/bin/date/netdate.c

  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 * 4. Neither the name of the University nor the names of its contributors
 14 *    may be used to endorse or promote products derived from this software
 15 *    without specific prior written permission.
 16 *
 17 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 20 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 27 * SUCH DAMAGE.
 28 */
 29
 30#if 0
 31#ifndef lint
 32static char sccsid[] = "@(#)netdate.c	8.1 (Berkeley) 5/31/93";
 33#endif /* not lint */
 34#endif
 35
 36#include <sys/cdefs.h>
 37__FBSDID("$FreeBSD$");
 38
 39#include <sys/param.h>
 40#include <sys/time.h>
 41#include <sys/socket.h>
 42
 43#include <netinet/in.h>
 44#include <netdb.h>
 45#define TSPTYPES
 46#include <protocols/timed.h>
 47
 48#include <err.h>
 49#include <errno.h>
 50#include <string.h>
 51#include <unistd.h>
 52
 53#include "extern.h"
 54
 55#define	WAITACK		2	/* seconds */
 56#define	WAITDATEACK	5	/* seconds */
 57
 58extern int retval;
 59
 60/*
 61 * Set the date in the machines controlled by timedaemons by communicating the
 62 * new date to the local timedaemon.  If the timedaemon is in the master state,
 63 * it performs the correction on all slaves.  If it is in the slave state, it
 64 * notifies the master that a correction is needed.
 65 * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
 66 */
 67int
 68netsettime(time_t tval)
 69{
 70	struct timeval tout;
 71	struct servent *sp;
 72	struct tsp msg;
 73	struct sockaddr_in lsin, dest, from;
 74	fd_set ready;
 75	long waittime;
 76	int s, port, timed_ack, found, lerr;
 77	socklen_t length;
 78	char hostname[MAXHOSTNAMELEN];
 79
 80	if ((sp = getservbyname("timed", "udp")) == NULL) {
 81		warnx("timed/udp: unknown service");
 82		return (retval = 2);
 83	}
 84
 85	dest.sin_port = sp->s_port;
 86	dest.sin_family = AF_INET;
 87	dest.sin_addr.s_addr = htonl((u_long)INADDR_ANY);
 88	s = socket(AF_INET, SOCK_DGRAM, 0);
 89	if (s < 0) {
 90		if (errno != EPROTONOSUPPORT)
 91			warn("timed");
 92		return (retval = 2);
 93	}
 94
 95	memset(&lsin, 0, sizeof(lsin));
 96	lsin.sin_family = AF_INET;
 97	for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
 98		lsin.sin_port = htons((u_short)port);
 99		if (bind(s, (struct sockaddr *)&lsin, sizeof(lsin)) >= 0)
100			break;
101		if (errno == EADDRINUSE)
102			continue;
103		if (errno != EADDRNOTAVAIL)
104			warn("bind");
105		goto bad;
106	}
107	if (port == IPPORT_RESERVED / 2) {
108		warnx("all ports in use");
109		goto bad;
110	}
111	memset(&msg, 0, sizeof(msg));
112	msg.tsp_type = TSP_SETDATE;
113	msg.tsp_vers = TSPVERSION;
114	if (gethostname(hostname, sizeof(hostname))) {
115		warn("gethostname");
116		goto bad;
117	}
118	(void)strlcpy(msg.tsp_name, hostname, sizeof(msg.tsp_name));
119	msg.tsp_seq = htons((u_short)0);
120	msg.tsp_time.tv_sec = htonl((u_long)tval);
121	msg.tsp_time.tv_usec = htonl((u_long)0);
122	length = sizeof(struct sockaddr_in);
123	if (connect(s, (struct sockaddr *)&dest, length) < 0) {
124		warn("connect");
125		goto bad;
126	}
127	if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
128		if (errno != ECONNREFUSED)
129			warn("send");
130		goto bad;
131	}
132
133	timed_ack = -1;
134	waittime = WAITACK;
135loop:
136	tout.tv_sec = waittime;
137	tout.tv_usec = 0;
138
139	FD_ZERO(&ready);
140	FD_SET(s, &ready);
141	found = select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout);
142
143	length = sizeof(lerr);
144	if (!getsockopt(s,
145	    SOL_SOCKET, SO_ERROR, (char *)&lerr, &length) && lerr) {
146		if (lerr != ECONNREFUSED)
147			warnc(lerr, "send (delayed error)");
148		goto bad;
149	}
150
151	if (found > 0 && FD_ISSET(s, &ready)) {
152		length = sizeof(struct sockaddr_in);
153		if (recvfrom(s, &msg, sizeof(struct tsp), 0,
154		    (struct sockaddr *)&from, &length) < 0) {
155			if (errno != ECONNREFUSED)
156				warn("recvfrom");
157			goto bad;
158		}
159		msg.tsp_seq = ntohs(msg.tsp_seq);
160		msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
161		msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
162		switch (msg.tsp_type) {
163		case TSP_ACK:
164			timed_ack = TSP_ACK;
165			waittime = WAITDATEACK;
166			goto loop;
167		case TSP_DATEACK:
168			(void)close(s);
169			return (0);
170		default:
171			warnx("wrong ack received from timed: %s",
172			    tsptype[msg.tsp_type]);
173			timed_ack = -1;
174			break;
175		}
176	}
177	if (timed_ack == -1)
178		warnx("can't reach time daemon, time set locally");
179
180bad:
181	(void)close(s);
182	return (retval = 2);
183}