NetBSD/usr.sbin/rdate/rdate.c

142 lines
3.9 KiB
C

/*
* Copyright (c) 1994 Christos Zoulas
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Christos Zoulas.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $Id: rdate.c,v 1.1 1994/06/02 22:55:07 deraadt Exp $
*/
/*
* rdate.c: Set the date from the specified host
*
* Uses the rfc868 time protocol at socket 37.
* Time is returned as the number of seconds since
* midnight January 1st 1900.
*/
#ifndef lint
static char rcsid[] = "$Id: rdate.c,v 1.1 1994/06/02 22:55:07 deraadt Exp $";
#endif /* lint */
#include <sys/types.h>
#include <sys/param.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
/* seconds from midnight Jan 1900 - 1970 */
#if __STDC__
#define DIFFERENCE 2208988800UL
#else
#define DIFFERENCE 2208988800
#endif
int
main(argc, argv)
int argc;
char *argv[];
{
int pr = 0, silent = 0, s;
time_t tim;
char *hname;
struct hostent *hp;
struct protoent *pp, ppp;
struct servent *sp, ssp;
struct sockaddr_in sa;
extern char *__progname;
extern int optind;
int c;
while ((c = getopt(argc, argv, "ps")) != -1)
switch (c) {
case 'p':
pr++;
break;
case 's':
silent++;
break;
default:
goto usage;
}
if (argc - 1 != optind) {
usage:
(void) fprintf(stderr, "Usage: %s [-ps] host\n", __progname);
return (1);
}
hname = argv[optind];
if ((hp = gethostbyname(hname)) == NULL) {
fprintf(stderr, "%s: ", __progname);
herror(hname);
exit(1);
}
if ((sp = getservbyname("time", "tcp")) == NULL) {
sp = &ssp;
sp->s_port = 37;
sp->s_proto = "tcp";
}
if ((pp = getprotobyname(sp->s_proto)) == NULL) {
pp = &ppp;
pp->p_proto = 6;
}
if ((s = socket(AF_INET, SOCK_STREAM, pp->p_proto)) == -1)
err(1, "Could not create socket");
bzero(&sa, sizeof sa);
sa.sin_family = AF_INET;
sa.sin_port = sp->s_port;
memcpy(&(sa.sin_addr.s_addr), hp->h_addr, hp->h_length);
if (connect(s, (struct sockaddr *) & sa, sizeof(sa)) == -1)
err(1, "Could not connect socket");
if (read(s, &tim, sizeof(time_t)) != sizeof(time_t))
err(1, "Could not read data");
(void) close(s);
tim = ntohl(tim) - DIFFERENCE;
if (!pr) {
struct timeval tv;
tv.tv_sec = tim;
tv.tv_usec = 0;
if (settimeofday(&tv, NULL) == -1)
err(1, "Could not set time of day");
}
if (!silent)
(void) fputs(ctime(&tim), stdout);
return 0;
}