rdate.c revision 1.11 
1/*	$NetBSD: rdate.c,v 1.11 2000/07/07 15:11:47 itojun Exp $	*/
2
3/*
4 * Copyright (c) 1994 Christos Zoulas
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. All advertising materials mentioning features or use of this software
16 *    must display the following acknowledgement:
17 *	This product includes software developed by Christos Zoulas.
18 * 4. 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, BUT
26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
31 */
32
33/*
34 * rdate.c: Set the date from the specified host
35 *
36 * 	Uses the rfc868 time protocol at socket 37.
37 *	Time is returned as the number of seconds since
38 *	midnight January 1st 1900.
39 */
40#include <sys/cdefs.h>
41#ifndef lint
42__RCSID("$NetBSD: rdate.c,v 1.11 2000/07/07 15:11:47 itojun Exp $");
43#endif/* lint */
44
45#include <sys/types.h>
46#include <sys/socket.h>
47#include <sys/time.h>
48
49#include <netinet/in.h>
50
51#include <ctype.h>
52#include <err.h>
53#include <netdb.h>
54#include <stdio.h>
55#include <string.h>
56#include <unistd.h>
57#include <util.h>
58
59/* seconds from midnight Jan 1900 - 1970 */
60#if __STDC__
61#define DIFFERENCE 2208988800UL
62#else
63#define DIFFERENCE 2208988800
64#endif
65
66extern char    *__progname;
67
68	int	main __P((int, char **));
69static	void	usage __P((void));
70
71static void
72usage()
73{
74	(void) fprintf(stderr, "Usage: %s [-psa] host\n", __progname);
75	(void) fprintf(stderr, "  -p: just print, don't set\n");
76	(void) fprintf(stderr, "  -s: just set, don't print\n");
77	(void) fprintf(stderr, "  -a: use adjtime instead of instant change\n");
78}
79
80int
81main(argc, argv)
82	int             argc;
83	char           *argv[];
84{
85	int             pr = 0, silent = 0, s;
86	int		slidetime = 0;
87	int		adjustment;
88	time_t          tim;
89	char           *hname, *emsg;
90	struct addrinfo	hints, *res, *res0;
91	int             c;
92	int		error;
93
94	adjustment = 0;
95	while ((c = getopt(argc, argv, "psa")) != -1)
96		switch (c) {
97		case 'p':
98			pr++;
99			break;
100
101		case 's':
102			silent++;
103			break;
104
105		case 'a':
106			slidetime++;
107			break;
108
109		default:
110			usage();
111			return 1;
112		}
113
114	if (argc - 1 != optind) {
115		usage();
116		return 1;
117	}
118	hname = argv[optind];
119
120	memset(&hints, 0, sizeof (hints));
121	hints.ai_family = PF_UNSPEC;
122	hints.ai_socktype = SOCK_STREAM;
123	hints.ai_flags = AI_CANONNAME;
124	error = getaddrinfo(hname, "time", &hints, &res0);
125	if (error)
126		errx(1, "%s: %s", gai_strerror(error), hname);
127
128	for (res = res0, s = -1; res != NULL; res = res->ai_next) {
129		s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
130		if (s < 0) {
131			emsg = "socket";
132			continue;
133		}
134
135		if (connect(s, res->ai_addr, res->ai_addrlen)) {
136			close(s);
137			s = -1;
138			emsg = "connect";
139			continue;
140		}
141
142		break;
143	}
144	if (s < 0)
145		err(1, "%s", emsg);
146
147	if (read(s, &tim, sizeof(time_t)) != sizeof(time_t))
148		err(1, "Could not read data");
149
150	(void) close(s);
151	tim = ntohl(tim) - DIFFERENCE;
152
153	if (!pr) {
154	    struct timeval  tv;
155	    if (!slidetime) {
156		    logwtmp("|", "date", "");
157		    tv.tv_sec = tim;
158		    tv.tv_usec = 0;
159		    if (settimeofday(&tv, NULL) == -1)
160			    err(1, "Could not set time of day");
161		    logwtmp("{", "date", "");
162	    } else {
163		    struct timeval tv_current;
164		    if (gettimeofday(&tv_current, NULL) == -1)
165			    err(1, "Could not get local time of day");
166		    adjustment = tv.tv_sec = tim - tv_current.tv_sec;
167		    tv.tv_usec = 0;
168		    if (adjtime(&tv, NULL) == -1)
169			    err(1, "Could not adjust time of day");
170	    }
171	}
172
173	if (!silent) {
174		(void) fputs(ctime(&tim), stdout);
175		if (slidetime)
176		    (void) fprintf(stdout,
177				   "%s: adjust local clock by %d seconds\n",
178				   __progname, adjustment);
179	}
180	return 0;
181}
182