/* vi: set sw=4 ts=4: */
/*
* The Rdate command will ask a time server for the RFC 868 time
- * and optionally set the system time.
+ * and optionally set the system time.
*
* by Sterling Huxley <sterling@europa.com>
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
- *
-*/
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
+ */
+//config:config RDATE
+//config: bool "rdate (6 kb)"
+//config: default y
+//config: help
+//config: The rdate utility allows you to synchronize the date and time of your
+//config: system clock with the date and time of a remote networked system using
+//config: the RFC868 protocol, which is built into the inetd daemon on most
+//config: systems.
+
+//applet:IF_RDATE(APPLET(rdate, BB_DIR_USR_SBIN, BB_SUID_DROP))
-#include <sys/time.h>
-#include <sys/types.h>
-#include <sys/socket.h>
-#include <netinet/in.h>
-#include <netdb.h>
-#include <stdio.h>
-#include <getopt.h>
-#include <string.h>
-#include <time.h>
-#include <stdlib.h>
-#include <unistd.h>
-#include "busybox.h"
+//kbuild:lib-$(CONFIG_RDATE) += rdate.o
+//usage:#define rdate_trivial_usage
+//usage: "[-s/-p] HOST"
+//usage:#define rdate_full_usage "\n\n"
+//usage: "Set and print time from HOST using RFC 868\n"
+//usage: "\n -s Only set system time"
+//usage: "\n -p Only print time"
-static const int RFC_868_BIAS = 2208988800UL;
+#include "libbb.h"
+
+enum { RFC_868_BIAS = 2208988800UL };
+
+static void socket_timeout(int sig UNUSED_PARAM)
+{
+ bb_error_msg_and_die("timeout connecting to time server");
+}
static time_t askremotedate(const char *host)
{
- unsigned long int nett, localt;
- const char *port="37";
+ uint32_t nett;
int fd;
- if (getservbyname("time", "tcp") != NULL)
- port="time";
-
- fd = xconnect(host, port);
+ /* Timeout for dead or inaccessible servers */
+ alarm(10);
+ signal(SIGALRM, socket_timeout);
- if (read(fd, (void *)&nett, 4) != 4) /* read time from server */
- bb_error_msg_and_die("%s did not send the complete time", host);
+ fd = create_and_connect_stream_or_die(host, bb_lookup_std_port("time", "tcp", 37));
- close(fd);
+ if (safe_read(fd, &nett, 4) != 4) /* read time from server */
+ bb_error_msg_and_die("%s: %s", host, "short read");
+ if (ENABLE_FEATURE_CLEAN_UP)
+ close(fd);
- /* convert from network byte order to local byte order.
- * RFC 868 time is the number of seconds
- * since 00:00 (midnight) 1 January 1900 GMT
- * the RFC 868 time 2,208,988,800 corresponds to 00:00 1 Jan 1970 GMT
- * Subtract the RFC 868 time to get Linux epoch
+ /* Convert from network byte order to local byte order.
+ * RFC 868 time is seconds since 1900-01-01 00:00 GMT.
+ * RFC 868 time 2,208,988,800 corresponds to 1970-01-01 00:00 GMT.
+ * Subtract the RFC 868 time to get Linux epoch.
*/
- localt= ntohl(nett) - RFC_868_BIAS;
-
- return(localt);
+ nett = ntohl(nett) - RFC_868_BIAS;
+
+ if (sizeof(time_t) > 4) {
+ /* Now we have 32-bit lsb of a wider time_t
+ * Imagine that nett = 0x00000001,
+ * current time cur = 0x123ffffffff.
+ * Assuming our time is not some 40 years off,
+ * remote time must be 0x12400000001.
+ * Need to adjust our time by (int32_t)(nett - cur).
+ */
+ time_t cur = time(NULL);
+ int32_t adjust = (int32_t)(nett - (uint32_t)cur);
+ return cur + adjust;
+ }
+ /* This is not going to work, but what can we do */
+ return (time_t)nett;
}
-int rdate_main(int argc, char **argv)
+int rdate_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
+int rdate_main(int argc UNUSED_PARAM, char **argv)
{
time_t remote_time;
- int opt;
- int setdate = 1;
- int printdate = 1;
-
- /* Interpret command line args */
- while ((opt = getopt(argc, argv, "sp")) > 0) {
- switch (opt) {
- case 's':
- printdate = 0;
- setdate = 1;
- break;
- case 'p':
- printdate = 1;
- setdate = 0;
- break;
- default:
- bb_show_usage();
- }
- }
+ unsigned flags;
- if (optind == argc)
- bb_show_usage();
+ flags = getopt32(argv, "^" "sp" "\0" "-1");
remote_time = askremotedate(argv[optind]);
- if (setdate) {
- if (stime(&remote_time) < 0)
- bb_perror_msg_and_die("Could not set time of day");
+ /* Manpages of various Unixes are confusing. What happens is:
+ * (no opts) set and print time
+ * -s: set time ("do not print the time")
+ * -p: print time ("do not set, just print the remote time")
+ * -sp: print time (that's what we do, not sure this is right)
+ */
+
+ if (!(flags & 2)) { /* no -p (-s may be present) */
+ if (time(NULL) == remote_time)
+ bb_error_msg("current time matches remote time");
+ else
+ if (stime(&remote_time) < 0)
+ bb_perror_msg_and_die("can't set time of day");
}
- if (printdate)
+ if (flags != 1) /* not lone -s */
printf("%s", ctime(&remote_time));
return EXIT_SUCCESS;
projects / oweals / busybox.git / blobdiff