usr/src/lib/libcmdutils/common/sysattrs.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 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #pragma ident   "%Z%%M% %I%     %E% SMI"
  28
  29 #include <unistd.h>
  30 #include <stdlib.h>
  31 #include <string.h>
  32 #include <libgen.h>
  33 #include <attr.h>
  34 #include <fcntl.h>
  35 #include <errno.h>
  36 #include "libcmdutils.h"
  37
  38 /*
  39  * Returns the status of attempting to obtain the extended system
  40  * attributes in the specified view.
  41  *
  42  * Note: If obtaining status for an extended attribute file, the caller must
  43  * chdir into the hidden directory prior to calling sysattr_status().
  44  *
  45  * Returns 1 if the extended system attributes were obtained, otherwise
  46  * returns 0.
  47  */
  48 int
  49 sysattr_status(char *file, xattr_view_t view)
  50 {
  51         nvlist_t        *response = NULL;
  52         int             saveerrno;
  53         int             status;
  54
  55         status = getattrat(AT_FDCWD, view, file, &response);
  56
  57         saveerrno = errno;
  58         if (response)
  59                 (void) nvlist_free(response);
  60         errno = saveerrno;
  61
  62         return (status == 0);
  63 }
  64
  65 /*
  66  * Returns the type of the specified in file.  If the file name matches
  67  * the name of either a read-only or read-write extended system attribute
  68  * file then sysattr_type() returns the type of file:
  69  *      return value    file type
  70  *      ------------    ---------
  71  *      _RO_SATTR       read-only extended system attribute file
  72  *      _RW_SATTR       read-write extended system attribute file
  73  *      _NOT_SATTR      neither a read-only or read-write extended system
  74  *                      attribute file.
  75  */
  76 int
  77 sysattr_type(char *file)
  78 {
  79         if (file == NULL) {
  80                 errno = ENOENT;
  81                 return (_NOT_SATTR);
  82         }
  83
  84         if (strcmp(basename(file), file) != 0) {
  85                 errno = EINVAL;
  86                 return (_NOT_SATTR);
  87         }
  88
  89         errno = 0;
  90         if (strcmp(file, VIEW_READONLY) == 0) {
  91                 return (_RO_SATTR);
  92         } else if (strcmp(file, VIEW_READWRITE) == 0) {
  93                 return (_RW_SATTR);
  94         } else {
  95                 return (_NOT_SATTR);
  96         }
  97 }
  98
  99 /*
 100  * Call sysattr_support() instead of pathconf(file, _PC_SATTR_ENABLED) or
 101  * pathconf(file, _PC_SATTR_EXISTS) so that if pathconf() fails over NFS, we
 102  * can still try to figure out if extended system attributes are supported by
 103  * testing for a valid extended system attribute file.
 104  *
 105  * 'name' can have the values _PC_SATTR_ENABLED or _PC_SATTR_EXISTS.
 106  *
 107  * Returns 1 if the underlying file system supports extended system attributes,
 108  * otherwise, returns -1.
 109  */
 110 int
 111 sysattr_support(char *file, int name)
 112 {
 113         int     rc;
 114
 115         errno = 0;
 116         if ((name != _PC_SATTR_ENABLED) &&
 117             (name != _PC_SATTR_EXISTS)) {
 118                 errno = EINVAL;
 119                 return (-1);
 120         }
 121         if (((rc = pathconf(file, name)) == 1) || (errno != EINVAL)) {
 122                 return (rc);
 123         }
 124         return (sysattr_status(file, XATTR_VIEW_READONLY));
 125 }