xref: /netbsd-src/bin/date/netdate.c (revision ae9172d6cd9432a6a1a56760d86b32c57a66c39c)
1 /*-
2  * Copyright (c) 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifndef lint
35 /*static char sccsid[] = "from: @(#)netdate.c	8.1 (Berkeley) 5/31/93";*/
36 static char *rcsid = "$Id: netdate.c,v 1.7 1994/09/22 09:24:52 mycroft Exp $";
37 #endif /* not lint */
38 
39 #include <sys/param.h>
40 #include <sys/time.h>
41 #include <sys/socket.h>
42 
43 #include <netinet/in.h>
44 #include <netdb.h>
45 #define TSPTYPES
46 #include <protocols/timed.h>
47 
48 #include <err.h>
49 #include <errno.h>
50 #include <stdio.h>
51 #include <string.h>
52 #include <unistd.h>
53 
54 #include "extern.h"
55 
56 #define	WAITACK		2	/* seconds */
57 #define	WAITDATEACK	5	/* seconds */
58 
59 extern int retval;
60 
61 /*
62  * Set the date in the machines controlled by timedaemons by communicating the
63  * new date to the local timedaemon.  If the timedaemon is in the master state,
64  * it performs the correction on all slaves.  If it is in the slave state, it
65  * notifies the master that a correction is needed.
66  * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
67  */
68 int
69 netsettime(tval)
70 	time_t tval;
71 {
72 	struct timeval tout;
73 	struct servent *sp;
74 	struct tsp msg;
75 	struct sockaddr_in sin, dest, from;
76 	fd_set ready;
77 	long waittime;
78 	int s, length, port, timed_ack, found, err;
79 	char hostname[MAXHOSTNAMELEN];
80 
81 	if ((sp = getservbyname("timed", "udp")) == NULL) {
82 		warnx("udp/timed: unknown service");
83 		return (retval = 2);
84 	}
85 
86 	memset(&dest, 0, sizeof(dest));
87 	dest.sin_port = sp->s_port;
88 	dest.sin_family = AF_INET;
89 	dest.sin_addr.s_addr = htonl((u_long)INADDR_ANY);
90 	s = socket(AF_INET, SOCK_DGRAM, 0);
91 	if (s < 0) {
92 		if (errno != EPROTONOSUPPORT)
93 			warn("timed");
94 		return (retval = 2);
95 	}
96 
97 	memset(&sin, 0, sizeof(sin));
98 	sin.sin_family = AF_INET;
99 	for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
100 		sin.sin_port = htons((u_short)port);
101 		if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
102 			break;
103 		if (errno == EADDRINUSE)
104 			continue;
105 		if (errno != EADDRNOTAVAIL)
106 			warn("bind");
107 		goto bad;
108 	}
109 	if (port == IPPORT_RESERVED / 2) {
110 		warnx("all ports in use");
111 		goto bad;
112 	}
113 	msg.tsp_type = TSP_SETDATE;
114 	msg.tsp_vers = TSPVERSION;
115 	if (gethostname(hostname, sizeof(hostname))) {
116 		warn("gethostname");
117 		goto bad;
118 	}
119 	(void)strncpy(msg.tsp_name, hostname, sizeof(hostname));
120 	msg.tsp_seq = htons((u_short)0);
121 	msg.tsp_time.tv_sec = htonl((u_long)tval);
122 	msg.tsp_time.tv_usec = htonl((u_long)0);
123 	length = sizeof(struct sockaddr_in);
124 	if (connect(s, (struct sockaddr *)&dest, length) < 0) {
125 		warn("connect");
126 		goto bad;
127 	}
128 	if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
129 		if (errno != ECONNREFUSED)
130 			warn("send");
131 		goto bad;
132 	}
133 
134 	timed_ack = -1;
135 	waittime = WAITACK;
136 loop:
137 	tout.tv_sec = waittime;
138 	tout.tv_usec = 0;
139 
140 	FD_ZERO(&ready);
141 	FD_SET(s, &ready);
142 	found = select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout);
143 
144 	length = sizeof(err);
145 	if (!getsockopt(s,
146 	    SOL_SOCKET, SO_ERROR, (char *)&err, &length) && err) {
147 		if (err != ECONNREFUSED)
148 			warn("send (delayed error)");
149 		goto bad;
150 	}
151 
152 	if (found > 0 && FD_ISSET(s, &ready)) {
153 		length = sizeof(struct sockaddr_in);
154 		if (recvfrom(s, &msg, sizeof(struct tsp), 0,
155 		    (struct sockaddr *)&from, &length) < 0) {
156 			if (errno != ECONNREFUSED)
157 				warn("recvfrom");
158 			goto bad;
159 		}
160 		msg.tsp_seq = ntohs(msg.tsp_seq);
161 		msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
162 		msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
163 		switch (msg.tsp_type) {
164 		case TSP_ACK:
165 			timed_ack = TSP_ACK;
166 			waittime = WAITDATEACK;
167 			goto loop;
168 		case TSP_DATEACK:
169 			(void)close(s);
170 			return (0);
171 		default:
172 			warnx("wrong ack received from timed: %s",
173 			    tsptype[msg.tsp_type]);
174 			timed_ack = -1;
175 			break;
176 		}
177 	}
178 	if (timed_ack == -1)
179 		warnx("can't reach time daemon, time set locally");
180 
181 bad:
182 	(void)close(s);
183 	return (retval = 2);
184 }
185