crypto/openssh/openbsd-compat/strtoull.c

   1 /*      $OpenBSD: strtoull.c,v 1.5 2005/08/08 08:05:37 espie Exp $ */
   2 /*-
   3  * Copyright (c) 1992 The Regents of the University of California.
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  * 3. Neither the name of the University nor the names of its contributors
  15  *    may be used to endorse or promote products derived from this software
  16  *    without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  28  * SUCH DAMAGE.
  29  */
  30
  31 /* OPENBSD ORIGINAL: lib/libc/stdlib/strtoull.c */
  32
  33 #include "includes.h"
  34 #ifndef HAVE_STRTOULL
  35
  36 #include <sys/types.h>
  37
  38 #include <ctype.h>
  39 #include <errno.h>
  40 #include <limits.h>
  41 #include <stdlib.h>
  42
  43 /*
  44  * Convert a string to an unsigned long long.
  45  *
  46  * Ignores `locale' stuff.  Assumes that the upper and lower case
  47  * alphabets and digits are each contiguous.
  48  */
  49 unsigned long long
  50 strtoull(const char *nptr, char **endptr, int base)
  51 {
  52         const char *s;
  53         unsigned long long acc, cutoff;
  54         int c;
  55         int neg, any, cutlim;
  56
  57         /*
  58          * See strtoq for comments as to the logic used.
  59          */
  60         s = nptr;
  61         do {
  62                 c = (unsigned char) *s++;
  63         } while (isspace(c));
  64         if (c == '-') {
  65                 neg = 1;
  66                 c = *s++;
  67         } else {
  68                 neg = 0;
  69                 if (c == '+')
  70                         c = *s++;
  71         }
  72         if ((base == 0 || base == 16) &&
  73             c == '0' && (*s == 'x' || *s == 'X')) {
  74                 c = s[1];
  75                 s += 2;
  76                 base = 16;
  77         }
  78         if (base == 0)
  79                 base = c == '0' ? 8 : 10;
  80
  81         cutoff = ULLONG_MAX / (unsigned long long)base;
  82         cutlim = ULLONG_MAX % (unsigned long long)base;
  83         for (acc = 0, any = 0;; c = (unsigned char) *s++) {
  84                 if (isdigit(c))
  85                         c -= '0';
  86                 else if (isalpha(c))
  87                         c -= isupper(c) ? 'A' - 10 : 'a' - 10;
  88                 else
  89                         break;
  90                 if (c >= base)
  91                         break;
  92                 if (any < 0)
  93                         continue;
  94                 if (acc > cutoff || (acc == cutoff && c > cutlim)) {
  95                         any = -1;
  96                         acc = ULLONG_MAX;
  97                         errno = ERANGE;
  98                 } else {
  99                         any = 1;
 100                         acc *= (unsigned long long)base;
 101                         acc += c;
 102                 }
 103         }
 104         if (neg && any > 0)
 105                 acc = -acc;
 106         if (endptr != 0)
 107                 *endptr = (char *) (any ? s - 1 : nptr);
 108         return (acc);
 109 }
 110 #endif /* !HAVE_STRTOULL */