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>
This commit is contained in:
Mimi Zohar 2011-09-20 11:23:49 -04:00
parent 6bce98edc3
commit b78049831f
2 changed files with 12 additions and 5 deletions

View File

@ -382,7 +382,7 @@ static inline char *pack_hex_byte(char *buf, u8 byte)
}
extern int hex_to_bin(char ch);
extern void hex2bin(u8 *dst, const char *src, size_t count);
extern int __must_check hex2bin(u8 *dst, const char *src, size_t count);
/*
* General tracing related utility functions - trace_printk(),

View File

@ -38,14 +38,21 @@ EXPORT_SYMBOL(hex_to_bin);
* @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);