source: branches/samba-3.2.x/source/utils/net_time.c

/* 
   Samba Unix/Linux SMB client library 
   net time command
   Copyright (C) 2001 Andrew Tridgell (tridge@samba.org)

   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 3 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, see <http://www.gnu.org/licenses/>.  */

#include "includes.h"
#include "utils/net.h"


/*
  return the time on a server. This does not require any authentication
*/
static time_t cli_servertime(const char *host, struct sockaddr_storage *pss, int *zone)
{
        struct nmb_name calling, called;
        time_t ret = 0;
        struct cli_state *cli = NULL;
        NTSTATUS status;

        cli = cli_initialise();
        if (!cli) {
                goto done;
        }

        status = cli_connect(cli, host, pss);
        if (!NT_STATUS_IS_OK(status)) {
                fprintf(stderr,"Can't contact server %s. Error %s\n", host, nt_errstr(status));
                goto done;
        }

        make_nmb_name(&calling, global_myname(), 0x0);
        if (host) {
                make_nmb_name(&called, host, 0x20);
        } else {
                make_nmb_name(&called, "*SMBSERVER", 0x20);
        }

        if (!cli_session_request(cli, &calling, &called)) {
                fprintf(stderr,"Session request failed\n");
                goto done;
        }
        if (!cli_negprot(cli)) {
                fprintf(stderr,"Protocol negotiation failed\n");
                goto done;
        }

        ret = cli->servertime;
        if (zone) *zone = cli->serverzone;

done:
        if (cli) {
                cli_shutdown(cli);
        }
        return ret;
}

/* find the servers time on the opt_host host */
static time_t nettime(int *zone)
{
        return cli_servertime(opt_host, opt_have_ip? &opt_dest_ip : NULL, zone);
}

/* return a time as a string ready to be passed to /bin/date */
static const char *systime(time_t t)
{
        static fstring s;
        struct tm *tm;

        tm = localtime(&t);
        if (!tm) {
                return "unknown";
        }

        fstr_sprintf(s, "%02d%02d%02d%02d%04d.%02d",
                 tm->tm_mon+1, tm->tm_mday, tm->tm_hour,
                 tm->tm_min, tm->tm_year + 1900, tm->tm_sec);
        return s;
}

int net_time_usage(int argc, const char **argv)
{
        d_printf(
"net time\n\tdisplays time on a server\n\n"\
"net time system\n\tdisplays time on a server in a format ready for /bin/date\n\n"\
"net time set\n\truns /bin/date with the time from the server\n\n"\
"net time zone\n\tdisplays the timezone in hours from GMT on the remote computer\n\n"\
"\n");
        net_common_flags_usage(argc, argv);
        return -1;
}

/* try to set the system clock using /bin/date */
static int net_time_set(int argc, const char **argv)
{
        time_t t = nettime(NULL);
        char *cmd;
        int result;

        if (t == 0) return -1;

        /* yes, I know this is cheesy. Use "net time system" if you want to
           roll your own. I'm putting this in as it works on a large number
           of systems and the user has a choice in whether its used or not */
        asprintf(&cmd, "/bin/date %s", systime(t));
        result = system(cmd);
        if (result)
                d_fprintf(stderr, "%s failed.  Error was (%s)\n",
                        cmd, strerror(errno));
        free(cmd);

        return result;
}

/* display the time on a remote box in a format ready for /bin/date */
static int net_time_system(int argc, const char **argv)
{
        time_t t = nettime(NULL);

        if (t == 0) return -1;

        printf("%s\n", systime(t));

        return 0;
}

/* display the time on a remote box in a format ready for /bin/date */
static int net_time_zone(int argc, const char **argv)
{
        int zone = 0;
        int hours, mins;
        char zsign;
        time_t t;

        t = nettime(&zone);

        if (t == 0) return -1;

        zsign = (zone > 0) ? '-' : '+';
        if (zone < 0) zone = -zone;

        zone /= 60;
        hours = zone / 60;
        mins = zone % 60;

        printf("%c%02d%02d\n", zsign, hours, mins);

        return 0;
}

/* display or set the time on a host */
int net_time(int argc, const char **argv)
{
        time_t t;
        struct functable func[] = {
                {"SYSTEM", net_time_system},
                {"SET", net_time_set},
                {"ZONE", net_time_zone},
                {NULL, NULL}
        };

        if (!opt_host && !opt_have_ip && 
            !find_master_ip(opt_target_workgroup, &opt_dest_ip)) {
                d_fprintf(stderr, "Could not locate a time server.  Try "\
                                 "specifying a target host.\n");
                net_time_usage(argc,argv);
                return -1;
        }

        if (argc != 0) {
                return net_run_function(argc, argv, func, net_time_usage);
        }

        /* default - print the time */
        t = cli_servertime(opt_host, opt_have_ip? &opt_dest_ip : NULL, NULL);
        if (t == 0) return -1;

        d_printf("%s", ctime(&t));
        return 0;
}