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