xref: /netbsd-src/bin/date/netdate.c (revision ae1bfcddc410612bc8c58b807e1830becb69a24c)
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 1.6 1994/02/03 12:50:21 deraadt 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 	bzero((char *)&dest, sizeof dest);
81 	dest.sin_port = sp->s_port;
82 	dest.sin_family = AF_INET;
83 	dest.sin_addr.s_addr = htonl((u_long)INADDR_ANY);
84 	s = socket(AF_INET, SOCK_DGRAM, 0);
85 	if (s < 0) {
86 		if (errno != EPROTONOSUPPORT)
87 			perror("date: timed");
88 		return(retval = 2);
89 	}
90 
91 	bzero((char *)&sin, sizeof(sin));
92 	sin.sin_family = AF_INET;
93 	for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
94 		sin.sin_port = htons((u_short)port);
95 		if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
96 			break;
97 		if (errno == EADDRINUSE)
98 			continue;
99 		if (errno != EADDRNOTAVAIL)
100 			perror("date: bind");
101 		goto bad;
102 	}
103 	if (port == IPPORT_RESERVED / 2) {
104 		(void)fprintf(stderr, "date: all ports in use.\n");
105 		goto bad;
106 	}
107 	msg.tsp_type = TSP_SETDATE;
108 	msg.tsp_vers = TSPVERSION;
109 	if (gethostname(hostname, sizeof(hostname))) {
110 		perror("date: gethostname");
111 		goto bad;
112 	}
113 	(void)strncpy(msg.tsp_name, hostname, sizeof(hostname));
114 	msg.tsp_seq = htons((u_short)0);
115 	msg.tsp_time.tv_sec = htonl((u_long)tval);
116 	msg.tsp_time.tv_usec = htonl((u_long)0);
117 	length = sizeof(struct sockaddr_in);
118 	if (connect(s, (struct sockaddr *)&dest, length) < 0) {
119 		perror("date: connect");
120 		goto bad;
121 	}
122 	if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
123 		if (errno != ECONNREFUSED)
124 			perror("date: send");
125 		goto bad;
126 	}
127 
128 	timed_ack = -1;
129 	waittime = WAITACK;
130 loop:
131 	tout.tv_sec = waittime;
132 	tout.tv_usec = 0;
133 
134 	FD_ZERO(&ready);
135 	FD_SET(s, &ready);
136 	found = select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout);
137 
138 	length = sizeof(err);
139 	if (!getsockopt(s, SOL_SOCKET, SO_ERROR, (char *)&err, &length)
140 	    && err) {
141 		if (err != ECONNREFUSED)
142 			perror("date: send (delayed error)");
143 		goto bad;
144 	}
145 
146 	if (found > 0 && FD_ISSET(s, &ready)) {
147 		length = sizeof(struct sockaddr_in);
148 		if (recvfrom(s, &msg, sizeof(struct tsp), 0,
149 		    (struct sockaddr *)&from, &length) < 0) {
150 			if (errno != ECONNREFUSED)
151 				perror("date: recvfrom");
152 			goto bad;
153 		}
154 		msg.tsp_seq = ntohs(msg.tsp_seq);
155 		msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
156 		msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
157 		switch (msg.tsp_type) {
158 		case TSP_ACK:
159 			timed_ack = TSP_ACK;
160 			waittime = WAITDATEACK;
161 			goto loop;
162 		case TSP_DATEACK:
163 			(void)close(s);
164 			return (0);
165 		default:
166 			(void)fprintf(stderr,
167 			    "date: wrong ack received from timed: %s.\n",
168 			    tsptype[msg.tsp_type]);
169 			timed_ack = -1;
170 			break;
171 		}
172 	}
173 	if (timed_ack == -1)
174 		(void)fprintf(stderr,
175 		    "date: can't reach time daemon, time set locally.\n");
176 
177 bad:
178 	(void)close(s);
179 	return(retval = 2);
180 }
181