1 /* $NetBSD: settimeofday.c,v 1.12 2007/11/23 12:39:16 uebayasi 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 1.12 2007/11/23 12:39:16 uebayasi 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 54 #ifdef __weak_alias 55 __weak_alias(settimeofday,_settimeofday) 56 #endif 57 58 int __clockctl_fd = -1; 59 60 int __settimeofday(const struct timeval *, const void *); 61 62 int 63 settimeofday(tv, tzp) 64 const struct timeval *tv; 65 const void *tzp; 66 { 67 struct clockctl_settimeofday args; 68 int rv; 69 70 /* 71 * try syscal first and attempt to switch to clockctl 72 * if that fails with EPERM 73 */ 74 if (__clockctl_fd == -1) { 75 rv = __settimeofday(tv, tzp); 76 77 /* 78 * switch to clockctl if we fail with EPERM, this 79 * may be cause by an attempt to set the time backwards 80 * but we should leave the access permission checking 81 * entirely to the kernel 82 */ 83 if (rv != -1 || errno != EPERM) 84 return rv; 85 86 __clockctl_fd = open(_PATH_CLOCKCTL, O_WRONLY, 0); 87 if (__clockctl_fd == -1) { 88 /* original error was EPERM - don't leak open errors */ 89 errno = EPERM; 90 return -1; 91 } 92 93 (void) fcntl(__clockctl_fd, F_SETFD, FD_CLOEXEC); 94 } 95 96 /* 97 * If __clockctl_fd >=0, clockctl has already been open 98 * and used, so we carry on using it. 99 */ 100 args.tv = tv; 101 args.tzp = tzp; 102 return ioctl(__clockctl_fd, CLOCKCTL_SETTIMEOFDAY, &args); 103 } 104