/*      $OpenBSD: getmntinfo.c,v 1.11 2019/06/28 13:32:41 deraadt Exp $ */
/*
 * Copyright (c) 1989, 1993
 *      The Regents of the University of California.  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. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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/mount.h>
#include <stdlib.h>

/*
 * Return information about mounted filesystems.
 */
int
getmntinfo(struct statfs **mntbufp, int flags)
{
        static struct statfs *mntbuf;
        static int mntsize;
        static size_t bufsize;

        if (mntsize <= 0 && (mntsize = getfsstat(0, 0, MNT_NOWAIT)) == -1)
                return (0);
        if (bufsize > 0 && (mntsize = getfsstat(mntbuf, bufsize, flags)) == -1)
                return (0);
        while (bufsize <= mntsize * sizeof(struct statfs)) {
                free(mntbuf);
                bufsize = (mntsize + 1) * sizeof(struct statfs);
                if ((mntbuf = malloc(bufsize)) == NULL) {
                        bufsize = 0;
                        return (0);
                }
                if ((mntsize = getfsstat(mntbuf, bufsize, flags)) == -1)
                        return (0);
        }
        *mntbufp = mntbuf;
        return (mntsize);
}