sysdeps/mach/hurd/symlink.c

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96, 97 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <string.h>
  20 #include <unistd.h>
  21 #include <hurd.h>
  22 #include <hurd/paths.h>
  23 #include <fcntl.h>
  24
  25 /* Make a link to FROM called TO.  */
  26 int
  27 __symlink (from, to)
  28      const char *from;
  29      const char *to;
  30 {
  31   error_t err;
  32   file_t dir, node;
  33   char *name;
  34   const size_t len = strlen (from) + 1;
  35   char buf[sizeof (_HURD_SYMLINK) + len];
  36
  37   /* A symlink is a file whose translator is "/hurd/symlink\0target\0".  */
  38
  39   memcpy (buf, _HURD_SYMLINK, sizeof (_HURD_SYMLINK));
  40   memcpy (&buf[sizeof (_HURD_SYMLINK)], from, len);
  41
  42   dir = __file_name_split (to, &name);
  43   if (dir == MACH_PORT_NULL)
  44     return -1;
  45
  46   /* Create a new, unlinked node in the target directory.  */
  47   err = __dir_mkfile (dir, O_WRITE, 0777 & ~_hurd_umask, &node);
  48
  49   if (! err)
  50     /* Set the node's translator to make it a symlink.  */
  51     err = __file_set_translator (node,
  52                                  FS_TRANS_EXCL|FS_TRANS_SET,
  53                                  FS_TRANS_EXCL|FS_TRANS_SET, 0,
  54                                  buf, sizeof (_HURD_SYMLINK) + len,
  55                                  MACH_PORT_NULL, MACH_MSG_TYPE_COPY_SEND);
  56
  57   if (! err)
  58     /* Link the node, now a valid symlink, into the target directory.  */
  59     err = __dir_link (dir, node, name, 1);
  60
  61   __mach_port_deallocate (__mach_task_self (), dir);
  62   __mach_port_deallocate (__mach_task_self (), node);
  63
  64   if (err)
  65     return __hurd_fail (err);
  66   return 0;
  67 }
  68
  69 weak_alias (__symlink, symlink)