kernel/syscall/mknod.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 (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright (c) 1994, 2010, Oracle and/or its affiliates. All rights reserved.
  24  */
  25
  26 /*      Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T     */
  27 /*        All Rights Reserved   */
  28
  29 /*
  30  * Portions of this source code were derived from Berkeley 4.3 BSD
  31  * under license from the Regents of the University of California.
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/isa_defs.h>
  36 #include <sys/types.h>
  37 #include <sys/sysmacros.h>
  38 #include <sys/user.h>
  39 #include <sys/systm.h>
  40 #include <sys/errno.h>
  41 #include <sys/stat.h>
  42 #include <sys/vnode.h>
  43 #include <sys/file.h>
  44 #include <sys/fcntl.h>
  45 #include <sys/mode.h>
  46 #include <sys/uio.h>
  47 #include <sys/mkdev.h>
  48 #include <sys/policy.h>
  49 #include <sys/debug.h>
  50
  51 /*
  52  * Create a special file, a regular file, or a FIFO.
  53  * fname - pathname passed by user
  54  * fmode - mode of pathname
  55  * dev = device number - b/c specials only
  56  */
  57 int
  58 mknodat(int fd, char *fname, mode_t fmode, dev_t dev)
  59 {
  60         vnode_t *startvp;
  61         vnode_t *vp;
  62         struct vattr vattr;
  63         int error;
  64         enum create why;
  65
  66         /*
  67          * Zero type is equivalent to a regular file.
  68          */
  69         if ((fmode & S_IFMT) == 0)
  70                 fmode |= S_IFREG;
  71
  72         /*
  73          * Must be privileged unless making a FIFO node.
  74          */
  75         if (((fmode & S_IFMT) != S_IFIFO) && secpolicy_sys_devices(CRED()) != 0)
  76                 return (set_errno(EPERM));
  77         /*
  78          * Set up desired attributes and vn_create the file.
  79          */
  80         vattr.va_type = IFTOVT(fmode);
  81         vattr.va_mode = fmode & MODEMASK;
  82         vattr.va_mask = VATTR_TYPE|VATTR_MODE;
  83         if (vattr.va_type == VCHR || vattr.va_type == VBLK) {
  84                 if (get_udatamodel() != DATAMODEL_NATIVE)
  85                         dev = expldev(dev);
  86                 if (dev == NODEV || (getemajor(dev)) == (major_t)NODEV)
  87                         return (set_errno(EINVAL));
  88                 vattr.va_rdev = dev;
  89                 vattr.va_mask |= VATTR_RDEV;
  90         }
  91
  92         if (fname == NULL)
  93                 return (set_errno(EFAULT));
  94         if ((error = fgetstartvp(fd, fname, &startvp)) != 0)
  95                 return (set_errno(error));
  96
  97         why = ((fmode & S_IFMT) == S_IFDIR) ? CRMKDIR : CRMKNOD;
  98         error = vn_createat(fname, UIO_USERSPACE, &vattr, EXCL, 0, &vp,
  99             why, 0,  PTOU(curproc)->u_cmask, startvp);
 100         if (startvp != NULL)
 101                 VN_RELE(startvp);
 102         if (error)
 103                 return (set_errno(error));
 104         VN_RELE(vp);
 105         return (0);
 106 }