xref: /freebsd/lib/libc/gen/dup3.c (revision 971f738679e2e57114366c0f69af99e07150f1ff)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2012 Jukka A. Ukkonen
5  * All rights reserved.
6  *
7  * This software was developed by Jukka Ukkonen for FreeBSD.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28  * SUCH DAMAGE.
29  */
30 
31 #include "namespace.h"
32 #include <unistd.h>
33 #include <fcntl.h>
34 #include <errno.h>
35 #include "un-namespace.h"
36 
37 int __dup3(int, int, int);
38 
39 int
__dup3(int oldfd,int newfd,int flags)40 __dup3(int oldfd, int newfd, int flags)
41 {
42 	int fdflags;
43 
44 	if (oldfd == newfd) {
45 		errno = EINVAL;
46 		return (-1);
47 	}
48 
49 	if ((flags & ~(O_CLOEXEC | O_CLOFORK)) != 0) {
50 		errno = EINVAL;
51 		return (-1);
52 	}
53 
54 	fdflags = ((flags & O_CLOEXEC) != 0 ? FD_CLOEXEC : 0) |
55 	    ((flags & O_CLOFORK) != 0 ? FD_CLOFORK : 0);
56 
57 	return (_fcntl(oldfd, F_DUP3FD | (fdflags << F_DUP3FD_SHIFT), newfd));
58 }
59 
60 __weak_reference(__dup3, dup3);
61 __weak_reference(__dup3, _dup3);
62