xref: /openbsd-src/usr.sbin/rdate/rfc868time.c (revision 893695cea05286a86be12c6215f6501df588dceb)
1 /*	$OpenBSD: rfc868time.c,v 1.13 2023/01/04 13:00:11 jsg Exp $	*/
2 /*	$NetBSD: rdate.c,v 1.4 1996/03/16 12:37:45 pk Exp $	*/
3 
4 /*
5  * Copyright (c) 1994 Christos Zoulas
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * rdate.c: Set the date from the specified host
31  *
32  *	Uses the rfc868 time protocol at socket 37 (tcp).
33  *	Time is returned as the number of seconds since
34  *	midnight January 1st 1900.
35  */
36 
37 #include <sys/socket.h>
38 #include <sys/time.h>
39 #include <netinet/in.h>
40 
41 #include <stdio.h>
42 #include <ctype.h>
43 #include <err.h>
44 #include <string.h>
45 #include <netdb.h>
46 #include <unistd.h>
47 #include <time.h>
48 
49 /* Obviously it is not just for SNTP clients... */
50 #include "ntpleaps.h"
51 
52 /* seconds from midnight Jan 1900 - 1970 */
53 #define DIFFERENCE 2208988800UL
54 
55 void
56 rfc868time_client(const char *hostname, int family, struct timeval *new,
57     struct timeval *adjust, int leapflag);
58 
59 
60 void
rfc868time_client(const char * hostname,int family,struct timeval * new,struct timeval * adjust,int leapflag)61 rfc868time_client(const char *hostname, int family, struct timeval *new,
62     struct timeval *adjust, int leapflag)
63 {
64 	struct addrinfo hints, *res0, *res;
65 	struct timeval old;
66 	u_int32_t tim;	/* RFC 868 states clearly this is an uint32 */
67 	int s;
68 	int error;
69 	u_int64_t td;
70 
71 	memset(&hints, 0, sizeof(hints));
72 	hints.ai_family = family;
73 	hints.ai_socktype = SOCK_STREAM;
74 	error = getaddrinfo(hostname, "time", &hints, &res0);
75 	if (error) {
76 		errx(1, "%s: %s", hostname, gai_strerror(error));
77 		/*NOTREACHED*/
78 	}
79 
80 	if (pledge("stdio inet", NULL) == -1)
81 		err(1, "pledge");
82 
83 	s = -1;
84 	for (res = res0; res; res = res->ai_next) {
85 		s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
86 		if (s == -1)
87 			continue;
88 
89 		if (connect(s, res->ai_addr, res->ai_addrlen) == -1) {
90 			close(s);
91 			s = -1;
92 			continue;
93 		}
94 
95 		break;
96 	}
97 	if (s == -1)
98 		err(1, "Could not connect socket");
99 	freeaddrinfo(res0);
100 
101 	if (read(s, &tim, sizeof(tim)) != sizeof(tim))
102 		err(1, "Could not read data");
103 
104 	(void) close(s);
105 	tim = ntohl(tim) - DIFFERENCE;
106 
107 	if (gettimeofday(&old, NULL) == -1)
108 		err(1, "Could not get local time of day");
109 
110 	td = SEC_TO_TAI64(old.tv_sec);
111 	if (leapflag)
112 		ntpleaps_sub(&td);
113 
114 	adjust->tv_sec = tim - TAI64_TO_SEC(td);
115 	adjust->tv_usec = 0;
116 
117 	new->tv_sec = old.tv_sec + adjust->tv_sec;
118 	new->tv_usec = 0;
119 }
120