rdate.c revision 1.7 
1/*	$NetBSD: rdate.c,v 1.7 1997/06/17 06:10:47 cgd 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#ifndef lint
41static char rcsid[] = "$NetBSD: rdate.c,v 1.7 1997/06/17 06:10:47 cgd Exp $";
42#endif/* lint */
43
44#include <sys/types.h>
45#include <sys/param.h>
46#include <stdio.h>
47#include <ctype.h>
48#include <string.h>
49#include <sys/time.h>
50#include <sys/socket.h>
51#include <netdb.h>
52#include <netinet/in.h>
53#include <util.h>
54
55/* seconds from midnight Jan 1900 - 1970 */
56#if __STDC__
57#define DIFFERENCE 2208988800UL
58#else
59#define DIFFERENCE 2208988800
60#endif
61
62extern char    *__progname;
63
64static void
65usage()
66{
67	(void) fprintf(stderr, "Usage: %s [-psa] host\n", __progname);
68	(void) fprintf(stderr, "  -p: just print, don't set\n");
69	(void) fprintf(stderr, "  -s: just set, don't print\n");
70	(void) fprintf(stderr, "  -a: use adjtime instead of instant change\n");
71}
72
73int
74main(argc, argv)
75	int             argc;
76	char           *argv[];
77{
78	int             pr = 0, silent = 0, s;
79	int		slidetime = 0;
80	int		adjustment;
81	time_t          tim;
82	char           *hname;
83	struct hostent *hp;
84	struct protoent *pp, ppp;
85	struct servent *sp, ssp;
86	struct sockaddr_in sa;
87	extern int      optind;
88	int             c;
89
90	while ((c = getopt(argc, argv, "psa")) != -1)
91		switch (c) {
92		case 'p':
93			pr++;
94			break;
95
96		case 's':
97			silent++;
98			break;
99
100		case 'a':
101			slidetime++;
102			break;
103
104		default:
105			usage();
106			return 1;
107		}
108
109	if (argc - 1 != optind) {
110		usage();
111		return 1;
112	}
113	hname = argv[optind];
114
115	if ((hp = gethostbyname(hname)) == NULL) {
116		warnx("%s: %s", hname, hstrerror(h_errno));
117		return 1;
118	}
119
120	if ((sp = getservbyname("time", "tcp")) == NULL) {
121		sp = &ssp;
122		sp->s_port = 37;
123		sp->s_proto = "tcp";
124	}
125	if ((pp = getprotobyname(sp->s_proto)) == NULL) {
126		pp = &ppp;
127		pp->p_proto = 6;
128	}
129	if ((s = socket(AF_INET, SOCK_STREAM, pp->p_proto)) == -1)
130		err(1, "Could not create socket");
131
132	bzero(&sa, sizeof sa);
133	sa.sin_family = AF_INET;
134	sa.sin_port = sp->s_port;
135
136	memcpy(&(sa.sin_addr.s_addr), hp->h_addr, hp->h_length);
137
138	if (connect(s, (struct sockaddr *) & sa, sizeof(sa)) == -1)
139		err(1, "Could not connect socket");
140
141	if (read(s, &tim, sizeof(time_t)) != sizeof(time_t))
142		err(1, "Could not read data");
143
144	(void) close(s);
145	tim = ntohl(tim) - DIFFERENCE;
146
147	if (!pr) {
148	    struct timeval  tv;
149	    if (!slidetime) {
150		    logwtmp("|", "date", "");
151		    tv.tv_sec = tim;
152		    tv.tv_usec = 0;
153		    if (settimeofday(&tv, NULL) == -1)
154			    err(1, "Could not set time of day");
155		    logwtmp("{", "date", "");
156	    } else {
157		    struct timeval tv_current;
158		    if (gettimeofday(&tv_current, NULL) == -1)
159			    err(1, "Could not get local time of day");
160		    adjustment = tv.tv_sec = tim - tv_current.tv_sec;
161		    tv.tv_usec = 0;
162		    if (adjtime(&tv, NULL) == -1)
163			    err(1, "Could not adjust time of day");
164	    }
165	}
166
167	if (!silent) {
168		(void) fputs(ctime(&tim), stdout);
169		if (slidetime)
170		    (void) fprintf(stdout,
171				   "%s: adjust local clock by %d seconds\n",
172				   __progname, adjustment);
173	}
174	return 0;
175}
176