Longest string needed to differentiate, newline, terminator */
382 char buf[4];
383
384 count = min(count, sizeof(buf) - 1);
385 if (copy_from_user(buf, s, count))
386 return -EFAULT;
387 buf[count] = '\0';
388 return kstrtobool(buf, res);
389}
390EXPORT_SYMBOL(kstrtobool_from_user);
391
392#define kstrto_from_user(f, g, type) \
393int f(const char __user *s, size_t count, unsigned int base, type *res) \
394{ \
395 /* sign, base 2 representation, newline, terminator */ \
396 char buf[1 + sizeof(type) * 8 + 1 + 1]; \
397 \
398 count = min(count, sizeof(buf) - 1); \
399 if (copy_from_user(buf, s, count)) \
400 return -EFAULT; \
401 buf[count] = '\0'; \
402 return g(buf, base, res); \
403} \
404EXPORT_SYMBOL(f)
405
406kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long);
407kstrto_from_user(kstrtoll_from_user, kstrtoll, long long);
408kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long);
409kstrto_from_user(kstrtol_from_user, kstrtol, long);
410kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int);
411kstrto_from_user(kstrtoint_from_user, kstrtoint, int);
412kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
413kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
414kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
415kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);
1/*
2 * Convert integer string representation to an integer.
3 * If an integer doesn't fit into specified type, -E is returned.
4 *
5 * Integer starts with optional sign.
6 * kstrtou*() functions do not accept sign "-".
7 *
8 * Radix 0 means autodetection: leading "0x" implies radix 16,
9 * leading "0" implies radix 8, otherwise radix is 10.
10 * Autodetection hints work after optional sign, but not before.
11 *
12 * If -E is returned, result is not touched.
13 */
14#include <linux/ctype.h>
15#include <linux/errno.h>
16#include <linux/kernel.h>
17#include <linux/math64.h>
18#include <linux/export.h>
19#include <linux/types.h>
20#include <asm/uaccess.h>
21#include "kstrtox.h"
22
23const char *_parse_integer_fixup_radix(const char *s, unsigned int *base)
24{
25 if (*base == 0) {
26 if (s[0] == '0') {
27 if (_tolower(s[1]) == 'x' && isxdigit(s[2]))
28 *base = 16;
29 else
30 *base = 8;
31 } else
32 *base = 10;
33 }
34 if (*base == 16 && s[0] == '0' && _tolower(s[1]) == 'x')
35 s += 2;
36 return s;
37}
38
39/*
40 * Convert non-negative integer string representation in explicitly given radix
41 * to an integer.
42 * Return number of characters consumed maybe or-ed with overflow bit.
43 * If overflow occurs, result integer (incorrect) is still returned.
44 *
45 * Don't you dare use this function.
46 */
47unsigned int _parse_integer(const char *s, unsigned int base, unsigned long long *p)
48{
49 unsigned long long res;
50 unsigned int rv;
51 int overflow;
52
53 res = 0;
54 rv = 0;
55 overflow = 0;
56 while (*s) {
57 unsigned int val;
58
59 if ('0' <= *s && *s <= '9')
60 val = *s - '0';
61 else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f')
62 val = _tolower(*s) - 'a' + 10;
63 else
64 break;
65
66 if (val >= base)
67 break;
68 /*
69 * Check for overflow only if we are within range of
70 * it in the max base we support (16)
71 */
72 if (unlikely(res & (~0ull << 60))) {
73 if (res > div_u64(ULLONG_MAX - val, base))
74 overflow = 1;
75 }
76 res = res * base + val;
77 rv++;
78 s++;
79 }
80 *p = res;
81 if (overflow)
82 rv |= KSTRTOX_OVERFLOW;
83 return rv;
84}
85
86static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res)
87{
88 unsigned long long _res;
89 unsigned int rv;
90
91 s = _parse_integer_fixup_radix(s, &base);
92 rv = _parse_integer(s, base, &_res);
93 if (rv & KSTRTOX_OVERFLOW)
94 return -ERANGE;
95 rv &= ~KSTRTOX_OVERFLOW;
96 if (rv == 0)
97 return -EINVAL;
98 s += rv;
99 if (*s == '\n')
100 s++;
101 if (*s)
102 return -EINVAL;
103 *res = _res;
104 return 0;
105}
106
107int kstrtoull(const char *s, unsigned int base, unsigned long long *res)
108{
109 if (s[0] == '+')
110 s++;
111 return _kstrtoull(s, base, res);
112}
113EXPORT_SYMBOL(kstrtoull);
114
115int kstrtoll(const char *s, unsigned int base, long long *res)
116{
117 unsigned long long tmp;
118 int rv;
119
120 if (s[0] == '-') {
121 rv = _kstrtoull(s + 1, base, &tmp);
122 if (rv < 0)
123 return rv;
124 if ((long long)(-tmp) >= 0)
125 return -ERANGE;
126 *res = -tmp;
127 } else {
128 rv = kstrtoull(s, base, &tmp);
129 if (rv < 0)
130 return rv;
131 if ((long long)tmp < 0)
132 return -ERANGE;
133 *res = tmp;
134 }
135 return 0;
136}
137EXPORT_SYMBOL(kstrtoll);
138
139/* Internal, do not use. */
140int _kstrtoul(const char *s, unsigned int base, unsigned long *res)
141{
142 unsigned long long tmp;
143 int rv;
144
145 rv = kstrtoull(s, base, &tmp);
146 if (rv < 0)
147 return rv;
148 if (tmp != (unsigned long long)(unsigned long)tmp)
149 return -ERANGE;
150 *res = tmp;
151 return 0;
152}
153EXPORT_SYMBOL(_kstrtoul);
154
155/* Internal, do not use. */
156int _kstrtol(const char *s, unsigned int base, long *res)
157{
158 long long tmp;
159 int rv;
160
161 rv = kstrtoll(s, base, &tmp);
162 if (rv < 0)
163 return rv;
164 if (tmp != (long long)(long)tmp)
165 return -ERANGE;
166 *res = tmp;
167 return 0;
168}
169EXPORT_SYMBOL(_kstrtol);
170
171int kstrtouint(const char *s, unsigned int base, unsigned int *res)
172{
173 unsigned long long tmp;
174 int rv;
175
176 rv = kstrtoull(s, base, &tmp);
177 if (rv < 0)
178 return rv;
179 if (tmp != (unsigned long long)(unsigned int)tmp)
180 return -ERANGE;
181 *res = tmp;
182 return 0;
183}
184EXPORT_SYMBOL(kstrtouint);
185
186int kstrtoint(const char *s, unsigned int base, int *res)
187{
188 long long tmp;
189 int rv;
190
191 rv = kstrtoll(s, base, &tmp);
192 if (rv < 0)
193 return rv;
194 if (tmp != (long long)(int)tmp)
195 return -ERANGE;
196 *res = tmp;
197 return 0;
198}
199EXPORT_SYMBOL(kstrtoint);
200
201int kstrtou16(const char *s, unsigned int base, u16 *res)
202{
203 unsigned long long tmp;
204 int rv;
205
206 rv = kstrtoull(s, base, &tmp);
207 if (rv < 0)
208 return rv;
209 if (tmp != (unsigned long long)(u16)tmp)
210 return -ERANGE;
211 *res = tmp;
212 return 0;
213}
214EXPORT_SYMBOL(kstrtou16);
215
216int kstrtos16(const char *s, unsigned int base, s16 *res)
217{
218 long long tmp;
219 int rv;
220
221 rv = kstrtoll(s, base, &tmp);
222 if (rv < 0)
223 return rv;
224 if (tmp != (long long)(s16)tmp)
225 return -ERANGE;
226 *res = tmp;
227 return 0;
228}
229EXPORT_SYMBOL(kstrtos16);
230
231int kstrtou8(const char *s, unsigned int base, u8 *res)
232{
233 unsigned long long tmp;
234 int rv;
235
236 rv = kstrtoull(s, base, &tmp);
237 if (rv < 0)
238 return rv;
239 if (tmp != (unsigned long long)(u8)tmp)
240 return -ERANGE;
241 *res = tmp;
242 return 0;
243}
244EXPORT_SYMBOL(kstrtou8);
245
246int kstrtos8(const char *s, unsigned int base, s8 *res)
247{
248 long long tmp;
249 int rv;
250
251 rv = kstrtoll(s, base, &tmp);
252 if (rv < 0)
253 return rv;
254 if (tmp != (long long)(s8)tmp)
255 return -ERANGE;
256 *res = tmp;
257 return 0;
258}
259EXPORT_SYMBOL(kstrtos8);
260
261#define kstrto_from_user(f, g, type) \
262int f(const char __user *s, size_t count, unsigned int base, type *res) \
263{ \
264 /* sign, base 2 representation, newline, terminator */ \
265 char buf[1 + sizeof(type) * 8 + 1 + 1]; \
266 \
267 count = min(count, sizeof(buf) - 1); \
268 if (copy_from_user(buf, s, count)) \
269 return -EFAULT; \
270 buf[count] = '\0'; \
271 return g(buf, base, res); \
272} \
273EXPORT_SYMBOL(f)
274
275kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long);
276kstrto_from_user(kstrtoll_from_user, kstrtoll, long long);
277kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long);
278kstrto_from_user(kstrtol_from_user, kstrtol, long);
279kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int);
280kstrto_from_user(kstrtoint_from_user, kstrtoint, int);
281kstrto_from_user(kstrtou16_from_user, kstrtou16, u16);
282kstrto_from_user(kstrtos16_from_user, kstrtos16, s16);
283kstrto_from_user(kstrtou8_from_user, kstrtou8, u8);
284kstrto_from_user(kstrtos8_from_user, kstrtos8, s8);