15eb39c25a
bb_lookup_port now takes 3 parameters but rdate has not been modified accordingly and fails to compile in the current CVS version. The modification below fixes the problem. Now, RFC868 allows both UDP and TCP implementations of the time protocol so this may not work if someone defines a udp time service other than 37 but who would do that?
122 lines
2.9 KiB
C
122 lines
2.9 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* The Rdate command will ask a time server for the RFC 868 time
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* and optionally set the system time.
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*
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* by Sterling Huxley <sterling@europa.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*
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*/
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#include <sys/time.h>
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#include <sys/types.h>
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#include <sys/socket.h>
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#include <netinet/in.h>
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#include <netdb.h>
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#include <stdio.h>
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#include <getopt.h>
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#include <string.h>
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#include <time.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <signal.h>
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#include "busybox.h"
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static const int RFC_868_BIAS = 2208988800UL;
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static void socket_timeout(int sig)
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{
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bb_error_msg_and_die("timeout connecting to time server");
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}
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static time_t askremotedate(const char *host)
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{
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unsigned long int nett, localt;
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struct sockaddr_in s_in;
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int fd;
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bb_lookup_host(&s_in, host);
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s_in.sin_port = bb_lookup_port("time", "tcp", 37);
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/* Add a timeout for dead or non accessable servers */
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alarm(10);
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signal(SIGALRM, socket_timeout);
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fd = xconnect(&s_in);
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if (safe_read(fd, (void *)&nett, 4) != 4) /* read time from server */
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bb_error_msg_and_die("%s did not send the complete time", host);
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close(fd);
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/* convert from network byte order to local byte order.
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* RFC 868 time is the number of seconds
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* since 00:00 (midnight) 1 January 1900 GMT
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* the RFC 868 time 2,208,988,800 corresponds to 00:00 1 Jan 1970 GMT
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* Subtract the RFC 868 time to get Linux epoch
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*/
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localt= ntohl(nett) - RFC_868_BIAS;
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return(localt);
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}
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int rdate_main(int argc, char **argv)
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{
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time_t remote_time;
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int opt;
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int setdate = 1;
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int printdate = 1;
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/* Interpret command line args */
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while ((opt = getopt(argc, argv, "sp")) > 0) {
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switch (opt) {
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case 's':
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printdate = 0;
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setdate = 1;
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break;
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case 'p':
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printdate = 1;
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setdate = 0;
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break;
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default:
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bb_show_usage();
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}
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}
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if (optind == argc)
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bb_show_usage();
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remote_time = askremotedate(argv[optind]);
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if (setdate) {
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time_t current_time;
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time(¤t_time);
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if (current_time == remote_time)
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bb_error_msg("Current time matches remote time.");
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else
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if (stime(&remote_time) < 0)
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bb_perror_msg_and_die("Could not set time of day");
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}
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if (printdate)
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printf("%s", ctime(&remote_time));
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return EXIT_SUCCESS;
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}
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