xref: /netbsd-src/bin/date/netdate.c (revision b1c86f5f087524e68db12794ee9c3e3da1ab17a0)
1 /* $NetBSD: netdate.c,v 1.27 2008/02/24 04:49:45 dholland 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 1.27 2008/02/24 04:49:45 dholland 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 extern int retval;
63 
64 static const char *
65 tsp_type_to_string(const struct tsp *msg)
66 {
67 	unsigned i;
68 
69 	i = msg->tsp_type;
70 	return i < TSPTYPENUMBER ? tsptype[i] : "unknown";
71 }
72 
73 /*
74  * Set the date in the machines controlled by timedaemons by communicating the
75  * new date to the local timedaemon.  If the timedaemon is in the master state,
76  * it performs the correction on all slaves.  If it is in the slave state, it
77  * notifies the master that a correction is needed.
78  * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
79  */
80 int
81 netsettime(time_t tval)
82 {
83 	struct sockaddr_in dest;
84 	struct tsp msg;
85 	char hostname[MAXHOSTNAMELEN];
86 	struct servent *sp;
87 	struct pollfd ready;
88 	int found, s, timed_ack, waittime;
89 
90 	if ((sp = getservbyname("timed", "udp")) == NULL) {
91 		warnx("udp/timed: unknown service");
92 		return (retval = 2);
93 	}
94 
95 	(void)memset(&dest, 0, sizeof(dest));
96 #ifdef BSD4_4
97 	dest.sin_len = sizeof(dest);
98 #endif
99 	dest.sin_family = AF_INET;
100 	dest.sin_port = sp->s_port;
101 	dest.sin_addr.s_addr = htonl(INADDR_ANY);
102 	s = socket(AF_INET, SOCK_DGRAM, 0);
103 	if (s < 0) {
104 		if (errno != EAFNOSUPPORT)
105 			warn("timed");
106 		return (retval = 2);
107 	}
108 
109 #ifdef IP_PORTRANGE
110 	{
111 		static const int on = IP_PORTRANGE_LOW;
112 
113 		if (setsockopt(s, IPPROTO_IP, IP_PORTRANGE,
114 			    &on, sizeof(on)) < 0) {
115 			warn("setsockopt");
116 			goto bad;
117 		}
118 	}
119 #endif
120 
121 	msg.tsp_type = TSP_SETDATE;
122 	msg.tsp_vers = TSPVERSION;
123 	if (gethostname(hostname, sizeof(hostname))) {
124 		warn("gethostname");
125 		goto bad;
126 	}
127 	strncpy(msg.tsp_name, hostname, sizeof(msg.tsp_name));
128 	msg.tsp_name[sizeof(msg.tsp_name) - 1] = '\0';
129 	msg.tsp_seq = htons((uint16_t)0);
130 	msg.tsp_time.tv_sec = htonl((uint32_t)tval); /* XXX: y2038 */
131 	msg.tsp_time.tv_usec = htonl((uint32_t)0);
132 	if (connect(s, (const struct sockaddr *)&dest, sizeof(dest)) < 0) {
133 		warn("connect");
134 		goto bad;
135 	}
136 	if (send(s, &msg, sizeof(msg), 0) < 0) {
137 		if (errno != ECONNREFUSED)
138 			warn("send");
139 		goto bad;
140 	}
141 
142 	timed_ack = -1;
143 	waittime = WAITACK;
144 	ready.fd = s;
145 	ready.events = POLLIN;
146 loop:
147 	found = poll(&ready, 1, waittime);
148 
149 	{
150 		socklen_t length;
151 		int error;
152 
153 		length = sizeof(error);
154 		if (!getsockopt(s, SOL_SOCKET, SO_ERROR, &error, &length)
155 		    && error) {
156 			if (error != ECONNREFUSED)
157 				warn("send (delayed error)");
158 			goto bad;
159 		}
160 	}
161 
162 	if (found > 0 && ready.revents & POLLIN) {
163 		ssize_t ret;
164 
165 		ret = recv(s, &msg, sizeof(msg), 0);
166 		if (ret < 0) {
167 			if (errno != ECONNREFUSED)
168 				warn("recv");
169 			goto bad;
170 		} else if ((size_t)ret < sizeof(msg)) {
171 			warnx("recv: incomplete packet");
172 			goto bad;
173 		}
174 
175 		msg.tsp_seq = ntohs(msg.tsp_seq);
176 		msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
177 		msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
178 		switch (msg.tsp_type) {
179 		case TSP_ACK:
180 			timed_ack = TSP_ACK;
181 			waittime = WAITDATEACK;
182 			goto loop;
183 		case TSP_DATEACK:
184 			(void)close(s);
185 			return (0);
186 		default:
187 			warnx("wrong ack received from timed: %s",
188 			    tsp_type_to_string(&msg));
189 			timed_ack = -1;
190 			break;
191 		}
192 	}
193 	if (timed_ack == -1)
194 		warnx("can't reach time daemon, time set locally");
195 
196 bad:
197 	(void)close(s);
198 	return (retval = 2);
199 }
200