rdate.c revision 1.8 
1/*	$NetBSD: rdate.c,v 1.8 1997/10/18 03:51:03 lukem 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 1.8 1997/10/18 03:51:03 lukem Exp $");
43#endif/* lint */
44
45#include <sys/types.h>
46#include <sys/param.h>
47#include <sys/socket.h>
48#include <sys/time.h>
49
50#include <netinet/in.h>
51
52#include <ctype.h>
53#include <err.h>
54#include <netdb.h>
55#include <stdio.h>
56#include <string.h>
57#include <unistd.h>
58#include <util.h>
59
60/* seconds from midnight Jan 1900 - 1970 */
61#if __STDC__
62#define DIFFERENCE 2208988800UL
63#else
64#define DIFFERENCE 2208988800
65#endif
66
67extern char    *__progname;
68
69	int	main __P((int, char **));
70static	void	usage __P((void));
71
72static void
73usage()
74{
75	(void) fprintf(stderr, "Usage: %s [-psa] host\n", __progname);
76	(void) fprintf(stderr, "  -p: just print, don't set\n");
77	(void) fprintf(stderr, "  -s: just set, don't print\n");
78	(void) fprintf(stderr, "  -a: use adjtime instead of instant change\n");
79}
80
81int
82main(argc, argv)
83	int             argc;
84	char           *argv[];
85{
86	int             pr = 0, silent = 0, s;
87	int		slidetime = 0;
88	int		adjustment;
89	time_t          tim;
90	char           *hname;
91	struct hostent *hp;
92	struct protoent *pp, ppp;
93	struct servent *sp, ssp;
94	struct sockaddr_in sa;
95	int             c;
96
97	adjustment = 0;
98	while ((c = getopt(argc, argv, "psa")) != -1)
99		switch (c) {
100		case 'p':
101			pr++;
102			break;
103
104		case 's':
105			silent++;
106			break;
107
108		case 'a':
109			slidetime++;
110			break;
111
112		default:
113			usage();
114			return 1;
115		}
116
117	if (argc - 1 != optind) {
118		usage();
119		return 1;
120	}
121	hname = argv[optind];
122
123	if ((hp = gethostbyname(hname)) == NULL) {
124		warnx("%s: %s", hname, hstrerror(h_errno));
125		return 1;
126	}
127
128	if ((sp = getservbyname("time", "tcp")) == NULL) {
129		sp = &ssp;
130		sp->s_port = 37;
131		sp->s_proto = "tcp";
132	}
133	if ((pp = getprotobyname(sp->s_proto)) == NULL) {
134		pp = &ppp;
135		pp->p_proto = 6;
136	}
137	if ((s = socket(AF_INET, SOCK_STREAM, pp->p_proto)) == -1)
138		err(1, "Could not create socket");
139
140	bzero(&sa, sizeof sa);
141	sa.sin_family = AF_INET;
142	sa.sin_port = sp->s_port;
143
144	memcpy(&(sa.sin_addr.s_addr), hp->h_addr, hp->h_length);
145
146	if (connect(s, (struct sockaddr *) & sa, sizeof(sa)) == -1)
147		err(1, "Could not connect socket");
148
149	if (read(s, &tim, sizeof(time_t)) != sizeof(time_t))
150		err(1, "Could not read data");
151
152	(void) close(s);
153	tim = ntohl(tim) - DIFFERENCE;
154
155	if (!pr) {
156	    struct timeval  tv;
157	    if (!slidetime) {
158		    logwtmp("|", "date", "");
159		    tv.tv_sec = tim;
160		    tv.tv_usec = 0;
161		    if (settimeofday(&tv, NULL) == -1)
162			    err(1, "Could not set time of day");
163		    logwtmp("{", "date", "");
164	    } else {
165		    struct timeval tv_current;
166		    if (gettimeofday(&tv_current, NULL) == -1)
167			    err(1, "Could not get local time of day");
168		    adjustment = tv.tv_sec = tim - tv_current.tv_sec;
169		    tv.tv_usec = 0;
170		    if (adjtime(&tv, NULL) == -1)
171			    err(1, "Could not adjust time of day");
172	    }
173	}
174
175	if (!silent) {
176		(void) fputs(ctime(&tim), stdout);
177		if (slidetime)
178		    (void) fprintf(stdout,
179				   "%s: adjust local clock by %d seconds\n",
180				   __progname, adjustment);
181	}
182	return 0;
183}
184