libpayload: UTF-16LE to ASCII conversion
This patch adds a simple function to convert a string in UTF-16LE
to ASCII.
TEST=Ran against a string found in a GPT with the intended outcome
BRANCH=none
BUG=none
Signed-off-by: Dan Ehrenberg <dehrenberg@chromium.org>
Change-Id: I50ca5bfdfbef9e084321b2beb1b8d4194ca5af9c
Reviewed-on: https://chromium-review.googlesource.com/231456
Reviewed-by: Julius Werner <jwerner@chromium.org>
diff --git a/payloads/libpayload/include/string.h b/payloads/libpayload/include/string.h
index 9e4f791..b75128a 100644
--- a/payloads/libpayload/include/string.h
+++ b/payloads/libpayload/include/string.h
@@ -68,6 +68,13 @@
/** @} */
/**
+ * @defgroup string Unicode functions
+ * @{
+ */
+char *utf16le_to_ascii(uint16_t *utf16_string, int maxlen);
+/** @} */
+
+/**
* @defgroup string OpenBSD based safe string functions
* @{
*/
diff --git a/payloads/libpayload/libc/string.c b/payloads/libpayload/libc/string.c
index cfa0b4a..883d158 100644
--- a/payloads/libpayload/libc/string.c
+++ b/payloads/libpayload/libc/string.c
@@ -643,3 +643,22 @@
{
printf("%s: %d\n", s?s:"(none)", errno);
}
+
+/**
+ * Simple routine to convert UTF-16 to ASCII, giving up with ? if too high.
+ * A single code point may convert to ?? if in not in the BMP.
+ * @param utf16_string A string encoded in UTF-16LE
+ * @param maxlen Maximum possible length of the string in code points
+ * @return Newly allocated ASCII string
+ */
+char *utf16le_to_ascii(uint16_t *utf16_string, int maxlen)
+{
+ char *ascii_string = xmalloc(maxlen + 1); /* +1 for trailing \0 */
+ ascii_string[maxlen] = '\0';
+ int i;
+ for (i = 0; i < maxlen; i++) {
+ uint16_t wchar = utf16_string[i];
+ ascii_string[i] = wchar > 0x7f ? '?' : (char)wchar;
+ }
+ return ascii_string;
+}
