minix/lib/libc/sys/settimeofday.c

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/* $NetBSD: settimeofday.c,v 1.14 2011/10/15 23:00:02 christos Exp $ */
/*
* Copyright (c) 2001 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Emmanuel Dreyfus.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
#if defined(LIBC_SCCS) && !defined(lint)
__RCSID("$NetBSD: settimeofday.c,v 1.14 2011/10/15 23:00:02 christos Exp $");
#endif /* LIBC_SCCS and not lint */
#include "namespace.h"
#include <sys/types.h>
#include <sys/ioctl.h>
#include <sys/syscall.h>
#include <sys/clockctl.h>
#include <errno.h>
#include <fcntl.h>
#include <paths.h>
#include <string.h>
#include <time.h>
#include <unistd.h>
int __clockctl_fd = -1;
int ____settimeofday50(const struct timeval *, const void *);
int
settimeofday(const struct timeval *tv, const void *tzp)
{
struct clockctl_settimeofday args;
int rv;
/*
* try syscal first and attempt to switch to clockctl
* if that fails with EPERM
*/
if (__clockctl_fd == -1) {
rv = ____settimeofday50(tv, tzp);
/*
* switch to clockctl if we fail with EPERM, this
* may be cause by an attempt to set the time backwards
* but we should leave the access permission checking
* entirely to the kernel
*/
if (rv != -1 || errno != EPERM)
return rv;
__clockctl_fd = open(_PATH_CLOCKCTL, O_WRONLY | O_CLOEXEC, 0);
if (__clockctl_fd == -1) {
/* original error was EPERM - don't leak open errors */
errno = EPERM;
return -1;
}
}
/*
* If __clockctl_fd >=0, clockctl has already been open
* and used, so we carry on using it.
*/
args.tv = tv;
args.tzp = tzp;
return ioctl(__clockctl_fd, CLOCKCTL_SETTIMEOFDAY, &args);
}