diff options
author | Eric Andersen <andersen@codepoet.org> | 2000-08-22 03:04:00 +0400 |
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committer | Eric Andersen <andersen@codepoet.org> | 2000-08-22 03:04:00 +0400 |
commit | 6ab22027d09a4038a89dd3d6d003a66a5490b818 (patch) | |
tree | 1d882f65e0dcc9b1efb0bb825ae9bf1a86ffc3e2 /util-linux/rdate.c | |
parent | fba9c00071eff20f65b8ff6b1e5fa7e5933e038d (diff) |
Oops. Forgot to commit rdate.c.
-Erik
Diffstat (limited to 'util-linux/rdate.c')
-rw-r--r-- | util-linux/rdate.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/util-linux/rdate.c b/util-linux/rdate.c new file mode 100644 index 000000000..0668d302a --- /dev/null +++ b/util-linux/rdate.c @@ -0,0 +1,135 @@ +/* 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); +} |