1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 #if 0
33 #ifndef lint
34 static char sccsid[] = "@(#)netdate.c 8.1 (Berkeley) 5/31/93";
35 #endif /* not lint */
36 #endif
37
38 #include <sys/cdefs.h>
39 __FBSDID("$FreeBSD: stable/12/bin/date/netdate.c 326025 2017-11-20 19:49:47Z pfg $");
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 <string.h>
53 #include <unistd.h>
54
55 #include "extern.h"
56
57 #define WAITACK 2 /* seconds */
58 #define WAITDATEACK 5 /* seconds */
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 */
67 int
netsettime(time_t tval)68 netsettime(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 != EAFNOSUPPORT)
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;
135 loop:
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
180 bad:
181 (void)close(s);
182 return (retval = 2);
183 }
184