xref: /illumos-gate/usr/src/ucblib/librpcsoc/rtime.c (revision 8b80e8cb6855118d46f605e91b5ed4ce83417395)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License, Version 1.0 only
6  * (the "License").  You may not use this file except in compliance
7  * with the License.
8  *
9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
10  * or http://www.opensolaris.org/os/licensing.
11  * See the License for the specific language governing permissions
12  * and limitations under the License.
13  *
14  * When distributing Covered Code, include this CDDL HEADER in each
15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
16  * If applicable, add the following below this CDDL HEADER, with the
17  * fields enclosed by brackets "[]" replaced with your own identifying
18  * information: Portions Copyright [yyyy] [name of copyright owner]
19  *
20  * CDDL HEADER END
21  */
22 /*
23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
24  * Use is subject to license terms.
25  */
26 
27 /*	Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T	*/
28 /*	  All Rights Reserved  	*/
29 
30 /*
31  * University Copyright- Copyright (c) 1982, 1986, 1988
32  * The Regents of the University of California
33  * All Rights Reserved
34  *
35  * University Acknowledgment- Portions of this document are derived from
36  * software developed by the University of California, Berkeley, and its
37  * contributors.
38  */
39 
40 #pragma ident	"%Z%%M%	%I%	%E% SMI"
41 
42 /*
43  * rtime - get time from remote machine
44  *
45  * gets time, obtaining value from host
46  * on the udp/time socket.  Since timeserver returns
47  * with time of day in seconds since Jan 1, 1900,  must
48  * subtract seconds before Jan 1, 1970 to get
49  * what unix uses.
50  */
51 
52 #include <sys/types.h>
53 #include <stdio.h>
54 #include <string.h>
55 #include <sys/socket.h>
56 #include <sys/time.h>
57 #include <errno.h>
58 #include <netinet/in.h>
59 #include <malloc.h>
60 
61 #define	NYEARS	(1970 - 1900)
62 #define	TOFFSET ((uint_t)60*60*24*(365*NYEARS + (NYEARS/4)))
63 
64 extern int _socket(int, int, int);
65 extern int _sendto(int, const char *, int, int,
66 	const struct sockaddr *, int);
67 extern int _recvfrom(int, char *, int, int,
68 	struct sockaddr *, int *);
69 extern int _connect(int, struct sockaddr *, int);
70 extern int __rpc_dtbsize();
71 extern ssize_t read(int, void *, size_t);
72 extern int close(int);
73 static void do_close();
74 
75 int
76 rtime(addrp, timep, timeout)
77 	struct sockaddr_in *addrp;
78 	struct timeval *timep;
79 	struct timeval *timeout;
80 {
81 	int s;
82 	fd_set readfds;
83 	int res;
84 	uint_t thetime;
85 	struct sockaddr_in from;
86 	int fromlen;
87 	int type;
88 
89 	if (timeout == NULL) {
90 		type = SOCK_STREAM;
91 	} else {
92 		type = SOCK_DGRAM;
93 	}
94 	s = _socket(AF_INET, type, 0);
95 	if (s < 0) {
96 		return (-1);
97 	}
98 	addrp->sin_family = AF_INET;
99 	addrp->sin_port = htons(IPPORT_TIMESERVER);
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_dtbsize(), &readfds, NULL,
111 			    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,
129 			sizeof (*addrp)) < 0) {
130 			do_close(s);
131 			return (-1);
132 		}
133 		res = read(s, (char *)&thetime, sizeof (thetime));
134 		do_close(s);
135 		if (res < 0) {
136 			return (-1);
137 		}
138 	}
139 	if (res != sizeof (thetime)) {
140 		errno = EIO;
141 		return (-1);
142 	}
143 	thetime = ntohl(thetime);
144 
145 	thetime = thetime - TOFFSET;
146 #ifdef _ILP32
147 	if (thetime > INT32_MAX)
148 		thetime = INT32_MAX;
149 #endif
150 	timep->tv_sec = thetime;
151 	timep->tv_usec = 0;
152 	return (0);
153 }
154 
155 static void
156 do_close(s)
157 	int s;
158 {
159 	int save;
160 
161 	save = errno;
162 	(void) close(s);
163 	errno = save;
164 }
165