| /* Duplicate a file descriptor to a given number, with flags. Hurd version. |
| Copyright (C) 1991-2014 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) |