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
41__weak_alias(asysctl,_asysctl)
42__weak_alias(asysctlbyname,_asysctlbyname)
43
44void *
45asysctl(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
80void *
81asysctlbyname(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