netdate.c revision 35773 
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#if 0
36static char const sccsid[] = "@(#)netdate.c	8.1 (Berkeley) 5/31/93";
37#endif
38static const char rcsid[] =
39	"$Id$";
40#endif /* not lint */
41
42#include <sys/param.h>
43#include <sys/time.h>
44#include <sys/socket.h>
45
46#include <netinet/in.h>
47#include <netdb.h>
48#define TSPTYPES
49#include <protocols/timed.h>
50
51#include <err.h>
52#include <errno.h>
53#include <string.h>
54#include <unistd.h>
55
56#include "extern.h"
57
58#define	WAITACK		2	/* seconds */
59#define	WAITDATEACK	5	/* seconds */
60
61extern int retval;
62
63/*
64 * Set the date in the machines controlled by timedaemons by communicating the
65 * new date to the local timedaemon.  If the timedaemon is in the master state,
66 * it performs the correction on all slaves.  If it is in the slave state, it
67 * notifies the master that a correction is needed.
68 * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
69 */
70int
71netsettime(tval)
72	time_t tval;
73{
74	struct timeval tout;
75	struct servent *sp;
76	struct tsp msg;
77	struct sockaddr_in sin, dest, from;
78	fd_set ready;
79	long waittime;
80	int s, length, port, timed_ack, found, err;
81	char hostname[MAXHOSTNAMELEN];
82
83	if ((sp = getservbyname("timed", "udp")) == NULL) {
84		warnx("udp/timed: unknown service");
85		return (retval = 2);
86	}
87
88	dest.sin_port = sp->s_port;
89	dest.sin_family = AF_INET;
90	dest.sin_addr.s_addr = htonl((u_long)INADDR_ANY);
91	s = socket(AF_INET, SOCK_DGRAM, 0);
92	if (s < 0) {
93		if (errno != EPROTONOSUPPORT)
94			warn("timed");
95		return (retval = 2);
96	}
97
98	memset(&sin, 0, sizeof(sin));
99	sin.sin_family = AF_INET;
100	for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
101		sin.sin_port = htons((u_short)port);
102		if (bind(s, (struct sockaddr *)&sin, sizeof(sin)) >= 0)
103			break;
104		if (errno == EADDRINUSE)
105			continue;
106		if (errno != EADDRNOTAVAIL)
107			warn("bind");
108		goto bad;
109	}
110	if (port == IPPORT_RESERVED / 2) {
111		warnx("all ports in use");
112		goto bad;
113	}
114	msg.tsp_type = TSP_SETDATE;
115	msg.tsp_vers = TSPVERSION;
116	if (gethostname(hostname, sizeof(hostname))) {
117		warn("gethostname");
118		goto bad;
119	}
120	(void)strncpy(msg.tsp_name, hostname, sizeof(msg.tsp_name) - 1);
121	msg.tsp_name[sizeof(msg.tsp_name) - 1] = '\0';
122	msg.tsp_seq = htons((u_short)0);
123	msg.tsp_time.tv_sec = htonl((u_long)tval);
124	msg.tsp_time.tv_usec = htonl((u_long)0);
125	length = sizeof(struct sockaddr_in);
126	if (connect(s, (struct sockaddr *)&dest, length) < 0) {
127		warn("connect");
128		goto bad;
129	}
130	if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
131		if (errno != ECONNREFUSED)
132			warn("send");
133		goto bad;
134	}
135
136	timed_ack = -1;
137	waittime = WAITACK;
138loop:
139	tout.tv_sec = waittime;
140	tout.tv_usec = 0;
141
142	FD_ZERO(&ready);
143	FD_SET(s, &ready);
144	found = select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout);
145
146	length = sizeof(err);
147	if (!getsockopt(s,
148	    SOL_SOCKET, SO_ERROR, (char *)&err, &length) && err) {
149		if (err != ECONNREFUSED)
150			warn("send (delayed error)");
151		goto bad;
152	}
153
154	if (found > 0 && FD_ISSET(s, &ready)) {
155		length = sizeof(struct sockaddr_in);
156		if (recvfrom(s, &msg, sizeof(struct tsp), 0,
157		    (struct sockaddr *)&from, &length) < 0) {
158			if (errno != ECONNREFUSED)
159				warn("recvfrom");
160			goto bad;
161		}
162		msg.tsp_seq = ntohs(msg.tsp_seq);
163		msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
164		msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
165		switch (msg.tsp_type) {
166		case TSP_ACK:
167			timed_ack = TSP_ACK;
168			waittime = WAITDATEACK;
169			goto loop;
170		case TSP_DATEACK:
171			(void)close(s);
172			return (0);
173		default:
174			warnx("wrong ack received from timed: %s",
175			    tsptype[msg.tsp_type]);
176			timed_ack = -1;
177			break;
178		}
179	}
180	if (timed_ack == -1)
181		warnx("can't reach time daemon, time set locally");
182
183bad:
184	(void)close(s);
185	return (retval = 2);
186}
187