contrib/bind-9.3/lib/lwres/strtoul.c

   1 /*
   2  * Copyright (C) 2004, 2005  Internet Systems Consortium, Inc. ("ISC")
   3  * Copyright (C) 2003  Internet Software Consortium.
   4  *
   5  * Permission to use, copy, modify, and 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)
  53 static char sccsid[] = "@(#)strtoul.c   8.1 (Berkeley) 6/4/93";
  54 #endif /* LIBC_SCCS and not lint */
  55
  56 /* $Id: strtoul.c,v 1.2.4.1 2005/06/08 02:08:31 marka Exp $ */
  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  */
  79 unsigned long
  80 lwres_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 }