| /* 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. |
| * |
| * 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 |
| * |
| */ |
| |
| #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 <signal.h> |
| |
| #include "busybox.h" |
| |
| |
| static const int RFC_868_BIAS = 2208988800UL; |
| |
| static void socket_timeout(int sig) |
| { |
| bb_error_msg_and_die("timeout connecting to time server"); |
| } |
| |
| static time_t askremotedate(const char *host) |
| { |
| unsigned long int nett, localt; |
| struct sockaddr_in s_in; |
| int fd; |
| |
| bb_lookup_host(&s_in, host); |
| s_in.sin_port = bb_lookup_port("time", 37); |
| |
| /* Add a timeout for dead or non accessable servers */ |
| alarm(10); |
| signal(SIGALRM, socket_timeout); |
| |
| fd = xconnect(&s_in); |
| |
| if (safe_read(fd, (void *)&nett, 4) != 4) /* read time from server */ |
| bb_error_msg_and_die("%s did not send the complete time", host); |
| |
| 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 |
| */ |
| localt= ntohl(nett) - RFC_868_BIAS; |
| |
| return(localt); |
| } |
| |
| int rdate_main(int argc, 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(); |
| } |
| } |
| |
| if (optind == argc) |
| bb_show_usage(); |
| |
| remote_time = askremotedate(argv[optind]); |
| |
| if (setdate) { |
| time_t current_time; |
| |
| time(¤t_time); |
| if (current_time == remote_time) |
| bb_error_msg("Current time matches remote time."); |
| else |
| if (stime(&remote_time) < 0) |
| bb_perror_msg_and_die("Could not set time of day"); |
| } |
| |
| if (printdate) |
| printf("%s", ctime(&remote_time)); |
| |
| return EXIT_SUCCESS; |
| } |