xref: /netbsd-src/bin/date/netdate.c (revision 4b30c543a0b21e3ba94f2c569e9a82b4fdb2075f)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * 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	5.2 (Berkeley) 2/25/91";*/
36 static char rcsid[] = "$Id: netdate.c,v 1.4 1993/08/01 19:00:17 mycroft Exp $";
37 #endif /* not lint */
38 
39 #include <sys/param.h>
40 #include <sys/time.h>
41 #include <sys/socket.h>
42 #include <sys/errno.h>
43 #include <netinet/in.h>
44 #include <netdb.h>
45 #define TSPTYPES
46 #include <protocols/timed.h>
47 #include <unistd.h>
48 #include <stdio.h>
49 #include <string.h>
50 
51 #define	WAITACK		2	/* seconds */
52 #define	WAITDATEACK	5	/* seconds */
53 
54 extern int retval;
55 
56 /*
57  * Set the date in the machines controlled by timedaemons by communicating the
58  * new date to the local timedaemon.  If the timedaemon is in the master state,
59  * it performs the correction on all slaves.  If it is in the slave state, it
60  * notifies the master that a correction is needed.
61  * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
62  */
63 netsettime(tval)
64 	time_t tval;
65 {
66 	struct timeval tout;
67 	struct servent *sp;
68 	struct tsp msg;
69 	struct sockaddr_in sin, dest, from;
70 	fd_set ready;
71 	long waittime;
72 	int s, length, port, timed_ack, found, err;
73 	char hostname[MAXHOSTNAMELEN];
74 
75 	if ((sp = getservbyname("timed", "udp")) == NULL) {
76 		(void)fprintf(stderr, "date: udp/timed: unknown service.n");
77 		return (retval = 2);
78 	}
79 
80 	dest.sin_port = sp->s_port;
81 	dest.sin_family = AF_INET;
82 	dest.sin_addr.s_addr = htonl((u_long)INADDR_ANY);
83 	s = socket(AF_INET, SOCK_DGRAM, 0);
84 	if (s < 0) {
85 		if (errno != EPROTONOSUPPORT)
86 			perror("date: timed");
87 		return(retval = 2);
88 	}
89 
90 	bzero((char *)&sin, sizeof(sin));
91 	sin.sin_family = AF_INET;
92 	for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
93 		sin.sin_port = htons((u_short)port);
94 		if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
95 			break;
96 		if (errno == EADDRINUSE)
97 			continue;
98 		if (errno != EADDRNOTAVAIL)
99 			perror("date: bind");
100 		goto bad;
101 	}
102 	if (port == IPPORT_RESERVED / 2) {
103 		(void)fprintf(stderr, "date: all ports in use.\n");
104 		goto bad;
105 	}
106 	msg.tsp_type = TSP_SETDATE;
107 	msg.tsp_vers = TSPVERSION;
108 	if (gethostname(hostname, sizeof(hostname))) {
109 		perror("date: gethostname");
110 		goto bad;
111 	}
112 	(void)strncpy(msg.tsp_name, hostname, sizeof(hostname));
113 	msg.tsp_seq = htons((u_short)0);
114 	msg.tsp_time.tv_sec = htonl((u_long)tval);
115 	msg.tsp_time.tv_usec = htonl((u_long)0);
116 	length = sizeof(struct sockaddr_in);
117 	if (connect(s, (struct sockaddr *)&dest, length) < 0) {
118 		perror("date: connect");
119 		goto bad;
120 	}
121 	if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
122 		if (errno != ECONNREFUSED)
123 			perror("date: send");
124 		goto bad;
125 	}
126 
127 	timed_ack = -1;
128 	waittime = WAITACK;
129 loop:
130 	tout.tv_sec = waittime;
131 	tout.tv_usec = 0;
132 
133 	FD_ZERO(&ready);
134 	FD_SET(s, &ready);
135 	found = select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout);
136 
137 	length = sizeof(err);
138 	if (!getsockopt(s, SOL_SOCKET, SO_ERROR, (char *)&err, &length)
139 	    && err) {
140 		if (err != ECONNREFUSED)
141 			perror("date: send (delayed error)");
142 		goto bad;
143 	}
144 
145 	if (found > 0 && FD_ISSET(s, &ready)) {
146 		length = sizeof(struct sockaddr_in);
147 		if (recvfrom(s, &msg, sizeof(struct tsp), 0,
148 		    (struct sockaddr *)&from, &length) < 0) {
149 			if (errno != ECONNREFUSED)
150 				perror("date: recvfrom");
151 			goto bad;
152 		}
153 		msg.tsp_seq = ntohs(msg.tsp_seq);
154 		msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
155 		msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
156 		switch (msg.tsp_type) {
157 		case TSP_ACK:
158 			timed_ack = TSP_ACK;
159 			waittime = WAITDATEACK;
160 			goto loop;
161 		case TSP_DATEACK:
162 			(void)close(s);
163 			return (0);
164 		default:
165 			(void)fprintf(stderr,
166 			    "date: wrong ack received from timed: %s.\n",
167 			    tsptype[msg.tsp_type]);
168 			timed_ack = -1;
169 			break;
170 		}
171 	}
172 	if (timed_ack == -1)
173 		(void)fprintf(stderr,
174 		    "date: can't reach time daemon, time set locally.\n");
175 
176 bad:
177 	(void)close(s);
178 	return(retval = 2);
179 }
180