lib: add error checking to hex2bin
hex2bin converts a hexadecimal string to its binary representation.
The original version of hex2bin did not do any error checking. This
patch adds error checking and returns the result.
Changelog v1:
- removed unpack_hex_byte()
- changed return code from boolean to int
Changelog:
- use the new unpack_hex_byte()
- add __must_check compiler option (Andy Shevchenko's suggestion)
- change function API to return error checking result
(based on Tetsuo Handa's initial patch)
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com>
diff --git a/lib/hexdump.c b/lib/hexdump.c
index f5fe6ba..51d5ae2 100644
--- a/lib/hexdump.c
+++ b/lib/hexdump.c
@@ -38,14 +38,21 @@
* @dst: binary result
* @src: ascii hexadecimal string
* @count: result length
+ *
+ * Return 0 on success, -1 in case of bad input.
*/
-void hex2bin(u8 *dst, const char *src, size_t count)
+int hex2bin(u8 *dst, const char *src, size_t count)
{
while (count--) {
- *dst = hex_to_bin(*src++) << 4;
- *dst += hex_to_bin(*src++);
- dst++;
+ int hi = hex_to_bin(*src++);
+ int lo = hex_to_bin(*src++);
+
+ if ((hi < 0) || (lo < 0))
+ return -1;
+
+ *dst++ = (hi << 4) | lo;
}
+ return 0;
}
EXPORT_SYMBOL(hex2bin);