1/*	$NetBSD: strtoul.c,v 1.2.6.1 2012/06/05 21:14:54 bouyer Exp $	*/
2
3/*
4 * Copyright (C) 2004, 2005, 2007  Internet Systems Consortium, Inc. ("ISC")
5 * Copyright (C) 2003  Internet Software Consortium.
6 *
7 * Permission to use, copy, modify, and/or distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
12 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
13 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
14 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
15 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
16 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
17 * PERFORMANCE OF THIS SOFTWARE.
18 */
19
20/*
21 * Copyright (c) 1990, 1993
22 *	The Regents of the University of California.  All rights reserved.
23 *
24 * Redistribution and use in source and binary forms, with or without
25 * modification, are permitted provided that the following conditions
26 * are met:
27 * 1. Redistributions of source code must retain the above copyright
28 *    notice, this list of conditions and the following disclaimer.
29 * 2. Redistributions in binary form must reproduce the above copyright
30 *    notice, this list of conditions and the following disclaimer in the
31 *    documentation and/or other materials provided with the distribution.
32 * 3. All advertising materials mentioning features or use of this software
33 *    must display the following acknowledgement:
34 *	This product includes software developed by the University of
35 *	California, Berkeley and its contributors.
36 * 4. Neither the name of the University nor the names of its contributors
37 *    may be used to endorse or promote products derived from this software
38 *    without specific prior written permission.
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
41 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
44 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50 * SUCH DAMAGE.
51 */
52
53/*! \file */
54#if defined(LIBC_SCCS) && !defined(lint)
55static char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
56#endif /* LIBC_SCCS and not lint */
57
58/* Id: strtoul.c,v 1.4 2007/06/19 23:47:22 tbox Exp  */
59
60#include <config.h>
61
62#include <limits.h>
63#include <ctype.h>
64#include <errno.h>
65
66#include <lwres/stdlib.h>
67
68#define DE_CONST(konst, var) \
69	do { \
70		union { const void *k; void *v; } _u; \
71		_u.k = konst; \
72		var = _u.v; \
73	} while (/*CONSTCOND*/0)
74
75/*!
76 * Convert a string to an unsigned long integer.
77 *
78 * Ignores `locale' stuff.  Assumes that the upper and lower case
79 * alphabets and digits are each contiguous.
80 */
81unsigned long
82lwres_strtoul(const char *nptr, char **endptr, int base) {
83	const char *s = nptr;
84	unsigned long acc;
85	unsigned char c;
86	unsigned long cutoff;
87	int neg = 0, any, cutlim;
88
89	/*
90	 * See strtol for comments as to the logic used.
91	 */
92	do {
93		c = *s++;
94	} while (isspace(c));
95	if (c == '-') {
96		neg = 1;
97		c = *s++;
98	} else if (c == '+')
99		c = *s++;
100	if ((base == 0 || base == 16) &&
101	    c == '0' && (*s == 'x' || *s == 'X')) {
102		c = s[1];
103		s += 2;
104		base = 16;
105	}
106	if (base == 0)
107		base = c == '0' ? 8 : 10;
108	cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
109	cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
110	for (acc = 0, any = 0;; c = *s++) {
111		if (!isascii(c))
112			break;
113		if (isdigit(c))
114			c -= '0';
115		else if (isalpha(c))
116			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
117		else
118			break;
119		if (c >= base)
120			break;
121		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
122			any = -1;
123		else {
124			any = 1;
125			acc *= base;
126			acc += c;
127		}
128	}
129	if (any < 0) {
130		acc = ULONG_MAX;
131		errno = ERANGE;
132	} else if (neg)
133		acc = -acc;
134	if (endptr != 0)
135		DE_CONST(any ? s - 1 : nptr, *endptr);
136	return (acc);
137}
138