xref: /netbsd-src/bin/date/netdate.c (revision 76dfffe33547c37f8bdd446e3e4ab0f3c16cea4b)
1 /*	$NetBSD: netdate.c,v 1.10 1995/09/07 06:21:06 jtc 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	8.2 (Berkeley) 4/28/95";
39 #else
40 static char rcsid[] = "$NetBSD: netdate.c,v 1.10 1995/09/07 06:21:06 jtc 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_len = sizeof(struct sockaddr_in);
93 	dest.sin_family = AF_INET;
94 	dest.sin_port = sp->s_port;
95 	dest.sin_addr.s_addr = htonl(INADDR_ANY);
96 	s = socket(AF_INET, SOCK_DGRAM, 0);
97 	if (s < 0) {
98 		if (errno != EPROTONOSUPPORT)
99 			warn("timed");
100 		return (retval = 2);
101 	}
102 
103 	memset(&sin, 0, sizeof(sin));
104 	sin.sin_len = sizeof(struct sockaddr_in);
105 	sin.sin_family = AF_INET;
106 	for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
107 		sin.sin_port = htons((u_short)port);
108 		if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
109 			break;
110 		if (errno == EADDRINUSE)
111 			continue;
112 		if (errno != EADDRNOTAVAIL)
113 			warn("bind");
114 		goto bad;
115 	}
116 	if (port == IPPORT_RESERVED / 2) {
117 		warnx("all ports in use");
118 		goto bad;
119 	}
120 	msg.tsp_type = TSP_SETDATE;
121 	msg.tsp_vers = TSPVERSION;
122 	if (gethostname(hostname, sizeof(hostname))) {
123 		warn("gethostname");
124 		goto bad;
125 	}
126 	(void)strncpy(msg.tsp_name, hostname, sizeof(hostname));
127 	msg.tsp_seq = htons((u_short)0);
128 	msg.tsp_time.tv_sec = htonl((u_long)tval);
129 	msg.tsp_time.tv_usec = htonl((u_long)0);
130 	length = sizeof(struct sockaddr_in);
131 	if (connect(s, (struct sockaddr *)&dest, length) < 0) {
132 		warn("connect");
133 		goto bad;
134 	}
135 	if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
136 		if (errno != ECONNREFUSED)
137 			warn("send");
138 		goto bad;
139 	}
140 
141 	timed_ack = -1;
142 	waittime = WAITACK;
143 loop:
144 	tout.tv_sec = waittime;
145 	tout.tv_usec = 0;
146 
147 	FD_ZERO(&ready);
148 	FD_SET(s, &ready);
149 	found = select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout);
150 
151 	length = sizeof(err);
152 	if (!getsockopt(s,
153 	    SOL_SOCKET, SO_ERROR, (char *)&err, &length) && err) {
154 		if (err != ECONNREFUSED)
155 			warn("send (delayed error)");
156 		goto bad;
157 	}
158 
159 	if (found > 0 && FD_ISSET(s, &ready)) {
160 		length = sizeof(struct sockaddr_in);
161 		if (recvfrom(s, &msg, sizeof(struct tsp), 0,
162 		    (struct sockaddr *)&from, &length) < 0) {
163 			if (errno != ECONNREFUSED)
164 				warn("recvfrom");
165 			goto bad;
166 		}
167 		msg.tsp_seq = ntohs(msg.tsp_seq);
168 		msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
169 		msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
170 		switch (msg.tsp_type) {
171 		case TSP_ACK:
172 			timed_ack = TSP_ACK;
173 			waittime = WAITDATEACK;
174 			goto loop;
175 		case TSP_DATEACK:
176 			(void)close(s);
177 			return (0);
178 		default:
179 			warnx("wrong ack received from timed: %s",
180 			    tsptype[msg.tsp_type]);
181 			timed_ack = -1;
182 			break;
183 		}
184 	}
185 	if (timed_ack == -1)
186 		warnx("can't reach time daemon, time set locally");
187 
188 bad:
189 	(void)close(s);
190 	return (retval = 2);
191 }
192