lib/acl-errno-valid.c

   1 /* Test whether ACLs are well supported on this system.
   2
   3    Copyright 2013-2018 Free Software Foundation, Inc.
   4
   5    This program is free software: you can redistribute it and/or modify
   6    it under the terms of the GNU General Public License as published by
   7    the Free Software Foundation; either version 3 of the License, or
   8    (at your option) any later version.
   9
  10    This program is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13    GNU General Public License for more details.
  14
  15    You should have received a copy of the GNU General Public License
  16    along with this program.  If not, see <https://www.gnu.org/licenses/>.
  17
  18    Written by Paul Eggert.  */
  19
  20 #include <config.h>
  21
  22 #include <acl.h>
  23
  24 #include <errno.h>
  25
  26 /* Return true if errno value ERRNUM indicates that ACLs are well
  27    supported on this system.  ERRNUM should be an errno value obtained
  28    after an ACL-related system call fails.  */
  29 bool
  30 acl_errno_valid (int errnum)
  31 {
  32   /* Recognize some common errors such as from an NFS mount that does
  33      not support ACLs, even when local drives do.  */
  34   switch (errnum)
  35     {
  36     case EBUSY: return false;
  37     case EINVAL: return false;
  38 #if defined __APPLE__ && defined __MACH__
  39     case ENOENT: return false;
  40 #endif
  41     case ENOSYS: return false;
  42
  43 #if defined ENOTSUP && ENOTSUP != EOPNOTSUPP
  44 # if ENOTSUP != ENOSYS /* Needed for the MS-Windows port of GNU Emacs.  */
  45     case ENOTSUP: return false;
  46 # endif
  47 #endif
  48
  49     case EOPNOTSUPP: return false;
  50     default: return true;
  51     }
  52 }