/contrib/bind9/lib/lwres/strtoul.c

  1/*
  2 * Copyright (C) 2004, 2005, 2007, 2012  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. All advertising materials mentioning features or use of this software
 31 *    must display the following acknowledgement:
 32 *	This product includes software developed by the University of
 33 *	California, Berkeley and its contributors.
 34 * 4. Neither the name of the University nor the names of its contributors
 35 *    may be used to endorse or promote products derived from this software
 36 *    without specific prior written permission.
 37 *
 38 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 39 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 40 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 41 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 42 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 43 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 44 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 45 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 46 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 47 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 48 * SUCH DAMAGE.
 49 */
 50
 51/*! \file */
 52#if defined(LIBC_SCCS) && !defined(lint)
 53static char sccsid[] = "@(#)strtoul.c	8.1 (Berkeley) 6/4/93";
 54#endif /* LIBC_SCCS and not lint */
 55
 56/* $Id$ */
 57
 58#include <config.h>
 59
 60#include <limits.h>
 61#include <ctype.h>
 62#include <errno.h>
 63
 64#include <lwres/stdlib.h>
 65
 66#define DE_CONST(konst, var) \
 67	do { \
 68		union { const void *k; void *v; } _u; \
 69		_u.k = konst; \
 70		var = _u.v; \
 71	} while (0)
 72
 73/*!
 74 * Convert a string to an unsigned long integer.
 75 *
 76 * Ignores `locale' stuff.  Assumes that the upper and lower case
 77 * alphabets and digits are each contiguous.
 78 */
 79unsigned long
 80lwres_strtoul(const char *nptr, char **endptr, int base) {
 81	const char *s = nptr;
 82	unsigned long acc;
 83	unsigned char c;
 84	unsigned long cutoff;
 85	int neg = 0, any, cutlim;
 86
 87	/*
 88	 * See strtol for comments as to the logic used.
 89	 */
 90	do {
 91		c = *s++;
 92	} while (isspace(c));
 93	if (c == '-') {
 94		neg = 1;
 95		c = *s++;
 96	} else if (c == '+')
 97		c = *s++;
 98	if ((base == 0 || base == 16) &&
 99	    c == '0' && (*s == 'x' || *s == 'X')) {
100		c = s[1];
101		s += 2;
102		base = 16;
103	}
104	if (base == 0)
105		base = c == '0' ? 8 : 10;
106	cutoff = (unsigned long)ULONG_MAX / (unsigned long)base;
107	cutlim = (unsigned long)ULONG_MAX % (unsigned long)base;
108	for (acc = 0, any = 0;; c = *s++) {
109		if (!isascii(c))
110			break;
111		if (isdigit(c))
112			c -= '0';
113		else if (isalpha(c))
114			c -= isupper(c) ? 'A' - 10 : 'a' - 10;
115		else
116			break;
117		if (c >= base)
118			break;
119		if (any < 0 || acc > cutoff || (acc == cutoff && c > cutlim))
120			any = -1;
121		else {
122			any = 1;
123			acc *= base;
124			acc += c;
125		}
126	}
127	if (any < 0) {
128		acc = ULONG_MAX;
129		errno = ERANGE;
130	} else if (neg)
131		acc = -acc;
132	if (endptr != 0)
133		DE_CONST(any ? s - 1 : nptr, *endptr);
134	return (acc);
135}