/*
	****************************************************************

		Copyright (c) 1992, Carnegie Mellon University

		All Rights Reserved

	Permission  is  hereby  granted   to  use,  copy,  modify,  and
	distribute  this software  provided  that the  above  copyright
	notice appears in  all copies and that  any distribution be for
	noncommercial purposes.

	Carnegie Mellon University disclaims all warranties with regard
	to this software.  In no event shall Carnegie Mellon University
	be liable for  any special, indirect,  or consequential damages
	or any damages whatsoever  resulting from loss of use, data, or
	profits  arising  out of  or in  connection  with  the  use  or
	performance of this software.

	****************************************************************
*/
/*
 * RDATE - A program to synchronise time using CMU-OpenVMS/IP
 *
 * AUTHOR
 *      Mark Prior,
 *      University Computing Services
 *      University of Adelaide
 *      GPO Box 498
 *      Adelaide SA 5113
 *      Australia
 *
 *      E-mail: mrp@sirius.ua.oz[.au]
 *
 * SYNOPSIS
 *      This program uses CMU-OpenVMS/IP to synchronise date/time on a VMS Vax
 *      with a Unix system on the LAN. This emulates the rdate function
 *      available under BSD Unix but uses the formatted port rather than the
 *      binary one. This enables the VMS machines to automatically change
 *      to/from Daylight saving (providing the Unix system has got it right).
 *
 *      We synchronise all our VMS hosts to a single Unix host once a week (on
 *      a Sunday morning at 4am).
 *
 * BUGS/FEATURES
 *      Should check that the time difference is not outrageous.
 *      Should handle more Unix date formats.
 */

#include <stdio.h>
#include <ssdef.h>
#include <descrip.h>
#include <iodef.h>
#include <ctype.h>
#include <opcdef.h>
#include <time.h>

#define DAYTIME 13

int SYS$ASSIGN(),SYS$BINTIM(),SYS$QIOW(),SYS$SETIME(),SYS$SNDOPR();

Do_Rdate(HostNm)
char    *HostNm;
{
	char    *p,*host,*strchr();
	char    date[26],rdate[26],buffer[BUFSIZ],month[4],now[24];
	long    time_buffer,timadr[2];
	int     status,day,year,hour,minute,second;
	short   channel;
	struct  {
		short   status,count;
		long    xstatus;
	} iosb;
	union {
		struct  OPC opc;
		char    msg[BUFSIZ+8];
	} opcmsg;
	$DESCRIPTOR(ip,"INET$DEVICE");
	$DESCRIPTOR(timbuf,now);
	$DESCRIPTOR(opc,opcmsg.msg);

	time(&time_buffer);
	strcpy(date,ctime(&time_buffer));
	*strchr(date,'\n') = '\0';
	/*
	 * Make a connection to the daytime socket on the Unix machine
	 */
	if ((status = SYS$ASSIGN(&ip,&channel,0,0)) != SS$_NORMAL)
		exit(status);
	if ((status = SYS$QIOW(0,channel,IO$_CREATE,&iosb,0,0,HostNm,DAYTIME,0,1,0,600)) != SS$_NORMAL)
		exit(status);
	if (iosb.status == SS$_ABORT)
		exit(iosb.xstatus);
	else if (iosb.status != SS$_NORMAL)
		exit(iosb.status);
	/*
	 * Read the time, don't bother to close the channel we will only get
	 * an abort message so why confuse the issue.
	 */
	if ((status = SYS$QIOW(0,channel,IO$_READVBLK,&iosb,0,0,rdate,26,0,0,0,0)) != SS$_NORMAL)
		exit(status);
	if (iosb.status == SS$_ABORT)
		exit(iosb.xstatus);
	else if (iosb.status != SS$_NORMAL)
		exit(iosb.status);
	/*
	 * BEWARE: This format is used by 4.3BSD and SunOS 4.0 but is different
	 * on Ultrix V2. Change the format if your Unix host uses another format
	 */
	if (sscanf(rdate,"%*s %s %d %d:%d:%d %d\n",month,&day,&hour,&minute,&second,&year) != 6) {
		fprintf(stderr,"Date returned from %s is of incompatible format\n",HostNm);
		exit(1);
	}
	*strchr(rdate,'\n') = '\0';
	for (p = month;*p;p++)
		*p = toupper(*p);
	/*
	 * Now change the format to VMS style date/time
	 */
	sprintf(now,"%2d-%s-%d %02d:%02d:%02d.00",day,month,year,hour,minute,second);
	timbuf.dsc$w_length = strlen(now);
	if ((status = SYS$BINTIM(&timbuf,&timadr)) != SS$_NORMAL)
		exit(status);
	if ((status = SYS$SETIME(&timadr)) != SS$_NORMAL)
		exit(status);
	sprintf(buffer,"RDATE: Time synchronised with %s.\r\nTime changed from %s to %s.",HostNm,date,rdate);
	/*
	 * All has gone well so make an operator log that we have modified
	 * the time.
	 */
	opcmsg.opc.opc$b_ms_type = OPC$_RQ_RQST;
	opcmsg.opc.opc$b_ms_target = OPC$M_NM_CENTRL;
	opcmsg.opc.opc$l_ms_rqstid = 0;
	strcpy(&opcmsg.msg[8],buffer);
	opc.dsc$w_length = strlen(buffer)+8;
	if ((status = SYS$SNDOPR(&opc,0)) != SS$_NORMAL)
		exit(status);
}