diff options
Diffstat (limited to 'lib/kstrtox.c')
| -rw-r--r-- | lib/kstrtox.c | 224 |
1 files changed, 224 insertions, 0 deletions
diff --git a/lib/kstrtox.c b/lib/kstrtox.c new file mode 100644 index 000000000000..a235f3cc471c --- /dev/null +++ b/lib/kstrtox.c @@ -0,0 +1,224 @@ +/* + * Convert integer string representation to an integer. + * If an integer doesn't fit into specified type, -E is returned. + * + * Integer starts with optional sign. + * kstrtou*() functions do not accept sign "-". + * + * Radix 0 means autodetection: leading "0x" implies radix 16, + * leading "0" implies radix 8, otherwise radix is 10. + * Autodetection hints work after optional sign, but not before. + * + * If -E is returned, result is not touched. + */ +#include <linux/ctype.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/math64.h> +#include <linux/module.h> +#include <linux/types.h> + +static inline char _tolower(const char c) +{ + return c | 0x20; +} + +static int _kstrtoull(const char *s, unsigned int base, unsigned long long *res) +{ + unsigned long long acc; + int ok; + + if (base == 0) { + if (s[0] == '0') { + if (_tolower(s[1]) == 'x' && isxdigit(s[2])) + base = 16; + else + base = 8; + } else + base = 10; + } + if (base == 16 && s[0] == '0' && _tolower(s[1]) == 'x') + s += 2; + + acc = 0; + ok = 0; + while (*s) { + unsigned int val; + + if ('0' <= *s && *s <= '9') + val = *s - '0'; + else if ('a' <= _tolower(*s) && _tolower(*s) <= 'f') + val = _tolower(*s) - 'a' + 10; + else if (*s == '\n' && *(s + 1) == '\0') + break; + else + return -EINVAL; + + if (val >= base) + return -EINVAL; + if (acc > div_u64(ULLONG_MAX - val, base)) + return -ERANGE; + acc = acc * base + val; + ok = 1; + + s++; + } + if (!ok) + return -EINVAL; + *res = acc; + return 0; +} + +int kstrtoull(const char *s, unsigned int base, unsigned long long *res) +{ + if (s[0] == '+') + s++; + return _kstrtoull(s, base, res); +} +EXPORT_SYMBOL(kstrtoull); + +int kstrtoll(const char *s, unsigned int base, long long *res) +{ + unsigned long long tmp; + int rv; + + if (s[0] == '-') { + rv = _kstrtoull(s + 1, base, &tmp); + if (rv < 0) + return rv; + if ((long long)(-tmp) >= 0) + return -ERANGE; + *res = -tmp; + } else { + rv = kstrtoull(s, base, &tmp); + if (rv < 0) + return rv; + if ((long long)tmp < 0) + return -ERANGE; + *res = tmp; + } + return 0; +} +EXPORT_SYMBOL(kstrtoll); + +/* Internal, do not use. */ +int _kstrtoul(const char *s, unsigned int base, unsigned long *res) +{ + unsigned long long tmp; + int rv; + + rv = kstrtoull(s, base, &tmp); + if (rv < 0) + return rv; + if (tmp != (unsigned long long)(unsigned long)tmp) + return -ERANGE; + *res = tmp; + return 0; +} +EXPORT_SYMBOL(_kstrtoul); + +/* Internal, do not use. */ +int _kstrtol(const char *s, unsigned int base, long *res) +{ + long long tmp; + int rv; + + rv = kstrtoll(s, base, &tmp); + if (rv < 0) + return rv; + if (tmp != (long long)(long)tmp) + return -ERANGE; + *res = tmp; + return 0; +} +EXPORT_SYMBOL(_kstrtol); + +int kstrtouint(const char *s, unsigned int base, unsigned int *res) +{ + unsigned long long tmp; + int rv; + + rv = kstrtoull(s, base, &tmp); + if (rv < 0) + return rv; + if (tmp != (unsigned long long)(unsigned int)tmp) + return -ERANGE; + *res = tmp; + return 0; +} +EXPORT_SYMBOL(kstrtouint); + +int kstrtoint(const char *s, unsigned int base, int *res) +{ + long long tmp; + int rv; + + rv = kstrtoll(s, base, &tmp); + if (rv < 0) + return rv; + if (tmp != (long long)(int)tmp) + return -ERANGE; + *res = tmp; + return 0; +} +EXPORT_SYMBOL(kstrtoint); + +int kstrtou16(const char *s, unsigned int base, u16 *res) +{ + unsigned long long tmp; + int rv; + + rv = kstrtoull(s, base, &tmp); + if (rv < 0) + return rv; + if (tmp != (unsigned long long)(u16)tmp) + return -ERANGE; + *res = tmp; + return 0; +} +EXPORT_SYMBOL(kstrtou16); + +int kstrtos16(const char *s, unsigned int base, s16 *res) +{ + long long tmp; + int rv; + + rv = kstrtoll(s, base, &tmp); + if (rv < 0) + return rv; + if (tmp != (long long)(s16)tmp) + return -ERANGE; + *res = tmp; + return 0; +} +EXPORT_SYMBOL(kstrtos16); + +int kstrtou8(const char *s, unsigned int base, u8 *res) +{ + unsigned long long tmp; + int rv; + + rv = kstrtoull(s, base, &tmp); + if (rv < 0) + return rv; + if (tmp != (unsigned long long)(u8)tmp) + return -ERANGE; + *res = tmp; + return 0; +} +EXPORT_SYMBOL(kstrtou8); + +int kstrtos8(const char *s, unsigned int base, s8 *res) +{ + long long tmp; + int rv; + + rv = kstrtoll(s, base, &tmp); + if (rv < 0) + return rv; + if (tmp != (long long)(s8)tmp) + return -ERANGE; + *res = tmp; + return 0; +} +EXPORT_SYMBOL(kstrtos8); |