/*
 * getvfsent.c - get a listing of installed filesystems
 * Written September 1994 by Garrett A. Wollman
 * This file is in the public domain.
 *
 * $FreeBSD: src/lib/libc/gen/getvfsent.c,v 1.14.2.1 2001/03/05 09:19:38 obrien Exp $
 */

#include <sys/param.h>
#include <sys/linker.h>
#include <sys/mount.h>
#include <sys/sysctl.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

/* XXX hide some compatibility problems. */
#undef getvfsbyname

static struct ovfsconf *_vfslist = NULL;
static struct ovfsconf _vfsconf;
static size_t _vfslistlen = 0;
static int _vfs_keeplist = 0;
static size_t _vfs_index = 0;

static int
initvfs(void)
{
        int mib[2] = { CTL_VFS, VFS_VFSCONF };
        size_t size = 0;
        int rv;

        rv = sysctl(mib, 2, NULL, &size, NULL, (size_t)0);
        if(rv < 0)
                return 0;

        if(_vfslist)
                free(_vfslist);
        _vfslist = malloc(size);
        if(!_vfslist)
                return 0;

        rv = sysctl(mib, 2, _vfslist, &size, NULL, (size_t)0);
        if(rv < 0) {
                free(_vfslist);
                _vfslist = NULL;
                return 0;
        }

        _vfslistlen = size / sizeof(_vfslist[0]);
        return 1;
}

struct ovfsconf *
getvfsent(void)
{
        if(!_vfslist && !initvfs())
                return 0;

        do {
                if(_vfs_index >= _vfslistlen)
                        return 0;

                _vfsconf = _vfslist[_vfs_index++];
        } while(!_vfsconf.vfc_vfsops);

        if(!_vfs_keeplist) {
                free(_vfslist);
                _vfslist = NULL;
        }
        return &_vfsconf;
}

struct ovfsconf *
getvfsbyname(const char *name)
{
        size_t i;

        if(!_vfslist && !initvfs())
                return 0;

        for(i = 0; i < _vfslistlen; i++) {
                if( ! strcmp(_vfslist[i].vfc_name, name) )
                        break;
        }

        if(i < _vfslistlen)
                _vfsconf = _vfslist[i];

        if(!_vfs_keeplist) {
                free(_vfslist);
                _vfslist = NULL;
        }

        if(i < _vfslistlen)
                return &_vfsconf;
        else
                return 0;
}

struct ovfsconf *
getvfsbytype(int type)
{
        size_t i;

        if(!_vfslist && !initvfs())
                return 0;

        for(i = 0; i < _vfslistlen; i++) {
                if(_vfslist[i].vfc_index == type)
                        break;
        }

        if(i < _vfslistlen)
                _vfsconf = _vfslist[i];

        if(!_vfs_keeplist) {
                free(_vfslist);
                _vfslist = NULL;
        }

        if(i < _vfslistlen)
                return &_vfsconf;
        else
                return 0;
}

void
setvfsent(int keep)
{
        if(_vfslist && !keep) {
                free(_vfslist);
                _vfslist = NULL;
        }

        _vfs_keeplist = keep;
        _vfs_index = 0;
}

void
endvfsent(void)
{
        if(_vfslist) {
                free(_vfslist);
                _vfslist = NULL;
        }

        _vfs_index = 0;
}

int
vfsisloadable(const char *name __unused)
{
        return 1;
}

int
vfsload(const char *name)
{
        int status;

        status = kldload(name);
        return status == -1 ? status : 0;
}