external/bsd/bind/dist/lib/lwres/strtoul.c

   1 /*      $NetBSD$        */
   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)
  55 static 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 (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  */
  81 unsigned long
  82 lwres_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 }