hurd/getdport.c

   1 /* Copyright (C) 1991,1992,1994,1995,1997,2007 Free Software Foundation, Inc.
   2
   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 <hurd.h>
  21
  22 /* This is initialized in dtable.c when that gets linked in.
  23    If dtable.c is not linked in, it will be zero.  */
  24 static file_t (*_default_hurd_getdport_fn) (int fd) = 0;
  25 weak_alias (_default_hurd_getdport_fn, _hurd_getdport_fn)
  26
  27 file_t
  28 __getdport (int fd)
  29 {
  30   if (_hurd_getdport_fn)
  31     /* dtable.c has defined the function to fetch a port from the real file
  32        descriptor table.  */
  33     return (*_hurd_getdport_fn) (fd);
  34
  35   /* getdport is the only use of file descriptors,
  36      so we don't bother allocating a real table.  */
  37
  38   if (_hurd_init_dtable == NULL)
  39     {
  40       /* Never had a descriptor table.  */
  41       errno = EBADF;
  42       return MACH_PORT_NULL;
  43     }
  44
  45   if (fd < 0 || (unsigned int) fd > _hurd_init_dtablesize ||
  46       _hurd_init_dtable[fd] == MACH_PORT_NULL)
  47     {
  48       errno = EBADF;
  49       return MACH_PORT_NULL;
  50     }
  51   else
  52     {
  53       __mach_port_mod_refs (__mach_task_self (), _hurd_init_dtable[fd],
  54                             MACH_PORT_RIGHT_SEND, 1);
  55       return _hurd_init_dtable[fd];
  56     }
  57 }
  58
  59 weak_alias (__getdport, getdport)