rtime.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 2009, Sun Microsystems, Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 * - Redistributions of source code must retain the above copyright notice,
10 *   this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright notice,
12 *   this list of conditions and the following disclaimer in the documentation
13 *   and/or other materials provided with the distribution.
14 * - Neither the name of Sun Microsystems, Inc. nor the names of its
15 *   contributors may be used to endorse or promote products derived
16 *   from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28 * POSSIBILITY OF SUCH DAMAGE.
29 */
30
31/*
32 * Copyright (c) 1988 by Sun Microsystems, Inc.
33
34 */
35
36/*
37 * rtime - get time from remote machine
38 *
39 * gets time, obtaining value from host
40 * on the udp/time socket.  Since timeserver returns
41 * with time of day in seconds since Jan 1, 1900,  must
42 * subtract seconds before Jan 1, 1970 to get
43 * what unix uses.
44 */
45#include "namespace.h"
46#include <stdlib.h>
47#include <string.h>
48#include <unistd.h>
49#include <errno.h>
50#include <sys/types.h>
51#include <sys/socket.h>
52#include <sys/time.h>
53#include <netinet/in.h>
54#include <stdio.h>
55#include <netdb.h>
56#include "un-namespace.h"
57
58#if defined(LIBC_SCCS) && !defined(lint)
59static char sccsid[] = 	"@(#)rtime.c	2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI";
60#endif
61#include <sys/cdefs.h>
62__FBSDID("$FreeBSD: stable/11/lib/libc/rpc/rtime.c 330897 2018-03-14 03:19:51Z eadler $");
63
64extern int _rpc_dtablesize( void );
65
66#define	NYEARS	(unsigned long)(1970 - 1900)
67#define	TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
68
69static void do_close( int );
70
71int
72rtime(struct sockaddr_in *addrp, 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(int s)
152{
153	int save;
154
155	save = errno;
156	(void)_close(s);
157	errno = save;
158}
159