xref: /freebsd/lib/libc/rpc/rtime.c (revision 65b71c48d226f3ef3eb1c4452dccc678a7d2ac96)
1 /*-
2  * Copyright (c) 2009, Sun Microsystems, Inc.
3  * 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 are met:
7  * - Redistributions of source code must retain the above copyright notice,
8  *   this list of conditions and the following disclaimer.
9  * - Redistributions in binary form must reproduce the above copyright notice,
10  *   this list of conditions and the following disclaimer in the documentation
11  *   and/or other materials provided with the distribution.
12  * - Neither the name of Sun Microsystems, Inc. nor the names of its
13  *   contributors may be used to endorse or promote products derived
14  *   from this software without specific prior written permission.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  * POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /*
30  * Copyright (c) 1988 by Sun Microsystems, Inc.
31 
32  */
33 
34 /*
35  * rtime - get time from remote machine
36  *
37  * gets time, obtaining value from host
38  * on the udp/time socket.  Since timeserver returns
39  * with time of day in seconds since Jan 1, 1900,  must
40  * subtract seconds before Jan 1, 1970 to get
41  * what unix uses.
42  */
43 #include "namespace.h"
44 #include <stdlib.h>
45 #include <string.h>
46 #include <unistd.h>
47 #include <errno.h>
48 #include <sys/types.h>
49 #include <sys/socket.h>
50 #include <sys/time.h>
51 #include <netinet/in.h>
52 #include <stdio.h>
53 #include <netdb.h>
54 #include "un-namespace.h"
55 
56 #if defined(LIBC_SCCS) && !defined(lint)
57 static char sccsid[] = 	"@(#)rtime.c	2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI";
58 #endif
59 #include <sys/cdefs.h>
60 __FBSDID("$FreeBSD$");
61 
62 extern int _rpc_dtablesize( void );
63 
64 #define NYEARS	(unsigned long)(1970 - 1900)
65 #define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
66 
67 static void do_close( int );
68 
69 int
70 rtime(struct sockaddr_in *addrp, struct timeval *timep,
71     struct timeval *timeout)
72 {
73 	int s;
74 	fd_set readfds;
75 	int res;
76 	unsigned long thetime;
77 	struct sockaddr_in from;
78 	socklen_t fromlen;
79 	int type;
80 	struct servent *serv;
81 
82 	if (timeout == NULL) {
83 		type = SOCK_STREAM;
84 	} else {
85 		type = SOCK_DGRAM;
86 	}
87 	s = _socket(AF_INET, type, 0);
88 	if (s < 0) {
89 		return(-1);
90 	}
91 	addrp->sin_family = AF_INET;
92 
93 	/* TCP and UDP port are the same in this case */
94 	if ((serv = getservbyname("time", "tcp")) == NULL) {
95 		return(-1);
96 	}
97 
98 	addrp->sin_port = serv->s_port;
99 
100 	if (type == SOCK_DGRAM) {
101 		res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
102 			     (struct sockaddr *)addrp, sizeof(*addrp));
103 		if (res < 0) {
104 			do_close(s);
105 			return(-1);
106 		}
107 		do {
108 			FD_ZERO(&readfds);
109 			FD_SET(s, &readfds);
110 			res = _select(_rpc_dtablesize(), &readfds,
111 				     (fd_set *)NULL, (fd_set *)NULL, timeout);
112 		} while (res < 0 && errno == EINTR);
113 		if (res <= 0) {
114 			if (res == 0) {
115 				errno = ETIMEDOUT;
116 			}
117 			do_close(s);
118 			return(-1);
119 		}
120 		fromlen = sizeof(from);
121 		res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
122 			       (struct sockaddr *)&from, &fromlen);
123 		do_close(s);
124 		if (res < 0) {
125 			return(-1);
126 		}
127 	} else {
128 		if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
129 			do_close(s);
130 			return(-1);
131 		}
132 		res = _read(s, (char *)&thetime, sizeof(thetime));
133 		do_close(s);
134 		if (res < 0) {
135 			return(-1);
136 		}
137 	}
138 	if (res != sizeof(thetime)) {
139 		errno = EIO;
140 		return(-1);
141 	}
142 	thetime = ntohl(thetime);
143 	timep->tv_sec = thetime - TOFFSET;
144 	timep->tv_usec = 0;
145 	return(0);
146 }
147 
148 static void
149 do_close(int s)
150 {
151 	int save;
152 
153 	save = errno;
154 	(void)_close(s);
155 	errno = save;
156 }
157