NetBSD/usr.sbin/rdate/rdate.c

181 lines
4.5 KiB
C

/* $NetBSD: rdate.c,v 1.22 2017/08/26 19:26:32 ginsbach Exp $ */
/*
* 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.
*
* 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.
*/
/*
* 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.
*/
#include <sys/cdefs.h>
#ifndef lint
__RCSID("$NetBSD: rdate.c,v 1.22 2017/08/26 19:26:32 ginsbach Exp $");
#endif /* lint */
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <err.h>
#include <netdb.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <util.h>
/* seconds from midnight Jan 1900 - 1970 */
#define DIFFERENCE 2208988800ULL
static void usage(void);
static void
usage(void)
{
(void) fprintf(stderr, "usage: %s [-46aps] host\n", getprogname());
(void) fprintf(stderr, " -4: use IPv4 addresses only\n");
(void) fprintf(stderr, " -6: use IPv6 addresses only\n");
(void) fprintf(stderr, " -a: use adjtime instead of instant change\n");
(void) fprintf(stderr, " -p: just print, don't set\n");
(void) fprintf(stderr, " -s: just set, don't print\n");
}
int
main(int argc, char *argv[])
{
int pr = 0, silent = 0, s;
int slidetime = 0;
int adjustment;
uint32_t data;
time_t tim;
char *hname;
const char *emsg = NULL;
struct addrinfo hints, *res, *res0;
int c;
int error;
int family = AF_UNSPEC;
adjustment = 0;
while ((c = getopt(argc, argv, "46aps")) != -1)
switch (c) {
case '4':
family = AF_INET;
break;
case '6':
family = AF_INET6;
break;
case 'a':
slidetime++;
break;
case 'p':
pr++;
break;
case 's':
silent++;
break;
default:
usage();
return 1;
}
if (argc - 1 != optind) {
usage();
return 1;
}
hname = argv[optind];
memset(&hints, 0, sizeof (hints));
hints.ai_family = family;
hints.ai_socktype = SOCK_STREAM;
hints.ai_flags = AI_CANONNAME;
error = getaddrinfo(hname, "time", &hints, &res0);
if (error)
errx(1, "%s: %s", gai_strerror(error), hname);
for (res = res0, s = -1; res != NULL; res = res->ai_next) {
s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
if (s < 0) {
emsg = "socket";
continue;
}
if (connect(s, res->ai_addr, res->ai_addrlen)) {
close(s);
s = -1;
emsg = "connect";
continue;
}
break;
}
if (s < 0)
err(1, "%s", emsg);
if (read(s, &data, sizeof(uint32_t)) != sizeof(uint32_t))
err(1, "Could not read data");
(void) close(s);
tim = ntohl(data) - DIFFERENCE;
if (!pr) {
struct timeval tv;
if (!slidetime) {
logwtmp("|", "date", "");
tv.tv_sec = tim;
tv.tv_usec = 0;
if (settimeofday(&tv, NULL) == -1)
err(1, "Could not set time of day");
logwtmp("{", "date", "");
} else {
struct timeval tv_current;
if (gettimeofday(&tv_current, NULL) == -1)
err(1, "Could not get local time of day");
adjustment = tv.tv_sec = tim - tv_current.tv_sec;
tv.tv_usec = 0;
if (adjtime(&tv, NULL) == -1)
err(1, "Could not adjust time of day");
}
}
if (!silent) {
(void) fputs(ctime(&tim), stdout);
if (slidetime)
(void) fprintf(stdout,
"%s: adjust local clock by %d seconds\n",
getprogname(), adjustment);
}
return 0;
}