Linux Cubed Series 4: GNU Archives/Linux Cubed Series 4 - GNU Archives.iso/gnu/glibc-1.09/glibc-1/glibc-1.09.1/sysdeps/mach/hurd/__fcntl.c

C/C++ Source or Header | 1994-07-18 | 4.7 KB | 189 lines

/* Copyright (C) 1992, 1993, 1994 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

#include <ansidecl.h>
#include <errno.h>
#include <fcntl.h>
#include <hurd.h>
#include <hurd/fd.h>
#include <stdarg.h>


/* Perform file control operations on FD.  */
int
DEFUN(__fcntl, (fd, cmd), int fd AND int cmd DOTS)
{
  va_list ap;
  struct hurd_fd *d;
  int result;

  HURD_CRITICAL_BEGIN;

  d = _hurd_fd_get (fd);

  if (d == NULL)
    {
      result = __hurd_fail (EBADF);
      goto out;
    }

  va_start (ap, cmd);

  switch (cmd)
    {
    default:            /* Bad command.  */
      __spin_unlock (&d->port.lock);
      errno = EINVAL;
      result = -1;
      break;

      /* First the descriptor-based commands, which do no RPCs.  */

    case F_DUPFD:        /* Duplicate the file descriptor.  */
      {
    struct hurd_fd *new;
    io_t port, ctty;
    struct hurd_userlink ulink, ctty_ulink;
    int flags;

    /* Extract the ports and flags from the file descriptor.  */
    flags = d->flags;
    ctty = _hurd_port_get (&d->ctty, &ctty_ulink);
    port = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D.  */

    /* Get a new file descriptor.  The third argument to __fcntl is the
       minimum file descriptor number for it.  */
    new = _hurd_alloc_fd (&result, va_arg (ap, int));
    if (new == NULL)
      /* _hurd_alloc_fd has set errno.  */
      result = -1;
    else
      {
        /* Give the ports each a user ref for the new descriptor.  */
        __mach_port_mod_refs (__mach_task_self (), port,
                  MACH_PORT_RIGHT_SEND, 1);
        if (ctty != MACH_PORT_NULL)
          __mach_port_mod_refs (__mach_task_self (), ctty,
                    MACH_PORT_RIGHT_SEND, 1);

        /* Install the ports and flags in the new descriptor.  */
        if (ctty != MACH_PORT_NULL)
          _hurd_port_set (&new->ctty, ctty);
        _hurd_port_locked_set (&new->port, port);
        /* Duplication clears the FD_CLOEXEC flag.  */
        new->flags = flags & ~FD_CLOEXEC;
      }

    _hurd_port_free (&d->port, &ulink, port);
    if (ctty != MACH_PORT_NULL)
      _hurd_port_free (&d->ctty, &ctty_ulink, port);

    break;
      }

    case F_GETFD:        /* Get descriptor flags.  */
      result = d->flags;
      __spin_unlock (&d->port.lock);
      break;

    case F_SETFD:        /* Set descriptor flags.  */
      d->flags = va_arg (ap, int);
      __spin_unlock (&d->port.lock);
      result = 0;
      break;


      /* Now the real io operations, done by RPCs to io servers.  */

    case F_GETLK:
    case F_SETLK:
    case F_SETLKW:
      {
    struct flock *fl = va_arg (ap, struct flock *);
    __spin_unlock (&d->port.lock);
    errno = fl?ENOSYS:EINVAL; /* XXX mib needs to implement io rpcs.  */
    result = -1;
    break;
      }

    case F_GETFL:        /* Get per-open flags.  */
      {
    struct hurd_userlink ulink;
    io_t port
      = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D.  */
    error_t err;

    err = __io_get_openmodes (port, &result);

    _hurd_port_free (&d->port, &ulink, port);

    if (err)
      result = __hurd_fail (err);
    break;
      }

    case F_SETFL:        /* Set per-open flags.  */
      {
    const int flags = va_arg (ap, int);
    struct hurd_userlink ulink;
    io_t port
      = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D.  */
    error_t err;

    err = __io_set_all_openmodes (port, flags);

    _hurd_port_free (&d->port, &ulink, port);

    result = err ? __hurd_fail (err) : 0;
    break;
      }

    case F_GETOWN:        /* Get owner.  */
      {
    struct hurd_userlink ulink;
    error_t err;
    io_t port
      = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D.  */
    err = __io_get_owner (port, &result);
    _hurd_port_free (&d->port, &ulink, port);
    result = err ? __hurd_fail (err) : 0;
    break;
      }

    case F_SETOWN:        /* Set owner.  */
      {
    pid_t owner = va_arg (ap, pid_t);
    error_t err;
    struct hurd_userlink ulink;
    io_t port
      = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D.  */
    err = __io_mod_owner (port, owner);
    _hurd_port_free (&d->port, &ulink, port);
    result = err ? __hurd_fail (err) : 0;
    break;
      }
    }

  va_end (ap);

 out:
  HURD_CRITICAL_END;

  return result;
}