xref: /dragonfly/lib/libc/rpc/rtime.c (revision 1847e88f)
1 /*
2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
3  * unrestricted use provided that this legend is included on all tape
4  * media and as a part of the software program in whole or part.  Users
5  * may copy or modify Sun RPC without charge, but are not authorized
6  * to license or distribute it to anyone else except as part of a product or
7  * program developed by the user.
8  *
9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
12  *
13  * Sun RPC is provided with no support and without any obligation on the
14  * part of Sun Microsystems, Inc. to assist in its use, correction,
15  * modification or enhancement.
16  *
17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
19  * OR ANY PART THEREOF.
20  *
21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
22  * or profits or other special, indirect and consequential damages, even if
23  * Sun has been advised of the possibility of such damages.
24  *
25  * Sun Microsystems, Inc.
26  * 2550 Garcia Avenue
27  * Mountain View, California  94043
28  *
29  * @(#)rtime.c	2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI
30  * $FreeBSD: src/lib/libc/rpc/rtime.c,v 1.5 2000/01/27 23:06:41 jasone Exp $
31  * $DragonFly: src/lib/libc/rpc/rtime.c,v 1.5 2005/11/13 12:27:04 swildner Exp $
32  */
33 
34 /*
35  * Copyright (c) 1988 by Sun Microsystems, Inc.
36 
37  */
38 
39 /*
40  * rtime - get time from remote machine
41  *
42  * gets time, obtaining value from host
43  * on the udp/time socket.  Since timeserver returns
44  * with time of day in seconds since Jan 1, 1900,  must
45  * subtract seconds before Jan 1, 1970 to get
46  * what unix uses.
47  */
48 #include "namespace.h"
49 #include <stdlib.h>
50 #include <string.h>
51 #include <unistd.h>
52 #include <errno.h>
53 #include <sys/types.h>
54 #include <sys/socket.h>
55 #include <sys/time.h>
56 #include <netinet/in.h>
57 #include <stdio.h>
58 #include <netdb.h>
59 #include "un-namespace.h"
60 
61 extern int _rpc_dtablesize ( void );
62 
63 #define NYEARS	(unsigned long)(1970 - 1900)
64 #define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
65 
66 static void do_close ( int );
67 
68 int
69 rtime(struct sockaddr_in *addrp, struct timeval *timep, struct timeval *timeout)
70 {
71 	int s;
72 	fd_set readfds;
73 	int res;
74 	unsigned long thetime;
75 	struct sockaddr_in from;
76 	int fromlen;
77 	int type;
78 	struct servent *serv;
79 
80 	if (timeout == NULL) {
81 		type = SOCK_STREAM;
82 	} else {
83 		type = SOCK_DGRAM;
84 	}
85 	s = _socket(AF_INET, type, 0);
86 	if (s < 0) {
87 		return(-1);
88 	}
89 	addrp->sin_family = AF_INET;
90 
91 	/* TCP and UDP port are the same in this case */
92 	if ((serv = getservbyname("time", "tcp")) == NULL) {
93 		return(-1);
94 	}
95 
96 	addrp->sin_port = serv->s_port;
97 
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_dtablesize(), &readfds,
109 				     (fd_set *)NULL, (fd_set *)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, sizeof(*addrp)) < 0) {
127 			do_close(s);
128 			return(-1);
129 		}
130 		res = _read(s, (char *)&thetime, sizeof(thetime));
131 		do_close(s);
132 		if (res < 0) {
133 			return(-1);
134 		}
135 	}
136 	if (res != sizeof(thetime)) {
137 		errno = EIO;
138 		return(-1);
139 	}
140 	thetime = ntohl(thetime);
141 	timep->tv_sec = thetime - TOFFSET;
142 	timep->tv_usec = 0;
143 	return(0);
144 }
145 
146 static void
147 do_close(int s)
148 {
149 	int save;
150 
151 	save = errno;
152 	_close(s);
153 	errno = save;
154 }
155