Back to index

glibc  2.9
faccessat.c
Go to the documentation of this file.
00001 /* Test for access to file, relative to open directory.  Hurd version.
00002    Copyright (C) 2006 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <errno.h>
00021 #include <fcntl.h>
00022 #include <stddef.h>
00023 #include <unistd.h>
00024 #include <sys/types.h>
00025 #include <hurd.h>
00026 #include <hurd/fd.h>
00027 
00028 int
00029 faccessat (fd, file, type, flag)
00030      int fd;
00031      const char *file;
00032      int type;
00033      int flag;
00034 {
00035   error_t err;
00036   file_t port;
00037   int allowed, flags;
00038 
00039   if ((flag & AT_EACCESS) == 0)
00040     {
00041       if (fd == AT_FDCWD || file[0] == '/')
00042        return __access (file, type);
00043       __set_errno (ENOTSUP);       /* XXX later */
00044       return -1;
00045     }
00046 
00047   port = __file_name_lookup_at (fd, flag &~ AT_EACCESS, file, 0, 0);
00048   if (port == MACH_PORT_NULL)
00049     return -1;
00050 
00051   /* Find out what types of access we are allowed to this file.  */
00052   err = __file_check_access (port, &allowed);
00053   __mach_port_deallocate (__mach_task_self (), port);
00054   if (err)
00055     return __hurd_fail (err);
00056 
00057   flags = 0;
00058   if (type & R_OK)
00059     flags |= O_READ;
00060   if (type & W_OK)
00061     flags |= O_WRITE;
00062   if (type & X_OK)
00063     flags |= O_EXEC;
00064 
00065   if (flags & ~allowed)
00066     /* We are not allowed all the requested types of access.  */
00067     return __hurd_fail (EACCES);
00068 
00069   return 0;
00070 }