| /* 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 "internal.h" |
| #define BB_DECLARE_EXTERN |
| #include "messages.c" |
| #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> |
| |
| |
| #define RFC_868_BIAS 2208988800UL |
| |
| int setdate= 0; |
| int printdate= 0; |
| |
| time_t askremotedate(char *host) |
| { |
| struct hostent *h; |
| struct sockaddr_in sin; |
| struct servent *tserv; |
| unsigned long int nett, localt; |
| int fd; |
| |
| if (!(h = gethostbyname(host))) { /* get the IP addr */ |
| errorMsg("%s: %s\n", host, strerror(errno)); |
| return(-1); |
| } |
| if ((tserv = getservbyname("time", "tcp")) == NULL) { /* find port # */ |
| errorMsg("%s: %s\n", "time", strerror(errno)); |
| return(-1); |
| } |
| if ((fd = socket(AF_INET, SOCK_STREAM, 0)) < 0) { /* get net connection */ |
| errorMsg("%s: %s\n", "socket", strerror(errno)); |
| return(-1); |
| } |
| |
| memcpy(&sin.sin_addr, h->h_addr, sizeof(sin.sin_addr)); |
| sin.sin_port= tserv->s_port; |
| sin.sin_family = AF_INET; |
| |
| if (connect(fd, &sin, sizeof(sin)) < 0) { /* connect to time server */ |
| errorMsg("%s: %s\n", host, strerror(errno)); |
| close(fd); |
| return(-1); |
| } |
| if (read(fd, &nett, 4) != 4) { /* read time from server */ |
| close(fd); |
| errorMsg("%s did not send the complete time\n", 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 time; |
| int opt; |
| |
| /* Interpret command line args */ |
| /* do special-case option parsing */ |
| if (argv[1] && (strcmp(argv[1], "--help") == 0)) |
| usage(rdate_usage); |
| |
| /* do normal option parsing */ |
| while ((opt = getopt(argc, argv, "Hsp")) > 0) { |
| switch (opt) { |
| default: |
| case 'H': |
| usage(rdate_usage); |
| return(FALSE); |
| break; |
| case 's': |
| setdate++; |
| break; |
| case 'p': |
| printdate++; |
| break; |
| } |
| } |
| |
| /* the default action is to set the date */ |
| if (printdate==0 && setdate==0) setdate++; |
| |
| if (optind == argc) { |
| usage(rdate_usage); |
| return(FALSE); |
| } |
| |
| if ((time= askremotedate(argv[optind])) == (time_t)-1) { |
| return(FALSE); |
| } |
| if (setdate) { |
| if (stime(&time) < 0) |
| fatalError("Could not set time of day: %s\n", strerror(errno)); |
| } |
| if (printdate) { |
| fprintf(stdout, "%s", ctime(&time)); |
| } |
| |
| return(TRUE); |
| } |