diff options
Diffstat (limited to 'lib/kstrtox.c')
| -rw-r--r-- | lib/kstrtox.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/lib/kstrtox.c b/lib/kstrtox.c index 94be244e8441..d8a5cf66c316 100644 --- a/lib/kstrtox.c +++ b/lib/kstrtox.c @@ -321,6 +321,70 @@ int kstrtos8(const char *s, unsigned int base, s8 *res) } EXPORT_SYMBOL(kstrtos8); +/** + * kstrtobool - convert common user inputs into boolean values + * @s: input string + * @res: result + * + * This routine returns 0 iff the first character is one of 'Yy1Nn0', or + * [oO][NnFf] for "on" and "off". Otherwise it will return -EINVAL. Value + * pointed to by res is updated upon finding a match. + */ +int kstrtobool(const char *s, bool *res) +{ + if (!s) + return -EINVAL; + + switch (s[0]) { + case 'y': + case 'Y': + case '1': + *res = true; + return 0; + case 'n': + case 'N': + case '0': + *res = false; + return 0; + case 'o': + case 'O': + switch (s[1]) { + case 'n': + case 'N': + *res = true; + return 0; + case 'f': + case 'F': + *res = false; + return 0; + default: + break; + } + default: + break; + } + + return -EINVAL; +} +EXPORT_SYMBOL(kstrtobool); + +/* + * Since "base" would be a nonsense argument, this open-codes the + * _from_user helper instead of using the helper macro below. + */ +int kstrtobool_from_user(const char __user *s, size_t count, bool *res) +{ + /* Longest string needed to differentiate, newline, terminator */ + char buf[4]; + + count = min(count, sizeof(buf) - 1); + if (copy_from_user(buf, s, count)) + return -EFAULT; + buf[count] = '\0'; + return kstrtobool(buf, res); +} +EXPORT_SYMBOL(kstrtobool_from_user); + #define kstrto_from_user(f, g, type) \ int f(const char __user *s, size_t count, unsigned int base, type *res) \ { \ |