sysdeps/mach/hurd/xmknodat.c

   1 /* Create a device file relative to an open directory.  Hurd version.
   2    Copyright (C) 1991-2018 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, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 #include <errno.h>
  20 #include <sys/stat.h>
  21 #include <hurd.h>
  22 #include <hurd/fd.h>
  23 #include <hurd/paths.h>
  24 #include <fcntl.h>
  25 #include <_itoa.h>
  26 #include <string.h>
  27 #include <sys/types.h>
  28 #include <sys/sysmacros.h>
  29
  30 /* Create a device file named PATH relative to FD, with permission and
  31    special bits MODE and device number DEV (which can be constructed
  32    from major and minor device numbers with the `makedev' macro
  33    above).  */
  34 int
  35 __xmknodat (int vers, int fd, const char *path, mode_t mode, dev_t *dev)
  36 {
  37   error_t errnode, err;
  38   file_t dir, node;
  39   char *name;
  40   char buf[100], *bp;
  41   const char *translator;
  42   size_t len;
  43
  44   if (vers != _MKNOD_VER)
  45     return __hurd_fail (EINVAL);
  46
  47   if (S_ISCHR (mode))
  48     {
  49       translator = _HURD_CHRDEV;
  50       len = sizeof (_HURD_CHRDEV);
  51     }
  52   else if (S_ISBLK (mode))
  53     {
  54       translator = _HURD_BLKDEV;
  55       len = sizeof (_HURD_BLKDEV);
  56     }
  57   else if (S_ISFIFO (mode))
  58     {
  59       translator = _HURD_FIFO;
  60       len = sizeof (_HURD_FIFO);
  61     }
  62   else if (S_ISREG (mode))
  63     {
  64       translator = NULL;
  65       len = 0;
  66     }
  67   else
  68     {
  69       errno = EINVAL;
  70       return -1;
  71     }
  72
  73   if (translator != NULL && ! S_ISFIFO (mode))
  74     {
  75       /* We set the translator to "ifmt\0major\0minor\0", where IFMT
  76          depends on the S_IFMT bits of our MODE argument, and MAJOR and
  77          MINOR are ASCII decimal (octal or hex would do as well)
  78          representations of our arguments.  Thus the convention is that
  79          CHRDEV and BLKDEV translators are invoked with two non-switch
  80          arguments, giving the major and minor device numbers in %i format. */
  81
  82       bp = buf + sizeof (buf);
  83       *--bp = '\0';
  84       bp = _itoa (minor (*dev), bp, 10, 0);
  85       *--bp = '\0';
  86       bp = _itoa (major (*dev), bp, 10, 0);
  87       memcpy (bp - len, translator, len);
  88       translator = bp - len;
  89       len = buf + sizeof (buf) - translator;
  90     }
  91
  92   dir = __file_name_split_at (fd, path, &name);
  93   if (dir == MACH_PORT_NULL)
  94     return -1;
  95
  96   /* Create a new, unlinked node in the target directory.  */
  97   errnode = err = __dir_mkfile (dir, O_WRITE, (mode & ~S_IFMT) & ~_hurd_umask, &node);
  98
  99   if (! err && translator != NULL)
 100     /* Set the node's translator to make it a device.  */
 101     err = __file_set_translator (node,
 102                                  FS_TRANS_EXCL | FS_TRANS_SET,
 103                                  FS_TRANS_EXCL | FS_TRANS_SET, 0,
 104                                  translator, len,
 105                                  MACH_PORT_NULL, MACH_MSG_TYPE_COPY_SEND);
 106
 107   if (! err)
 108     /* Link the node, now a valid device, into the target directory.  */
 109     err = __dir_link (dir, node, name, 1);
 110
 111   __mach_port_deallocate (__mach_task_self (), dir);
 112   if (! errnode)
 113     __mach_port_deallocate (__mach_task_self (), node);
 114
 115   if (err)
 116     return __hurd_fail (err);
 117   return 0;
 118 }
 119
 120 libc_hidden_def (__xmknodat)