xref: /dragonfly/lib/libc/rpc/rtime.c (revision a68e0df0)
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 1.9 2005/03/10 00:57:01 stefanf 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  * rtime - get time from remote machine
40  *
41  * gets time, obtaining value from host
42  * on the udp/time socket.  Since timeserver returns
43  * with time of day in seconds since Jan 1, 1900,  must
44  * subtract seconds before Jan 1, 1970 to get
45  * what unix uses.
46  */
47 #include "namespace.h"
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 #include <errno.h>
52 #include <sys/types.h>
53 #include <sys/socket.h>
54 #include <sys/time.h>
55 #include <netinet/in.h>
56 #include <stdio.h>
57 #include <netdb.h>
58 #include "un-namespace.h"
59 
60 extern int _rpc_dtablesize(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(int);
66 
67 int
68 rtime(struct sockaddr_in *addrp, struct timeval *timep, struct timeval *timeout)
69 {
70 	int s;
71 	fd_set readfds;
72 	int res;
73 	unsigned long thetime;
74 	struct sockaddr_in from;
75 	socklen_t fromlen;
76 	int type;
77 	struct servent *serv;
78 
79 	if (timeout == NULL) {
80 		type = SOCK_STREAM;
81 	} else {
82 		type = SOCK_DGRAM;
83 	}
84 	s = _socket(AF_INET, type, 0);
85 	if (s < 0) {
86 		return(-1);
87 	}
88 	addrp->sin_family = AF_INET;
89 
90 	/* TCP and UDP port are the same in this case */
91 	if ((serv = getservbyname("time", "tcp")) == NULL) {
92 		return(-1);
93 	}
94 
95 	addrp->sin_port = serv->s_port;
96 
97 	if (type == SOCK_DGRAM) {
98 		res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
99 			     (struct sockaddr *)addrp, sizeof(*addrp));
100 		if (res < 0) {
101 			do_close(s);
102 			return(-1);
103 		}
104 		do {
105 			FD_ZERO(&readfds);
106 			FD_SET(s, &readfds);
107 			res = _select(_rpc_dtablesize(), &readfds,
108 				     NULL, NULL, timeout);
109 		} while (res < 0 && errno == EINTR);
110 		if (res <= 0) {
111 			if (res == 0) {
112 				errno = ETIMEDOUT;
113 			}
114 			do_close(s);
115 			return(-1);
116 		}
117 		fromlen = sizeof(from);
118 		res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
119 			       (struct sockaddr *)&from, &fromlen);
120 		do_close(s);
121 		if (res < 0) {
122 			return(-1);
123 		}
124 	} else {
125 		if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
126 			do_close(s);
127 			return(-1);
128 		}
129 		res = _read(s, (char *)&thetime, sizeof(thetime));
130 		do_close(s);
131 		if (res < 0) {
132 			return(-1);
133 		}
134 	}
135 	if (res != sizeof(thetime)) {
136 		errno = EIO;
137 		return(-1);
138 	}
139 	thetime = ntohl(thetime);
140 	timep->tv_sec = thetime - TOFFSET;
141 	timep->tv_usec = 0;
142 	return(0);
143 }
144 
145 static void
146 do_close(int s)
147 {
148 	int save;
149 
150 	save = errno;
151 	_close(s);
152 	errno = save;
153 }
154