/* getutime.c - getutime */

#include 
#include 

/*------------------------------------------------------------------------
 * getutime  -  Obtain time in seconds past Jan 1, 1970, UCT (GMT)
 *------------------------------------------------------------------------
 */
status  getutime(
          uint32  *timvar               /* Location to store the result */
        )
{
        uint32  now;                    /* Current time in xinu format  */
        int32   retval;                 /* Return value from call       */
        uid32   slot;                   /* Slot in UDP table            */
        struct  ntp {                   /* Format of an NTP message     */
                byte    livn;           /* LI:2 VN:3 and mode:3 fields  */
                byte    strat;          /* Stratum                      */
                byte    poll;           /* Poll interval                */
                byte    precision;      /* Precision                    */
                uint32  rootdelay;      /* Root delay                   */
                uint32  rootdisp;       /* Root dispersion              */
                uint32  refid;          /* Reference identifier         */
                uint32  reftimestamp[2];/* Reference timestamp          */
                uint32  oritimestamp[2];/* Originate timestamp          */
                uint32  rectimestamp[2];/* Receive timestamp            */
                uint32  trntimestamp[2];/* Transmit timestamp           */
        } ntpmsg;

        if (Date.dt_bootvalid) {        /* Return time from local info  */
                *timvar = Date.dt_boot + clktime;
                return OK;
        }

        /* Verify that we have obtained an IP address */

        if (getlocalip() == SYSERR) {
                return SYSERR;
        }

        /* If the DHCP response did not contain an NTP server address   */
        /*      use the default server                                  */

        if (NetData.ntpserver == 0) {
                if (dnslookup(TIMESERVER, &NetData.ntpserver) == SYSERR) {
                        return SYSERR;
                }
        }

        /* Contact the time server to get the date and time */

        slot = udp_register(NetData.ntpserver, TIMERPORT, TIMELPORT);
        if (slot == SYSERR) {
                fprintf(stderr,"getutime: cannot register a udp port %d\n",
                                        TIMERPORT);
                return SYSERR;
        }

        /* Send a request message to the NTP server */

        memset((char *)&ntpmsg, 0x00, sizeof(ntpmsg));
        ntpmsg.livn = 0x1b;     /* Client request, protocol version 3 */
        retval = udp_send(slot, (char *)&ntpmsg, sizeof(ntpmsg));
        if (retval == SYSERR) {
                fprintf(stderr,"getutime: cannot send to the server\n");
                udp_release(slot);
                return SYSERR;
        }

        /* Read the response from the NTP server */

        retval = udp_recv(slot, (char *) &ntpmsg, sizeof(ntpmsg),
                                                         TIMETIMEOUT);
        if ( (retval == SYSERR) || (retval == TIMEOUT) ) {
                udp_release(slot);
                return SYSERR;
        }
        udp_release(slot);

        /* Extract the seconds since Jan 1900 and convert */

        now = ntim2xtim( ntohl(ntpmsg.trntimestamp[0]) );
        Date.dt_boot = now - clktime;
        Date.dt_bootvalid = TRUE;
        *timvar = now;
        return OK;
}