1/*
2 * Copyright (C) 2004, 2005, 2007, 2014  Internet Systems Consortium, Inc. ("ISC")
3 * Copyright (C) 2003  Internet Software Consortium.
4 *
5 * Permission to use, copy, modify, and/or distribute this software for any
6 * purpose with or without fee is hereby granted, provided that the above
7 * copyright notice and this permission notice appear in all copies.
8 *
9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/*
19 * Copyright (c) 1990, 1993
20 *	The Regents of the University of California.  All rights reserved.
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 *    notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 *    notice, this list of conditions and the following disclaimer in the
29 *    documentation and/or other materials provided with the distribution.
30 * 3. Neither the name of the University nor the names of its contributors
31 *    may be used to endorse or promote products derived from this software
32 *    without specific prior written permission.
33 *
34 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 */
46
47/*! \file */
48#if defined(LIBC_SCCS) && !defined(lint)
49static char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
50#endif /* LIBC_SCCS and not lint */
51
52/* $Id: strtoul.c,v 1.4 2007/06/19 23:47:22 tbox Exp $ */
53
54#include <config.h>
55
56#include <limits.h>
57#include <ctype.h>
58#include <errno.h>
59
60#include <lwres/stdlib.h>
61
62#define DE_CONST(konst, var) \
63	do { \
64		union { const void *k; void *v; } _u; \
65		_u.k = konst; \
66		var = _u.v; \
67	} while (0)
68
69/*!
70 * Convert a string to an unsigned long integer.
71 *
72 * Ignores `locale' stuff.  Assumes that the upper and lower case
73 * alphabets and digits are each contiguous.
74 */
75unsigned long
76lwres_strtoul(const char *nptr, char **endptr, int base) {
77	const char *s = nptr;
78	unsigned long acc;
79	unsigned char c;
80	unsigned long cutoff;
81	int neg = 0, any, cutlim;
82
83	/*
84	 * See strtol for comments as to the logic used.
85	 */
86	do {
87		c = *s++;
88	} while (isspace(c));
89	if (c == '-') {
90		neg = 1;
91		c = *s++;
92	} else if (c == '+')
93		c = *s++;
94	if ((base == 0 || base == 16) &&
95	    c == '0' && (*s == 'x' || *s == 'X')) {
96		c = s[1];
97		s += 2;
98		base = 16;
99	}
100	if (base == 0)
101		base = c == '0' ? 8 : 10;
102	cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
103	cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
104	for (acc = 0, any = 0;; c = *s++) {
105		if (!isascii(c))
106			break;
107		if (isdigit(c))
108			c -= '0';
109		else if (isalpha(c))
110			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
111		else
112			break;
113		if (c >= base)
114			break;
115		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
116			any = -1;
117		else {
118			any = 1;
119			acc *= base;
120			acc += c;
121		}
122	}
123	if (any < 0) {
124		acc = ULONG_MAX;
125		errno = ERANGE;
126	} else if (neg)
127		acc = -acc;
128	if (endptr != 0)
129		DE_CONST(any ? s - 1 : nptr, *endptr);
130	return (acc);
131}
132