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 if (rv == 0) 96 return -EINVAL; 97 s += rv; 98 if (*s == '\n') 99 s++; 100 if (*s) 101 return -EINVAL; 102 *res = _res; 103 return 0; 104} 105 106/** 107 * kstrtoull - convert a string to an unsigned long long 108 * @s: The start of the string. The string must be null-terminated, and may also 109 * include a single newline before its terminating null. The first character 110 * may also be a plus sign, but not a minus sign. 111 * @base: The number base to use. The maximum supported base is 16. If base is 112 * given as 0, then the base of the string is automatically detected with the 113 * conventional semantics - If it begins with 0x the number will be parsed as a 114 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 115 * parsed as an octal number. Otherwise it will be parsed as a decimal. 116 * @res: Where to write the result of the conversion on success. 117 * 118 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 119 * Used as a replacement for the obsolete simple_strtoull. Return code must 120 * be checked. 121 */ 122int kstrtoull(const char *s, unsigned int base, unsigned long long *res) 123{ 124 if (s[0] == '+') 125 s++; 126 return _kstrtoull(s, base, res); 127} 128EXPORT_SYMBOL(kstrtoull); 129 130/** 131 * kstrtoll - convert a string to a long long 132 * @s: The start of the string. The string must be null-terminated, and may also 133 * include a single newline before its terminating null. The first character 134 * may also be a plus sign or a minus sign. 135 * @base: The number base to use. The maximum supported base is 16. If base is 136 * given as 0, then the base of the string is automatically detected with the 137 * conventional semantics - If it begins with 0x the number will be parsed as a 138 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 139 * parsed as an octal number. Otherwise it will be parsed as a decimal. 140 * @res: Where to write the result of the conversion on success. 141 * 142 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 143 * Used as a replacement for the obsolete simple_strtoull. Return code must 144 * be checked. 145 */ 146int kstrtoll(const char *s, unsigned int base, long long *res) 147{ 148 unsigned long long tmp; 149 int rv; 150 151 if (s[0] == '-') { 152 rv = _kstrtoull(s + 1, base, &tmp); 153 if (rv < 0) 154 return rv; 155 if ((long long)(-tmp) >= 0) 156 return -ERANGE; 157 *res = -tmp; 158 } else { 159 rv = kstrtoull(s, base, &tmp); 160 if (rv < 0) 161 return rv; 162 if ((long long)tmp < 0) 163 return -ERANGE; 164 *res = tmp; 165 } 166 return 0; 167} 168EXPORT_SYMBOL(kstrtoll); 169 170/* Internal, do not use. */ 171int _kstrtoul(const char *s, unsigned int base, unsigned long *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 long)tmp) 180 return -ERANGE; 181 *res = tmp; 182 return 0; 183} 184EXPORT_SYMBOL(_kstrtoul); 185 186/* Internal, do not use. */ 187int _kstrtol(const char *s, unsigned int base, long *res) 188{ 189 long long tmp; 190 int rv; 191 192 rv = kstrtoll(s, base, &tmp); 193 if (rv < 0) 194 return rv; 195 if (tmp != (long long)(long)tmp) 196 return -ERANGE; 197 *res = tmp; 198 return 0; 199} 200EXPORT_SYMBOL(_kstrtol); 201 202/** 203 * kstrtouint - convert a string to an unsigned int 204 * @s: The start of the string. The string must be null-terminated, and may also 205 * include a single newline before its terminating null. The first character 206 * may also be a plus sign, but not a minus sign. 207 * @base: The number base to use. The maximum supported base is 16. If base is 208 * given as 0, then the base of the string is automatically detected with the 209 * conventional semantics - If it begins with 0x the number will be parsed as a 210 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 211 * parsed as an octal number. Otherwise it will be parsed as a decimal. 212 * @res: Where to write the result of the conversion on success. 213 * 214 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 215 * Used as a replacement for the obsolete simple_strtoull. Return code must 216 * be checked. 217 */ 218int kstrtouint(const char *s, unsigned int base, unsigned int *res) 219{ 220 unsigned long long tmp; 221 int rv; 222 223 rv = kstrtoull(s, base, &tmp); 224 if (rv < 0) 225 return rv; 226 if (tmp != (unsigned long long)(unsigned int)tmp) 227 return -ERANGE; 228 *res = tmp; 229 return 0; 230} 231EXPORT_SYMBOL(kstrtouint); 232 233/** 234 * kstrtoint - convert a string to an int 235 * @s: The start of the string. The string must be null-terminated, and may also 236 * include a single newline before its terminating null. The first character 237 * may also be a plus sign or a minus sign. 238 * @base: The number base to use. The maximum supported base is 16. If base is 239 * given as 0, then the base of the string is automatically detected with the 240 * conventional semantics - If it begins with 0x the number will be parsed as a 241 * hexadecimal (case insensitive), if it otherwise begins with 0, it will be 242 * parsed as an octal number. Otherwise it will be parsed as a decimal. 243 * @res: Where to write the result of the conversion on success. 244 * 245 * Returns 0 on success, -ERANGE on overflow and -EINVAL on parsing error. 246 * Used as a replacement for the obsolete simple_strtoull. Return code must 247 * be checked. 248 */ 249int kstrtoint(const char *s, unsigned int base, int *res) 250{ 251 long long tmp; 252 int rv; 253 254 rv = kstrtoll(s, base, &tmp); 255 if (rv < 0) 256 return rv; 257 if (tmp != (long long)(int)tmp) 258 return -ERANGE; 259 *res = tmp; 260 return 0; 261} 262EXPORT_SYMBOL(kstrtoint); 263 264int kstrtou16(const char *s, unsigned int base, u16 *res) 265{ 266 unsigned long long tmp; 267 int rv; 268 269 rv = kstrtoull(s, base, &tmp); 270 if (rv < 0) 271 return rv; 272 if (tmp != (unsigned long long)(u16)tmp) 273 return -ERANGE; 274 *res = tmp; 275 return 0; 276} 277EXPORT_SYMBOL(kstrtou16); 278 279int kstrtos16(const char *s, unsigned int base, s16 *res) 280{ 281 long long tmp; 282 int rv; 283 284 rv = kstrtoll(s, base, &tmp); 285 if (rv < 0) 286 return rv; 287 if (tmp != (long long)(s16)tmp) 288 return -ERANGE; 289 *res = tmp; 290 return 0; 291} 292EXPORT_SYMBOL(kstrtos16); 293 294int kstrtou8(const char *s, unsigned int base, u8 *res) 295{ 296 unsigned long long tmp; 297 int rv; 298 299 rv = kstrtoull(s, base, &tmp); 300 if (rv < 0) 301 return rv; 302 if (tmp != (unsigned long long)(u8)tmp) 303 return -ERANGE; 304 *res = tmp; 305 return 0; 306} 307EXPORT_SYMBOL(kstrtou8); 308 309int kstrtos8(const char *s, unsigned int base, s8 *res) 310{ 311 long long tmp; 312 int rv; 313 314 rv = kstrtoll(s, base, &tmp); 315 if (rv < 0) 316 return rv; 317 if (tmp != (long long)(s8)tmp) 318 return -ERANGE; 319 *res = tmp; 320 return 0; 321} 322EXPORT_SYMBOL(kstrtos8); 323 324#define kstrto_from_user(f, g, type) \ 325int f(const char __user *s, size_t count, unsigned int base, type *res) \ 326{ \ 327 /* sign, base 2 representation, newline, terminator */ \ 328 char buf[1 + sizeof(type) * 8 + 1 + 1]; \ 329 \ 330 count = min(count, sizeof(buf) - 1); \ 331 if (copy_from_user(buf, s, count)) \ 332 return -EFAULT; \ 333 buf[count] = '\0'; \ 334 return g(buf, base, res); \ 335} \ 336EXPORT_SYMBOL(f) 337 338kstrto_from_user(kstrtoull_from_user, kstrtoull, unsigned long long); 339kstrto_from_user(kstrtoll_from_user, kstrtoll, long long); 340kstrto_from_user(kstrtoul_from_user, kstrtoul, unsigned long); 341kstrto_from_user(kstrtol_from_user, kstrtol, long); 342kstrto_from_user(kstrtouint_from_user, kstrtouint, unsigned int); 343kstrto_from_user(kstrtoint_from_user, kstrtoint, int); 344kstrto_from_user(kstrtou16_from_user, kstrtou16, u16); 345kstrto_from_user(kstrtos16_from_user, kstrtos16, s16); 346kstrto_from_user(kstrtou8_from_user, kstrtou8, u8); 347kstrto_from_user(kstrtos8_from_user, kstrtos8, s8); 348