rtime.c revision 56698 
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"; */
57static const char rcsid[] = "$FreeBSD: head/lib/libc/rpc/rtime.c 56698 2000-01-27 23:07:25Z jasone $";
58#endif
59
60extern 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
65static void do_close __P(( int ));
66
67int
68rtime(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
148static void
149do_close(s)
150	int s;
151{
152	int save;
153
154	save = errno;
155	(void)_close(s);
156	errno = save;
157}
158