1 /* $NetBSD: asysctl.c,v 1.2 2017/01/10 17:45:58 christos Exp $ */
2
3 /*-
4 * Copyright (c) 2014 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Joerg Sonnenberger.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __RCSID("$NetBSD: asysctl.c,v 1.2 2017/01/10 17:45:58 christos Exp $");
34
35 #include "namespace.h"
36 #include <sys/sysctl.h>
37 #include <errno.h>
38 #include <limits.h>
39 #include <stdlib.h>
40
__weak_alias(asysctl,_asysctl)41 __weak_alias(asysctl,_asysctl)
42 __weak_alias(asysctlbyname,_asysctlbyname)
43
44 void *
45 asysctl(const int *oids, size_t oidlen, size_t *len)
46 {
47 void *data;
48
49 *len = 0;
50 data = NULL;
51
52 for (;;) {
53 if (sysctl(oids, (u_int)oidlen, data, len, NULL, 0) == 0) {
54 if (*len == 0) {
55 free(data);
56 return NULL;
57 }
58 if (data != NULL)
59 return data;
60 errno = ENOMEM;
61 }
62 free(data);
63 if (errno == ENOMEM && *len != SIZE_MAX) {
64 if (*len > SIZE_MAX / 2)
65 *len = SIZE_MAX;
66 else
67 *len *= 2;
68 data = malloc(*len);
69 if (data == NULL) {
70 *len = SIZE_MAX;
71 return NULL;
72 }
73 continue;
74 }
75 *len = SIZE_MAX;
76 return NULL;
77 }
78 }
79
80 void *
asysctlbyname(const char * gname,size_t * len)81 asysctlbyname(const char *gname, size_t *len)
82 {
83 int name[CTL_MAXNAME];
84 u_int namelen;
85
86 if (sysctlgetmibinfo(gname, &name[0], &namelen, NULL, NULL, NULL,
87 SYSCTL_VERSION)) {
88 *len = SIZE_MAX;
89 return NULL;
90 }
91 return asysctl(&name[0], namelen, len);
92 }
93