external/bsd/bind/dist/lib/isc/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 1.7 2007/06/19 23:47:17 tbox Exp */
  59
  60 #include <config.h>
  61
  62 #include <limits.h>
  63 #include <ctype.h>
  64 #include <errno.h>
  65
  66 #include <isc/stdlib.h>
  67 #include <isc/util.h>
  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  */
  75 unsigned long
  76 isc_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 }