freebsd-src/lib/libgeom/geom_getxml.c
Warner Losh b3e7694832 Remove $FreeBSD$: two-line .h pattern
Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/
2023-08-16 11:54:16 -06:00

129 lines
3.6 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (c) 2003 Poul-Henning Kamp
* All rights reserved.
* Copyright (c) 2022 Alexander Motin <mav@FreeBSD.org>
*
* 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.
*/
#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
/*
* Size of confxml buffer to request via getxml control request. It is
* expected to be sufficient for single geom and its parents. In case of
* overflow fall back to requesting full confxml via sysctl interface.
*/
#define GEOM_GETXML_BUFFER 65536
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);
}
char *
geom_getxml_geom(const char *class, const char *geom, int parents)
{
struct gctl_req *r;
char *p;
const char *errstr;
int nargs = 0;
p = malloc(GEOM_GETXML_BUFFER);
if (p == NULL)
return (NULL);
r = gctl_get_handle();
gctl_ro_param(r, "class", -1, class);
gctl_ro_param(r, "verb", -1, "getxml");
gctl_ro_param(r, "parents", sizeof(parents), &parents);
if (geom) {
gctl_ro_param(r, "arg0", -1, geom);
nargs = 1;
}
gctl_ro_param(r, "nargs", sizeof(nargs), &nargs);
p[0] = '\0';
gctl_add_param(r, "output", GEOM_GETXML_BUFFER, p,
GCTL_PARAM_WR | GCTL_PARAM_ASCII);
errstr = gctl_issue(r);
if (errstr != NULL && errstr[0] != '\0') {
gctl_free(r);
free(p);
return (geom_getxml());
}
gctl_free(r);
return (p);
}