1 /* $NetBSD: adjtime.c,v 1.12 2011/10/15 23:00:02 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: adjtime.c,v 1.12 2011/10/15 23:00:02 christos Exp $"); 37 #endif /* LIBC_SCCS and not lint */ 38 39 #include "namespace.h" 40 #include <errno.h> 41 #include <fcntl.h> 42 #include <paths.h> 43 #include <unistd.h> 44 #include <time.h> 45 #include <string.h> 46 #include <sys/types.h> 47 #include <sys/ioctl.h> 48 #include <sys/syscall.h> 49 50 #include <sys/clockctl.h> 51 52 extern int __clockctl_fd; 53 54 int ____adjtime50(const struct timeval *, struct timeval *); 55 56 int 57 adjtime(const struct timeval *delta, struct timeval *olddelta) 58 { 59 struct clockctl_adjtime args; 60 int rv; 61 62 /* 63 * we always attempt the syscall first and switch to 64 * clockctl if that fails with EPERM 65 */ 66 if (__clockctl_fd == -1) { 67 rv = ____adjtime50(delta, olddelta); 68 69 /* 70 * try via clockctl if the call fails with EPERM 71 */ 72 if (rv != -1 || errno != EPERM) 73 return rv; 74 75 /* 76 * If this fails, it means that we are not root 77 * and we cannot open clockctl. This is a failure. 78 */ 79 __clockctl_fd = open(_PATH_CLOCKCTL, O_WRONLY | O_CLOEXEC, 0); 80 if (__clockctl_fd == -1) { 81 /* original error was EPERM - don't leak open errors */ 82 errno = EPERM; 83 return -1; 84 } 85 } 86 87 /* 88 * If __clockctl_fd >=0, clockctl has already been open 89 * and used, so we carry on using it. 90 */ 91 args.delta = delta; 92 args.olddelta = olddelta; 93 return ioctl(__clockctl_fd, CLOCKCTL_ADJTIME, &args); 94 } 95