xref: /minix/bin/date/netdate.c (revision ebfedea0)
1 /* $NetBSD: netdate.c,v 1.30 2011/01/29 02:16:52 christos 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. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)netdate.c	8.2 (Berkeley) 4/28/95";
36 #else
37 __RCSID("$NetBSD: netdate.c,v 1.30 2011/01/29 02:16:52 christos Exp $");
38 #endif
39 #endif /* not lint */
40 
41 #include <sys/param.h>
42 #include <sys/time.h>
43 #include <sys/socket.h>
44 
45 #include <netinet/in.h>
46 #include <netdb.h>
47 #define TSPTYPES
48 #include <protocols/timed.h>
49 
50 #include <err.h>
51 #include <errno.h>
52 #include <poll.h>
53 #include <stdio.h>
54 #include <string.h>
55 #include <unistd.h>
56 
57 #include "extern.h"
58 
59 #define	WAITACK		2000	/* milliseconds */
60 #define	WAITDATEACK	5000	/* milliseconds */
61 
62 static const char *
63 tsp_type_to_string(const struct tsp *msg)
64 {
65 	unsigned i;
66 
67 	i = msg->tsp_type;
68 	return i < TSPTYPENUMBER ? tsptype[i] : "unknown";
69 }
70 
71 /*
72  * Set the date in the machines controlled by timedaemons by communicating the
73  * new date to the local timedaemon.  If the timedaemon is in the master state,
74  * it performs the correction on all slaves.  If it is in the slave state, it
75  * notifies the master that a correction is needed.
76  * Returns 0 on success.  Returns > 0 on failure.
77  */
78 int
79 netsettime(time_t tval)
80 {
81 	struct sockaddr_in dest;
82 	struct tsp msg;
83 	char hostname[MAXHOSTNAMELEN];
84 	struct servent *sp;
85 	struct pollfd ready;
86 	int found, s, timed_ack, waittime;
87 
88 	if ((sp = getservbyname("timed", "udp")) == NULL) {
89 		warnx("udp/timed: unknown service");
90 		return 2;
91 	}
92 
93 	(void)memset(&dest, 0, sizeof(dest));
94 #ifdef BSD4_4
95 	dest.sin_len = sizeof(dest);
96 #endif
97 	dest.sin_family = AF_INET;
98 	dest.sin_port = sp->s_port;
99 	dest.sin_addr.s_addr = htonl(INADDR_ANY);
100 	s = socket(AF_INET, SOCK_DGRAM, 0);
101 	if (s == -1) {
102 		if (errno != EAFNOSUPPORT)
103 			warn("timed");
104 		return 2;
105 	}
106 
107 #ifdef IP_PORTRANGE
108 	{
109 		static const int on = IP_PORTRANGE_LOW;
110 
111 		if (setsockopt(s, IPPROTO_IP, IP_PORTRANGE, &on,
112 		    sizeof(on)) == -1) {
113 			warn("setsockopt");
114 			goto bad;
115 		}
116 	}
117 #endif
118 
119 	msg.tsp_type = TSP_SETDATE;
120 	msg.tsp_vers = TSPVERSION;
121 	if (gethostname(hostname, sizeof(hostname)) == -1) {
122 		warn("gethostname");
123 		goto bad;
124 	}
125 	(void)strlcpy(msg.tsp_name, hostname, sizeof(msg.tsp_name));
126 	msg.tsp_seq = htons((in_port_t)0);
127 	msg.tsp_time.tv_sec = htonl((in_addr_t)tval); /* XXX: y2038 */
128 	msg.tsp_time.tv_usec = htonl((in_addr_t)0);
129 	if (connect(s, (const void *)&dest, sizeof(dest)) == -1) {
130 		warn("connect");
131 		goto bad;
132 	}
133 	if (send(s, &msg, sizeof(msg), 0) == -1) {
134 		if (errno != ECONNREFUSED)
135 			warn("send");
136 		goto bad;
137 	}
138 
139 	timed_ack = -1;
140 	waittime = WAITACK;
141 	ready.fd = s;
142 	ready.events = POLLIN;
143 loop:
144 	found = poll(&ready, 1, waittime);
145 
146 	{
147 		socklen_t len;
148 		int error;
149 
150 		len = sizeof(error);
151 		if (getsockopt(s, SOL_SOCKET, SO_ERROR, &error, &len) == -1) {
152 			warn("getsockopt");
153 			goto bad;
154 		}
155 		if (error) {
156 			if (error != ECONNREFUSED) {
157 				errno = error;
158 				warn("send (delayed error)");
159 			}
160 			goto bad;
161 		}
162 	}
163 
164 	if (found > 0 && ready.revents & POLLIN) {
165 		ssize_t ret;
166 
167 		if ((ret = recv(s, &msg, sizeof(msg), 0)) == -1) {
168 			if (errno != ECONNREFUSED)
169 				warn("recv");
170 			goto bad;
171 		} else if ((size_t)ret < sizeof(msg)) {
172 			warnx("recv: incomplete packet");
173 			goto bad;
174 		}
175 
176 		msg.tsp_seq = ntohs(msg.tsp_seq);
177 		msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
178 		msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
179 		switch (msg.tsp_type) {
180 		case TSP_ACK:
181 			timed_ack = TSP_ACK;
182 			waittime = WAITDATEACK;
183 			goto loop;
184 		case TSP_DATEACK:
185 			(void)close(s);
186 			return 0;
187 		default:
188 			warnx("wrong ack received from timed: %s",
189 			    tsp_type_to_string(&msg));
190 			timed_ack = -1;
191 			break;
192 		}
193 	}
194 	if (timed_ack == -1)
195 		warnx("can't reach time daemon, time set locally");
196 
197 bad:
198 	(void)close(s);
199 	return 2;
200 }
201