3adc1c7681
fetching dynamically sized data via sysctl.
93 lines
2.6 KiB
C
93 lines
2.6 KiB
C
/* $NetBSD: asysctl.c,v 1.1 2014/06/13 15:45:05 joerg Exp $ */
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/*-
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* Copyright (c) 2014 The NetBSD Foundation, Inc.
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* All rights reserved.
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*
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* This code is derived from software contributed to The NetBSD Foundation
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* by Joerg Sonnenberger.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
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* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
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* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
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* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__RCSID("$NetBSD: asysctl.c,v 1.1 2014/06/13 15:45:05 joerg Exp $");
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#include "namespace.h"
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#include <sys/sysctl.h>
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#include <errno.h>
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#include <limits.h>
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#include <stdlib.h>
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__weak_alias(asysctl,_asysctl)
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__weak_alias(asysctlbyname,_asysctlbyname)
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void *
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asysctl(const int *oids, size_t oidlen, size_t *len)
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{
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void *data;
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*len = 0;
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data = NULL;
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for (;;) {
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if (sysctl(oids, oidlen, data, len, NULL, 0) == 0) {
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if (*len == 0) {
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free(data);
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return NULL;
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}
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if (data != NULL)
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return data;
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errno = ENOMEM;
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}
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free(data);
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if (errno == ENOMEM && *len != SIZE_MAX) {
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if (*len > SIZE_MAX / 2)
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*len = SIZE_MAX;
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else
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*len *= 2;
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data = malloc(*len);
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if (data == NULL) {
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*len = SIZE_MAX;
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return NULL;
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}
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continue;
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}
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*len = SIZE_MAX;
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return NULL;
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}
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}
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void *
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asysctlbyname(const char *gname, size_t *len)
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{
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int name[CTL_MAXNAME];
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u_int namelen;
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if (sysctlgetmibinfo(gname, &name[0], &namelen, NULL, NULL, NULL,
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SYSCTL_VERSION)) {
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*len = SIZE_MAX;
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return NULL;
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}
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return asysctl(&name[0], namelen, len);
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}
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