clock_settime.c revision 1.2 1 /* $NetBSD: clock_settime.c,v 1.2 2001/09/17 23:32:33 thorpej 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 "namespace.h"
35
36 #include <sys/types.h>
37 #include <sys/ioctl.h>
38 #include <sys/syscall.h>
39
40 #include <fcntl.h>
41 #include <paths.h>
42 #include <string.h>
43 #include <time.h>
44 #include <unistd.h>
45
46 #include <sys/clockctl.h>
47
48 #ifdef __weak_alias
49 __weak_alias(clock_settime,_clock_settime)
50 #endif
51
52 int
53 clock_settime(clock_id, tp)
54 clockid_t clock_id;
55 const struct timespec *tp;
56 {
57 struct clockctl_clock_settime_args args;
58 int error;
59 int fd;
60 quad_t q;
61 int rv;
62
63 /*
64 * Root always uses the settimeofday syscall
65 */
66 if (geteuid() == 0)
67 goto try_syscall;
68
69 /*
70 * Try to use /dev/clockctl, and revert to
71 * settimeofday syscall if it fails.
72 */
73 fd = open(_PATH_CLOCKCTL, O_WRONLY, 0);
74 if (fd == -1)
75 goto try_syscall;
76
77 args.clock_id = clock_id;
78 (void)memcpy (&args.tp, tp, sizeof(tp));
79 error = ioctl(fd, CLOCKCTL_CLOCK_SETTIME, &args);
80 (void)close(fd);
81 if (!error)
82 return 0;
83
84 try_syscall:
85 q = __syscall((quad_t)SYS_clock_settime, clock_id, tp);
86 if (/* LINTED constant */ sizeof (quad_t) == sizeof (register_t) ||
87 /* LINTED constant */ BYTE_ORDER == LITTLE_ENDIAN)
88 rv = (int)q;
89 else
90 rv = (int)((u_quad_t)q >> 32);
91 return rv;
92 }
93