kernel/syscall/sysfs.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 1993 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
  28 /*        All Rights Reserved   */
  29
  30 /*
  31  * Portions of this source code were derived from Berkeley 4.3 BSD
  32  * under license from the Regents of the University of California.
  33  */
  34
  35 #pragma ident   "%Z%%M% %I%     %E% SMI"
  36
  37 #include <sys/types.h>
  38 #include <sys/t_lock.h>
  39 #include <sys/param.h>
  40 #include <sys/errno.h>
  41 #include <sys/fstyp.h>
  42 #include <sys/systm.h>
  43 #include <sys/mount.h>
  44 #include <sys/vfs.h>
  45 #include <sys/vnode.h>
  46 #include <sys/cmn_err.h>
  47 #include <sys/buf.h>
  48 #include <sys/debug.h>
  49 #include <sys/pathname.h>
  50
  51 /*
  52  * System call to map fstype numbers to names, and vice versa.
  53  */
  54
  55 static int sysfsind(char *);
  56 static int sysfstyp(int, char *);
  57
  58 int
  59 sysfs(int opcode, long a1, long a2)
  60 {
  61         int error;
  62
  63         switch (opcode) {
  64         case GETFSIND:
  65                 error = sysfsind((char *)a1);
  66                 break;
  67         case GETFSTYP:
  68                 error = sysfstyp((int)a1, (char *)a2);
  69                 break;
  70         case GETNFSTYP:
  71                 /*
  72                  * Return number of fstypes configured in the system.
  73                  */
  74                 return (nfstype - 1);
  75         default:
  76                 error = set_errno(EINVAL);
  77         }
  78
  79         return (error);
  80 }
  81
  82 static int
  83 sysfsind(char *fsname)
  84 {
  85         /*
  86          * Translate fs identifier to an index into the vfssw structure.
  87          */
  88         struct vfssw *vswp;
  89         char fsbuf[FSTYPSZ];
  90         int retval;
  91         size_t len = 0;
  92
  93         retval = copyinstr(fsname, fsbuf, FSTYPSZ, &len);
  94         if (retval == ENOENT)                   /* XXX */
  95                 retval = EINVAL;                /* XXX */
  96         if (len == 1)                   /* Includes null byte */
  97                 retval = EINVAL;
  98         if (retval)
  99                 return (set_errno(retval));
 100         /*
 101          * Search the vfssw table for the fs identifier
 102          * and return the index.
 103          */
 104         if ((vswp = vfs_getvfssw(fsbuf)) != NULL) {
 105                 retval = vswp - vfssw;
 106                 vfs_unrefvfssw(vswp);
 107                 return (retval);
 108         }
 109
 110         return (set_errno(EINVAL));
 111 }
 112
 113 static int
 114 sysfstyp(int index, char *cbuf)
 115 {
 116         /*
 117          * Translate fstype index into an fs identifier.
 118          */
 119         char *src;
 120         struct vfssw *vswp;
 121         char *osrc;
 122         int error = 0;
 123
 124         if (index <= 0 || index >= nfstype)
 125                 return (set_errno(EINVAL));
 126         RLOCK_VFSSW();
 127         vswp = &vfssw[index];
 128
 129         osrc = src = vswp->vsw_name;
 130         while (*src++)
 131                 ;
 132
 133         if (copyout(osrc, cbuf, src - osrc))
 134                 error = set_errno(EFAULT);
 135         RUNLOCK_VFSSW();
 136         return (error);
 137 }