freebsd-dev/contrib/ntp/libntp/hextoint.c
Cy Schubert 2b15cb3d09 MFV ntp 4.2.8p1 (r258945, r275970, r276091, r276092, r276093, r278284)
Thanks to roberto for providing pointers to wedge this into HEAD.

Approved by:	roberto
2015-03-30 13:30:15 +00:00

43 lines
673 B
C

/*
* hextoint - convert an ascii string in hex to an unsigned
* long, with error checking
*/
#include <config.h>
#include <ctype.h>
#include "ntp_stdlib.h"
int
hextoint(
const char *str,
u_long *pu
)
{
register u_long u;
register const char *cp;
cp = str;
if (*cp == '\0')
return 0;
u = 0;
while (*cp != '\0') {
if (!isxdigit((unsigned char)*cp))
return 0;
if (u & 0xF0000000)
return 0; /* overflow */
u <<= 4;
if ('0' <= *cp && *cp <= '9')
u += *cp++ - '0';
else if ('a' <= *cp && *cp <= 'f')
u += *cp++ - 'a' + 10;
else if ('A' <= *cp && *cp <= 'F')
u += *cp++ - 'A' + 10;
else
return 0;
}
*pu = u;
return 1;
}