summaryrefslogtreecommitdiff
path: root/usr.sbin/rdate/rdate.c
blob: f829c8fea069573f085a1a4c577221777f375afe (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
/*	$OpenBSD: rdate.c,v 1.6 1997/01/21 17:44:05 kstailey Exp $	*/
/*	$NetBSD: rdate.c,v 1.4 1996/03/16 12:37:45 pk Exp $	*/

/*
 * Copyright (c) 1994 Christos Zoulas
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Christos Zoulas.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * rdate.c: Set the date from the specified host
 * 
 * 	Uses the rfc868 time protocol at socket 37.
 *	Time is returned as the number of seconds since
 *	midnight January 1st 1900.
 */
#ifndef lint
#if 0
from: static char rcsid[] = "$NetBSD: rdate.c,v 1.3 1996/02/22 06:59:18 thorpej Exp $";
#else
static char rcsid[] = "$OpenBSD: rdate.c,v 1.6 1997/01/21 17:44:05 kstailey Exp $";
#endif
#endif				/* lint */

#include <sys/types.h>
#include <sys/param.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <time.h>

/* seconds from midnight Jan 1900 - 1970 */
#if __STDC__
#define DIFFERENCE 2208988800UL
#else
#define DIFFERENCE 2208988800
#endif

extern char    *__progname;

static void
usage()
{
	(void) fprintf(stderr, "Usage: %s [-psa] host\n", __progname);
	(void) fprintf(stderr, "  -p: just print, don't set\n");
	(void) fprintf(stderr, "  -s: just set, don't print\n");
	(void) fprintf(stderr, "  -a: use adjtime instead of instant change\n");
}

int
main(argc, argv)
	int             argc;
	char           *argv[];
{
	int             pr = 0, silent = 0, s;
	int		slidetime = 0;
	int		adjustment;
	time_t          tim;
	char           *hname;
	struct hostent *hp;
	struct protoent *pp, ppp;
	struct servent *sp, ssp;
	struct sockaddr_in sa;
	extern int      optind;
	int             c;

	while ((c = getopt(argc, argv, "psa")) != -1)
		switch (c) {
		case 'p':
			pr++;
			break;

		case 's':
			silent++;
			break;

		case 'a':
			slidetime++;
			break;

		default:
			usage();
			return 1;
		}

	if (argc - 1 != optind) {
		usage();
		return 1;
	}
	hname = argv[optind];

	if ((hp = gethostbyname(hname)) == NULL) {
		warnx("%s: %s", hname, hstrerror(h_errno));
		return 1;
	}

	if ((sp = getservbyname("time", "tcp")) == NULL) {
		sp = &ssp;
		sp->s_port = 37;
		sp->s_proto = "tcp";
	}
	if ((pp = getprotobyname(sp->s_proto)) == NULL) {
		pp = &ppp;
		pp->p_proto = 6;
	}
	if ((s = socket(AF_INET, SOCK_STREAM, pp->p_proto)) == -1)
		err(1, "Could not create socket");

	bzero(&sa, sizeof sa);
	sa.sin_family = AF_INET;
	sa.sin_port = sp->s_port;

	memcpy(&(sa.sin_addr.s_addr), hp->h_addr, hp->h_length);

	if (connect(s, (struct sockaddr *) & sa, sizeof(sa)) == -1)
		err(1, "Could not connect socket");

	if (read(s, &tim, sizeof(time_t)) != sizeof(time_t))
		err(1, "Could not read data");

	(void) close(s);
	tim = ntohl(tim) - DIFFERENCE;

	if (!pr) {
	    struct timeval  tv;
	    if (!slidetime) {
		    tv.tv_sec = tim;
		    tv.tv_usec = 0;
		    if (settimeofday(&tv, NULL) == -1)
			    err(1, "Could not set time of day");
	    } else {
		    struct timeval tv_current;
		    if (gettimeofday(&tv_current, NULL) == -1)
			    err(1, "Could not get local time of day");
		    adjustment = tv.tv_sec = tim - tv_current.tv_sec;
		    tv.tv_usec = 0;
		    if (adjtime(&tv, NULL) == -1)
			    err(1, "Could not adjust time of day");
	    }
	}

	if (!silent) {
		struct tm      *ltm;
		char		buf[80];

		ltm = localtime(&tim);
		strftime(buf, 80, "%a %b %d %H:%M:%S %Z %Y\n", ltm);
		(void) fputs(buf, stdout);

		if (slidetime)
		    (void) fprintf(stdout, 
				   "%s: adjust local clock by %d seconds\n",
				   __progname, adjustment);
	}
	return 0;
}