xref: /illumos-gate/usr/src/contrib/bhyve/lib/libutil/expand_number.c (revision 32640292339b07090f10ce34d455f98711077343)
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 
30 #include <sys/types.h>
31 #include <ctype.h>
32 #include <errno.h>
33 #include <inttypes.h>
34 #include <libutil.h>
35 #include <stdint.h>
36 
37 int
expand_number(const char * buf,uint64_t * num)38 expand_number(const char *buf, uint64_t *num)
39 {
40 	char *endptr;
41 	uintmax_t umaxval;
42 	uint64_t number;
43 	unsigned shift;
44 	int serrno;
45 
46 	serrno = errno;
47 	errno = 0;
48 	umaxval = strtoumax(buf, &endptr, 0);
49 #ifdef __FreeBSD__
50 	if (umaxval > UINT64_MAX)
51 		errno = ERANGE;
52 #endif
53 	if (errno != 0)
54 		return (-1);
55 	errno = serrno;
56 	number = umaxval;
57 
58 	switch (tolower((unsigned char)*endptr)) {
59 	case 'e':
60 		shift = 60;
61 		break;
62 	case 'p':
63 		shift = 50;
64 		break;
65 	case 't':
66 		shift = 40;
67 		break;
68 	case 'g':
69 		shift = 30;
70 		break;
71 	case 'm':
72 		shift = 20;
73 		break;
74 	case 'k':
75 		shift = 10;
76 		break;
77 	case 'b':
78 	case '\0': /* No unit. */
79 		*num = number;
80 		return (0);
81 	default:
82 		/* Unrecognized unit. */
83 		errno = EINVAL;
84 		return (-1);
85 	}
86 
87 	if ((number << shift) >> shift != number) {
88 		/* Overflow */
89 		errno = ERANGE;
90 		return (-1);
91 	}
92 	*num = number << shift;
93 	return (0);
94 }
95