diff options
Diffstat (limited to 'libc/sysdeps/mach/hurd/dup2.c')
| -rw-r--r-- | libc/sysdeps/mach/hurd/dup2.c | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/libc/sysdeps/mach/hurd/dup2.c b/libc/sysdeps/mach/hurd/dup2.c new file mode 100644 index 000000000..3abd30cfb --- /dev/null +++ b/libc/sysdeps/mach/hurd/dup2.c @@ -0,0 +1,134 @@ +/* Copyright (C) 1991, 92, 93, 94, 95, 97, 2002 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; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#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. Return FD2 or -1. */ +int +__dup2 (fd, fd2) + int fd; + int fd2; +{ + struct hurd_fd *d; + + /* Extract the ports and flags from FD. */ + d = _hurd_fd_get (fd); + if (d == NULL) + { + errno = EBADF; + return -1; + } + + HURD_CRITICAL_BEGIN; + + __spin_lock (&d->port.lock); + if (d->port.port == MACH_PORT_NULL) + { + __spin_unlock (&d->port.lock); + errno = EBADF; + fd2 = -1; + } + else if (fd2 == fd) + /* FD is valid and FD2 is already the same; just return it. */ + __spin_unlock (&d->port.lock); + else + { + struct hurd_userlink ulink, ctty_ulink; + int 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) + { + errno = EBADF; + fd2 = -1; + } + else + { + /* Get a hold of the destination descriptor. */ + struct hurd_fd *d2; + + 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); + /* We still hold FD1's lock, but this is safe because + _hurd_alloc_fd will only examine the cells starting + at FD2. */ + 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); + } + } + + 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); + d2->flags = flags & ~FD_CLOEXEC; /* Dup clears FD_CLOEXEC. */ + _hurd_port_set (&d2->ctty, ctty); + _hurd_port_locked_set (&d2->port, port); /* Unlocks D2. */ + } + } + __mutex_unlock (&_hurd_dtable_lock); + + _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 (__dup2) +weak_alias (__dup2, dup2) |