xref: /freebsd/lib/libc/rpc/rtime.c (revision ad30f8e79bd1007cc2476e491bd21b4f5e389e0a)
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 
30 /*
31  * Copyright (c) 1988 by Sun Microsystems, Inc.
32 
33  */
34 
35 /*
36  * rtime - get time from remote machine
37  *
38  * gets time, obtaining value from host
39  * on the udp/time socket.  Since timeserver returns
40  * with time of day in seconds since Jan 1, 1900,  must
41  * subtract seconds before Jan 1, 1970 to get
42  * what unix uses.
43  */
44 #include "namespace.h"
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 #include <errno.h>
49 #include <sys/types.h>
50 #include <sys/socket.h>
51 #include <sys/time.h>
52 #include <netinet/in.h>
53 #include <stdio.h>
54 #include <netdb.h>
55 #include "un-namespace.h"
56 
57 #if defined(LIBC_SCCS) && !defined(lint)
58 static char sccsid[] = 	"@(#)rtime.c	2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI";
59 #endif
60 #include <sys/cdefs.h>
61 __FBSDID("$FreeBSD$");
62 
63 extern int _rpc_dtablesize( void );
64 
65 #define NYEARS	(unsigned long)(1970 - 1900)
66 #define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
67 
68 static void do_close( int );
69 
70 int
71 rtime(addrp, timep, timeout)
72 	struct sockaddr_in *addrp;
73 	struct timeval *timep;
74 	struct timeval *timeout;
75 {
76 	int s;
77 	fd_set readfds;
78 	int res;
79 	unsigned long thetime;
80 	struct sockaddr_in from;
81 	socklen_t fromlen;
82 	int type;
83 	struct servent *serv;
84 
85 	if (timeout == NULL) {
86 		type = SOCK_STREAM;
87 	} else {
88 		type = SOCK_DGRAM;
89 	}
90 	s = _socket(AF_INET, type, 0);
91 	if (s < 0) {
92 		return(-1);
93 	}
94 	addrp->sin_family = AF_INET;
95 
96 	/* TCP and UDP port are the same in this case */
97 	if ((serv = getservbyname("time", "tcp")) == NULL) {
98 		return(-1);
99 	}
100 
101 	addrp->sin_port = serv->s_port;
102 
103 	if (type == SOCK_DGRAM) {
104 		res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
105 			     (struct sockaddr *)addrp, sizeof(*addrp));
106 		if (res < 0) {
107 			do_close(s);
108 			return(-1);
109 		}
110 		do {
111 			FD_ZERO(&readfds);
112 			FD_SET(s, &readfds);
113 			res = _select(_rpc_dtablesize(), &readfds,
114 				     (fd_set *)NULL, (fd_set *)NULL, timeout);
115 		} while (res < 0 && errno == EINTR);
116 		if (res <= 0) {
117 			if (res == 0) {
118 				errno = ETIMEDOUT;
119 			}
120 			do_close(s);
121 			return(-1);
122 		}
123 		fromlen = sizeof(from);
124 		res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
125 			       (struct sockaddr *)&from, &fromlen);
126 		do_close(s);
127 		if (res < 0) {
128 			return(-1);
129 		}
130 	} else {
131 		if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
132 			do_close(s);
133 			return(-1);
134 		}
135 		res = _read(s, (char *)&thetime, sizeof(thetime));
136 		do_close(s);
137 		if (res < 0) {
138 			return(-1);
139 		}
140 	}
141 	if (res != sizeof(thetime)) {
142 		errno = EIO;
143 		return(-1);
144 	}
145 	thetime = ntohl(thetime);
146 	timep->tv_sec = thetime - TOFFSET;
147 	timep->tv_usec = 0;
148 	return(0);
149 }
150 
151 static void
152 do_close(s)
153 	int s;
154 {
155 	int save;
156 
157 	save = errno;
158 	(void)_close(s);
159 	errno = save;
160 }
161