xref: /illumos-gate/usr/src/contrib/bhyve/lib/libutil/expand_number.c (revision 7b34a9a5df26271af0da06974fc361c468cd48d3)
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: head/lib/libutil/expand_number.c 255069 2013-08-30 11:21:52Z pluknet $");
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 }
94