getdport.c 1.8 KB

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  1. /* Copyright (C) 1991-2026 Free Software Foundation, Inc.
  2. This file is part of the GNU C Library.
  3. The GNU C Library is free software; you can redistribute it and/or
  4. modify it under the terms of the GNU Lesser General Public
  5. License as published by the Free Software Foundation; either
  6. version 2.1 of the License, or (at your option) any later version.
  7. The GNU C Library is distributed in the hope that it will be useful,
  8. but WITHOUT ANY WARRANTY; without even the implied warranty of
  9. MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  10. Lesser General Public License for more details.
  11. You should have received a copy of the GNU Lesser General Public
  12. License along with the GNU C Library; if not, see
  13. <https://www.gnu.org/licenses/>. */
  14. #include <hurd.h>
  15. /* This is initialized in dtable.c when that gets linked in.
  16. If dtable.c is not linked in, it will be zero. */
  17. static file_t (*_default_hurd_getdport_fn) (int fd) = 0;
  18. weak_alias (_default_hurd_getdport_fn, _hurd_getdport_fn)
  19. file_t
  20. __getdport (int fd)
  21. {
  22. if (_hurd_getdport_fn)
  23. /* dtable.c has defined the function to fetch a port from the real file
  24. descriptor table. */
  25. return (*_hurd_getdport_fn) (fd);
  26. /* getdport is the only use of file descriptors,
  27. so we don't bother allocating a real table. */
  28. if (_hurd_init_dtable == NULL)
  29. /* Never had a descriptor table. */
  30. return __hurd_fail (EBADF), MACH_PORT_NULL;
  31. if (fd < 0 || (unsigned int) fd > _hurd_init_dtablesize
  32. || _hurd_init_dtable[fd] == MACH_PORT_NULL)
  33. return __hurd_fail (EBADF), MACH_PORT_NULL;
  34. else
  35. {
  36. __mach_port_mod_refs (__mach_task_self (), _hurd_init_dtable[fd],
  37. MACH_PORT_RIGHT_SEND, 1);
  38. return _hurd_init_dtable[fd];
  39. }
  40. }
  41. weak_alias (__getdport, getdport)