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/*-
* Copyright (c) 2003 Poul-Henning Kamp
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The names of the authors may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* $FreeBSD$
*/
#include <sys/types.h>
#include <sys/sysctl.h>
#include <errno.h>
#include <stdlib.h>
#include <string.h>
#include "libgeom.h"
/*
* Amount of extra space we allocate to try and anticipate the size of
* confxml.
*/
#define GEOM_GETXML_SLACK 4096
/*
* Number of times to retry in the face of the size of confxml exceeding
* that of our buffer.
*/
#define GEOM_GETXML_RETRIES 4
char *
geom_getxml(void)
{
char *p;
size_t l = 0;
int mib[3];
size_t sizep;
int retries;
sizep = sizeof(mib) / sizeof(*mib);
if (sysctlnametomib("kern.geom.confxml", mib, &sizep) != 0)
return (NULL);
if (sysctl(mib, sizep, NULL, &l, NULL, 0) != 0)
return (NULL);
l += GEOM_GETXML_SLACK;
for (retries = 0; retries < GEOM_GETXML_RETRIES; retries++) {
p = malloc(l);
if (p == NULL)
return (NULL);
if (sysctl(mib, sizep, p, &l, NULL, 0) == 0)
return (reallocf(p, strlen(p) + 1));
free(p);
if (errno != ENOMEM)
return (NULL);
/*
* Our buffer wasn't big enough. Make it bigger and
* try again.
*/
l *= 2;
}
return (NULL);
}
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