xref: /dragonfly/lib/libc/rpc/rtime.c (revision 984263bc)
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 <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 
55 #if defined(LIBC_SCCS) && !defined(lint)
56 /* from: static char sccsid[] = 	"@(#)rtime.c	2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI"; */
57 static const char rcsid[] = "$FreeBSD: src/lib/libc/rpc/rtime.c,v 1.5 2000/01/27 23:06:41 jasone Exp $";
58 #endif
59 
60 extern int _rpc_dtablesize __P(( void ));
61 
62 #define NYEARS	(unsigned long)(1970 - 1900)
63 #define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
64 
65 static void do_close __P(( int ));
66 
67 int
68 rtime(addrp, timep, timeout)
69 	struct sockaddr_in *addrp;
70 	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 	int 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(s)
150 	int s;
151 {
152 	int save;
153 
154 	save = errno;
155 	(void)_close(s);
156 	errno = save;
157 }
158