[PATCH v3 1/3] lib/string: introduce ascii2utf16le() helper
From: Richard Leitner <richard.leitner@skidata.com>
Date: 2017-02-06 14:04:06
Also in:
lkml
Subsystem:
generic string library, library code, the rest · Maintainers:
Kees Cook, Andrew Morton, Linus Torvalds
For USB string descriptors we need to convert ASCII strings to UTF16-LE. Therefore make a simple helper function (based on ascii2desc from drivers/usb/core/hcd.c) for that purpose. Signed-off-by: Richard Leitner <richard.leitner@skidata.com> --- include/linux/string.h | 1 + lib/string.c | 26 ++++++++++++++++++++++++++ 2 files changed, 27 insertions(+)
diff --git a/include/linux/string.h b/include/linux/string.h
index 26b6f6a..48fd0c6 100644
--- a/include/linux/string.h
+++ b/include/linux/string.h@@ -135,6 +135,7 @@ static inline int strtobool(const char *s, bool *res) } int match_string(const char * const *array, size_t n, const char *string); +unsigned int ascii2utf16le(char const *s, u8 *buf, unsigned int len); #ifdef CONFIG_BINARY_PRINTF int vbin_printf(u32 *bin_buf, size_t size, const char *fmt, va_list args);
diff --git a/lib/string.c b/lib/string.c
index ed83562..a113e3e 100644
--- a/lib/string.c
+++ b/lib/string.c@@ -952,3 +952,29 @@ char *strreplace(char *s, char old, char new) return s; } EXPORT_SYMBOL(strreplace); + +/** + * ascii2utf16le() - Helper routine for producing UTF-16LE string descriptors + * @s: Null-terminated ASCII (actually ISO-8859-1) string + * @buf: Buffer for UTF-16LE string + * @len: Length (in bytes; may be odd) of UTF-16LE buffer. + * + * Return: The number of bytes filled in: 2*strlen(s) or @len, whichever is less + */ +unsigned int ascii2utf16le(char const *s, u8 *buf, unsigned int len) +{ + unsigned int n, t = 2 * strlen(s); + + if (len > t) + len = t; + n = len; + while (n--) { + t = (unsigned char)*s++; + *buf++ = t; + if (!n--) + break; + *buf++ = t >> 8; + } + return len; +} +EXPORT_SYMBOL(ascii2utf16le);
--
2.1.4