1/*	$NetBSD: settimeofday.c,v 1.13 2009/01/11 02:46:30 christos Exp $ */
2
3/*
4 * Copyright (c) 2001 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Emmanuel Dreyfus.
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 * 3. The name of the author may not be used to endorse or promote products
19 *    derived from this software without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
26 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
27 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
28 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
29 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <sys/cdefs.h>
35#if defined(LIBC_SCCS) && !defined(lint)
36__RCSID("$NetBSD: settimeofday.c,v 1.13 2009/01/11 02:46:30 christos Exp $");
37#endif /* LIBC_SCCS and not lint */
38
39#include "namespace.h"
40
41#include <sys/types.h>
42#include <sys/ioctl.h>
43#include <sys/syscall.h>
44
45#include <sys/clockctl.h>
46
47#include <errno.h>
48#include <fcntl.h>
49#include <paths.h>
50#include <string.h>
51#include <time.h>
52#include <unistd.h>
53
54int __clockctl_fd = -1;
55
56int ____settimeofday50(const struct timeval *, const void *);
57
58int
59settimeofday(const struct timeval *tv, const void *tzp)
60{
61	struct clockctl_settimeofday args;
62	int rv;
63
64	/*
65	 * try syscal first and attempt to switch to clockctl
66	 * if that fails with EPERM
67	 */
68	if (__clockctl_fd == -1) {
69		rv = ____settimeofday50(tv, tzp);
70
71		/*
72		 * switch to clockctl if we fail with EPERM, this
73		 * may be cause by an attempt to set the time backwards
74		 * but we should leave the access permission checking
75		 * entirely to the kernel
76		 */
77		if (rv != -1 || errno != EPERM)
78			return rv;
79
80		__clockctl_fd = open(_PATH_CLOCKCTL, O_WRONLY | O_CLOEXEC, 0);
81		if (__clockctl_fd == -1) {
82			/* original error was EPERM - don't leak open errors */
83			errno = EPERM;
84			return -1;
85		}
86	}
87
88	/*
89	 * If __clockctl_fd >=0, clockctl has already been open
90	 * and used, so we carry on using it.
91	 */
92	args.tv = tv;
93	args.tzp = tzp;
94	return ioctl(__clockctl_fd, CLOCKCTL_SETTIMEOFDAY, &args);
95}
96