libc/rpc/rtime.c

1 /*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2009, Sun Microsystems, Inc.
5 * 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 are met:
9 * - Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 * - Neither the name of Sun Microsystems, Inc. nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31 /*
32 * Copyright (c) 1988 by Sun Microsystems, Inc.
33
34 */
35
36 /*
37 * rtime - get time from remote machine
38 *
39 * gets time, obtaining value from host
40 * on the udp/time socket. Since timeserver returns
41 * with time of day in seconds since Jan 1, 1900, must
42 * subtract seconds before Jan 1, 1970 to get
43 * what unix uses.
44 */
45#include "namespace.h"
46#include <stdlib.h>
47#include <string.h>
48#include <unistd.h>
49#include <errno.h>
50#include <sys/types.h>
51#include <sys/socket.h>
52#include <sys/time.h>
53#include <netinet/in.h>
54#include <stdio.h>
55#include <netdb.h>
56#include "un-namespace.h"
57
58#if defined(LIBC_SCCS) && !defined(lint)
59 static char sccsid[] = "@(#)rtime.c 2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI";
60#endif
61#include <sys/cdefs.h>
62 __FBSDID("$FreeBSD$");
63
64 extern int _rpc_dtablesize( void );
65
66#define NYEARS (unsigned long)(1970 - 1900)
67#define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
68
69 static void do_close( int );
70
71 int
72 rtime(struct sockaddr_in *addrp, struct timeval *timep,
73 struct timeval *timeout)
74{
75 int s;
76 fd_set readfds;
77 int res;
78 unsigned long thetime;
79 struct sockaddr_in from;
80 socklen_t fromlen;
81 int type;
82 struct servent *serv;
83
84 if (timeout == NULL) {
85 type = SOCK_STREAM;
86 } else {
87 type = SOCK_DGRAM;
88 }
89 s = _socket(AF_INET, type, 0);
90 if (s < 0) {
91 return(-1);
92 }
93 addrp->sin_family = AF_INET;
94
95 /* TCP and UDP port are the same in this case */
96 if ((serv = getservbyname("time", "tcp")) == NULL) {
97 return(-1);
98 }
99
100 addrp->sin_port = serv->s_port;
101
102 if (type == SOCK_DGRAM) {
103 res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
104 (struct sockaddr *)addrp, sizeof(*addrp));
105 if (res < 0) {
106 do_close(s);
107 return(-1);
108 }
109 do {
110 FD_ZERO(&readfds);
111 FD_SET(s, &readfds);
112 res = _select(_rpc_dtablesize(), &readfds,
113 (fd_set *)NULL, (fd_set *)NULL, timeout);
114 } while (res < 0 && errno == EINTR);
115 if (res <= 0) {
116 if (res == 0) {
117 errno = ETIMEDOUT;
118 }
119 do_close(s);
120 return(-1);
121 }
122 fromlen = sizeof(from);
123 res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
124 (struct sockaddr *)&from, &fromlen);
125 do_close(s);
126 if (res < 0) {
127 return(-1);
128 }
129 } else {
130 if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
131 do_close(s);
132 return(-1);
133 }
134 res = _read(s, (char *)&thetime, sizeof(thetime));
135 do_close(s);
136 if (res < 0) {
137 return(-1);
138 }
139 }
140 if (res != sizeof(thetime)) {
141 errno = EIO;
142 return(-1);
143 }
144 thetime = ntohl(thetime);
145 timep->tv_sec = thetime - TOFFSET;
146 timep->tv_usec = 0;
147 return(0);
148}
149
150 static void
151 do_close(int s)
152{
153 int save;
154
155 save = errno;
156 (void)_close(s);
157 errno = save;
158}
159