compat_dup3.c revision 1.3 
1/*	$NetBSD: compat_dup3.c,v 1.3 2025/07/17 18:28:58 kre Exp $ */
2
3/*-
4 * Copyright (c) 2024 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Christos Zoulas.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31#include <sys/cdefs.h>
32#if defined(LIBC_SCCS) && !defined(lint)
33__RCSID("$NetBSD: compat_dup3.c,v 1.3 2025/07/17 18:28:58 kre Exp $");
34#endif /* LIBC_SCCS and not lint */
35
36#include "namespace.h"
37#define __LIBC12_SOURCE__
38#include <fcntl.h>
39#include <compat/include/unistd.h>
40
41__warn_references(dup3,
42    "warning: reference to compatibility dup3(); include <unistd.h> to generate correct reference")
43
44#ifndef	FD_CLOFORK			/*XXX temporary*/
45#define	FD_CLOFORK	0		/*XXX temporary*/
46#endif					/*XXX temporary*/
47#ifndef	O_CLOFORK			/*XXX temporary*/
48#define	O_CLOFORK	0x08000000	/*XXX temporary*/
49#endif					/*XXX temporary*/
50int
51dup3(int oldfd, int newfd, int flags)
52{
53	int fdflags;
54
55	if (oldfd != newfd) {
56		return __dup3100(oldfd, newfd, flags);
57	}
58	if (flags & (O_NONBLOCK|O_NOSIGPIPE)) {
59		int e = fcntl(newfd, F_GETFL, 0);
60		if (e == -1)
61			return -1;
62		e |= flags & (O_NONBLOCK|O_NOSIGPIPE);
63		e = fcntl(newfd, F_SETFL, e);
64		if (e == -1)
65			return -1;
66	}
67
68	switch (flags & (O_CLOEXEC|O_CLOFORK)) {
69	case O_CLOEXEC|O_CLOFORK:
70		fdflags = FD_CLOEXEC|FD_CLOFORK;
71		break;
72	case O_CLOEXEC:
73		fdflags = FD_CLOEXEC;
74		break;
75	case O_CLOFORK:
76		fdflags = FD_CLOFORK;
77		break;
78	default:
79		return 0;
80	}
81	return fcntl(newfd, F_SETFD, fdflags);
82}
83