lib/libutil/expand_number.c

   1 /*-
   2  * Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org>
   3  * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
   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  *
  15  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
  16  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  18  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
  19  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  20  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  21  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  22  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  23  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  24  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  25  * SUCH DAMAGE.
  26  */
  27
  28 #include <sys/cdefs.h>
  29 __FBSDID("$FreeBSD$");
  30
  31 #include <sys/types.h>
  32 #include <ctype.h>
  33 #include <errno.h>
  34 #include <inttypes.h>
  35 #include <libutil.h>
  36 #include <stdint.h>
  37
  38 int
  39 expand_number(const char *buf, uint64_t *num)
  40 {
  41         char *endptr;
  42         uintmax_t umaxval;
  43         uint64_t number;
  44         unsigned shift;
  45         int serrno;
  46
  47         serrno = errno;
  48         errno = 0;
  49         umaxval = strtoumax(buf, &endptr, 0);
  50         if (umaxval > UINT64_MAX)
  51                 errno = ERANGE;
  52         if (errno != 0)
  53                 return (-1);
  54         errno = serrno;
  55         number = umaxval;
  56
  57         switch (tolower((unsigned char)*endptr)) {
  58         case 'e':
  59                 shift = 60;
  60                 break;
  61         case 'p':
  62                 shift = 50;
  63                 break;
  64         case 't':
  65                 shift = 40;
  66                 break;
  67         case 'g':
  68                 shift = 30;
  69                 break;
  70         case 'm':
  71                 shift = 20;
  72                 break;
  73         case 'k':
  74                 shift = 10;
  75                 break;
  76         case 'b':
  77         case '\0': /* No unit. */
  78                 *num = number;
  79                 return (0);
  80         default:
  81                 /* Unrecognized unit. */
  82                 errno = EINVAL;
  83                 return (-1);
  84         }
  85
  86         if ((number << shift) >> shift != number) {
  87                 /* Overflow */
  88                 errno = ERANGE;
  89                 return (-1);
  90         }
  91         *num = number << shift;
  92         return (0);
  93 }