usr/src/common/util/strtoul.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1988 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 #if     defined(_KERNEL) && !defined(_BOOT)
  31 #include <sys/errno.h>
  32 #else   /* _KERNEL && !_BOOT */
  33 #if     !defined(_BOOT) && !defined(_KMDB)
  34 #include "lint.h"
  35 #endif  /* !_BOOT && !_KMDB */
  36 #include <errno.h>
  37 #include <ctype.h>
  38 #include <limits.h>
  39 #include <stdlib.h>
  40 #endif  /* _KERNEL && !_BOOT */
  41 #include "strtolctype.h"
  42 #include <sys/types.h>
  43
  44 #if     defined(_KERNEL) && !defined(_BOOT)
  45 int
  46 ddi_strtoul(const char *str, char **nptr, int base, unsigned long *result)
  47 #else   /* _KERNEL && !_BOOT */
  48 unsigned long
  49 strtoul(const char *str, char **nptr, int base)
  50 #endif  /* _KERNEL && !_BOOT */
  51 {
  52         unsigned long val;
  53         int c;
  54         int xx;
  55         int neg = 0;
  56         unsigned long multmax;
  57         const char **ptr = (const char **)nptr;
  58         const unsigned char *ustr = (const unsigned char *)str;
  59
  60         if (ptr != (const char **)0)
  61                 *ptr = (char *)ustr; /* in case no number is formed */
  62         if (base < 0 || base > MBASE || base == 1) {
  63                 /* base is invalid -- should be a fatal error */
  64 #if     defined(_KERNEL) && !defined(_BOOT)
  65                 return (EINVAL);
  66 #else   /* _KERNEL && !_BOOT */
  67                 errno = EINVAL;
  68                 return (0);
  69 #endif  /* _KERNEL && !_BOOT */
  70         }
  71         if (!isalnum(c = *ustr)) {
  72                 while (isspace(c))
  73                         c = *++ustr;
  74                 switch (c) {
  75                 case '-':
  76                         neg++;
  77                         /* FALLTHROUGH */
  78                 case '+':
  79                         c = *++ustr;
  80                 }
  81         }
  82         if (base == 0)
  83                 if (c != '0')
  84                         base = 10;
  85                 else if (ustr[1] == 'x' || ustr[1] == 'X')
  86                         base = 16;
  87                 else
  88                         base = 8;
  89         /*
  90          * for any base > 10, the digits incrementally following
  91          *      9 are assumed to be "abc...z" or "ABC...Z"
  92          */
  93         if (!lisalnum(c) || (xx = DIGIT(c)) >= base) {
  94                 /* no number formed */
  95 #if     defined(_KERNEL) && !defined(_BOOT)
  96                 return (EINVAL);
  97 #else   /* _KERNEL && !_BOOT */
  98                 return (0);
  99 #endif  /* _KERNEL && !_BOOT */
 100         }
 101         if (base == 16 && c == '0' && (ustr[1] == 'x' || ustr[1] == 'X') &&
 102             isxdigit(ustr[2]))
 103                 c = *(ustr += 2); /* skip over leading "0x" or "0X" */
 104
 105         multmax = ULONG_MAX / (unsigned long)base;
 106         val = DIGIT(c);
 107         for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; ) {
 108                 if (val > multmax)
 109                         goto overflow;
 110                 val *= base;
 111                 if (ULONG_MAX - val < xx)
 112                         goto overflow;
 113                 val += xx;
 114                 c = *++ustr;
 115         }
 116         if (ptr != (const char **)0)
 117                 *ptr = (char *)ustr;
 118 #if     defined(_KERNEL) && !defined(_BOOT)
 119         *result = neg ? -val : val;
 120         return (0);
 121 #else   /* _KERNEL && !_BOOT */
 122         return (neg ? -val : val);
 123 #endif  /* _KERNEL && !_BOOT */
 124
 125 overflow:
 126         for (c = *++ustr; lisalnum(c) && (xx = DIGIT(c)) < base; (c = *++ustr))
 127                 ;
 128         if (ptr != (const char **)0)
 129                 *ptr = (char *)ustr;
 130 #if     defined(_KERNEL) && !defined(_BOOT)
 131         return (ERANGE);
 132 #else   /* _KERNEL && !_BOOT */
 133         errno = ERANGE;
 134         return (ULONG_MAX);
 135 #endif  /* _KERNEL && !_BOOT */
 136 }