1 /* $NetBSD: clock_settime.c,v 1.11 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: clock_settime.c,v 1.11 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 <errno.h> 46 #include <fcntl.h> 47 #include <paths.h> 48 #include <string.h> 49 #include <time.h> 50 #include <unistd.h> 51 52 #include <sys/clockctl.h> 53 54 extern int __clockctl_fd; 55 56 int ____clock_settime50(clockid_t, const struct timespec *); 57 58 int 59 clock_settime(clockid_t clock_id, const struct timespec *tp) 60 { 61 struct clockctl_clock_settime args; 62 int rv; 63 64 /* 65 * always try the syscall first and attempt to switch to 66 * clockctl if that fails. 67 */ 68 if (__clockctl_fd == -1) { 69 rv = ____clock_settime50(clock_id, tp); 70 71 /* 72 * return unless we failed with EPERM 73 */ 74 if (rv != -1 || errno != EPERM) 75 return rv; 76 77 /* 78 * If this fails, it means that we are not root 79 * and we cannot open clockctl. This is a failure. 80 */ 81 __clockctl_fd = open(_PATH_CLOCKCTL, O_WRONLY, 0); 82 if (__clockctl_fd == -1) { 83 /* original error was EPERM - don't leak open errors */ 84 errno = EPERM; 85 return -1; 86 } 87 88 (void) fcntl(__clockctl_fd, F_SETFD, FD_CLOEXEC); 89 } 90 91 /* 92 * If __clockctl_fd >=0, clockctl has already been open 93 * and used, so we carry on using it. 94 */ 95 args.clock_id = clock_id; 96 args.tp = tp; 97 return ioctl(__clockctl_fd, CLOCKCTL_CLOCK_SETTIME, &args); 98 } 99