rtime.c revision 143344 
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)
58static 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: head/lib/libc/rpc/rtime.c 143344 2005-03-10 00:57:01Z stefanf $");
62
63extern 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
68static void do_close( int );
69
70int
71rtime(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
151static void
152do_close(s)
153	int s;
154{
155	int save;
156
157	save = errno;
158	(void)_close(s);
159	errno = save;
160}
161