xref: /netbsd-src/bin/date/netdate.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
1 /*	$NetBSD: netdate.c,v 1.8 1995/03/21 09:03:54 cgd Exp $	*/
2 
3 /*-
4  * Copyright (c) 1990, 1993
5  *	The Regents of the University of California.  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 the University of
18  *	California, Berkeley and its contributors.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)netdate.c	8.1 (Berkeley) 5/31/93";
39 #else
40 static char rcsid[] = "$NetBSD: netdate.c,v 1.8 1995/03/21 09:03:54 cgd Exp $";
41 #endif
42 #endif /* not lint */
43 
44 #include <sys/param.h>
45 #include <sys/time.h>
46 #include <sys/socket.h>
47 
48 #include <netinet/in.h>
49 #include <netdb.h>
50 #define TSPTYPES
51 #include <protocols/timed.h>
52 
53 #include <err.h>
54 #include <errno.h>
55 #include <stdio.h>
56 #include <string.h>
57 #include <unistd.h>
58 
59 #include "extern.h"
60 
61 #define	WAITACK		2	/* seconds */
62 #define	WAITDATEACK	5	/* seconds */
63 
64 extern int retval;
65 
66 /*
67  * Set the date in the machines controlled by timedaemons by communicating the
68  * new date to the local timedaemon.  If the timedaemon is in the master state,
69  * it performs the correction on all slaves.  If it is in the slave state, it
70  * notifies the master that a correction is needed.
71  * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
72  */
73 int
74 netsettime(tval)
75 	time_t tval;
76 {
77 	struct timeval tout;
78 	struct servent *sp;
79 	struct tsp msg;
80 	struct sockaddr_in sin, dest, from;
81 	fd_set ready;
82 	long waittime;
83 	int s, length, port, timed_ack, found, err;
84 	char hostname[MAXHOSTNAMELEN];
85 
86 	if ((sp = getservbyname("timed", "udp")) == NULL) {
87 		warnx("udp/timed: unknown service");
88 		return (retval = 2);
89 	}
90 
91 	memset(&dest, 0, sizeof(dest));
92 	dest.sin_port = sp->s_port;
93 	dest.sin_family = AF_INET;
94 	dest.sin_addr.s_addr = htonl((u_long)INADDR_ANY);
95 	s = socket(AF_INET, SOCK_DGRAM, 0);
96 	if (s < 0) {
97 		if (errno != EPROTONOSUPPORT)
98 			warn("timed");
99 		return (retval = 2);
100 	}
101 
102 	memset(&sin, 0, sizeof(sin));
103 	sin.sin_family = AF_INET;
104 	for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
105 		sin.sin_port = htons((u_short)port);
106 		if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
107 			break;
108 		if (errno == EADDRINUSE)
109 			continue;
110 		if (errno != EADDRNOTAVAIL)
111 			warn("bind");
112 		goto bad;
113 	}
114 	if (port == IPPORT_RESERVED / 2) {
115 		warnx("all ports in use");
116 		goto bad;
117 	}
118 	msg.tsp_type = TSP_SETDATE;
119 	msg.tsp_vers = TSPVERSION;
120 	if (gethostname(hostname, sizeof(hostname))) {
121 		warn("gethostname");
122 		goto bad;
123 	}
124 	(void)strncpy(msg.tsp_name, hostname, sizeof(hostname));
125 	msg.tsp_seq = htons((u_short)0);
126 	msg.tsp_time.tv_sec = htonl((u_long)tval);
127 	msg.tsp_time.tv_usec = htonl((u_long)0);
128 	length = sizeof(struct sockaddr_in);
129 	if (connect(s, (struct sockaddr *)&dest, length) < 0) {
130 		warn("connect");
131 		goto bad;
132 	}
133 	if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
134 		if (errno != ECONNREFUSED)
135 			warn("send");
136 		goto bad;
137 	}
138 
139 	timed_ack = -1;
140 	waittime = WAITACK;
141 loop:
142 	tout.tv_sec = waittime;
143 	tout.tv_usec = 0;
144 
145 	FD_ZERO(&ready);
146 	FD_SET(s, &ready);
147 	found = select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout);
148 
149 	length = sizeof(err);
150 	if (!getsockopt(s,
151 	    SOL_SOCKET, SO_ERROR, (char *)&err, &length) && err) {
152 		if (err != ECONNREFUSED)
153 			warn("send (delayed error)");
154 		goto bad;
155 	}
156 
157 	if (found > 0 && FD_ISSET(s, &ready)) {
158 		length = sizeof(struct sockaddr_in);
159 		if (recvfrom(s, &msg, sizeof(struct tsp), 0,
160 		    (struct sockaddr *)&from, &length) < 0) {
161 			if (errno != ECONNREFUSED)
162 				warn("recvfrom");
163 			goto bad;
164 		}
165 		msg.tsp_seq = ntohs(msg.tsp_seq);
166 		msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
167 		msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
168 		switch (msg.tsp_type) {
169 		case TSP_ACK:
170 			timed_ack = TSP_ACK;
171 			waittime = WAITDATEACK;
172 			goto loop;
173 		case TSP_DATEACK:
174 			(void)close(s);
175 			return (0);
176 		default:
177 			warnx("wrong ack received from timed: %s",
178 			    tsptype[msg.tsp_type]);
179 			timed_ack = -1;
180 			break;
181 		}
182 	}
183 	if (timed_ack == -1)
184 		warnx("can't reach time daemon, time set locally");
185 
186 bad:
187 	(void)close(s);
188 	return (retval = 2);
189 }
190