mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-29 16:21:07 +00:00
140 lines
4.1 KiB
C
140 lines
4.1 KiB
C
/* Duplicate a file descriptor to a given number, with flags. Hurd version.
|
|
Copyright (C) 1991-2012 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 Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 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
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
|
not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <unistd.h>
|
|
#include <hurd.h>
|
|
#include <hurd/fd.h>
|
|
|
|
/* Duplicate FD to FD2, closing the old FD2 and making FD2 be
|
|
open on the same file as FD is, and setting FD2's flags according to FLAGS.
|
|
Return FD2 or -1. */
|
|
int
|
|
__dup3 (int fd, int fd2, int flags)
|
|
{
|
|
struct hurd_fd *d;
|
|
|
|
/* Both passing flags different from O_CLOEXEC and FD2 being the same as FD
|
|
are invalid. */
|
|
if ((flags & ~O_CLOEXEC
|
|
|| fd2 == fd)
|
|
/* ... with the exception in case that dup2 behavior is requested: if FD
|
|
is valid and FD2 is already the same then just return it. */
|
|
&& ! (flags == -1
|
|
&& fd2 == fd))
|
|
return __hurd_fail (EINVAL);
|
|
|
|
/* Extract the ports and flags from FD. */
|
|
d = _hurd_fd_get (fd);
|
|
if (d == NULL)
|
|
return __hurd_fail (EBADF);
|
|
|
|
HURD_CRITICAL_BEGIN;
|
|
|
|
__spin_lock (&d->port.lock);
|
|
if (d->port.port == MACH_PORT_NULL)
|
|
{
|
|
__spin_unlock (&d->port.lock);
|
|
fd2 = __hurd_fail (EBADF);
|
|
}
|
|
else if (fd2 == fd)
|
|
__spin_unlock (&d->port.lock);
|
|
else
|
|
{
|
|
struct hurd_userlink ulink, ctty_ulink;
|
|
int d_flags = d->flags;
|
|
io_t ctty = _hurd_port_get (&d->ctty, &ctty_ulink);
|
|
io_t port = _hurd_port_locked_get (&d->port, &ulink); /* Unlocks D. */
|
|
|
|
if (fd2 < 0)
|
|
fd2 = __hurd_fail (EBADF);
|
|
else
|
|
{
|
|
/* Get a hold of the destination descriptor. */
|
|
struct hurd_fd *d2;
|
|
|
|
__mutex_lock (&_hurd_dtable_lock);
|
|
|
|
if (fd2 >= _hurd_dtablesize)
|
|
{
|
|
/* The table is not large enough to hold the destination
|
|
descriptor. Enlarge it as necessary to allocate this
|
|
descriptor. */
|
|
__mutex_unlock (&_hurd_dtable_lock);
|
|
d2 = _hurd_alloc_fd (NULL, fd2);
|
|
if (d2)
|
|
__spin_unlock (&d2->port.lock);
|
|
__mutex_lock (&_hurd_dtable_lock);
|
|
}
|
|
else
|
|
{
|
|
d2 = _hurd_dtable[fd2];
|
|
if (d2 == NULL)
|
|
{
|
|
/* Must allocate a new one. We don't initialize the port
|
|
cells with this call so that if it fails (out of
|
|
memory), we will not have already added user
|
|
references for the ports, which we would then have to
|
|
deallocate. */
|
|
d2 = _hurd_dtable[fd2] = _hurd_new_fd (MACH_PORT_NULL,
|
|
MACH_PORT_NULL);
|
|
}
|
|
}
|
|
__mutex_unlock (&_hurd_dtable_lock);
|
|
|
|
if (d2 == NULL)
|
|
{
|
|
fd2 = -1;
|
|
if (errno == EINVAL)
|
|
errno = EBADF; /* POSIX.1-1990 6.2.1.2 ll 54-55. */
|
|
}
|
|
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 slot. */
|
|
__spin_lock (&d2->port.lock);
|
|
if (flags & O_CLOEXEC)
|
|
d2->flags = d_flags | FD_CLOEXEC;
|
|
else
|
|
/* dup clears FD_CLOEXEC. */
|
|
d2->flags = d_flags & ~FD_CLOEXEC;
|
|
_hurd_port_set (&d2->ctty, ctty);
|
|
_hurd_port_locked_set (&d2->port, port); /* Unlocks D2. */
|
|
}
|
|
}
|
|
|
|
_hurd_port_free (&d->port, &ulink, port);
|
|
if (ctty != MACH_PORT_NULL)
|
|
_hurd_port_free (&d->ctty, &ctty_ulink, port);
|
|
}
|
|
|
|
HURD_CRITICAL_END;
|
|
|
|
return fd2;
|
|
}
|
|
libc_hidden_def (__dup3)
|
|
weak_alias (__dup3, dup3)
|