bind/lib/isc/str.c

/*
 * Copyright (C) 1999, 2000  Internet Software Consortium.
 * 
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM DISCLAIMS
 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
 * CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
 * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
 * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
 * ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 */

#include <ctype.h>
#include <string.h>
#include <isc/str.h>

static char digits[] = "0123456789abcdefghijklmnoprstuvwxyz";

isc_uint64_t
isc_strtouq(char *source, char **end, int base) {
	isc_uint64_t tmp;
	isc_uint64_t overflow;
	char *s = source;
	char *o;
	char c;
	
	if ((base < 0) || (base == 1) || (base > 36)) {
		*end = source;
		return (0);
	}

	while (*s != 0 && isascii(*s&0xff) && isspace(*s&0xff))
		s++;
	if (*s == '+' /* || *s == '-' */)
		s++;
	if (base == 0) {
		if (*s == '0' && (*(s+1) == 'X' || *(s+1) == 'x')) {
			s += 2;
			base = 16;
		} else if (*s == '0')
			base = 8;
		else
			base = 10;
	}
	if (*s == 0) {
		*end = source;
		return (0);
	}
	overflow = ~0;
	overflow /= base;
	tmp = 0;
		
	while ((c = *s) != 0) {
		c = tolower(c);
		/* end ? */
		if ((o = strchr(digits, c)) == NULL) {
			*end = s;
			return (tmp);
		}
		/* end ? */
		if ((o - digits) >= base) {
			*end = s;
			return (tmp);
		}
		/* overflow ? */
		if (tmp > overflow) {
			*end = source;
			return (0);
		}
		tmp *= base;
		/* overflow ? */
		if ((tmp + (o - digits)) < tmp) {
			*end = source;
			return (0);
		}
		tmp += o - digits;
		s++;
	}
	*end = s;
	return (tmp);
}