1 /* $NetBSD: rdate.c,v 1.22 2017/08/26 19:26:32 ginsbach 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 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28 /*
29 * rdate.c: Set the date from the specified host
30 *
31 * Uses the rfc868 time protocol at socket 37.
32 * Time is returned as the number of seconds since
33 * midnight January 1st 1900.
34 */
35 #include <sys/cdefs.h>
36 #ifndef lint
37 __RCSID("$NetBSD: rdate.c,v 1.22 2017/08/26 19:26:32 ginsbach Exp $");
38 #endif /* lint */
39
40 #include <sys/types.h>
41 #include <sys/socket.h>
42 #include <sys/time.h>
43
44 #include <netinet/in.h>
45
46 #include <err.h>
47 #include <netdb.h>
48 #include <stdio.h>
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <util.h>
53
54 /* seconds from midnight Jan 1900 - 1970 */
55 #define DIFFERENCE 2208988800ULL
56
57 static void usage(void);
58
59 static void
usage(void)60 usage(void)
61 {
62 (void) fprintf(stderr, "usage: %s [-46aps] host\n", getprogname());
63 (void) fprintf(stderr, " -4: use IPv4 addresses only\n");
64 (void) fprintf(stderr, " -6: use IPv6 addresses only\n");
65 (void) fprintf(stderr, " -a: use adjtime instead of instant change\n");
66 (void) fprintf(stderr, " -p: just print, don't set\n");
67 (void) fprintf(stderr, " -s: just set, don't print\n");
68 }
69
70 int
main(int argc,char * argv[])71 main(int argc, char *argv[])
72 {
73 int pr = 0, silent = 0, s;
74 int slidetime = 0;
75 int adjustment;
76 uint32_t data;
77 time_t tim;
78 char *hname;
79 const char *emsg = NULL;
80 struct addrinfo hints, *res, *res0;
81 int c;
82 int error;
83 int family = AF_UNSPEC;
84
85 adjustment = 0;
86 while ((c = getopt(argc, argv, "46aps")) != -1)
87 switch (c) {
88 case '4':
89 family = AF_INET;
90 break;
91
92 case '6':
93 family = AF_INET6;
94 break;
95
96 case 'a':
97 slidetime++;
98 break;
99
100 case 'p':
101 pr++;
102 break;
103
104 case 's':
105 silent++;
106 break;
107
108 default:
109 usage();
110 return 1;
111 }
112
113 if (argc - 1 != optind) {
114 usage();
115 return 1;
116 }
117 hname = argv[optind];
118
119 memset(&hints, 0, sizeof (hints));
120 hints.ai_family = family;
121 hints.ai_socktype = SOCK_STREAM;
122 hints.ai_flags = AI_CANONNAME;
123 error = getaddrinfo(hname, "time", &hints, &res0);
124 if (error)
125 errx(1, "%s: %s", gai_strerror(error), hname);
126
127 for (res = res0, s = -1; res != NULL; res = res->ai_next) {
128 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
129 if (s < 0) {
130 emsg = "socket";
131 continue;
132 }
133
134 if (connect(s, res->ai_addr, res->ai_addrlen)) {
135 close(s);
136 s = -1;
137 emsg = "connect";
138 continue;
139 }
140
141 break;
142 }
143 if (s < 0)
144 err(1, "%s", emsg);
145
146 if (read(s, &data, sizeof(uint32_t)) != sizeof(uint32_t))
147 err(1, "Could not read data");
148
149 (void) close(s);
150 tim = ntohl(data) - DIFFERENCE;
151
152 if (!pr) {
153 struct timeval tv;
154 if (!slidetime) {
155 logwtmp("|", "date", "");
156 tv.tv_sec = tim;
157 tv.tv_usec = 0;
158 if (settimeofday(&tv, NULL) == -1)
159 err(1, "Could not set time of day");
160 logwtmp("{", "date", "");
161 } else {
162 struct timeval tv_current;
163 if (gettimeofday(&tv_current, NULL) == -1)
164 err(1, "Could not get local time of day");
165 adjustment = tv.tv_sec = tim - tv_current.tv_sec;
166 tv.tv_usec = 0;
167 if (adjtime(&tv, NULL) == -1)
168 err(1, "Could not adjust time of day");
169 }
170 }
171
172 if (!silent) {
173 (void) fputs(ctime(&tim), stdout);
174 if (slidetime)
175 (void) fprintf(stdout,
176 "%s: adjust local clock by %d seconds\n",
177 getprogname(), adjustment);
178 }
179 return 0;
180 }
181