expand_number.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 2007 Eric Anderson <anderson@FreeBSD.org>
5 * Copyright (c) 2007 Pawel Jakub Dawidek <pjd@FreeBSD.org>
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30#include <sys/cdefs.h>
31__FBSDID("$FreeBSD: stable/11/lib/libutil/expand_number.c 330897 2018-03-14 03:19:51Z eadler $");
32
33#include <sys/types.h>
34#include <ctype.h>
35#include <errno.h>
36#include <inttypes.h>
37#include <libutil.h>
38#include <stdint.h>
39
40int
41expand_number(const char *buf, uint64_t *num)
42{
43	char *endptr;
44	uintmax_t umaxval;
45	uint64_t number;
46	unsigned shift;
47	int serrno;
48
49	serrno = errno;
50	errno = 0;
51	umaxval = strtoumax(buf, &endptr, 0);
52	if (umaxval > UINT64_MAX)
53		errno = ERANGE;
54	if (errno != 0)
55		return (-1);
56	errno = serrno;
57	number = umaxval;
58
59	switch (tolower((unsigned char)*endptr)) {
60	case 'e':
61		shift = 60;
62		break;
63	case 'p':
64		shift = 50;
65		break;
66	case 't':
67		shift = 40;
68		break;
69	case 'g':
70		shift = 30;
71		break;
72	case 'm':
73		shift = 20;
74		break;
75	case 'k':
76		shift = 10;
77		break;
78	case 'b':
79	case '\0': /* No unit. */
80		*num = number;
81		return (0);
82	default:
83		/* Unrecognized unit. */
84		errno = EINVAL;
85		return (-1);
86	}
87
88	if ((number << shift) >> shift != number) {
89		/* Overflow */
90		errno = ERANGE;
91		return (-1);
92	}
93	*num = number << shift;
94	return (0);
95}
96