busybox

/* 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 "busybox.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, (struct sockaddr *)&sin, sizeof(sin)) < 0) {    /* connect to time server */

        errorMsg("%s: %s\n", host, strerror(errno));

        close(fd);

        return(-1);

    }

    if (read(fd, (void *)&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;

​