sysdeps/mach/hurd/linkat.c

   1 /* Make a link between file names relative to open directories.  Hurd version.
   2    Copyright (C) 2006 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library 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 GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 #include <errno.h>
  21 #include <fcntl.h>
  22 #include <stddef.h>
  23 #include <unistd.h>
  24 #include <hurd.h>
  25 #include <hurd/fd.h>
  26
  27
  28 /* Make a link to FROM relative to FROMFD called TO relative to TOFD.  */
  29 int
  30 linkat (fromfd, from, tofd, to, flags)
  31      int fromfd;
  32      const char *from;
  33      int tofd;
  34      const char *to;
  35      int flags;
  36 {
  37   error_t err;
  38   file_t oldfile, linknode, todir;
  39   char *toname;
  40
  41   oldfile = __file_name_lookup_at (fromfd, flags, from, 0, 0);
  42   if (oldfile == MACH_PORT_NULL)
  43     return -1;
  44
  45   /* The file_getlinknode RPC returns the port that should be passed to
  46      the receiving filesystem (the one containing TODIR) in dir_link.  */
  47
  48   err = __file_getlinknode (oldfile, &linknode);
  49   __mach_port_deallocate (__mach_task_self (), oldfile);
  50   if (err)
  51     return __hurd_fail (err);
  52
  53   todir = __file_name_split_at (tofd, to, &toname);
  54   if (todir != MACH_PORT_NULL)
  55     {
  56       err = __dir_link (todir, linknode, toname, 1);
  57       __mach_port_deallocate (__mach_task_self (), todir);
  58     }
  59   __mach_port_deallocate (__mach_task_self (), linknode);
  60   if (todir == MACH_PORT_NULL)
  61     return -1;
  62
  63   if (err)
  64     return __hurd_fail (err);
  65   return 0;
  66 }