rtime.c revision 261046 
1/*-
2 * Copyright (c) 2009, Sun Microsystems, Inc.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 * - Redistributions of source code must retain the above copyright notice,
8 *   this list of conditions and the following disclaimer.
9 * - Redistributions in binary form must reproduce the above copyright notice,
10 *   this list of conditions and the following disclaimer in the documentation
11 *   and/or other materials provided with the distribution.
12 * - Neither the name of Sun Microsystems, Inc. nor the names of its
13 *   contributors may be used to endorse or promote products derived
14 *   from this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29/*
30 * Copyright (c) 1988 by Sun Microsystems, Inc.
31
32 */
33
34/*
35 * rtime - get time from remote machine
36 *
37 * gets time, obtaining value from host
38 * on the udp/time socket.  Since timeserver returns
39 * with time of day in seconds since Jan 1, 1900,  must
40 * subtract seconds before Jan 1, 1970 to get
41 * what unix uses.
42 */
43#include "namespace.h"
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#include "un-namespace.h"
55
56#if defined(LIBC_SCCS) && !defined(lint)
57static char sccsid[] = 	"@(#)rtime.c	2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI";
58#endif
59#include <sys/cdefs.h>
60__FBSDID("$FreeBSD: stable/10/lib/libc/rpc/rtime.c 261046 2014-01-22 23:45:27Z mav $");
61
62extern int _rpc_dtablesize( void );
63
64#define NYEARS	(unsigned long)(1970 - 1900)
65#define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
66
67static void do_close( int );
68
69int
70rtime(addrp, timep, timeout)
71	struct sockaddr_in *addrp;
72	struct timeval *timep;
73	struct timeval *timeout;
74{
75	int s;
76	fd_set readfds;
77	int res;
78	unsigned long thetime;
79	struct sockaddr_in from;
80	socklen_t fromlen;
81	int type;
82	struct servent *serv;
83
84	if (timeout == NULL) {
85		type = SOCK_STREAM;
86	} else {
87		type = SOCK_DGRAM;
88	}
89	s = _socket(AF_INET, type, 0);
90	if (s < 0) {
91		return(-1);
92	}
93	addrp->sin_family = AF_INET;
94
95	/* TCP and UDP port are the same in this case */
96	if ((serv = getservbyname("time", "tcp")) == NULL) {
97		return(-1);
98	}
99
100	addrp->sin_port = serv->s_port;
101
102	if (type == SOCK_DGRAM) {
103		res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
104			     (struct sockaddr *)addrp, sizeof(*addrp));
105		if (res < 0) {
106			do_close(s);
107			return(-1);
108		}
109		do {
110			FD_ZERO(&readfds);
111			FD_SET(s, &readfds);
112			res = _select(_rpc_dtablesize(), &readfds,
113				     (fd_set *)NULL, (fd_set *)NULL, timeout);
114		} while (res < 0 && errno == EINTR);
115		if (res <= 0) {
116			if (res == 0) {
117				errno = ETIMEDOUT;
118			}
119			do_close(s);
120			return(-1);
121		}
122		fromlen = sizeof(from);
123		res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
124			       (struct sockaddr *)&from, &fromlen);
125		do_close(s);
126		if (res < 0) {
127			return(-1);
128		}
129	} else {
130		if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
131			do_close(s);
132			return(-1);
133		}
134		res = _read(s, (char *)&thetime, sizeof(thetime));
135		do_close(s);
136		if (res < 0) {
137			return(-1);
138		}
139	}
140	if (res != sizeof(thetime)) {
141		errno = EIO;
142		return(-1);
143	}
144	thetime = ntohl(thetime);
145	timep->tv_sec = thetime - TOFFSET;
146	timep->tv_usec = 0;
147	return(0);
148}
149
150static void
151do_close(s)
152	int s;
153{
154	int save;
155
156	save = errno;
157	(void)_close(s);
158	errno = save;
159}
160