xref: /freebsd/lib/libc/rpc/rtime.c (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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