common/syscall/sysfs.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 1993 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

/*  Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */

/*
 * Portions of this source code were derived from Berkeley 4.3 BSD
 * under license from the Regents of the University of California.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <sys/t_lock.h>
#include <sys/param.h>
#include <sys/errno.h>
#include <sys/fstyp.h>
#include <sys/systm.h>
#include <sys/mount.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/cmn_err.h>
#include <sys/buf.h>
#include <sys/debug.h>
#include <sys/pathname.h>

/*
 * System call to map fstype numbers to names, and vice versa.
 */

static int sysfsind(char *);
static int sysfstyp(int, char *);

int
sysfs(int opcode, long a1, long a2)
{
    int error;

    switch (opcode) {
    case GETFSIND:
        error = sysfsind((char *)a1);
        break;
    case GETFSTYP:
        error = sysfstyp((int)a1, (char *)a2);
        break;
    case GETNFSTYP:
        /*
         * Return number of fstypes configured in the system.
         */
        return (nfstype - 1);
    default:
        error = set_errno(EINVAL);
    }

    return (error);
}

static int
sysfsind(char *fsname)
{
    /*
     * Translate fs identifier to an index into the vfssw structure.
     */
    struct vfssw *vswp;
    char fsbuf[FSTYPSZ];
    int retval;
    size_t len = 0;

    retval = copyinstr(fsname, fsbuf, FSTYPSZ, &len);
    if (retval == ENOENT)           /* XXX */
        retval = EINVAL;        /* XXX */
    if (len == 1)           /* Includes null byte */
        retval = EINVAL;
    if (retval)
        return (set_errno(retval));
    /*
     * Search the vfssw table for the fs identifier
     * and return the index.
     */
    if ((vswp = vfs_getvfssw(fsbuf)) != NULL) {
        retval = vswp - vfssw;
        vfs_unrefvfssw(vswp);
        return (retval);
    }

    return (set_errno(EINVAL));
}

static int
sysfstyp(int index, char *cbuf)
{
    /*
     * Translate fstype index into an fs identifier.
     */
    char *src;
    struct vfssw *vswp;
    char *osrc;
    int error = 0;

    if (index <= 0 || index >= nfstype)
        return (set_errno(EINVAL));
    RLOCK_VFSSW();
    vswp = &vfssw[index];

    osrc = src = vswp->vsw_name;
    while (*src++)
        ;

    if (copyout(osrc, cbuf, src - osrc))
        error = set_errno(EFAULT);
    RUNLOCK_VFSSW();
    return (error);
}