xref: /illumos-gate/usr/src/ucblib/librpcsoc/rtime.c (revision 86d949f9497332fe19be6b5d711d265eb957439f)
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 /*
41  * rtime - get time from remote machine
42  *
43  * gets time, obtaining value from host
44  * on the udp/time socket.  Since timeserver returns
45  * with time of day in seconds since Jan 1, 1900,  must
46  * subtract seconds before Jan 1, 1970 to get
47  * what unix uses.
48  */
49 
50 #include <sys/types.h>
51 #include <stdio.h>
52 #include <string.h>
53 #include <sys/socket.h>
54 #include <sys/time.h>
55 #include <errno.h>
56 #include <netinet/in.h>
57 #include <malloc.h>
58 
59 #define	NYEARS	(1970 - 1900)
60 #define	TOFFSET ((uint_t)60*60*24*(365*NYEARS + (NYEARS/4)))
61 
62 extern int _socket(int, int, int);
63 extern int _sendto(int, const char *, int, int,
64 	const struct sockaddr *, int);
65 extern int _recvfrom(int, char *, int, int,
66 	struct sockaddr *, int *);
67 extern int _connect(int, struct sockaddr *, int);
68 extern int __rpc_dtbsize();
69 extern ssize_t read(int, void *, size_t);
70 extern int close(int);
71 static void do_close();
72 
73 int
74 rtime(addrp, timep, timeout)
75 	struct sockaddr_in *addrp;
76 	struct timeval *timep;
77 	struct timeval *timeout;
78 {
79 	int s;
80 	fd_set readfds;
81 	int res;
82 	uint_t thetime;
83 	struct sockaddr_in from;
84 	int fromlen;
85 	int type;
86 
87 	if (timeout == NULL) {
88 		type = SOCK_STREAM;
89 	} else {
90 		type = SOCK_DGRAM;
91 	}
92 	s = _socket(AF_INET, type, 0);
93 	if (s < 0) {
94 		return (-1);
95 	}
96 	addrp->sin_family = AF_INET;
97 	addrp->sin_port = htons(IPPORT_TIMESERVER);
98 	if (type == SOCK_DGRAM) {
99 		res = _sendto(s, (char *)&thetime, sizeof (thetime), 0,
100 		    (struct sockaddr *)addrp, sizeof (*addrp));
101 		if (res < 0) {
102 			do_close(s);
103 			return (-1);
104 		}
105 		do {
106 			FD_ZERO(&readfds);
107 			FD_SET(s, &readfds);
108 			res = select(__rpc_dtbsize(), &readfds, NULL,
109 			    NULL, timeout);
110 		} while (res < 0 && errno == EINTR);
111 		if (res <= 0) {
112 			if (res == 0) {
113 				errno = ETIMEDOUT;
114 			}
115 			do_close(s);
116 			return (-1);
117 		}
118 		fromlen = sizeof (from);
119 		res = _recvfrom(s, (char *)&thetime, sizeof (thetime), 0,
120 		    (struct sockaddr *)&from, &fromlen);
121 		do_close(s);
122 		if (res < 0) {
123 			return (-1);
124 		}
125 	} else {
126 		if (_connect(s, (struct sockaddr *)addrp,
127 			sizeof (*addrp)) < 0) {
128 			do_close(s);
129 			return (-1);
130 		}
131 		res = read(s, (char *)&thetime, sizeof (thetime));
132 		do_close(s);
133 		if (res < 0) {
134 			return (-1);
135 		}
136 	}
137 	if (res != sizeof (thetime)) {
138 		errno = EIO;
139 		return (-1);
140 	}
141 	thetime = ntohl(thetime);
142 
143 	thetime = thetime - TOFFSET;
144 #ifdef _ILP32
145 	if (thetime > INT32_MAX)
146 		thetime = INT32_MAX;
147 #endif
148 	timep->tv_sec = thetime;
149 	timep->tv_usec = 0;
150 	return (0);
151 }
152 
153 static void
154 do_close(s)
155 	int s;
156 {
157 	int save;
158 
159 	save = errno;
160 	(void) close(s);
161 	errno = save;
162 }
163