1/*
2 * Copyright (c) 1990, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * Copyright (c) 2011 The FreeBSD Foundation
6 * All rights reserved.
7 * Portions of this software were developed by David Chisnall
8 * under sponsorship from the FreeBSD Foundation.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 * 4. Neither the name of the University nor the names of its contributors
19 *    may be used to endorse or promote products derived from this software
20 *    without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35#if defined(LIBC_SCCS) && !defined(lint)
36static char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
37#endif /* LIBC_SCCS and not lint */
38#include <sys/cdefs.h>
39__FBSDID("$FreeBSD$");
40
41#include "stand.h"
42#include <limits.h>
43
44/*
45 * Convert a string to an unsigned long integer.
46 *
47 * Assumes that the upper and lower case
48 * alphabets and digits are each contiguous.
49 */
50unsigned long
51strtoul(const char * __restrict nptr, char ** __restrict endptr, int base)
52{
53	const char *s;
54	unsigned long acc;
55	char c;
56	unsigned long cutoff;
57	int neg, any, cutlim;
58
59	/*
60	 * See strtol for comments as to the logic used.
61	 */
62	s = nptr;
63	do {
64		c = *s++;
65	} while (isspace((unsigned char)c));
66	if (c == '-') {
67		neg = 1;
68		c = *s++;
69	} else {
70		neg = 0;
71		if (c == '+')
72			c = *s++;
73	}
74	if ((base == 0 || base == 16) &&
75	    c == '0' && (*s == 'x' || *s == 'X') &&
76	    ((s[1] >= '0' && s[1] <= '9') ||
77	    (s[1] >= 'A' && s[1] <= 'F') ||
78	    (s[1] >= 'a' && s[1] <= 'f'))) {
79		c = s[1];
80		s += 2;
81		base = 16;
82	}
83	if (base == 0)
84		base = c == '0' ? 8 : 10;
85	acc = any = 0;
86	if (base < 2 || base > 36)
87		goto noconv;
88
89	cutoff = ULONG_MAX / base;
90	cutlim = ULONG_MAX % base;
91	for ( ; ; c = *s++) {
92		if (c >= '0' && c <= '9')
93			c -= '0';
94		else if (c >= 'A' && c <= 'Z')
95			c -= 'A' - 10;
96		else if (c >= 'a' && c <= 'z')
97			c -= 'a' - 10;
98		else
99			break;
100		if (c >= base)
101			break;
102		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
103			any = -1;
104		else {
105			any = 1;
106			acc *= base;
107			acc += c;
108		}
109	}
110	if (any < 0) {
111		acc = ULONG_MAX;
112		errno = ERANGE;
113	} else if (!any) {
114noconv:
115		errno = EINVAL;
116	} else if (neg)
117		acc = -acc;
118	if (endptr != NULL)
119		*endptr = (char *)(any ? s - 1 : nptr);
120	return (acc);
121}
122